JP2024020697A - Method for manufacturing press-formed product with asymmetric flange portion - Google Patents

Abstract

[Problem] A method for manufacturing a press-formed product having an asymmetrical flange portion that can prevent twisting after release of a press-formed product in which the shape of a pair of flange portions is asymmetrical in the width direction without changing the shape from the original target shape. I will provide a. [Solution] A method for manufacturing a press-molded product having an asymmetric flange portion according to the present invention includes: a top plate portion 3; a pair of vertical wall portions 5 continuous to the top plate portion 3; and a pair of vertical wall portions 5 continuous to the vertical wall portion 5. This is a method for manufacturing a press-formed product 1 having a target shape, in which the shape of the pair of flange parts 7 is asymmetrical in the width direction, and the shape is smaller than the flange equivalent part 19a of a developed blank in which the target shape is developed. A blank manufacturing process of manufacturing a blank 11 having at least a part of the wide flange-equivalent part 11a, and a press-forming process of press-forming an intermediate product 13 in which the flange part 15 is wider than the target shape using the manufactured blank 11. and a trimming step of trimming the wide flange portion 15 of the intermediate product 13 into a target shape. [Selection diagram] Figure 1

Description

The present invention relates to a method for manufacturing a press-formed product having a hat cross-sectional shape, which includes a top plate, a pair of vertical walls continuous to both sides of the top plate in the width direction, and a pair of flange parts continuous to the vertical walls. . In particular, the present invention relates to a method for manufacturing a press-formed product having an asymmetrical flange portion, which manufactures a press-formed product in which the shape of the pair of flange portions is asymmetrical.

As the collision safety of automobile bodies continues to improve due to stricter collision safety standards for automobiles, it is also necessary to reduce the weight of automobile bodies in order to improve fuel efficiency and shift to electric vehicles in response to carbon dioxide emission regulations. In order to improve the collision safety of these car bodies while reducing their weight, the use of high-strength steel plates of 590 MPa or higher (also known as high-tensile steel) is progressing in car body structural parts.
High tensile strength materials have high strength and have a large residual stress after press forming, so springback after mold release has been an issue. In particular, in the case of long press-formed products, torsional springback is likely to occur, causing the shape of the press-formed product after release from the mold to deviate from the target shape, which has been a problem.

Automotive parts where torsional springback is an issue, such as bumper parts, include a top plate, a pair of vertical walls continuous to the top plate, and a pair of flanges continuous to the vertical walls. An example of this is a hat-shaped part with a cross section. In a long part with such a hat cross-section, if the shape of the pair of flange parts is asymmetrical, for example, the shape or arrangement of the bead-shaped part provided on the flange part is asymmetrical, the press after mold release The molded product was prone to torsional springback.

Therefore, conventionally, as in Patent Document 1, a method has been disclosed in which the residual stress of the press-formed product is leveled by adding an extra-thickness bead to the flange portion of the target shape, thereby suppressing the torsion after mold release. ing.
Furthermore, as in Patent Document 2, a method is disclosed in which twisting after mold release is suppressed by forming a fillet part on the punch shoulder or die shoulder to relieve tensile stress during press molding. .

Japanese Patent Application Publication No. 2009-255117 Japanese Patent Application Publication No. 2009-202189

However, the press-formed product formed by the press-forming method of Patent Document 1 has a bead formed on the flange portion to prevent twisting, and therefore has a different shape from the original target shape. Furthermore, due to the formation of the bead, the shape of the flange portion becomes asymmetrical in the left and right width directions of the press-formed product, so there is a problem that new twisting is likely to occur due to this.

Further, the press-formed product formed by the press-forming method described in Patent Document 2 also had a fillet portion at the punch shoulder and the die shoulder, so the shape was different from the original target shape. Furthermore, after such a press-formed product is assembled into a car body, if compressive stress is applied to the press-formed product due to a collision with the car body, the press-formed product becomes prone to bending starting from the fillet, which deteriorates its rigidity and collision resistance. There was a problem.

