JP7173300B2 - Method for manufacturing press-molded products - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a press-molded product.
This application claims priority based on Japanese Patent Application No. 2019-071411 filed in Japan on April 3, 2019, the content of which is incorporated herein.

The transmission component has a hub portion that protrudes on both sides in a direction along the rotation shaft and is attached to the rotation shaft from a functional aspect as the transmission component. In order to form such a hub portion, for example, there is a method of welding two members. In this method, one side of the hub portion is formed from a portion of a single metal plate by plastic working such as burring. After that, the member that will be the other side of the hub portion is welded to the other side of the metal plate on which the portion that will be the one side of the hub portion is formed, thereby forming the transmission component as described above. As another method, there is a powder sintering method in which metal powder is sintered in a mold having a shape corresponding to the transmission part. The method of welding the two members described above requires a step of processing the two members, and further requires a step of welding, resulting in an increase in the number of manufacturing steps. For this reason, the method of welding the two members described above results in a high manufacturing cost and a long takt time for manufacturing. Also, in the method of sintering, a step of heat treatment for sintering is required, which increases the manufacturing cost and lengthens the tact time for manufacturing.

Further, in Patent Document 1, after projecting to one side of a metal plate by press working, a part of the portion projecting to one side is projecting to the other side by press working, thereby forming a sheet of metal. A technique is disclosed in which tubular portions are projected from a plate on both sides of the metal plate. With such a technique, it is possible to reduce the number of steps compared to the method of welding the two members or the method of sintering. However, in the technique described in Patent Document 1, when a part of the portion overhanging to one side is overhanging to the other side by press working, the original metal plate and the portion overhanging to one side are separated. There is a problem that an acute-angled defect is formed at the bent inner corner portion. In addition, in Patent Document 2, after forming a cup vertical wall portion protruding from the cup bottom, the cup vertical wall portion is drawn and formed to increase the thickness of the cup vertical wall portion and the cup shoulder portion and to increase the thickness of the cup vertical wall portion and the cup shoulder portion. It is disclosed that the part is molded. However, even the technique described in Patent Document 2 does not disclose a specific means for solving the problem of the formation of defects that are folded at an acute angle in the inner portions of the cup bottom and cup vertical wall. Processing methods for solving such problems are proposed in Patent Documents 3 and 4, for example.

Specifically, in Patent Document 3, a step of forming a cylindrical portion on one side of a plate-shaped material by plastic working, and a step of plastically forming a front end side inner peripheral portion of the cylindrical portion formed on the one side to a base side inner peripheral portion. A method of manufacturing a metal member has been proposed in which a step of thickening the root portion by deformation and a step of pushing out the thickened root-side inner circumferential portion toward the other side of the plate-shaped material have been proposed. In addition, in the manufacturing method of Patent Document 2, by performing the above three steps, it is possible to form a component in which the cylindrical portion protrudes on both sides of the original plate-shaped material. By forming the cylindrical portion projecting to the other side with the thickened portion, the original cylindrical portion of the cylindrical portion projecting to the one side is not pushed out, and the defect of being bent at an acute angle as described above can be eliminated. It is supposed that it can control that it is formed. Further, in Patent Document 4, when forming a molded product including a stretch flange portion, a flange peripheral portion, and a flange extension portion in which the stretch flange portion extends from the corner portion side, the stretch flange portion and the flange periphery It has been proposed to use, as a workpiece, a burring molded product in which the outer radius of curvature of the corner portion between the corners is small or substantially perpendicular. Then, by pushing the end face of the stretch flange portion of the work material, the material constituting the stretch flange portion is moved to form the flange extension portion, and as described above, the outer curvature radius of the corner portion It is considered that by using a work material with a small angle or a substantially right angle, no folding occurs inside the corner portion.

JP-A-11-10275 WO2014/109240 JP 2018-83215 A JP 2017-196632 A

However, in the manufacturing method disclosed in Patent Document 3, in addition to the step of forming a flange-shaped overhanging portion on one side and the step of forming a flange-shaped overhanging portion on the other side, the original metal plate portion A further process is required for suppressing defects bent at an acute angle in the inner portion between the flange-like portion projecting to one side. That is, it is necessary to further carry out a step of thickening the root portion of the portion that protrudes like a flange on one side. For this reason, even the manufacturing method disclosed in Patent Document 1 has a problem that the number of processes increases, the manufacturing cost increases, and the takt time related to manufacturing increases. Further, in the manufacturing method disclosed in Patent Document 4, when the flange-shaped overhanging portion formed on one side is pushed in to form the flange-shaped overhanging portion on the other side, the corner portion of the workpiece is is limited to a small radius of curvature at or near a right angle. In actual machining, the radius of curvature of the outer portion is not limited to a small radius of curvature that is right-angled or nearly right-angled. There has been a demand for a technique for forming a flange-like protruding portion in the

Therefore, the present invention has been made in view of the above-mentioned circumstances, and a press-formed product having portions protruding in a flange shape on both sides from a single metal plate is formed at an acute angle to the inner portion that protrudes in the shape of a flange. To provide a method for manufacturing a press-formed product capable of being manufactured in a small number of steps without causing a broken defect.

