CN113661021B

CN113661021B - Method for producing press-molded article

Info

Publication number: CN113661021B
Application number: CN202080026611.7A
Authority: CN
Inventors: 吉川伸麻
Original assignee: Nippon Steel and Sumitomo Metal Corp
Current assignee: Nippon Steel Corp
Priority date: 2019-04-03
Filing date: 2020-04-02
Publication date: 2023-07-14
Anticipated expiration: 2040-04-02
Also published as: WO2020204129A1; CN113661021A; JP7173300B2; MX2021011759A; JPWO2020204129A1

Abstract

The method for manufacturing the press-molded product comprises the following steps: a first processing step of forming a first flange portion (30) and a corner portion, which protrude toward a first side X1 in a first direction X with respect to a plate-like base portion (20), by plastically deforming a part of a single metal plate; and a second processing step of pressing the front end of the first flange (30) formed on the first side X1 in the first direction X against the second side X2 in the first direction X to cause the material of the first flange (30) to flow toward the second side X2 in the first direction X, thereby forming a second flange (40) extending toward the second side X2 in the first direction X with respect to the base (20); the thickness T2 of the second flange portion is smaller than the thickness T1 of the first flange portion after the second machining step, and the product R x T2/T1 of the ratio of the thickness T2 to the thickness T1 and the radius R outside the corner portion is smaller than 3.5.

Description

Method for producing press-molded article

Technical Field

The present invention relates to a method for producing a press-molded article.

The present application claims priority based on japanese patent application No. 2019-071411, filed on 4/3 of 2019, the contents of which are incorporated herein by reference.

Background

The transmission member has a hub portion which is attached to the rotation shaft so as to protrude from both sides of a functional surface of the transmission member in a direction along the rotation shaft. In order to form such a boss portion, there is a method of welding two members, for example. In this method, a portion which is one side of the boss portion is formed from a part of one metal plate by plastic working such as burring. Then, the other member as the other side of the boss portion and the other side of the metal plate formed with the portion as one side of the boss portion are joined by welding, thereby forming the above-described transmission member. As another method, there is a method of sintering a powder obtained by sintering a metal powder by a mold formed in a shape corresponding to a transmission member. The above-described method of welding two members requires a step of processing the two members, a step of welding, and a large number of manufacturing steps. Therefore, in the above-described method of welding two members, the manufacturing cost increases, and the tact time spent in manufacturing also increases. In addition, in the method of sintering, a step of performing a heat treatment for sintering is also required, and the manufacturing cost increases, and the takt time spent in manufacturing also increases.

Further, patent document 1 discloses the following technique: after the metal plate is protruded to one side by press working, a part of the portion protruded to one side is protruded to the other side by press working, whereby the cylindrical portion is protruded to both sides of the metal plate from one metal plate. In such a technique, the number of steps can be reduced as compared with the above-described method of welding two members or the above-described method of performing sintering. However, in the technique described in patent document 1, when a part of the portion protruding to one side is protruded to the other side by press working, there is a problem that a defect that the original metal plate is folded at an acute angle is formed at an inner corner portion where the portion protruding to one side is folded. Further, patent document 2 discloses that: after forming the cup longitudinal wall portion protruding from the bottom of the cup, the cup longitudinal wall portion is deep-drawn to form the cup longitudinal wall portion and the shoulder portion, thereby thickening the cup longitudinal wall portion and the shoulder portion, and forming the remainder protruding from the bottom surface. However, the technology described in patent document 2 does not disclose a specific solution to the problem of forming a defect that is folded at an acute angle between the bottom of the cup and the inner portion of the vertical wall of the cup. Processing methods for solving such problems are proposed in, for example, patent documents 3 and 4.

Specifically, patent document 3 proposes a method for manufacturing a metal member, which comprises: a step of forming a cylindrical portion on one side of the plate-like blank by plastic working; a step of plastically deforming the tip-side inner peripheral portion of the tube portion formed on one side into a root-side inner peripheral portion, and thickening the root portion; and extruding the thickened root-side inner peripheral portion to the other side of the plate-like blank. In the manufacturing method of patent document 2, by performing the three steps, a member having cylindrical portions extending to both sides with respect to the original plate-like blank can be formed. Further, since the cylindrical portion extending to the other side is formed of the thickened portion, the cylindrical portion extending to the one side is not extruded enough, and the above-described defect of folding at an acute angle can be suppressed. Further, patent document 4 proposes: when molding a molded article including an elongated flange portion, a flange peripheral portion, and a flange extending portion in which the elongated flange portion extends from the corner side, a burring molded article having a smaller or substantially right angle radius of curvature outside the corner between the elongated flange portion and the flange peripheral portion is used as a workpiece. The flange extending portion is formed by pushing in the end face of the elongated flange portion of the workpiece, and the material constituting the elongated flange portion is moved, so that the workpiece having a smaller or substantially right angle radius of curvature outside the corner portion is used as described above, and thus the folding-in does not occur inside the corner portion.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 11-10275

Patent document 2: international publication No. 2014/109240

Patent document 3: japanese patent application laid-open No. 2018-83215

Patent document 4: japanese patent laid-open No. 2017-196632

Disclosure of Invention

Problems to be solved by the invention

However, in the manufacturing method disclosed in patent document 3, in addition to the step of forming the flange-like projected portion on one side and the step of forming the flange-like projected portion on the other side, a step for suppressing the defect of folding at an acute angle in the inner portion between the original metal plate portion and the flange-like projected portion on one side is required. That is, it is also necessary to perform a step of thickening the root portion of the portion protruding toward one side in a flange shape. Therefore, the manufacturing method disclosed in patent document 1 also has problems in that the number of steps is increased, the manufacturing cost is high, and the tact time taken for manufacturing is long. In the manufacturing method disclosed in patent document 4, when the flange-like projected portion formed on one side is pushed in and the flange-like projected portion formed on the other side, the radius of curvature of the outside of the corner of the workpiece is defined as a small radius of curvature at or substantially close to a right angle. In actual processing, the radius of curvature of the outer portion is not limited to a right angle or a smaller radius of curvature substantially close to a right angle, but a technique is required in which a portion protruding in a flange shape is formed on both sides so that a defect that folds in at an acute angle does not occur in the inner portion in the case of various radii of curvature.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a press-molded article, which is capable of manufacturing a press-molded article having portions protruding in a flange shape on both sides from a single metal plate in a small number of steps without causing a defect of folding in an acute angle at an inner portion protruding in a flange shape.