The present invention has been made to solve the above problem, and can prevent twisting after release of a press-formed product in which the shape of a pair of flange parts is asymmetrical without changing the shape from the original target shape. A method for manufacturing a press-molded product having an asymmetric flange portion is provided.

(1) The method for manufacturing a press-molded product having an asymmetrical flange according to the present invention includes a top plate, a pair of vertical walls continuous to both sides of the top plate in the width direction, and a pair of vertical walls continuous to the vertical walls. A method for manufacturing a press-formed product having a hat cross-sectional shape with a pair of flange portions, the shapes of the pair of flange portions being asymmetrical, as a target shape, the flange-equivalent portion of a developed blank developed from the target shape. A blank manufacturing step of manufacturing a blank having at least a portion thereof corresponding to a flange wider than the target shape, and using the manufactured blank, the top plate portion and the vertical wall portion have the same shape as the target shape, and the flange portion has the same shape as the target shape. The present invention is characterized by comprising a press-forming step of press-molding an intermediate product having a hat cross-sectional shape wider than the target shape, and a trimming step of trimming the wide flange portion of the intermediate product to obtain the target shape. It is something to do.

(2) Furthermore, the method for manufacturing a press-molded product having an asymmetric flange according to the present invention includes: a top plate portion; a pair of vertical wall portions continuous on both sides of the top plate portion in the width direction; A method for manufacturing a press-formed product having a target shape, which has a hat cross-sectional shape including a pair of continuous flanges, and in which the shape or arrangement of bead-shaped parts formed on the pair of flanges is asymmetric, the method comprising: A blank having a flange equivalent portion at least in part that is wider than the flange equivalent portion of the developed blank in which the target shape has been developed is provided, and the wide flange equivalent portion has a portion corresponding to the bead shape portion that is asymmetric in shape or arrangement. A blank manufacturing process is performed in which the top plate portion and the vertical wall portion are the same as the target shape, the flange portion is wider than the target shape, and the flange portion is It is characterized by comprising a press-forming step of press-molding an intermediate product having a hat cross-sectional shape on which a bead-shaped portion is formed, and a trimming step of trimming the wide flange portion of the intermediate product to obtain the target shape. That is.

(3) Furthermore, in the method described in (1) or (2) above, the blank is a steel plate having a tensile strength of 590 MPa class or higher.

INDUSTRIAL APPLICABILITY The present invention can prevent twisting after mold release without changing the shape from the original target shape in manufacturing a press-formed product in which the shape of a pair of flange portions is asymmetrical.
As a result, even when using high-strength materials, it is possible to obtain press-formed products with a stable and good shape, reducing the need for shape correction of press-formed products after press-forming and mold modifications during press-forming, and It can greatly contribute to improving the production efficiency and yield of molded products.

FIG. 3 is an explanatory diagram of a method for manufacturing a press-formed product having an asymmetric flange portion according to an embodiment of the present invention. 2(a) is a perspective view, FIG. 2(b) is a top view, and FIG. 2(c) is a side view. FIG. FIG. 3(a) is a diagram showing the longitudinal stress of the intermediate product after the press-forming process, and FIG. 3(b) is a diagram showing the longitudinal stress of the press-formed product after the trimming process. It is a figure which shows the displacement of the press-formed product in the press-forming direction after mold release in embodiment. It is a figure which shows the conventional blank shape. It is a figure which shows the displacement of the press-formed product in the press-forming direction after mold release in a conventional example. It is a figure which shows the longitudinal direction stress of the press-formed product in a conventional example.

A method for manufacturing a press-formed product having an asymmetric flange portion according to the present embodiment will be explained using the target shape shown in FIG. 2 as an example.
The press-formed product 1 shown in FIG. 2 includes a top plate portion 3, a pair of vertical wall portions 5 continuous to both sides of the top plate portion 3 in the width direction, and a pair of flange portions 7 continuous to the vertical wall portions 5. It has a hat cross-sectional shape.