In order to solve the above problems, the present invention employs the following means.
That is, in a method for manufacturing a press-formed product according to one aspect of the present invention, by plastically deforming a part of a single metal plate, the first direction is the thickness direction of the plate-shaped base with respect to the base. forming a first flange projecting in the first direction, forming a curved corner between the base and the first flange, along the first flange A first pad is arranged on each side, a second pad is arranged on the side opposite to the first pad across the first flange, and a second pad is arranged on the side opposite to the first flange across the base forming a gap smaller than the gap between the first pad and the second pad and disposing a third pad between the first pad and the second pad; A punch that presses a tip surface formed on the first side in the first direction of the first flange portion is disposed between the pad and the punch so as to be able to advance and retreat in the first direction, and the first flange portion By pressing the tip surface of the first direction second side opposite to the first direction first side across the base, the material of the first flange portion is the first A second flange portion projecting toward the second side in the first direction is formed with respect to the base portion by flowing in the second direction side, and the curvature radius of the inner portion between the first flange portion and the base portion On the other hand, the curvature radius of the inner portion of the second flange portion and the base portion is small, and the second flange portion has a thickness T1 of the first flange portion after forming the second flange portion. The thickness T2 of the portion is thin, and 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, R×T2/T1, which is the product of the bend outer radius R (mm) of the corner in a cross section transverse to the extension direction of the corner after the corner is formed, is less than 3.5.
According to this method, first, as a first processing step, a first flange portion projecting to the first side in the first direction with respect to the plate-like base portion by plastically deforming a part of one metal plate. and corners. Next, as a second processing step, the tip surface formed on the first side in the first direction of the first flange portion is pressed toward the second side in the first direction, thereby forming the first flange portion. The material is caused to flow to the second side in the first direction to form a second flange portion that overhangs the base portion to the second side in the first direction. Here, in the initial stage of the second processing step, the tip surface of the first flange portion is pressed so that the corner portion formed by the base portion and the first flange portion falls into the range of the second flange portion. tries to plastically deform to However, the thickness T2 of the second flange portion is made smaller than the thickness T1 of the first flange portion after performing the second processing step, and the thickness T2 of the second flange portion after performing the second processing step is reduced. The product R×T2/T1 of the ratio of the thickness T2 of the second flange portion to the thickness T1 of the first flange portion and the outer radius R of the corner portion after the first processing step is less than 3.5 By doing so, it is possible to suppress the depression of the corner formed by the base and the first flange into the range of the second flange. For this reason, in the second processing step, the second flange is formed by the second processing step while suppressing the formation of an acute folded defect in the inner portion of the corner due to the corner being depressed. part can be formed.

Further, in the method for manufacturing a press-formed product, the plane including the surface along the second flange portion after forming the second flange portion in the third pad is the first may be positioned on the first flange side in a direction orthogonal to the plane along the first flange with respect to a plane including the plane along the flange. In other words, after forming the second flange portion, the plane including the surface of the third pad along the second flange portion passes through the inside of the first flange portion.
According to this method, in the second processing step, the surface along the second flange portion of the third pad after the second processing step is different from the surface along the first flange portion of the first pad. By being positioned on the first flange side in a direction perpendicular to the surface along the first flange, especially at the corners, the material on the third pad side is the third pad and the second pad It is possible to further suppress the formation of sharp fold-like defects in the inner portions of the corners.

Further, in the method for manufacturing a press-formed product, the surface of the second pad along the first flange portion and the second flange portion is formed linearly along the first direction. It is good as a thing.
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 linearly along the first direction. In particular, at the corners, the material on the third pad side is suppressed from falling into the gap between the third pad and the second pad, so that sharp fold-like defects are formed further inside the corners. can be suppressed. In addition, the first flange portion and the second flange portion can form surfaces that are linearly connected to each other while having different thicknesses.

Further, in the method for manufacturing a press-formed product, when forming the second flange portion, the tip surface formed on the first side in the first direction of the first flange portion is moved in the first direction. By pressing to the second side, from the start of processing to flow the material of the first flange portion to the second side in the first direction until at least partway through the completion of the processing, the first While applying an external force toward the first side in the first direction from the second side in the first direction of the connection portion connected to the flange portion of the, the first flange portion is plastically deformed. good.
According to this method, from the start of processing in which the material of the first flange portion flows to the second side in the first direction to at least halfway through the completion of the processing, the first flange portion at the base is connected An external force is applied from the second side in the first direction of the connecting portion toward the first side in the first direction. By plastically deforming the first flange portion, stress is applied so that each material of the first flange portion and the base portion connected to the first flange portion plastically flows toward the second side in the first direction of the base portion. occur. However, from the start of processing to flow the material of the first flange portion applying an external force toward the first side in the first direction to the second side in the first direction, at least halfway to the completion of the processing In the process, the external force can suppress plastic flow toward the second side in the first direction from the base. For this reason, the material plastically flows from both the base and the first flange to the second side in the first direction of the base, so that the inner portion where the base and the first flange are connected is bent at an acute angle. It is possible to suppress the formation of such defects. Then, after a certain amount of deformation due to the processing from the start of the processing that causes the material of the first flange portion to flow in the first direction to the second side, the portion generated by the deformation is further removed to the tip of the first flange portion. By deforming to the second side in the first direction by the pressing force acting on the surface, it is possible to form the second flange portion while further suppressing the occurrence of defects in the shape of sharp folds. .

According to the present invention, a press-formed product having portions protruding on both sides from a single metal plate is manufactured in a small number of steps without causing defects such as sharp folds in the inner portion protruding like a flange. can do.