Means for solving the problems

In order to solve the above problems, the present invention adopts the following technical means.

That is, in the method for manufacturing a press-molded article according to an aspect of the present invention, a first flange portion extending toward a first side in a first direction, which is a thickness direction of a plate-like base portion, is formed by plastically deforming a part of a single metal plate, and a corner portion extending in a curved shape is formed between the base portion and the first flange portion; disposing a first pad along the first flange portion; a second pad disposed opposite to the first pad with the first flange interposed therebetween; a third pad is disposed on the opposite side of the first flange portion with the base portion interposed therebetween so as to form a gap smaller than a gap between the first pad and the second pad; a punch for pressing a distal end surface of the first flange portion formed on a first side in the first direction is disposed between the first pad and the second pad so as to be movable in the first direction; a second flange portion extending toward the first direction second side with respect to the base portion by pressing the distal end surface of the first flange portion toward the first direction second side so that the material of the first flange portion flows toward the first direction second side; the thickness T2 of the second flange portion is smaller than the thickness T1 of the first flange portion after the second flange portion is formed; the product of the ratio of the thickness T2 mm of the second flange portion after forming the second flange portion to the thickness T1 mm of the first flange portion and the radius R (mm) of the outside of the bend of the corner portion in a cross section of the corner portion in the extending direction thereof after forming the corner portion, that is, R×T2/T1 is less than 3.5.

According to this method, first, as a first processing step, a part of a sheet metal plate is plastically deformed to form a first flange portion and a corner portion that protrude toward a first side in a first direction with respect to a plate-like base portion. Then, as a second processing step, the tip end of the first flange portion formed on the first side in the first direction is pressed against the second side in the first direction, whereby the material of the first flange portion is caused to flow toward the second side in the first direction, and a second flange portion protruding toward the second side in the first direction with respect to the base portion is formed. Here, in the initial stage of the second processing step, the front end surface of the first flange portion is pushed so that the corner portion formed by the base portion and the first flange portion is to be plastically deformed to fall into the range as the second flange portion. However, by making the thickness T2 of the second flange portion smaller than the thickness T1 of the first flange portion after the second processing step is performed, and making the product of the ratio of the thickness T2 of the second flange portion to the thickness T1 of the first flange portion after the second processing step is performed and the radius R outside the corner portion after the first processing step, that is, r×t2/T1, smaller than 3.5, it is possible to suppress the corner portion formed by the base portion and the first flange portion from falling into the range as the second flange portion. Therefore, in the second processing step, the second flange portion can be formed by the second processing step while suppressing the defect of the folded shape in which the corner portion falls into the inner portion of the corner portion to form an acute angle.

In the method of manufacturing a press-molded article, the third pad may include a plane including a surface along the second flange after the second flange is formed, and the third pad may be located on the first flange side in a direction perpendicular to the surface along the first flange with respect to a plane including a surface along the first flange in the first pad. In other words, after the second flange portion is formed, a plane including a surface along the second flange portion in the third pad passes through the inside of the first flange portion.

According to this method, in the second processing step, the surface of the second flange portion of the third pad is positioned on the first flange portion side in the direction orthogonal to the surface along the first flange portion of the first pad with respect to the surface along the first flange portion after the second processing step is performed, and in particular, it is possible to suppress the material on the third pad side from falling into the gap between the third pad and the second pad at the corner portion, and further suppress the defect of the folded shape forming an acute angle at the inner side portion of the corner portion.

In the method of manufacturing a press-molded article, the second pad may be formed in a straight line along the first direction along the surfaces of the first flange portion and the second flange portion.

According to this method, in the second processing step, the surfaces of the second pad along the first flange portion and the second flange portion are formed in a straight line along the first direction, so that it is possible to suppress, particularly at the corner portion, the material on the third pad side from falling into the gap between the third pad and the second pad, and further suppress the defect of the folded shape forming an acute angle at the inner portion of the corner portion. Further, the first flange portion and the second flange portion can be formed with surfaces that are linearly connected and have different thicknesses.

In the method of manufacturing the press-molded product, when forming the second flange portion, the first flange portion may be plastically deformed while applying an external force from the first direction second side to the first direction first side at least in the middle of completing the process from the start of the process of pressing the distal end surface of the first flange portion formed on the first direction first side to the first direction second side to cause the material of the first flange portion to flow to the first direction second side.

According to this method, an external force is applied from the first-direction second side toward the first-direction first side at the connecting portion in the base portion connected to the first flange portion from the start of the process of flowing the material of the first flange portion to the first-direction second side until at least halfway through the process. By plastically deforming the first flange portion, stress is generated so that each material of the first flange portion and the base portion connected to the first flange portion plastically flows to the first direction second side of the base portion. However, in the process from the start of the process of applying the external force to the first side in the first direction to flow the material of the first flange portion to the second side in the first direction until at least the way of completing the process, the plastic flow to the second side in the first direction than the base portion can be suppressed by the external force. Therefore, it is possible to suppress the defect that the material flows plastically from both the base portion and the first flange portion to the first direction second side of the base portion to form an acute angle at the inner side portion connecting the base portion and the first flange portion. Further, after a certain amount of deformation by the processing has occurred from the start of the processing of flowing the material of the first flange portion to the second side in the first direction, the portion resulting from the deformation is deformed to the second side in the first direction by the pressing force acting on the distal end surface of the first flange portion, whereby the defect of the folded-in shape that an acute angle has occurred can be further suppressed, and the second flange portion can be formed.

Effects of the invention

According to the present invention, it is possible to manufacture a press-molded article having flange-like projecting portions on both sides from one metal plate in a fewer number of steps without causing a defect of folding in at an acute angle in the flange-like projecting inner portion.

Drawings

Fig. 1 is a partially cut-away perspective view showing a press-molded article produced by the method for producing a press-molded article according to embodiment 1.

Fig. 2 is a detailed view of the portion a of fig. 1.

Fig. 3 is a flowchart illustrating a method for manufacturing a press-molded article according to embodiment 1.

Fig. 4 is a perspective view of a steel sheet used in the method for manufacturing a press-molded article according to embodiment 1.

Fig. 5A is a process diagram illustrating a first processing step in the method for manufacturing a press-molded article according to embodiment 1.

Fig. 5B is a process diagram illustrating a first processing step in the method for manufacturing a press-molded article according to embodiment 1.