As shown in FIG. 2(b), bead-shaped portions 9 are formed asymmetrically in the width direction on the pair of flange portions 7 of the press-formed product 1, and the shape of the pair of flange portions 7 is asymmetrical. It has become.
When the press-molded product 1 having the hat cross-sectional shape shown in FIG. 2 is manufactured by a conventional method, it is likely to spring back and twist when released from the mold after press-forming. This point will be explained below.

FIG. 5 shows the shape of a blank used in the conventional method. The blank 19 shown in FIG. 5 is produced by punching out a metal plate having the same shape as the expanded blank obtained by expanding the press-formed product 1 shown in FIG.
Since the conventional blank 19 has a shape developed from the target shape, as shown in FIG. It has become.

FIG. 6 shows the FEM analysis results when such a blank 19 is formed into a target shape.
FIG. 6 is a top view of the shape of the press-formed product 1 after press-forming a blank 19 made of 1180 MPa grade material into a target shape and releasing the mold. Here, the longitudinal direction of the press-formed product 1 is the X direction, the width direction is the Y direction, and the press forming direction is the Z direction.

Displacement in the press forming direction (Z direction) is shown in shading in the figure. Here, the displacement in the press-forming direction (Z direction) is defined by comparing the press-formed product 1 after release from the mold with the target shape using the central part in the longitudinal direction of the top plate as a fixed point, and comparing each part of the press-formed product 1 with the target shape. It shows how much the shape is displaced toward the front of the page, and the magnitude of the displacement is shown by shading.
Further, the displacements at the four corners of the press-formed product 1 are shown numerically in the figure. If the displacement in the Z direction is significantly different between the left and right sides in the width direction, this indicates that twist has occurred in the relevant portion.
Hereinafter, the characteristics of the shape and the twist occurring at each end will be explained separately for the left half of the press-formed product 1 from the center in the longitudinal direction (see broken line) and the right half of the paper.

First, in the left half of the press-formed product 1 from the center in the longitudinal direction (broken line) in the plane of the drawing, the bead-shaped portions 9 formed on the pair of flange portions 7 are arranged symmetrically. The Z-direction displacement of the upper left corner of the page is 12.6 mm, and the Z-direction displacement of the lower left corner of the page is 12.3 mm, and the Z-direction displacements of the two corners are almost the same. Therefore, it can be seen that almost no twist occurs at the end of the press-formed product 1 on the left side in the drawing.

On the other hand, in the right half of the press-formed product 1 from the center in the longitudinal direction (broken line) in the drawing, the bead-shaped portions 9 formed on the pair of flange portions are arranged asymmetrically in the width direction. The Z-direction displacement of the upper right corner of the paper is 9.6 mm, and the Z direction displacement of the lower right corner of the paper is 13.9 mm, resulting in a difference of 4.3 mm. Therefore, it can be seen that at the end of the press-formed product 1 on the right side in the drawing, a twist amount of 4.3 mm has occurred.

The reason why the above twist occurs will be explained using FIG. 7.
FIG. 7 shows the stress at the bottom dead center of the press molding of the blank 19 shown in FIG. 5. Note that the stress shown in FIG. 7 is a compressive stress in the longitudinal direction (X direction), and is the average value in the thickness direction.

Comparing the portion surrounded by the broken line in FIG. 7 (the portion where the bead-shaped portions 9 are disposed asymmetrically in the width direction), it can be seen that the stress distribution is asymmetric. As described above, the stress distribution of the flange portion 7 at the bottom dead center of the molding is different on the left and right sides in the width direction, which causes twisting in the press-formed product 1 after release from the mold.