1 is a partially broken perspective view showing a press-formed product manufactured by the method for manufacturing a press-formed product according to the first embodiment; FIG. FIG. 2 is a detailed view of part A in FIG. 1; It is a flow figure explaining the manufacturing method of the press-formed article of 1st Embodiment. 1 is a perspective view of a steel plate used in the method of manufacturing a press-formed product according to the first embodiment; FIG. It is process drawing explaining the 1st processing process in the manufacturing method of the press-formed product of 1st Embodiment. It is process drawing explaining the 1st processing process in the manufacturing method of the press-formed product of 1st Embodiment. FIG. 4 is a cross-sectional view of an intermediate product formed by a first processing step in the method for manufacturing a press-formed product of the first embodiment; It is process drawing explaining the second processing process in the manufacturing method of the press-formed product of 1st Embodiment. It is process drawing explaining the second processing process in the manufacturing method of the press-formed product of 1st Embodiment. It is process drawing explaining the second processing process in the manufacturing method of the press-formed product of 1st Embodiment. It is process drawing explaining the second processing process in the manufacturing method of the press-formed product of 1st Embodiment. It is a perspective view which shows the press-formed product of the 1st modification of 1st Embodiment. FIG. 7 is a cross-sectional view showing a press-formed product manufactured by a method for manufacturing a press-formed product according to a second modification of the first embodiment; It is process drawing explaining the manufacturing method of the press-formed product of the 2nd modification of 1st Embodiment. It is process drawing explaining the manufacturing method of the press-formed product of the 2nd modification of 1st Embodiment. It is process drawing explaining the manufacturing method of the press-formed product of the 2nd modification of 1st Embodiment. It is process drawing explaining the 2nd processing process in the manufacturing method of the press-formed product of 2nd Embodiment. It is process drawing explaining the 2nd processing process in the manufacturing method of the press-formed product of 2nd Embodiment. It is process drawing explaining the 2nd processing process in the manufacturing method of the press-formed product of 2nd Embodiment. It is process drawing explaining the 2nd processing process in the manufacturing method of the press-formed product of 2nd Embodiment. FIG. 10 is a cross-sectional view showing the shape of the inner portion after completion of the second processing step, which is the analysis result of the method for manufacturing the press-formed product of the invention example. FIG. 10 is a cross-sectional view showing the shape of the inner portion after completion of the second processing step, which is an analysis result of the manufacturing method of the press-formed product of the comparative example.

(First embodiment)
A first embodiment according to the present invention will be described below with reference to FIGS. 1 to 7. FIG. 1 and 2 show an example of a press-formed product manufactured by the method for manufacturing a press-formed product according to this embodiment. As shown in FIG. 1, the press-formed product 10 of the present embodiment is, for example, a gear or a clutch attached to a rotating shaft rotatable around the center line L as a transmission component. Note that FIG. 1 omits functional parts as transmission parts, such as teeth of gears and braking surfaces of clutches. As shown in FIG. 1, the press-formed product 10 includes a plate-shaped base portion 20, a first flange portion 30 projecting from a first surface 20a of the base portion 20, and a second flange portion 30 on the side opposite to the first surface 20a of the base portion 20. and a second flange portion 40 projecting from the two surfaces 20b. In this embodiment, the base 20 is formed in a disc shape. The press-formed product 10 has the above-described functional portions as the target press-formed product 10 in the base portion 20, but the functional portions are omitted in FIG.

Moreover, in this 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 cylindrically formed along the outer peripheral edge of the base portion 20 and arranged coaxially with respect to the center line L. As shown in FIG. 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. 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 linearly connected along the first direction X. As shown in FIG.

As shown in FIG. 2, the thickness T2 of the second flange portion 40 is thinner than the thickness T1 of the first flange portion 30 in this embodiment. Further, at the base end 30c of the first flange portion 30, the inner side of the first flange portion 30 and the base portion 20 where the inner peripheral surface 30b of the first flange portion 30 and the first surface 20a of the base portion 20 are connected The portion 30d is formed to have a concave curved surface. Similarly, at the proximal end 40c of the second flange portion 40, the second flange portion 40 and the base portion 20 are connected to the inner peripheral surface 40b of the second flange portion 40 and the second surface 20b of the base portion 20. The inner portion 40d is formed in a concave curved surface shape. The radius of curvature R40 of the inner portion 40d is preferably smaller than the radius of curvature R30 of the inner portion 30d.

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

In this embodiment, the thickness T2 of the second flange portion 40 is thinner than the thickness T1 of the first flange portion 30, and the outer peripheral surface 30a of the first flange portion 30 and the second flange portion 40 are Since the outer diameter of the outer peripheral surface 40 a is substantially equal, the inner diameter of the inner peripheral surface 30 b of the first flange portion 30 is smaller than the inner diameter of the inner peripheral surface 40 b of the second flange portion 40 . In addition, although the details of the structure of the press-formed product 10 have been described above, as long as the base portion 20, the first flange portion 30 and the second flange portion 40 are provided, the first flange portion 30 and the second flange portion Except for the relationship of the thickness of the portion 40, the details of the structure such as the shape of the connecting portion between the base portion 20 and the first flange portion 30 and the second flange portion 40 are not limited. Further, when the press-molded product 10 is a transmission component or the like, a hub portion attached to the rotating shaft is provided on the center side of the base portion 20, but is omitted in FIG. The hub portion may be formed simultaneously by the processing steps of the present embodiment described below, or may be processed to form the shape of the hub portion separately, or a member corresponding to the hub portion may be attached.

Next, a method for manufacturing the press-formed product of this embodiment will be described. In addition, as shown in FIG. 1, the direction in which the first flange portion 30 and the second flange portion 40 protrude (protrude) in the press-formed product 10 manufactured by the method for manufacturing a press-formed product of the present embodiment, That is, the first direction X is the thickness direction of the base portion 20 and the direction in which the center line L to which the press-formed product 10 is attached extends. Then, the side where the first flange portion 30 protrudes along the first direction X with respect to the base portion 20 is the first side X1, and the side where the second flange portion 40 protrudes opposite to the first side X1. is called the second side X2.

FIG. 3 shows a flowchart of the method for manufacturing a press-formed product according to this embodiment. As shown in FIG. 3, the method for manufacturing the press-formed product 10 of the present embodiment includes a first processing step S1 for forming the first flange portion 30, and a second processing step S1 for forming the second flange portion 40. and step S2. Details will be described below.