Fig. 6 is a cross-sectional view of an intermediate product formed by the first processing step in the method for manufacturing a press-molded product according to embodiment 1.

Fig. 7A is a process diagram illustrating a second processing step in the method for manufacturing a press-molded article according to embodiment 1.

Fig. 7B is a process diagram illustrating a second processing step in the method for manufacturing a press-molded article according to embodiment 1.

Fig. 7C is a process diagram illustrating a second processing step in the method for manufacturing a press-molded article according to embodiment 1.

Fig. 7D is a process diagram illustrating a second processing step in the method for manufacturing a press-molded article according to embodiment 1.

Fig. 8 is a perspective view showing a press-molded article according to modification 1 of embodiment 1.

Fig. 9 is a cross-sectional view showing a press-molded article manufactured by the method for manufacturing a press-molded article according to modification 2 of embodiment 1.

Fig. 10A is a process diagram illustrating a method for manufacturing a press-molded article according to modification 2 of embodiment 1.

Fig. 10B is a process diagram illustrating a method for manufacturing a press-molded article according to modification 2 of embodiment 1.

Fig. 10C is a process diagram illustrating a method for manufacturing a press-molded article according to modification 2 of embodiment 1.

Fig. 11A is a process diagram illustrating a second processing step in the method for manufacturing a press-molded article according to embodiment 2.

Fig. 11B is a process diagram illustrating a second processing step in the method for manufacturing a press-molded article according to embodiment 2.

Fig. 11C is a process diagram illustrating a second processing step in the method for manufacturing a press-molded article according to embodiment 2.

Fig. 11D is a process diagram illustrating a second processing step in the method for manufacturing a press-molded article according to embodiment 2.

Fig. 12 is a cross-sectional view showing the result of analysis of the method for manufacturing a press-molded article according to the example of the invention, and showing the shape of the inner portion after the completion of the second processing step.

Fig. 13 is a cross-sectional view showing the result of analysis of the method for manufacturing the press-molded article of the comparative example, and showing the shape of the inner portion after the completion of the second processing step.

Detailed Description

(embodiment 1)

Embodiment 1 of the present invention will be described below with reference to fig. 1 to 7. Fig. 1 and 2 show examples of press-molded articles manufactured by the method for manufacturing press-molded articles according to the present embodiment. As shown in fig. 1, the press-molded product 10 of the present embodiment is, for example, a gear or a clutch that is mounted as a transmission member on a rotation shaft rotatable about a center line L. In fig. 1, the teeth of the gear and the braking surface of the clutch are omitted as functional parts of the transmission member. As shown in fig. 1, the press-molded article 10 includes a plate-shaped base portion 20, a first flange portion 30 extending from a first surface 20a of the base portion 20, and a second flange portion 40 extending from a second surface 20b of the base portion 20 opposite to the first surface 20 a. In the present embodiment, the base 20 is formed in a disk shape. The press-molded article 10 has the above-described functional portion of the press-molded article 10 as an object at the base 20, but this functional portion is omitted in fig. 1.

In the present embodiment, the first flange portion 30 and the second flange portion 40 protrude from the first surface 20a and the second surface 20b of the base portion 20, respectively. The first flange portion 30 and the second flange portion 40 are formed in a cylindrical shape along the outer peripheral edge of the base portion 20, and are arranged coaxially with respect to the center line L. The outer peripheral surface 30a of the first flange portion 30 and the outer peripheral surface 40a of the second flange portion 40 have substantially equal outer diameters. In other words, the outer peripheral surface 30a of the first flange portion 30 and the outer peripheral surface 40a of the second flange portion 40 are connected to each other in a straight line along the first direction X.

As shown in fig. 2, in the present embodiment, the thickness T2 of the second flange portion 40 is smaller than the thickness T1 of the first flange portion 30. Further, at the base end 30c of the first flange 30, the inner peripheral surface 30b of the first flange 30 and the inner portion 30d of the base 20 connecting the first surface 20a of the base 20 and the first flange 30 are formed in a concave curved surface shape. Similarly, at the base end 40c of the second flange 40, the inner peripheral surface 40b of the second flange 40 and the inner portion 40d of the base 20, which connect the second surface 20b of the base 20 with the inner peripheral surface 40b of the second flange 40, are formed in a concave curved surface shape. Preferably, the radius of curvature R40 of the inner portion 40d is small relative to the radius of curvature R30 of the inner portion 30 d.

Here, the thicknesses T1, T2 are defined as follows. That is, a line extending along the first face 20a of the base 20 toward the first flange portion 30 is defined as an extension line L21. Further, an intersection point of the extension line L21 and the outer peripheral surface 30a of the first flange portion 30 facing the opposite side from the base portion 20 is defined as an intersection point P31. Further, a line extending from the inner peripheral surface 30b of the first flange portion 30 facing the base portion 20 toward the base portion 20 is defined as an extension line L30. Further, the intersection point of the extension line L30 and the extension line L21 is defined as an intersection point P32. The distance between the intersection point P31 and the intersection point P32 is defined as the thickness T1 of the first flange portion 30. In other words, the thickness T1 of the first flange portion 30 is the thickness of the base end 30c of the first flange portion 30 in the case where the inner portion 30d formed in the concave curved surface shape is removed. Further, a line extending along the second face 20b of the base 20 toward the second flange portion 40 is defined as an extension line L22. Further, an intersection point of the extension line L22 and the outer peripheral surface 40b of the second flange portion 40 facing the opposite side from the base portion 20 is defined as an intersection point P41. Further, a line extending from the inner peripheral surface 40a of the second flange portion 40 facing the base portion 20 toward the base portion 20 is defined as an extension line L40. Further, the intersection point of the extension line L40 and the extension line L22 is defined as an intersection point P42. The distance between the intersection point P41 and the intersection point P42 is defined as the thickness T2 of the second flange 40. In other words, the thickness T2 of the second flange portion 40 is the thickness of the base end 40c of the second flange portion 40 in the case where the inner portion 40d formed in the concave curved surface shape is removed.