Therefore, as a result of intensive study, the inventor found that when an intermediate product is press-formed using a blank with a conventional blank shape that has a wide extra wall part on the outside of the flange-corresponding part, the stress distribution will be lower at the left and right ends of the flange part in the width direction. It was found that it spread to the sides. Furthermore, it has been found that by trimming the wide extra wall portion from the intermediate product, it is possible to remove areas with different stress distributions on the left and right sides in the width direction, thereby suppressing the above-mentioned twisting. The method for manufacturing a press-molded product having an asymmetric flange portion according to the present embodiment is based on this knowledge.
Note that the press-formed products that are susceptible to twisting and which are the object of the present invention include, in addition to curved parts in side view as shown in FIG. be.

The present embodiment is a method for manufacturing a press-formed product 1 having a pair of flange portions 7 in which bead-shaped portions 9 are asymmetrically formed as shown in FIG. 2 as a target shape, including a blank manufacturing step; It includes a press molding process and a trimming process.
Each step will be explained in detail below.

<Blank production process>
The blank manufacturing process is a process of manufacturing a blank 11 as shown in FIG. 1(a) by punching a metal plate or the like.
The blank 11 of this embodiment has a shape in which an extra wall portion is provided on the outside of a flange-equivalent portion (corresponding to the flange-equivalent portion 19a of the conventional blank 19) in a developed shape obtained by developing a target shape. Therefore, the blank 11 has a flange equivalent portion 11a that is wider than the flange equivalent portion 19a of the conventional blank 19 (see FIG. 5).

FIG. 1(a) shows a blank shape in which the pair of flange-equivalent portions 11a of the blank 11 are each made wider by 20 mm, and a blank shape in which they are made wider by 40 mm.
Note that the flange-equivalent portion 11a of the blank 11 does not need to be wide over its entire length. As shown in FIG. 1(a), it is only necessary that the portion of the flange portion 7 having the target shape including the portion where the bead-shaped portion 9 asymmetrical in the width direction is formed is wide.

Furthermore, although the blank 11 shown in FIG. 1(a) has the flange-equivalent portions 11a widened by the same amount to make the left and right shapes of the flange-equivalent portions 11a almost symmetrical in the width direction, the present invention is limited to this. Instead, the shape of the flange-equivalent portion 11a may be asymmetrical.
However, it is preferable to make the widths of the pair of flange-equivalent parts 11a the same, since this makes it difficult for stress to be biased in the top plate part 3 and the vertical wall part 5 during press molding of the intermediate product 13, which will be described later.

<Press molding process>
The press molding process is a process of press molding an intermediate product 13 as shown in FIG. 1(b) using the blank 11 produced in the blank production process. Note that FIG. 1(b) shows an example in which a blank 11 in which the flange equivalent portion 11a is made wider by 40 mm is used.

In the intermediate product 13, the top plate part 3 and the vertical wall part 5 have the same shape as the target shape (see FIG. 2), and the flange part 15 has a hat cross-sectional shape wider than the flange part 7 of the target shape. A bead-shaped portion 17 corresponding to the target-shaped bead-shaped portion 9 is formed. In FIG. 1(b), parts having the same shape as the target shape are given the same reference numerals.

<Trimming process>
The trimming process is a process of trimming the wide flange portion 15 of the intermediate product 13, as shown in FIG. 1(c). Specifically, the target shape (press-formed product 1) is obtained by removing the excess thickness explained in the blank production process.

FIG. 3 shows the results obtained by FEM analysis of the stress distribution of the intermediate product 13 at the bottom dead center of the press molding after the press molding process and the residual stress distribution of the press molded product 1 after the trimming process. The stress shown in FIG. 3 is a compressive stress in the longitudinal direction (X direction) as in FIG. 7, and is the average value in the thickness direction.

FIG. 3(a) shows the stress distribution at the bottom dead center of the press-forming of the intermediate product 13 in the press-forming process. As shown in FIG. 3A, it can be seen that the compressive stress generated in the wide flange portion 15 is concentrated on the right side of the flange portion 15 in the drawing and near the end portion in the width direction. Further, when comparing the pair of flange portions 15, the stress distribution is not symmetrical.