In the first processing step S1, as shown in FIG. 4, a single steel plate 11, which is a disc-shaped metal plate, is used. In the first processing step S1, the outer peripheral edge portion 11a of the steel plate 11 is plastically deformed to form a portion to be the first flange portion 30 on the first side X1 in the first direction X, which is the thickness direction of the steel plate 11. protrude. As a working method for plastic deformation, various known methods can be applied, and for example, drawing or burring is used. Drawing is performed in the first working step S1 of the present embodiment. That is, as shown in FIG. 5A, the steel plate 11 is divided into a pad 100 arranged on the first direction X first side X1 of the steel plate 11 and a pad arranged on the first direction X second side X2 of the steel plate 11. sandwiched between 101 and Then, as shown in FIG. 5B, the punch 102 is advanced from the first direction X second side X2 to the first side X1 toward the outer peripheral edge portion 11a of the steel plate 11, thereby moving the outer peripheral edge portion 11a of the steel plate 11 to the first side X1. A portion 31 that becomes a first flange portion is formed by projecting in one direction X first side X1. FIG. 6 shows the intermediate product 12 formed by performing the first processing step S1. The intermediate product 12 is formed from the steel plate 11 as described above, and includes the portion 21 that will be the base portion and the portion 31 that will be the first flange portion. In the first processing step S1, the thickness T31 of the portion 31 to be the first flange portion may be different from the thickness T1 of the first flange portion 30 in the press-formed product 10 as the finished product.

Here, the corner portion 100a of the pad 100 is formed in a convex curved shape. Therefore, in the first processing step S1, the portion 31 to be the first flange portion and the portion 21 to be the base portion are formed at the connection portion between the portion 31 to be the first flange portion and the portion 21 to be the base portion. A connecting corner portion 12a extends in a curved shape when viewed in cross section along the center line L. As shown in FIG. Then, the bending outer radius R (mm) of the corner portion 12a in the cross section across the extending direction of the corner portion 12a, that is, the curvature radius of the outer peripheral surface of the corner portion 12a, and the second processing step S2 described later were performed. The ratio between the thickness T2 (mm) of the second flange portion 40 and the thickness T1 (mm) of the first flange portion 30 is formed so as to satisfy the following relational expression.
R×T2/T1<3.5 (1)

Next, the second processing step S2 is performed. In the second processing step S2, by plastically deforming the portion 31 to be the first flange portion in the intermediate product 12 to flow the material of the portion 31 to be the first flange portion, the first flange portion 30 and A second flange portion 40 is formed. 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. As shown in FIG.

The first pad 120 is formed in a columnar shape extending along the first direction X. As shown in FIG. The outer peripheral surface 120a of the first pad 120 is formed linearly along the center line L. As shown in FIG. The first pad 120 is arranged along the inner peripheral surface 31b of the portion 31 that will be the first flange portion of the intermediate product 12 installed in the processing device 110, as will be described later. In this embodiment, the outer peripheral surface 120a of the first pad 120 is in contact with the portion 31 serving as the first flange portion when the intermediate product 12 is installed in the processing device 110 . Also, the first pad 120 abuts on the portion 21 serving as the base. In the first pad 120, the lower surface 120b in contact with the base portion 21 and the outer peripheral surface 120a are connected by a convex curved surface 120c. The curvature radius of the convex curved surface 120c is the first flange portion 30 and the base portion 20 where the inner peripheral surface 30b of the first flange portion 30 and the first surface 20a of the base portion 20 are connected in the press-formed product 10 after molding. corresponds to the curvature radius R30 of the inner portion 30d.

The second pad 130 is a cylindrical member. The second pad 130 is arranged with a gap on the radially outer peripheral side of the first pad 120 so as to be coaxial with the first pad 120 with respect to the center line L. As shown in FIG. An inner peripheral surface 130a of the second pad 130 is formed linearly along the first direction X. As shown in FIG. The inner peripheral surface 130a of the second pad 130 is arranged along the outer peripheral surface 31a of the first flange portion 31 of the intermediate product 12 installed in the processing apparatus 110, as will be described later. In this embodiment, the inner peripheral surface 130a of the second pad 130 is in contact with the portion 31 serving as the first flange portion when the intermediate product 12 is installed in the processing device 110 . A separation 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. As shown in FIG. In addition, the thickness T31 of the portion of the intermediate product 12 that becomes the first flange portion is the separation distance D1 before the second processing step S2 is performed, and the thickness of the first flange portion 30 after the second processing step S2 is performed. It may be smaller than the thickness T1. The second pad 130 sandwiches the first pad 120 and the portion 31 forming the first flange portion along the first direction X, and extends to a range forming the second flange portion 40 . In this embodiment, the inner peripheral surface 130a of the second pad 130 is formed linearly along the first direction X. As shown in FIG.

The third pad 140 is a cylindrical member. The third pad 140 is arranged radially inward of the second pad 130 so as to be coaxial with the center line L of the first pad 120 and the second pad 130 . An outer peripheral surface 140a of the third pad 140 is formed linearly along the center line L. As shown in FIG. In this embodiment, the third pad 140 is arranged along the inner peripheral surface 40b of the second flange portion 40 of the press-formed product 10 when the intermediate product 12 is installed in the processing device 110. . The third pad 140 abuts on the base portion 21 and sandwiches the base portion 21 together with the first pad 120 . A separation 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 portion 40. As shown in FIG. The third pad 140 sandwiches the second flange portion 40 along the first direction X with the second pad 130 formed by the second processing step S2. In the third pad 140, the upper surface 140b in contact with the base portion 21 and the outer peripheral surface 140a are connected by a convex curved surface 140c. The curvature radius of the convex curved surface 140c is the second flange portion 40 and the base portion where the inner peripheral surface 40a of the second flange portion 40 and the second surface 20b of the base portion 20 in the press-formed product 10 after molding are connected. 20 and the radius of curvature R40 of the inner portion 40d. In a cross section along the center line L, it is preferable that the radius of curvature of the convex surface 140c is smaller than the radius of curvature of the convex surface 120c.