In the present embodiment, the thickness T2 of the second flange portion 40 is smaller than the thickness T1 of the first flange portion 30, and the outer peripheral surface 30a of the first flange portion 30 and the outer peripheral surface 40a of the second flange portion 40 have substantially the same outer diameter, so that the inner diameter of the inner peripheral surface 30b of the first flange portion 30 is smaller than the inner diameter of the inner peripheral surface 40b of the second flange portion 40. Further, although the structure of the press-molded product 10 is described in detail above, the structure such as the shape of the connecting portion between the base 20 and the first flange portion 30 and the second flange portion 40 is not limited as long as the base 20, the first flange portion 30, and the second flange portion 40 are provided, except for the relation between the thicknesses of the first flange portion 30 and the second flange portion 40. In the case where the press-molded product 10 is a transmission member or the like, a boss portion attached to the rotation shaft is provided on the center side of the base portion 20, but is omitted in fig. 1. The boss portion may be formed simultaneously by the processing steps of the present embodiment described below, or may be formed by separately performing processing to form the boss portion or mounting a member corresponding to the boss portion.

Next, a method for manufacturing a press-molded article according to the present embodiment will be described. As shown in fig. 1, the direction in which the first flange portion 30 and the second flange portion 40 of the press-molded article 10 manufactured by the method for manufacturing a press-molded article according to the present embodiment extend (protrude), that is, the thickness direction of the base 20 and the direction in which the center line L of the mounted press-molded article 10 extends are set as the first direction X. The side of the base 20 extending in the first direction X is referred to as a first side X1, and the side of the base extending in the second direction X2 is referred to as a second side X2.

Fig. 3 is a flowchart showing a method for manufacturing a press-molded article according to the present embodiment. As shown in fig. 3, the method for manufacturing the press-molded article 10 according to the present embodiment includes a first process S1 for forming the first flange portion 30 and a second process S2 for forming the second flange portion 40. Details are described below.

In the first processing step S1, as shown in fig. 4, one steel sheet 11 is used as a metal plate formed into a circular plate shape. In the first working step S1, the outer peripheral edge portion 11a of the steel sheet 11 is plastically deformed, and the portion as the first flange portion 30 is projected to the first side X1 in the first direction X, which is the thickness direction of the steel sheet 11. As a processing method of plastic deformation, various known methods can be applied, for example, drawing processing and burring processing. In the first working step S1 of the present embodiment, drawing is performed. That is, as shown in fig. 5A, the steel plate 11 is sandwiched between the pad 100 disposed on the first side X1 of the steel plate 11 in the first direction X and the pad 101 disposed on the second side X2 of the steel plate 11 in the first direction X. As shown in fig. 5B, the punch 102 is inserted into the outer peripheral edge 11a of the steel plate 11 from the first direction X second side X2 to the first side X1, and the outer peripheral edge 11a of the steel plate 11 is projected to the first direction X first side X1 to form a portion 31 as a first flange. Fig. 6 shows an intermediate product 12 formed by performing the first processing step S1. The intermediate product 12 is formed of the steel plate 11 as described above, and includes the portion 21 as the base portion and the portion 31 as the first flange portion. In the first processing step S1, the thickness T31 of the portion 31 as the first flange portion may be different from the thickness T1 of the first flange portion 30 of the press-molded article 10 as the completed article.

Here, the corner portions 100a of the pad 100 are formed in a convex curved surface shape. Therefore, in the first working step S1, the corner 12a connecting the portion 31 serving as the first flange portion and the portion 21 serving as the base portion at the connecting portion between the portion 31 serving as the first flange portion and the portion 21 serving as the base portion extends in a curved shape in a cross section along the center line L. The radius R (mm) of the outer side of the corner 12a in the cross section of the corner 12a along the extending direction, that is, the radius of curvature of the outer peripheral surface of the corner 12a, and the ratio of the thickness T2 (mm) of the second flange 40 to the thickness T1 (mm) of the first flange 30 after the second processing step S2 described later are set to satisfy the following relational expression.

R×T2/T1<3.5…(1)

Next, a second processing step S2 is performed. In the second processing step S2, the first flange portion 30 and the second flange portion 40 are formed by plastically deforming the portion 31 of the intermediate product 12 as the first flange portion to flow the material of the portion 31 as the first flange portion. Here, in the second processing step S2, a processing device 110 as shown in fig. 7A is used. As shown in fig. 7A, the processing device 110 includes a first pad 120, a second pad 130, a third pad 140, and a punch 150.

The first pad 120 is formed in a cylindrical shape extending along the first direction X. The outer peripheral surface 120a of the first pad 120 is formed in a straight line along the center line L. As will be described later, the first pad 120 is disposed along the inner peripheral surface 31b of the portion 31 as the first flange portion of the intermediate product 12 provided in the processing device 110. In the present embodiment, in a state where the intermediate product 12 is provided in the processing device 110, the outer peripheral surface 120a of the first pad 120 is in contact with the portion 31 that is the first flange portion. Further, the first pad 120 abuts against the portion 21 as a base. In the first pad 120, a lower surface 120b and an outer peripheral surface 120a that come into contact with the portion 21 as a base portion are connected by a convex curved surface 120 c. The radius of curvature of the convex curved surface 120c corresponds to the radius of curvature R30 of the first flange portion 30 and the inner portion 30d of the base portion 20, which connect the inner peripheral surface 30b of the first flange portion 30 and the first surface 20a of the base portion 20 of the press-molded article 10 after molding.

The second pad 130 is a cylindrical member. The second shim plate 130 is disposed coaxially with the first shim plate 120 with respect to the center line L, with a gap on the radially outer peripheral side of the first shim plate 120. The inner circumferential surface 130a of the second pad 130 is formed in a straight line along the first direction X. As will be described later, the inner peripheral surface 130a of the second pad 130 is disposed along the outer peripheral surface 31a of the portion 31 of the intermediate product 12 provided in the processing device 110 as the first flange portion. In the present embodiment, in a state where the intermediate product 12 is provided in the processing device 110, the inner peripheral surface 130a of the second pad 130 is in contact with the portion 31 that is the first flange portion. The distance D1 between the inner peripheral surface 130a of the second pad 130 and the outer peripheral surface 120a of the first pad is substantially equal to the thickness T1 of the first flange portion 30. The thickness T31 of the intermediate product 12 as the first flange portion may be smaller than the distance D1 before the second working step S2 is performed and the thickness T1 of the first flange portion 30 after the second working step S2 is performed. The second shim plate 130 sandwiches the first shim plate 120 and the portion 31 as the first flange portion along the first direction X, and extends to a range where the second flange portion 40 is formed. In the present embodiment, the inner peripheral surface 130a of the second pad 130 is formed in a straight line along the first direction X.

