JP7399905B2 - Press molds and press molded products - Google Patents

Description

The present invention relates to a press mold and a press-formed product for press-forming a long open cross-section member formed by bending a plate material into a U-shaped cross-section as a press-formed product.

An example of a long open cross-section member formed by press-forming a plate material into a U-shaped cross section is a center pillar hinge reinforcement for a vehicle (hereinafter referred to as hinge RF). The hinge RF is welded and fixed to the inner circumferential surface of the center pillar as a reinforcing member of the center pillar having a closed cross-section structure. The welding surface of the hinge RF requires high forming accuracy, and it is necessary to prevent wrinkles from occurring on the welding surface during press forming of the hinge RF. Therefore, it has been proposed to form a wrinkle removing bead between the welding protrusions at the same time as the plurality of welding protrusions forming the welding surface when press forming the hinge RF (see Patent Document 1).

JP 2020-1653 Publication

In the case of the invention of Patent Document 1, when pressing the hinge RF, an extra wrinkle removing bead is formed in addition to the welding protrusion, so there is a problem that the pressing load becomes large.

An object of the present invention is to provide a gap around the part where the control surface is formed to accommodate the excess material that causes wrinkles when press-forming a press-formed product with a control surface that requires high forming accuracy. The purpose is to suppress the formation of wrinkles on the control surface during press molding without increasing the processing load.

A press mold according to a first aspect of the present invention is a press mold for press-forming a long open cross-section member formed by bending a plate material as a work into a U-shaped cross section as a press-formed product, and wherein the open cross-section member a first mold for press-forming an open side surface of the member; and a second mold for press-forming a closed side surface of the open cross-section member opposite to the open side surface with the plate material sandwiched between the first mold and the first mold. The first mold and the second mold each include a top plate molding part that molds a top plate part that is a bent central part of the open cross-section member, and a top plate molding part that forms a top plate part that is a bent center part of the open cross-section member; and a vertical wall molding part for molding a vertical wall part of the first mold and the second mold, and each of the vertical wall molding parts of the first mold and the second mold requires molding accuracy in the vertical wall part of the open cross-section member. a management surface molding part that molds a management surface part that is to be controlled, and a management surface outside molding part that molds a management surface external part that does not require molding precision compared to the management surface part in the vertical wall part of the open cross-section member, In each of the vertical wall forming sections of the first mold, the outside control surface forming section includes a space adjacent to the control surface forming section that can receive excess material generated in the workpiece due to the press forming. The management surface molding part is formed so that its molding surface protrudes toward the management surface molding part of the second mold compared to the management surface outside molding part, and The excess metal receiving part is formed by recessing its molding surface in a direction away from the molding part outside the management surface of the second mold compared to the molding part outside the management surface other than the excess metal receiving part, and In each of the vertical wall molding parts of the second mold, the management surface molding part has its molding surface recessed in a direction away from the management surface molding part of the first mold compared to the outside management surface molding part. gaps between the control surface molding parts in the vertical wall molding parts of the first mold and the second mold, and gaps during press molding between the control surface molding parts. The gaps are sized to sandwich the plate material between the control surface molding parts and between the non-control surface molding parts, and each of the vertical wall molding parts of the first mold and the second mold The gap during press molding between the excess thickness receiving part of the first mold and the outside-of-control-surface molding part of the second mold is defined in the thickness direction of the plate material with the plate material sandwiched between them. It is said that the size exceeds the thickness of the board.

A second invention of the present invention is the press mold according to the first invention, wherein the first mold and the second mold are arranged in the vertical wall forming part for molding each vertical wall part of the open cross-section member. Both outer sides are provided with molding surface exteriors that are surfaces facing each other in the pressing direction, and the molding surface exterior of the first mold includes a portion corresponding to the excess thickness receiving portion of the first mold, The surface of the second mold that faces the outside of the molding surface is provided with a recessed part that is recessed relative to the surroundings, and the outside of the molding surface of the second mold includes A portion corresponding to the molding portion is provided with a protrusion in which a surface facing the outside of the molding surface of the first mold is protruded relative to the surroundings, and the protrusion and the depression are formed at the bottom dead center during press molding. The parts are shaped and positioned so that they fit into each other.

A third invention of the present invention is the press mold according to the first or second invention, wherein the management surface molding portions of the first mold and the second mold are arranged along the longitudinal direction of the open cross-section member. A plurality of them are arranged, and the excess metal receiving part of the first mold is arranged to be sandwiched between the respective management surface molding parts.

A fourth invention of the present invention is the press mold according to any one of the first to third inventions, wherein the press molded product is a center pillar hinge reinforcement for a vehicle.

A fifth invention of the present invention is a press-formed product formed by the press die according to any one of the first to fourth inventions, wherein the management surface portion is a surface portion that is welded to another member. .

According to the present invention, the excess thickness that occurs due to the molding of the control surface portion of the vertical wall portion is removed from the plate material sandwiched between the control surface molding portions of the first mold and the second mold. It is absorbed by deforming within the gap between. Therefore, the press working load when press forming the outside of the control surface of the vertical wall portion of the open cross section member is small, and the press working load of the entire press forming can be suppressed.