The punch 150 is a cylindrical member. The punch 150 is coaxial with the first pad 120 and the second pad 130 with respect to the centerline L and is arranged between the first pad 120 and the second pad 130 . The punch 150 can advance and retreat in the first direction X. As shown in FIG. Although not shown, the third pad 140 is fixed to the main body of the apparatus. Further, although not shown, the punch 150 is provided with an operating force by a hydraulic device or the like provided in the apparatus main body. As a result, in the intermediate product 12 in which the portion 21 serving as the base portion is sandwiched between the first pad 120 and the third pad 140, the tip end surface 31c of the portion 31 serving as the first flange portion is oriented in the first direction X. It advances from the first side X1 toward the second side X2, and further presses the tip end surface 31c of the portion 31 to be the first flange portion toward the second side X2 to extend the portion 31 to be the first flange portion. It is possible to apply an external force to

An intermediate product 12 is set in such a processing apparatus 110 as shown in FIG. 7A. Specifically, the base portion 21 of the intermediate product 12 is arranged between the first pad 120 and the third pad 140 . Also, the center line of the intermediate product 12 is aligned with the center line L. Also, the portion 31 to be the first flange portion is arranged to extend toward the punch 150 . Then, the first pad 120 and the third pad 140 sandwich and press the portion 21 that becomes the base. In this state, the portion 31 that becomes 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 advanced in the first direction X second side X2. As the punch 150 advances, the punch 150 first comes into contact with the tip end surface 31c of the portion 31 that becomes the first flange portion. As shown in FIG. 7C, as the punch 150 advances further, an external force directed in the first direction X from the first side X1 to the second side X2 is applied from the punch 150 to the portion 31 that becomes the first flange portion. be done. Therefore, the portion 31 to be the first flange is plastically deformed between the first pad 120 and the second pad 130, and the material of the portion 31 to be the first flange is changed in the first direction X The second flange portion 40 is formed by flowing from the first side X1 toward the second side X2 to a range that becomes the second flange portion 40 . Here, in the initial stage of the second processing step S2 as shown in FIG. 7B, by pressing the tip end surface 31c of the portion 31 to be the first flange portion, the portion 21 to be the base portion and the first flange portion The corner portion 12 a formed by the portion 31 that becomes the second flange portion 40 attempts to plastically deform so as to drop into the range that becomes the second flange portion 40 . However, the thickness T2 of the second flange portion is made smaller than the thickness T1 of the first flange portion 30 after performing the second processing step S2, and processing is performed so as to satisfy the expression (1). By doing so, it is possible to prevent the corner portion 12a from sagging into the range where the second flange portion 40 is to be formed. For this reason, in the second processing step S2, the second processing step S2 is performed while suppressing the formation of an acute bent defect in the inner portion 30d of the corner portion 12a due to the corner portion 12a falling. The second flange portion 40 can be formed by.

Then, as shown in FIG. 7D, by moving the punch 150 by a predetermined amount in the first direction X second side X2, the first flange portion 30 has a predetermined length, and the second flange portion 40 project from the base portion 20 in the first direction X second side X2 by a predetermined length to complete the press-formed product 10 .

As described above, according to the method for manufacturing the press-formed product 10 of the present embodiment, in the second processing step S2, the thickness T1 of the first flange portion 30 after performing the second processing step S2 On the other hand, while reducing the thickness T2 of the second flange portion 40, so as to satisfy the above formula (1), in the second processing step S2, the tip surface 31c of the portion 31 to be the first flange portion is plastically deformed, it is possible to form the second flange portion 40 while suppressing the formation of acute-angled folded defects in the inner portion 30d. That is, only by performing the two steps of the first processing step S1 and the second processing step S2, both sides of the single steel plate 11 can be prevented from forming a sharp fold-like defect in the inner portion 30d. It is possible to manufacture a press-formed product 10 having a portion that overhangs.

Further, as shown in FIG. 7A, a plane PL140 including the outer peripheral surface 140a along the second flange portion 40 of the third pad 140 after performing the second processing step S2 is the first surface of the first pad 120. It is positioned on the side of the first flange portion 30 in a direction orthogonal to the outer peripheral surface 140a (radial direction orthogonal to the first direction X) with respect to a plane PL120 including the outer peripheral surface 120a along the flange portion 30 . In other words, the plane PL140 including the outer peripheral surface 140a along the second flange portion 140 of the third pad 140 passes through the inside of the first flange portion 30 after the second processing step S2 is performed. For this reason, especially at the corner 12a, the material on the side of the third pad 140 is prevented from falling into the gap between the third pad 140 and the second pad 130, and is folded at an acute angle to the inner portion 30d of the corner 12a. Formation of such defects can be further suppressed.

Further, in the second processing step S2, the inner peripheral surface 130a along the first flange portion 30 and the second flange portion 40 of the second pad 130 is formed linearly along the first direction X. It is For this reason, especially at the corner 12a, the material on the side of the third pad 140 is prevented from falling into the gap between the third pad 140 and the second pad 130, and is folded at an acute angle to the inner portion 30d of the corner 12a. Formation of such defects can be further suppressed. In addition, the first flange portion 30 and the second flange portion 40 can form the outer peripheral surfaces 30a and 40a that are linearly connected while having different thicknesses T1 and T2.

Further, in the second processing step S2, in a cross section along the center line L, the radius of curvature of the convex curved surface 140c of the third pad 140 relative to the radius of curvature of the convex curved surface 120c of the first pad 120 of the processing device 110 is making it smaller. That is, by forming the press-formed product 10 so that the radius of curvature R40 of the inner portion 40d is smaller than the radius of curvature R30 of the inner portion 30d, the sharp bent defect in the inner portion 30d of the corner portion 12a is formed. can be further suppressed from being formed.

In this embodiment, the portion 31 to be the first flange portion is formed by plastically deforming the portion on the outer peripheral edge side in the first processing step S1 of the disk-shaped steel plate 11, and the second In the second processing step S2, the first flange portion 30 and the second flange portion 40 are formed by pressing the tip surface 31c of the portion 31 to be the first flange portion and plastically deforming it. It is not limited. The present invention is not limited to steel plates, and can be applied to metal plates of various materials as long as the metal materials can be plastically worked.