The third pad 140 is a cylindrical member. The third pad 140 is disposed on the radially inner peripheral side of the second pad 130 so as to be coaxial with the first pad 120 and the second pad 130 with respect to the center line L. The outer peripheral surface 140a of the third pad 140 is formed in a straight line along the center line L. In the present embodiment, the third pad 140 is disposed along the inner peripheral surface 40b of the second flange portion 40 of the press-molded article 10 in a state where the intermediate product 12 is provided in the processing device 110. The third pad 140 abuts against the portion 21 as the base portion, and sandwiches the portion 21 as the base portion together with the first pad 120. The distance D2 between the outer peripheral surface 140a of the third pad 140 and the inner peripheral surface 130a of the second pad 130 is substantially equal to the thickness T2 of the second flange 40. The third shim plate 140 sandwiches the second flange portion 40 formed in the second working process S2 with the second shim plate 130 along the first direction X. In the third pad 140, an upper surface 140b and an outer peripheral surface 140a that come into contact with the portion 21 as a base are connected by a convex curved surface 140 c. The radius of curvature of the convex curved surface 140c corresponds to the radius of curvature R40 of the second flange portion 40 and the inner portion 40d of the base portion 20 connecting the inner peripheral surface 40a of the second flange portion 40 and the second surface 20b of the base portion 20 of the press-molded article 10 after molding. In the cross section along the center line L, the radius of curvature of the convex curved surface 140c is preferably smaller than the radius of curvature of the convex curved surface 120 c.

The punch 150 is a cylindrical member. The punch 150 is disposed between the first pad 120 and the second pad 130 so as to be coaxial with the first pad 120 and the second pad 130 with respect to the center line L. The punch 150 is capable of advancing and retracting in a first direction X. Although not shown, the third pad 140 is fixed to the apparatus main body. Although not shown, the punch 150 is applied with an operating force by a hydraulic device or the like provided in the device main body. Accordingly, the front end surface 31c of the portion 31 as the first flange portion of the intermediate product 12 of the portion 21 as the base portion sandwiched between the first pad 120 and the third pad 140 is brought in from the first side X1 toward the second side X2 in the first direction X, and the front end surface 31c of the portion 31 as the first flange portion is pushed toward the second side X2, whereby an external force can be applied to the portion 31 as the first flange portion.

In such a processing apparatus 110, as shown in fig. 7A, an intermediate product 12 is provided. Specifically, the intermediate product 12 has the portion 21 as the base portion disposed between the first pad 120 and the third pad 140. Further, the center line of the intermediate product 12 is aligned with the center line L. Further, the portion 31 as the first flange portion is disposed so as to extend toward the punch 150. The first pad 120 and the third pad 140 sandwich the portion 21 as a base and press the portion. In this state, the portion 31 serving as the first flange portion is sandwiched between the first pad 120 and the second pad 130.

Next, as shown in fig. 7B, the punch 150 is moved toward the second side X2 in the first direction X. By the entry of the punch 150, first, the punch 150 abuts against the front end surface 31c of the portion 31 as the first flange portion. As shown in fig. 7C, the external force is applied from the punch 150 from the first side X1 toward the second side X2 in the first direction X to the portion 31 as the first flange portion by the punch 150 further entering. Accordingly, the portion 31 as the first flange portion is plastically deformed between the first pad 120 and the second pad 130, and the material of the portion 31 as the first flange portion flows from the first side X toward the second side X2 in the first direction X toward the range as the second flange portion 40, forming the second flange portion 40. Here, as shown in fig. 7B, in the initial stage of the second working step S2, the front end surface 31c of the portion 31 as the first flange is pressed, and the corner 12a formed by the portion 21 as the base and the portion 31 as the first flange is plastically deformed to fall within the range as the second flange 40. However, by performing the machining so that the thickness T2 of the second flange portion is smaller than the thickness T1 of the first flange portion 30 after the second machining step S2 is performed and the expression (1) is satisfied, it is possible to suppress the corner portion 12a from falling into the range as the second flange portion 40. Therefore, in the second processing step S2, the second flange 40 can be formed by the second processing step S2 while suppressing the defect of the folded shape forming an acute angle at the inner portion 30d of the corner 12a due to the corner 12a falling.

As shown in fig. 7D, by moving the punch 150 by a predetermined amount toward the second side X2 in the first direction X, the first flange 30 can be made a predetermined length, and the second flange 40 can be extended from the base 20 by a predetermined length toward the second side X2 in the first direction X, thereby completing the press-molded article 10.

As described above, according to the method of manufacturing the press-molded article 10 of the present embodiment, in the second processing step S2, the tip end surface 31c of the portion 31 as the first flange portion is pressed and plastically deformed so that the thickness T2 of the second flange portion 40 is smaller than the thickness T1 of the first flange portion 30 after the second processing step S2 is performed and the expression (1) is satisfied, and in the second processing step S2, the defect of the folded-in shape in which the inner portion 30d forms an acute angle can be suppressed, and the second flange portion 40 can be formed. That is, by performing only two steps of the first and second processing steps S1 and S2, the press-formed product 10 having the protruding portions on both sides can be manufactured from one sheet of the steel sheet 11 without forming the sharp-angled fold-in defect in the inner portion 30 d.

As shown in fig. 7A, after the second processing step S2, the plane PL140 including the outer peripheral surface 140a along the second flange 40 in the third pad 140 is located on the first flange 30 side in the direction orthogonal to the outer peripheral surface 140a (the radial direction orthogonal to the first direction X) with respect to the plane PL120 including the outer peripheral surface 120a along the first flange 30 in the first pad 120. In other words, after the second working step S2 is performed, the plane PL140 including the outer peripheral surface 140a along the second flange 140 of the third pad 140 passes through the inside of the first flange 30. Therefore, in particular, the material on the third pad 140 side in the corner 12a is suppressed from falling into the gap between the third pad 140 and the second pad 130, and the defect of the folded shape forming an acute angle in the inner portion 30d of the corner 12a can be further suppressed.

In the second working step S2, the second shim plate 130 is formed in a straight line along the first flange 30 and the inner peripheral surface 130a of the second flange 40 in the first direction X. Therefore, in particular, the material on the third pad 140 side of the corner 12a is prevented from falling into the gap between the third pad 140 and the second pad 130, and the defect of the folded shape forming an acute angle at the inner side portion 30d of the corner 12a can be further prevented. Further, the first flange portion 30 and the second flange portion 40 can form outer

peripheral surfaces

30a, 40a having different thicknesses T1, T2 and being connected in a straight line.