FIG. 3(b) shows the residual stress distribution of the press-formed product 1 after trimming the intermediate product 13 of FIG. 3(a). As shown in FIG. 3(b), when the flange portion 15 of the intermediate product 13 is trimmed to the target shape, the area where compressive stress was concentrated is removed, and compressive residual stress is generated in the flange portion 7 of the press-formed product 1. It can be seen that this decreases. Furthermore, the residual stress distribution is almost symmetrical.

FIG. 4 shows the displacement of the press-formed product 1 manufactured in this embodiment in the press-forming direction (Z direction).
Similar to FIG. 6, FIG. 4 compares the press-formed product 1 after release from the mold with the target shape using the longitudinal center as a fixed point, and shows how far each part of the press-formed product 1 is toward the front of the paper with respect to the target shape. Displacement is indicated by shading.
Similar to the conventional example shown in FIG. 6, the magnitude of twist occurring at each end will be explained by dividing the press-formed product 1 from the longitudinal center (see broken line) into the left half of the paper and the right half of the paper.

In the left half of the press-formed product 1 from the center in the longitudinal direction (dashed line) on the paper, the displacement in the Z direction of the upper left corner of the paper is 10.6 mm, the displacement of the lower left corner of the paper in the Z direction is 11.6 mm, and the two corners The Z-direction displacements of the parts were almost the same. Therefore, almost no twisting occurred at the end of the press-formed product 1 manufactured in this embodiment on the left side in the drawing, as in the conventional example.

In addition, in the right half of the press-formed product 1 from the center in the longitudinal direction (broken line) on the paper, the displacement in the Z direction at the upper right corner in the paper is 16.4 mm, and the displacement in the Z direction at the lower right corner in the paper is 16.3 mm. As a result, the Z-direction displacements of the two corners became almost the same. Therefore, it can be seen that even with respect to the right end of the press-formed product 1 in the drawing, where 4.3 mm of twist occurred in the conventional example (Fig. 6), the twist was significantly reduced, springback was suppressed, and the shape became better. .

As described above, according to the present embodiment, when manufacturing the press-formed product 1 in which the shape of the pair of flange portions 7 is asymmetrical in the width direction, it is possible to reduce twisting that occurs at the longitudinal ends after mold release.

In the press-formed product 1 having the target shape in the above embodiment, bead-shaped portions 9 of the same shape are arranged asymmetrically in the width direction on a pair of flange portions 7, and the shape of the flange portion 7 is asymmetrical in the width direction. However, the shape of the press-formed product targeted by the present invention is not limited to this.
For example, the shape of the bead-shaped portion 9 formed on one flange portion 7 of the press-formed product may be different from the shape of the bead-shaped portion 9 formed on the other flange portion 7. Even when the shapes of the bead-shaped portions 9 are different, the present invention is effective because the shapes of the pair of flange portions 7 become asymmetrical in the width direction and the press-formed product is likely to be twisted.

Furthermore, regardless of the presence or absence of a bead-shaped part, the hat has a cross-sectional shape that includes a top plate part, a pair of vertical walls, and a pair of flanges, and the shape of the pair of flange parts is asymmetrical in the width direction. The present invention is effective when manufacturing a press-formed product having a target shape.

As described above, in this embodiment, the intermediate product 13 having the wide flange portion 15 is press-molded, and the flange portion 15 is trimmed to obtain the target shape. During this trimming, the stress balance changes, so the stress (tensile stress) in the top plate portion 3 becomes relatively large, and upward warping may occur.