Moreover, the shape of the metal plate is not limited to a disc shape, and various shapes can be applied. Further, the shape of the first flange portion 30 and the second flange portion 40 is not limited to a cylindrical shape continuous around the center line L as described above, and the first flange formed in a flat plate shape The portion and the second flange portion may each extend from the base portion. FIG. 8 shows a first modification of this embodiment. As shown in FIG. 8, the press-formed product 10A of this modification includes a rectangular plate-shaped base portion 20A, a first flange portion 30A projecting from a first surface 20Aa of the base portion 20A, and a first surface 20Aa of the base portion 20A. and a second flange portion 40A projecting from the second surface 20Ab on the opposite side. The first flange portion 30A protrudes toward the first side X1 in the first direction X from a pair of opposing sides of the rectangular base portion 20A. The first flange portion 30A is formed in a rectangular flat plate shape. Further, the second flange portion 40A protrudes toward the second side X2 in the first direction X from the pair of sides of the base portion 20A from which the first flange portion 30A protrudes. The second flange portion 40A is formed in a rectangular flat plate shape. Also in such a modification, the thickness T2 of the second flange portion 40A is smaller than the thickness T1 of the first flange portion 30A, and the portion that becomes the first flange portion 40A in the first processing step S1 The relationship between the outer radius R of the corner portion 12Aa and the thickness T1 of the first flange portion 30A and the thickness T2 of the second flange portion 40A at the connection portion between the base portion 20A and the portion that becomes the base portion 20A is expressed by the above equation (1) may be satisfied. By doing so, even in the press-formed product 10A of the present modification, in the second processing step S2, the tip surface of the portion to be the first flange portion 30A is pressed and plastically deformed to form an acute bent shape. It is possible to form the second flange portion 40A while suppressing the formation of the defects in the inner portion.

Further, 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 linearly when viewed in a direction perpendicular to the center line L (that is, in the radial direction). , and have substantially the same outer diameter, but the present invention is not limited to this. For example, the outer diameter of the outer peripheral surface 40 a of the second flange portion 40 may be smaller than the outer diameter of the outer peripheral surface 30 a of the first flange portion 30 . Further, for example, the outer peripheral surface of at least one of the first flange portion 30 and the second flange portion 40 is formed so that the outer diameter gradually decreases along the first direction X from the distal side toward the proximal side. It may be formed in a tapered shape. In this case, the thickness T2 of the second flange portion 40 should be made smaller than the thickness T1 of the first flange portion 30 at least. By appropriately changing the shape of the second pad 130 according to the shape of the first flange portion and the second flange portion, the desired shape of the first flange portion and the second flange portion can be formed. can be done. In the case of forming the tapered shape as well, as shown in FIG. The distance between the intersection point P41 and the intersection point 42 may be defined as the thickness T2.

Alternatively, 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 described above. 9 and 10 (FIGS. 10A to 1C) show a second modification of this embodiment. As shown in FIG. 9, the press-formed product 10B of this modification includes a disk-shaped base portion 20B and a first flange portion 30B projecting in the first direction X first side X1 on the center side of the base portion 20B. and a second flange portion 40B projecting in the first direction X second side X2 on the center side of the base portion 20B. The first flange portion 30B is formed in a tubular shape in this modified example. Further, the second flange portion 40B is also formed in a tubular shape in this modified example. The first flange portion 30B and the second flange portion 40B are arranged coaxially with respect to the center line L. As shown in FIG. A hole formed inside the first flange portion 30B and a hole formed inside the second flange portion 40B communicate with each other. In this modified example, the inner peripheral surface of the first flange portion 30B and the inner peripheral surface of the second flange portion 40B are connected to each other with substantially equal inner diameters, and are formed in a straight line.

Such a press-formed product 10B is formed from a metal plate 11B having a through hole 11b formed in the center, as shown in FIG. 10A. As shown in FIG. 10B, first, in a first processing step S1, a portion 31B that becomes a first flange portion becomes a base portion by plastic working around the through hole 11b of the disk-shaped metal plate 11B. It can be formed to protrude from the portion 21B in the first direction X first side X1. As a method of plastic working, various known methods can be applied, and for example, burring processing can be mentioned. That is, by sandwiching the base portion 21B between the pads 100B and 101B and advancing the cylindrical punch 102B from the first direction X second side X2 to the first side X1 of the base portion 21B, the through hole is formed. A portion 31B that becomes the first flange portion can be formed by plastically deforming the portion around 11b. At this time, the corner portion 12Ba connecting the portion 21B serving as the base portion and the portion 31B serving as the first flange portion is formed in a curved shape in a cross section along the center line L according to the shape of the corner portion of the pad 100B. be.

After that, as shown in FIG. 10C, in a second processing step S2, the tip surface 31Bc of the portion 31B to be the first flange portion is pressed with a punch 150B, and the portion to be the first flange portion is pressed in the same manner as in the above embodiment. 31B is plastically deformed. Specifically, the first pad 120B and the third pad 140B sandwich and hold down the base portion 21B. Also, the portion 31B that becomes the first flange portion is arranged between the first pad 120B and the third pad 130B. Then, the punch 150B is advanced from the first side X1 in the first direction X to the second side X2 between the first pad 120B and the third pad 130B, thereby forming the first flange portion 31B. pushes the tip surface 31Bc of the . Here, also in this modified example, the thickness T2 of the second flange portion 40B is made smaller than the thickness T1 of the first flange portion 30B after the second processing step S2 is performed, while the corner portion 12Ba is The relationship between the outer radius R and the thickness T1 of the first flange portion 30B and the thickness T2 of the second flange portion 40B satisfies the above formula (1). As a result, it is possible to suppress the formation of an acute bent defect in the inner portion 30Bd where the base portion 20B and the first flange portion 30B are connected.