In the second processing step S2, the radius of curvature of the convex curved surface 140c of the third pad 140 is made smaller than the radius of curvature of the convex curved surface 120c of the first pad 120 of the processing device 110 in a cross section along the center line L. That is, as the press-molded article 10, the radius of curvature R40 of the inner portion 40d is made smaller than the radius of curvature R30 of the inner portion 30d, and thus the defect of the folded shape forming an acute angle at the inner portion 30d of the corner 12a can be further suppressed.

In the present embodiment, the portion 31 as the first flange portion is formed by plastically deforming the portion on the outer peripheral side in the first working step S1, and the first flange portion 30 and the second flange portion 40 are formed by plastically deforming the tip end surface 31c of the portion 31 as the first flange portion by pressing in the second working step S2, with respect to the disc-shaped one steel sheet 11, but the present invention is not limited thereto. The present invention is not limited to the steel sheet, and may be applied to metal sheets of various materials as long as the metal sheets can be subjected to plastic working.

The shape of the metal plate is not limited to a disk shape, and various shapes can be applied. The shape of the first flange portion 30 and the second flange portion 40 is not limited to the cylindrical shape described above, and the first flange portion and the second flange portion formed in a flat plate shape may be protruded from the base portion, respectively. Fig. 8 shows a first modification of the present embodiment. As shown in fig. 8, the press-molded article 10A of the present modification includes a rectangular plate-shaped base portion 20A, a first flange portion 30A extending from a first surface 20Aa of the base portion 20A, and a second flange portion 40A extending from a second surface 20Ab of the base portion 20A opposite to the first surface 20 Aa. The first flange portion 30A extends from a pair of opposite sides of the rectangular base portion 20A toward the first side X1 in the first direction X. The first flange portion 30A is formed in a rectangular flat plate shape. Further, the second flange portion 40A projects from a pair of sides of the base portion 20A projecting from the first flange portion 30A toward the second side X2 in the first direction X. The second flange portion 40A is formed in a rectangular flat plate shape. In such a modification, the thickness T2 of the second flange portion 40A may be smaller than the thickness T1 of the first flange portion 30A, and the relationship between the radius R of the outside of the corner portion 12Aa at the connection portion between the portion serving as the first flange portion 40A and the portion serving as the base portion 20A in the first processing step S1, the thickness T1 of the first flange portion 30A, and the thickness T2 of the second flange portion 40A may be set to satisfy the above expression (1). As described above, in the press-molded article 10A according to the present modification, the tip end surface of the portion that is the first flange portion 30A can be pushed and plastically deformed in the second processing step S2, and the second flange portion 40A can be formed while suppressing the defect that the inner portion forms an acute angle in a folded-in shape.

In the present embodiment, the outer peripheral surface 30a of the first flange portion 30 and the outer peripheral surface 40a of the second flange portion 40 are formed in a straight line when viewed in a direction (i.e., radial direction) orthogonal to the center line L, but the outer diameters are substantially equal. For example, the outer diameter of the outer peripheral surface 40a of the second flange portion 40 may be smaller than the outer diameter of the outer peripheral surface 30a of the first flange portion 30. For example, the outer peripheral surface of at least one of the first flange portion 30 and the second flange portion 40 may be tapered so that the outer diameter gradually decreases from the distal end side toward the proximal end side along the first direction X. In this case, at least the thickness T2 of the second flange portion 40 may be made smaller than the thickness T1 of the first flange portion 30. The shape of the second pad 130 is appropriately changed according to the shapes of the first flange portion and the second flange portion, so that the first flange portion and the second flange portion having desired shapes can be formed. In addition, in the case of forming the taper shape, as shown in fig. 2, the distance between the intersection point P31 and the intersection point P32 may be defined as a thickness T1 and the distance between the intersection point P41 and the intersection point 42 may be defined as a thickness T2 based on the extension lines L21, L22, L30, and L40.

The first flange portion 30B and the second flange portion 40B may be formed on the center side of a metal plate such as the steel plate. Fig. 9 and 10 (fig. 10A to 10C) show a second modification of the present embodiment. As shown in fig. 9, the press-molded article 10B of the present modification includes a disk-shaped base portion 20B, a first flange portion 30B extending from the center side of the base portion 20B to the first side X1 in the first direction X, and a second flange portion 40B extending from the center side of the base portion 20B to the second side X2 in the first direction X. The first flange portion 30B is formed in a cylindrical shape in this modification. The second flange portion 40B is also formed in a cylindrical shape in this modification. The first flange portion 30B and the second flange portion 40B are coaxially arranged with respect to the center line L. The hole formed in the first flange portion 30B and the hole formed in the second flange portion 40B communicate with each other. In the present modification, the inner diameters of the inner peripheral surface of the first flange portion 30B and the inner peripheral surface of the second flange portion 40B are substantially equal to each other, and are formed in a straight line shape.

As shown in fig. 10A, the press-molded product 10B is molded from a metal plate 11B having a through hole 11B formed in the center thereof. As shown in fig. 10B, first, in the first processing step S1, the periphery of the through hole 11B of the circular plate-shaped metal plate 11B is subjected to plastic working, so that a portion 31B as a first flange portion can be formed to protrude from a portion 21B as a base portion to a first side X1 in the first direction X. As a method of plastic working, various known methods can be applied, and for example, inner edge flanging can be given. That is, by sandwiching the portion 21B as the base with the

backing plates

100B, 101B and allowing the cylindrical punch 102B to enter from the first direction X second side X2 to the first side X1 of the portion 21B as the base, the portion 31B as the first flange portion can be formed by plastically deforming the portion around the through hole 11B. At this time, the corner 12Ba connecting the portion 21B as the base with the portion 31B as the first flange is formed in a curve shape in a cross section along the center line L according to the shape of the corner of the pad 100B.

Then, as shown in fig. 10C, in the second working step S2, the tip end surface 31Bc of the portion 31B as the first flange portion is pressed by the punch 150B, and the portion 31B as the first flange portion is plastically deformed as in the above-described embodiment. Specifically, the portion 21B as a base is sandwiched and pressed by the first pad 120B and the third pad 140B. Further, a portion 31B as a first flange portion is arranged between the first pad 120B and the third pad 130B. The punch 150B is moved in from the first side X1 to the second side X2 in the first direction X between the first pad 120B and the third pad 130B, thereby pressing the distal end surface 31Bc of the portion 31B serving as the first flange portion. Here, in the present modification, the thickness T2 of the second flange 40B is made smaller than the thickness T1 of the first flange 30B after the second processing step S2 is performed, and the radius R of the outside of the corner 12Ba is made to satisfy the above expression (1) in relation to the thickness T1 of the first flange 30B and the thickness T2 of the second flange 40B. This can suppress the defect of the folded shape forming an acute angle in the inner portion 30Bd connecting the base portion 20B and the first flange portion 30B.