In the case of the press-formed product 1 of the present embodiment shown in FIG. 4, when comparing the Z-direction displacement of the upper left corner of the paper and the Z-direction displacement of the upper right corner of the paper, the difference was 5.8 mm. Further, when comparing the Z-direction displacement of the lower left corner of the paper and the Z-direction displacement of the lower right corner of the paper, the difference was 4.7 mm.
On the other hand, in the case of the conventional example shown in FIG. 6, when comparing the Z-direction displacement of the upper left corner of the paper and the Z-direction displacement of the upper right corner of the paper, the difference was 3.0 mm. Further, when comparing the Z-direction displacement of the lower left corner of the paper and the Z-direction displacement of the lower right corner of the paper, the difference was 1.6 mm.

As described above, in the press-formed product 1 of this embodiment shown in FIG. 4, the difference between the Z-direction displacement of the end on the left side of the paper and the Z-direction displacement of the end on the right side of the paper is larger than that of the conventional example.
In order to suppress such upward warping of the top plate 3 due to stress (tensile stress), it is preferable to press-form the top plate 3 using a mold in which the radius of curvature of the top plate 3 is smaller than the target shape, for example.

The effect of preventing twisting of the press-formed product according to the present invention has been confirmed, and will be described below.
In this example, a press-formed product having the asymmetric flange portion in the width direction described in the embodiment was manufactured using the press-formed product 1 of FIG. 2 as a target shape.
Three types of steel plates with tensile strengths of 590 MPa class, 980 MPa class, and 1180 MPa class (all plate thicknesses of 1.8 mm) were used as blanks in this example.

In the conventional example, a developed blank (see FIG. 5) developed into a target shape was press-formed to produce a press-formed product having the target shape.
In the invention example, a blank having a flange-equivalent part wider than the flange-equivalent part of the conventional blank is produced, the blank is press-formed into an intermediate product, and the flange part of the intermediate product is trimmed to produce a press-formed product in the target shape. was manufactured. In addition, in the invention example, the width expansion of the flange-equivalent portion of the blank was set to 20 mm, and the width was set to 40 mm.
Table 1 shows the amount of twist of the press-formed products in the conventional example and the invention example.

The amount of twist shown in Table 1 indicates the amount of twist at the right end of the press-formed product. Specifically, it is the amount of twist at the end of the press-formed product 1 on the right side of the paper in FIGS. 4 and 6, and the difference between the Z-direction displacement of the upper right corner of the paper and the Z-direction displacement of the lower right corner of the paper is calculated. This is the value.
Note that, as explained in the embodiment, the above-mentioned Z-direction displacement is the displacement in the press-forming direction when comparing the press-formed product after release from the mold with the target shape using the longitudinal center part of the top plate as a fixing point. .

No. 1 to No. 3 are examples in which 590 MPa grade material was used for the blank.
Conventional example No. 1 was obtained by press-forming a developed blank into the target shape, and the amount of twist was 1.7 mm.

On the other hand, in invention example No. 2, the flange-equivalent part of the blank was made wider by 20 mm on each side than the flange-equivalent part in the developed blank in which the target shape was developed, and the blank was manufactured using the blank. The amount of twist of the press-formed product was 0.6 mm. No. 2 had a lower amount of twist than No. 1 and was good.
In addition, invention example No. 3 is one in which the flange-equivalent part of the blank is made wider by 40 mm on each side than the flange-equivalent part in the developed blank in which the target shape is developed, and the press molding produced using the blank is made wider by 40 mm on each side. The amount of twist of the product was 0.4 mm. No. 3, which had a larger amount of width expansion than No. 2, had even better results as the amount of twist was further reduced.

No. 4 to No. 6 are examples in which 980 MPa grade material was used for the blank.
Conventional example No. 4 was obtained by press-forming a developed blank into the target shape, and the amount of twist was 3.2 mm.

On the other hand, in invention example No. 5, the flange-equivalent part of the blank was made wider by 20 mm on each side than the flange-equivalent part of the developed blank in which the target shape was developed, and the blank was manufactured using the blank. The amount of twist of the press-formed product was 0.4 mm. No. 5 had a lower amount of twist than No. 4, which was good.
In addition, invention example No. 6 is one in which the flange-equivalent part of the blank is made wider by 40 mm on each side than the flange-equivalent part in the developed blank in which the target shape is developed, and the press molding produced using the blank is The amount of twist of the product was 0.3 mm. No. 6, which had a larger amount of width expansion than No. 5, had even better results as the amount of twist was further reduced.