Further, 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 in the second modification, the first flange portion 30B and the second flange portion 30B are formed on the center side of the metal plate. Although the second flange portion 40B is formed, the first flange portion and the second flange portion may be formed on both the center side and the outer peripheral side of the metal plate. In this case, the first processing step S1 and the second processing step S2 may be performed separately for each of the center side and the outer periphery side of the metal plate, or may be performed at the same time depending on the shape of the mold. 1st processing process S1 and each 2nd processing process S2 may be performed simultaneously. Further, in the above-described embodiment and modification, the first working step S1 and the second working step S2 have been described, but the present invention is not limited to performing only these steps. Alternatively, other steps such as a step of surface treatment may be performed.

(Second embodiment)
Next, a second embodiment of the invention will be described. FIG. 11 shows a second embodiment of the invention. In this embodiment, members common to those used in the previous embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

The method of manufacturing a press-formed product of this embodiment differs from that of the first embodiment in the second processing step S2. That is, as shown in FIG. 11A, in the press working device 110C of the second working step S2 of the present embodiment, in addition to the first pad 120, the second pad 130, the third pad 140, and the punch 150, A fourth pad 160 is also provided. In this embodiment, fourth pad 160 is a cylindrical member. The fourth pad 160 is arranged on the side opposite to the punch 150 in the first direction X second side X2 with the portion 31 serving as the first flange portion interposed therebetween. The fourth pad 160 is arranged between the second pad 130 and the third pad 140 and is provided coaxially with respect to the center line L thereof. The fourth pad 160 is provided so as to move back and forth in the first direction X. As shown in FIG. Then, the fourth pad 160 advances from the first direction X second side X2 toward the first side X1 by a hydraulic device or the like (not shown), and moves in the first direction X with respect to the corner portion 12a of the intermediate product 12. An external force can be applied toward the first side X1.

Then, as shown in FIG. 11B, in the second processing step S2 of the present embodiment, first, the fourth pad 160 is advanced in the first direction X first side X1 and brought into contact with the corner 12a. Then, from the timing when the punch 150 starts to press the tip end surface 31c of the portion 31 to be the first flange portion in the first direction X second side X2, the fourth pad 160 moves the corner portion 12a to the first The corner portion 12a of the intermediate product 12 is pressed in the first direction X1, and an external force directed from the second side X2 in the first direction X toward the first side X1 is applied. The magnitude of the external force applied to intermediate product 12 by fourth pad 160 is less than the magnitude of external force applied to intermediate product 12 by punch 150 . Then, as shown in FIG. 11C , the punch 150 plastically deforms the portion 31 that will become the first flange portion, and the material tends to flow into the range that will become the second flange portion 40 . 160 moves in the first direction X from the first side X1 toward the second side X2 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 applied during the formation of the second flange portion 40 as shown in FIG. 11D. You can release it at any time.

As described above, according to the method for manufacturing a press-formed product of the present embodiment, from the start of processing for flowing the material of the portion 31 that will be the first flange portion in the first direction X second side X2, the processing At least halfway to the completion of , external force is applied from the first direction X second side X2 to the first side X1 of the corner 12a connected to the first flange portion 31 in the base portion 21 giving. By plastically deforming the portion 31 to be the first flange portion, each material of the first flange portion 30 and the base portion 20 connected to the first flange portion has the first direction X second direction of the base portion 20 A stress is induced to plastically flow to side X2. However, in the process from the start of processing to flow the material of the portion 31 to be the first flange portion in the first direction X second side X2 to at least halfway through the completion of the processing, the first direction X The plastic flow from the base portion 21 to the first direction X second side X2 can be suppressed by the external force applied toward the one side X1. Therefore, the base 20 and the first flange 30 are connected by plastic flow of material from both the base 21 and the first flange 31 in the first direction X second side X2. It is possible to suppress the formation of sharp fold-like defects in the inner portion 30d. Then, from the start of processing to flow the material of the portion 31 to be the first flange portion in the first direction X second side X2, after a certain amount of deformation due to the processing has occurred, the first flange portion is further formed. By deforming the portion generated by the deformation in the first direction X second side X2 by the pressing force acting on the tip surface 31c of the portion 31, it is possible to suppress the occurrence of sharp fold-like defects. The second flange portion 40 can be formed while

Next, examples relating to the method of manufacturing the press-formed product of the first embodiment will be described with reference to FIGS. 1 to 7, 12 and 13. FIG. Specifically, regarding the press-formed product 10 as shown in FIG. While changing the outer radius R of the corner portion 12a before performing the second processing step S2, it was confirmed whether or not an acute folded defect occurred in the inner portion 30d in each shape. Confirmation was performed by analysis using the finite element method. As the material of the steel plate 11, SAPH440 defined in JIS G 3113 (hot-rolled steel plate and steel strip for automobile structure) was used.

The shape of the intermediate product 12 before performing the second processing step S2 was formed so as to correspond to thicknesses T1=4 mm and 6 mm, respectively, which will be described later. As shown in FIG. 6, for the portion 31 that becomes the first flange portion, the height H31 that protrudes in the first direction X first side X1 from the first surface 21a of the portion 21 that becomes the base portion is 40 mm. did. In the intermediate product 12 corresponding to the thickness T1=4 mm, the diameter of the inner peripheral surface 31b of the portion 31 that becomes the first flange portion is 80 mm, the diameter of the outer peripheral surface 31a is 88 mm, and the thickness T31 is 4 mm. In the intermediate product 12 corresponding to the thickness T1=6 mm, the diameter of the inner peripheral surface 31b of the portion 31 that becomes the first flange portion is 80 mm, the diameter of the outer peripheral surface 31a is 92 mm, and the thickness T31 is 6 mm. The outer radius R of the corner portion 12a was 0.1 mm and varied from 0.5 to 6.0 mm in increments of 0.5 mm.