In the above embodiment, the first flange portion 30 and the second flange portion 40 are formed on the outer peripheral edge side of the metal plate, and the first flange portion 30B and the second flange portion 40B are formed on the center side of the metal plate in the second modification, but the first flange portion and the second flange portion may be formed on both the center side and the outer peripheral edge side of the metal plate. In this case, the first and second processing steps S1 and S2 may be performed on the center and outer peripheral sides of the metal plate, respectively, or the first and second processing steps S1 and S2 may be performed simultaneously by a mold having a shape that can be performed simultaneously. In the above embodiment and modification, the first working step S1 and the second working step S2 have been described, but the working steps are not limited to the above working steps, and other working steps such as a working step of performing other plastic working, a cutting step, and a surface treatment step may be performed.

(embodiment 2)

Next, embodiment 2 of the present invention will be described. Fig. 11 is a diagram showing embodiment 2 of the present invention. In this embodiment, the same reference numerals are given to the components common to those used in the above embodiment, and the description thereof is omitted.

In the method for manufacturing a press-molded article according to the present embodiment, the second processing step S2 is different from embodiment 1. That is, as shown in fig. 11A, the press working apparatus 110C in the second working step S2 of the present embodiment includes a fourth backing plate 160 in addition to the first backing plate 120, the second backing plate 130, the third backing plate 140, and the punch 150. In the present embodiment, the fourth pad 160 is a cylindrical member. The fourth pad 160 is disposed on the second side X2 of the first direction X, that is, on the opposite side to the punch 150, with the portion 31 as the first flange portion interposed therebetween. The fourth pad 160 is disposed between the second pad 130 and the third pad 140, and is disposed coaxially with respect to the center line L. The fourth pad 160 is provided to be capable of advancing and retreating in the first direction X. Further, the fourth pad 160 is moved from the first direction X second side X2 toward the first side X1 by a hydraulic device or the like, not shown, and an external force can be applied to the corner 12a of the intermediate product 12 toward the first direction X first side X1.

As shown in fig. 11B, in the second working step S2 of the present embodiment, the fourth shim plate 160 is first brought into contact with the corner 12a by being brought into contact with the first side X1 in the first direction X. Then, at the timing of starting the pressing of the distal end surface 31c of the portion 31, which is the first flange portion, to the first direction X and the second side X2 from the punch 150, the fourth pad 160 presses the corner portion 12a to the first direction X1, and applies an external force from the first direction X and the second side X2 to the first side X1 to the corner portion 12a of the intermediate product 12. The magnitude of the external force applied to intermediate product 12 by fourth backing plate 160 is smaller than the magnitude of the external force applied to intermediate product 12 by punch 150. As shown in fig. 11C, the portion 31 serving as the first flange portion is plastically deformed by the punch 150, and the material is to flow in the range of the second flange portion 40, whereas the fourth pad 160 moves from the first side X1 toward the second side X2 in the first direction X while applying an external force to the intermediate product 12. The external force applied to the intermediate product 12 by the fourth pad 160 may be applied until the formation of the second flange portion 40 is completed, or may be released at a timing until the second flange portion 40 is formed as shown in fig. 11D.

As described above, according to the method of manufacturing a press-molded product of the present embodiment, an external force is applied from the first direction X second side X2 toward the first side X1 to the corner 12a connected to the portion 31 serving as the first flange in the portion 21 serving as the base at least halfway through the completion of the processing from the start of the processing of flowing the material of the portion 31 serving as the first flange to the first direction X second side X2. By plastically deforming the portion 31 as the first flange portion, stress is generated in each material of the first flange portion 30 and the base portion 20 connected to the first flange portion, so that it plastically flows toward the first direction X second side X2 of the base portion 20. However, in the process from the start of the process of flowing the material of the portion 31 as the first flange portion to the first direction X second side X2 until at least the way of the process is completed, the plastic flow from the portion 21 as the base portion to the first direction X second side X2 can be suppressed by the external force applied toward the first direction X first side X1. Therefore, it is possible to suppress the defect that the material flows plastically from both the portion 21 as the base portion and the portion 31 as the first flange portion to the first direction X second side X2 to form an acute angle in the inner portion 30d connecting the base portion 20 and the first flange portion 30. After a predetermined amount of deformation is generated from the start of the process of flowing the material of the portion 31 as the first flange portion in the first direction X and the second side X2, the portion generated in the deformation is deformed in the first direction X and the second side X2 by the pressing force acting on the distal end surface 31c of the portion 31 as the first flange portion, so that the occurrence of the defect of the folded shape of the acute angle can be suppressed, and the second flange portion 40 can be formed.

Examples

Next, an example of a method for manufacturing a press-molded article according to embodiment 1 will be described with reference to fig. 1 to 7, 12, and 13. Specifically, in the press-molded article 10 shown in fig. 1, it is confirmed whether or not a defect in the form of a folded-in acute angle occurs in the inner portion 30d in each shape while changing the thickness T1 of the first flange portion 30 and the thickness T2 of the second flange portion 40 after the second processing step S2 is performed, and the radius R outside the corner portion 12a before the second processing step S2 is performed. The confirmation is performed by analysis by the finite element method. As a blank material of the steel sheet 11, SAPH440 defined in JIS G3113 (hot-rolled steel sheet and steel strip for automobile construction) was used.

The intermediate product 12 before the second processing step S2 is formed so as to correspond to each of thicknesses t1=4 mm and 6mm described later. As shown in fig. 6, regarding the portion 31 as the first flange portion, the height H31 extending from the first surface 21a of the portion 21 as the base portion to the first side X1 in the first direction X is set to 40mm. In the intermediate product 12 corresponding to the thickness t1=4mm, the diameter of the inner peripheral surface 31b of the portion 31 as the first flange portion was 80mm, the diameter of the outer peripheral surface 31a was 88mm, and the thickness T31 was 4mm. In the intermediate product 12 corresponding to the thickness t1=6mm, the diameter of the inner peripheral surface 31b of the portion 31 as the first flange portion was 80mm, the diameter of the outer peripheral surface 31a was 92mm, and the thickness T31 was 6mm. The radius R outside the corner 12a is set to a value of 0.1mm and 0.5mm each time in the range of 0.5 to 6.0 mm.