No. 7 to No. 9 are examples in which 1180 MPa grade material was used for the blank.
Conventional example No. 7 was obtained by press-forming a developed blank with a target shape into the target shape, and the amount of twist was 4.3 mm.

On the other hand, in invention example No. 8, the flange-equivalent part of the blank was made wider by 20 mm on each side than the flange-equivalent part in the developed blank in which the target shape was developed, and the blank was manufactured using the blank. The amount of twist of the press-formed product was 0.5 mm. No. 8 had a lower amount of twist than No. 7 and was good.
Furthermore, invention example No. 9 is one in which the flange-equivalent part of the blank is made wider by 40 mm on each side than the flange-equivalent part in the developed blank in which the target shape is developed, and the press molding produced using the blank is made wider by 40 mm on each side. The amount of twist of the product was 0.1 mm. No. 9, which had a larger amount of width expansion than No. 8, had even better results as the amount of twist was further reduced.

As shown in the above examples, the present invention can obtain a sufficient torsion suppressing effect even when a steel plate having a tensile strength of 590 MPa or higher is used for the blank.

From the above, it was confirmed that the method of the present invention is effective in preventing twisting of press-formed products due to springback after press-forming.

1 Press-formed product 3 Top plate part 5 Vertical wall part 7 Flange part 9 Bead-shaped part 11 Blank 11a Flange-equivalent part 13 Intermediate product 15 Flange part 17 Bead-shaped part 19 Blank (conventional example)
19a Flange equivalent part

Claims (3)

It has a hat cross-sectional shape that includes a top plate portion, a pair of vertical wall portions continuous to both sides of the top plate portion in the width direction, and a pair of flange portions continuous to the vertical wall portions, and the shape of the pair of flange portions. A method for manufacturing a press-formed product having an asymmetrical flange portion, which manufactures a press-formed product having an asymmetrical shape as a target shape, the method comprising:
a blank manufacturing step of manufacturing a blank having at least a part of the flange equivalent portion wider than the flange equivalent portion of the expanded blank developed with the target shape;
a press-forming step of using the produced blank to press-form an intermediate product having a hat cross-sectional shape in which the top plate portion and the vertical wall portion are the same as the target shape, and the flange portion is wider than the target shape;
A method for manufacturing a press-formed product having an asymmetrical flange portion, comprising the step of trimming the wide flange portion of the intermediate product to obtain the target shape. It has a hat cross-sectional shape comprising a top plate part, a pair of vertical walls continuous to both sides in the width direction of the top plate part, and a pair of flange parts continuous to the vertical walls, and formed on the pair of flange parts. A method for manufacturing a press-formed product having an asymmetrical flange portion, the method comprising manufacturing a press-formed product having an asymmetrical bead-shaped portion having an asymmetrical shape or arrangement as a target shape, the method comprising:
A blank having at least a part of the flange-equivalent part wider than the flange-equivalent part of the developed blank in which the target shape is developed is attached to the wide flange-equivalent part at a part corresponding to the bead-shaped part whose shape or arrangement is asymmetrical. A blank manufacturing process for manufacturing a blank that includes;
Using the produced blank, a hat with a cross-sectional shape in which the top plate part and the vertical wall part are the same as the target shape, the flange part is wider than the target shape, and a bead-shaped part is formed in the flange part is formed. a press forming process for press forming an intermediate product;
A method for manufacturing a press-formed product having an asymmetrical flange portion, comprising the step of trimming the wide flange portion of the intermediate product to obtain the target shape. 3. The method for manufacturing a press-formed product having an asymmetric flange portion according to claim 1, wherein the blank is a steel plate having a tensile strength of 590 MPa or higher.