Then, the second processing step S2 was performed. In both the invention example and the comparative example, the front end surface 31c of the portion 31 to be the first flange portion is pressed with a load of 4000 kN by the punch 150 to plastically deform, and the second surface 21b of the portion 21 to be the base portion is moved in the first direction. A second flange portion 40 projecting to the X second side X2 was formed. The second flange portion 40 has a height H40 (see FIG. 1) projected from the second surface 20b of the base portion 20 in the first direction X second side X2 to be 10 mm. Moreover, the thickness T1 of the first flange portion 30 was set to two types of 4 mm and 6 mm. When the thickness T1=4.0 mm, the thickness T2 of the second flange portion 40 is set to 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0 mm. The plate thickness ratio T2/T1 was changed to 0.25, 0, 38, 0.50, 0.63, 0.75, 0.88 and 1.0. Further, when the thickness T1=6.0 mm, the thickness T2 of the second flange portion 40 is set to 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, and 6.0 mm, respectively, whereby the plate thickness ratio T2/T1 is 0.33, 0.42, 0.50, 0.58, 0.67, 0.75, It was changed to 0.83, 0.92, 1.00. Then, at each plate thickness ratio T2/T1, the radius R of the corner portion 12a is changed as described above, and the inner portion 30d where the first flange portion 30 and the base portion 20 are connected is bent at an acute angle. I checked to see if there were any defects.

12 and 13 and Tables 1 and 2 show the analysis results. Table 1 is a table of the plate thickness ratio T2/T1 and the outer radius R of the corner portion 12a when T1=4.0 mm. Table 2 is a table of the plate thickness ratio T2/T1 and the outer radius R of the corner portion 12a when T1=6.0 mm. Each cell in Tables 1 and 2 shows the value of R×T2/T1 calculated by the formula (1) under each analysis condition. Under the condition (comparative example) where the value of R×T2/T1 is underlined in each cell, as shown in FIG. This is clear from the analysis results. That is, it is clear from the analysis results that when T2/T1 is 1 or more (T2 is equal to T1 or T2 is greater than T1), defect D is formed regardless of the value of R×T2/T1. became. Analysis results show that even if the plate thickness ratio T2/T1 is less than 1 (T2 is smaller than T1), the defect D is formed when the value of R×T2/T1 is 3.5 or more. became clear from In addition, under the conditions (invention example) where each cell is not underlined, as shown in FIG. 12, the inner portion 30d can be formed in a smooth concave curve shape without any sharp fold-like defects D being observed. did it. That is, when the plate thickness ratio T2/T1 is less than 1.00 (T2 is smaller than T1) and the value of R × T2/T1 calculated by the formula (1) is less than 3.5, the first By the processing step S1 and the second processing step S2, the first flange portion 30 and the second flange portion 40 are formed while forming a smooth concave curve-shaped inner portion 30d without forming a folded defect D. could be formed.

As described above, the embodiments and examples of the present invention have been described in detail with reference to the drawings. be

It is possible to manufacture a press-formed product having flange-like overhanging portions on both sides from a single metal plate in a small number of processes without causing defects such as sharply bent inner portions of the flange-like overhanging portions. It is possible to provide a method for manufacturing a press-molded product that is possible. Therefore, industrial applicability is high.

10, 10A, 10B Press-formed products 11, 11B Steel plate (metal plate)
12a, 12Ba Corners 20, 20A, 20B Base 21c Connection portion
30, 30A, 30B first flange portions 40, 40A, 40B second flange portions 120, 120B first pads 130, 130B second pads 140, 140B third pads 150, 150B punch S1 first processing Step S2 Second processing step R Corner outside radius T1 First flange thickness T2 Second flange thickness X First direction X1 First side X2 Second side

Claims (4)

By plastically deforming a part of a single metal plate, a first flange portion projecting to the first side in the first direction, which is the thickness direction of the plate-shaped base, is formed, and forming a curved corner between the base and the first flange;
Disposing a first pad along the first flange,
Disposing a second pad on the opposite side of the first pad across the first flange,
A gap smaller than the gap between the first pad and the second pad is formed between the second pad and the third pad on the side opposite to the first flange part with the base part interposed therebetween. Arrange pads,
Between the first pad and the second pad, a punch that presses a tip surface formed on the first side in the first direction of the first flange portion can be moved back and forth in the first direction. allotted to
By pressing the tip surface of the first flange portion toward the second side in the first direction opposite to the first side in the first direction across the base portion, the first flange portion is Forming a second flange portion projecting to the second side in the first direction with respect to the base portion by causing the material to flow to the second side in the first direction;
the radius of curvature of the inner portion of the second flange portion and the base portion is smaller than the radius of curvature of the inner portion of the first flange portion and the base portion;
The thickness T2 of the second flange portion is thinner than the thickness T1 of the first flange portion after forming the second flange portion,
The ratio of the thickness T2 (mm) of the second flange after forming the second flange and the thickness T1 (mm) of the first flange, and after forming the corner A method for producing a press-formed product, wherein R×T2/T1, which is the product of the corner portion and the outside radius R (mm) of the bend in the cross section across the extending direction of the corner portion, is less than 3.5. The plane including the surface along the second flange portion after forming the second flange portion in the third pad is relative to the plane including the surface along the first flange portion in the first pad 2. The method of manufacturing a press-formed product according to claim 1, wherein the first flange portion is positioned on the side of the first flange portion in a direction orthogonal to a plane along the first flange portion. 3. Manufacture of the press-formed product according to claim 2, wherein the surfaces of the second pad along the first flange portion and the second flange portion are formed linearly along the first direction. Method. When forming the second flange portion, by pressing the tip surface formed on the first side in the first direction of the first flange portion toward the second side in the first direction, the second flange portion is formed. From the start of processing in which the material of one flange portion flows to the second side in the first direction until at least halfway through to the completion of the processing, the connection portion of the base portion connected to the first flange portion 4. The first flange portion is plastically deformed while applying an external force from the second side in the first direction toward the first side in the first direction. A method for manufacturing a press-molded product.

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