Then, a second processing step S2 is performed. Both the invention example and the comparative example were formed by pressing the front end surface 31c of the portion 31 as the first flange portion with a load of 4000kN by the punch 150 to plastically deform the front end surface 31c, thereby forming the second flange portion 40 extending from the second surface 21b of the portion 21 as the base portion to the second side X2 in the first direction X. The second flange 40 has a height H40 (see fig. 1) of 10mm extending from the second surface 20b of the base 20 to the second side X2 in the first direction X. Further, the thickness T1 of the first flange portion 30 is set to two of 4mm and 6 mm. When the thickness t1=4.0 mm, the thickness T2 of the second flange portion 40 is changed to 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0mm, respectively, whereby the plate thickness ratio T2/T1 is changed to 0.25, 0.38, 0.50, 0.63, 0.75, 0.88, 1.0. When the thickness t1=6.0 mm, the thickness T2 of the second flange portion 40 is changed to 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0mm, and the plate thickness ratio T2/T1 is changed to 0.33, 0.42, 0.50, 0.58, 0.67, 0.75, 0.83, 0.92, 1.00, respectively. Further, it was confirmed whether or not a sharp-angled fold-in defect did not occur at the inner portion 30d connecting the first flange portion 30 and the base portion 20 in each of the corner portions 12a by changing the radius R of the corner portion 12a as described above at each plate thickness ratio T2/T1.

Fig. 12 and 13 and tables 1 and 2 show analysis results. Table 1 is a table of the plate thickness ratio T2/T1 and the radius R of the outside of the corner 12a at t1=4.0 mm. Table 2 is a table of the plate thickness ratio T2/T1 and the radius R of the outer side of the corner 12a at t1=6.0 mm. Each cell in table 1 and table 2 shows the value of r×t2/T1 calculated from the formula (1) under each analysis condition. As shown in fig. 13, under the condition (comparative example) that the value of r×t2/T1 is underlined in each cell, it is clear from the analysis result that the acute-angled folded defect D is formed in the inner portion 30D. That is, from the analysis result, when T2/T1 is 1 or more (T2 is the same as T1 or T2 is larger than T1), the defect D is formed regardless of the value of r×t2/T1. Further, from the analysis result, even if the plate thickness ratio T2/T1 is smaller than 1 (T2 is smaller than T1), the defect D is formed when the value of r×t2/T1 is 3.5 or more. In addition, under the condition (inventive example) that each cell is not underlined, as shown in fig. 12, the defect D in the folded shape having an acute angle is not visible with respect to the inner portion 30D, and can be formed in a smooth concave curve. That is, the plate thickness ratio T2/T1 is smaller than 1.00 (T2 is smaller than T1), and the value of r×t2/T1 calculated by the expression (1) is smaller than 3.5, whereby the first and second processing steps S1 and S2 can form the smooth concave curved inner portion 30D without forming the folded-in defect D, and can form the first and

second flange portions

30 and 40.

[ Table 1 ]

[ Table 2 ]

The embodiments and examples of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to the embodiments, and design changes and the like without departing from the scope of the gist of the present invention are also included.

Industrial applicability

It is possible to provide a method for producing a press-molded article, by which a press-molded article having portions protruding in a flange shape on both sides can be produced from a single metal plate in a fewer number of steps without causing defects that are folded in at an acute angle at the inner portion protruding in the flange shape. Thus, the industrial availability is high.

Description of the reference numerals

10. 10A, 10B press-formed articles; 11. 11B steel plate (metal plate); 12a, 12Ba corners; 20. 20A, 20B base; 21c a connecting portion; 30. 30A, 30B first flange portions; 40. 40A, 40B second flange portions; 120. 120B first backing plate; 130. 130B a second backing plate; 140. 140B a third pad; 150. a 150B punch; s1, a first machining procedure; s2, a second processing procedure; radius outside the R corner; t1 thickness of the first flange portion; thickness of the T2 second flange portion; x is the first direction; x1 a first side; x2 second side.

Claims

1. A method for manufacturing a press-formed article,

forming a first flange portion extending toward a first side in a first direction, which is a thickness direction of a plate-like base portion, by plastically deforming a part of a single metal plate, and forming a corner portion extending in a curved shape between the base portion and the first flange portion;

disposing a first pad along the first flange portion;

disposing a second pad on the opposite side of the first pad with the first flange portion interposed therebetween;

a third pad is disposed on the opposite side of the first flange portion with the base portion interposed therebetween so as to form a gap with the second pad smaller than a gap between the first pad and the second pad;

a punch is disposed between the first pad and the second pad so as to be movable in a first direction, and the punch pushes a distal end surface of the first flange portion formed on a first side in the first direction;

a second flange portion extending toward the first direction second side with respect to the base portion by pressing the distal end surface of the first flange portion toward the first direction second side so that the material of the first flange portion flows toward the first direction second side;

The thickness T2 of the second flange portion is smaller than the thickness T1 of the first flange portion after the second flange portion is formed;

the ratio of the thickness T2 of the second flange portion after the formation of the second flange portion to the thickness T1 of the first flange portion is mm, and the radius R of the outside of the bend of the corner portion in a cross section of the corner portion in the extending direction after the formation of the corner portion is mm, that is, r×t2/T1 is less than 3.5.

2. The method for producing a press-molded article according to claim 1,

the third pad includes a plane including a surface along the second flange after the second flange is formed, and is located on the first flange side in a direction orthogonal to the surface along the first flange with respect to a plane including a surface along the first flange in the first pad.

3. The method for producing a press-molded article according to claim 2,

the second pad is formed in a linear shape along the first direction along the surfaces of the first flange portion and the second flange portion.

4. The method for producing a press-molded article according to claim 1 or 2,

when forming the second flange portion, the first flange portion is plastically deformed while applying an external force from the first direction second side of the connecting portion connected to the first flange portion in the base portion to the first direction first side on the way to completion of the processing, from the start of the processing in which the material of the first flange portion flows to the first direction second side by pressing the tip end surface of the first flange portion formed on the first direction first side to the first direction second side.

5. The method for producing a press-molded article according to claim 3,