FIG. 1 is an overall perspective view showing an example of a center pillar disposed on a side of a vehicle. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1; FIG. 2 is a perspective view showing a hinge RF as an example of a press-formed product press-formed by the press die of the present invention. FIG. 3 is a perspective view showing a blank product before the hinge RF is press-molded. It is an explanatory view showing one process of press forming using a press die as one embodiment of the present invention, and shows a process in which the pad and bending blade, which are the upper die, are at the top dead center. FIG. 6 is an explanatory diagram similar to FIG. 5, showing a process in which the pad as the upper die and the bending blade are in contact with the workpiece. This is an explanatory diagram similar to FIG. 5, showing a process in which the pad as the upper die and the bending blade are at the bottom dead center, and corresponds to the cross section taken along the line VII-VII in FIGS. 9 and 10. FIG. 7 is a perspective view showing the workpiece in a state where molding has started in the step of FIG. 6; FIG. 3 is a perspective view of the molding surface portion of the upper mold that contacts the workpiece, the vertical wall molding portion, and the outside of the molding surface that does not contact the workpiece, as seen diagonally from above. FIG. 2 is a perspective view of the molding surface portion of the lower mold that contacts the workpiece, the vertical wall molding portion, and the outside of the molding surface that does not contact the workpiece, as seen diagonally from above. 10 is a perspective view similar to FIG. 9, showing one management surface molding part and its surroundings in an enlarged manner. 11 is a perspective view similar to FIG. 10, showing one management surface molded portion and its surroundings in an enlarged manner. 9 is an explanatory diagram showing how the management surface portion of the hinge RF is molded, and corresponds to a cross section taken along the line XI-XI in FIGS. 9 and 10. FIG. 8 is an explanatory diagram showing how the outside of the management surface of the hinge RF is molded, and corresponds to FIG. 7. FIG.

<An embodiment of an open cross-section member (pressed product)>
FIG. 3 shows an embodiment of an open cross-section member that is a pressed product using a press die of the present invention. This embodiment is an example in which a center pillar hinge reinforcement (hereinafter referred to as hinge RF) 20 for a vehicle is a long open cross-section member formed by bending a plate material into a U-shaped cross section. 1 and 2 show a center pillar for a vehicle that includes a hinge RF20. The hinge RF20 is used as a reinforcing member for the center pillar 10, which has a closed cross-sectional structure, as is well known. The center pillar 10 has a closed cross-sectional structure by welding an inner panel 14 to the open side surface of a center pillar reinforcement (hereinafter referred to as center pillar RF) 12 having a hat-shaped cross section. The hinge RF20 is welded and fixed to the inner peripheral surface of the center pillar RF12. In each figure, each direction indicated by an arrow indicates each direction in a normal state of the vehicle. In the following description, descriptions regarding directions will be made with this direction as a reference.

The center pillar 10 in FIG. 1 is installed on the left side in the direction of travel of the vehicle. A pillar member is disposed on the side of the vehicle as a vehicle structural member. Pillar members include a front pillar (not shown) commonly referred to as an A-pillar from the front of the vehicle, a center pillar 10 commonly referred to as a B-pillar, and a rear pillar (not shown) commonly referred to as a C-pillar. In this pillar member, the strength of the center pillar 10 is important because of the need to cope with side collisions of vehicles. Therefore, as shown in FIG. 2, the center pillar 10 is provided with a hinge RF20 as a reinforcing member in order to reinforce its strength. In this embodiment, a high-tensile steel plate is used for the hinge RF20 due to the recent demand for higher strength.

The center pillar RF12 has a hat-shaped cross section with an open side surface on the inner side in the vehicle width direction, and includes a first top plate portion 12A, a first vertical wall portion 12B, and a flange portion 12C. The first top plate portion 12A is disposed on the lower side (outside in the vehicle width direction) as seen in FIG. 2, and a pair of left and right first vertical wall portions 12B extend upward from the ridgeline at both ends as seen in FIG. It is located. The pair of left and right first vertical wall portions 12B are arranged so as to be inclined in a direction in which the distance between them widens upward (inward in the vehicle width direction) as viewed in FIG. As seen in FIG. 2, the flange portions 12C are integrally connected to the upper ends of the pair of first vertical wall portions 12B, and are arranged so as to extend in opposite directions.

As shown in FIG. 2, the inner panel 14 is formed into a substantially flat plate shape, and both side edge portions (left and right end portions as viewed in FIG. 2) 14C in the longitudinal direction of the vehicle are formed to extend in the longitudinal direction. The side edge portions 14C of the inner panel 14 are overlapped with both flange portions 12C of the center pillar RF12 in the vehicle width direction, and are welded together by spot welding to form a closed cross section. Note that in FIG. 1, welding locations are indicated by black circles, and in FIG. 2, welding locations are indicated by x marks. Further, welding and joining is not limited to spot welding, and may be welded and joined by other welding such as laser welding.

As shown in FIG. 1, the center pillar 10 is arranged in an elongated shape extending in the vertical direction of the vehicle. The bending region BE is located slightly below the central portion in the longitudinal direction, and is arranged in a gently curved shape protruding outward in the vehicle width direction. In addition, the center pillar 10 is arranged in an inclined shape such that the upper end position thereof is further rearward of the vehicle than the lower end position.

Therefore, as shown in FIGS. 1 and 2, the elongated center pillar 10 is formed to have a closed cross-sectional structure extending in the vertical direction of the vehicle, and forms one closed space inside. Note that, as shown in FIG. 1, the center pillar 10 is joined to the roof side rail 18 via a substantially T-shaped attachment portion 16 formed at the upper end of the center pillar RF12. Further, the center pillar 10 is joined to the side sill 19 via a substantially T-shaped attachment portion 17 formed at the lower end of the center pillar RF12.

The center pillar RF12 is a steel plate member with a tensile strength of 590 MPa or more. In this embodiment, a high tensile strength steel plate with a tensile strength of 1180 MPa is used. The center pillar RF12 is molded by cold pressing or hot stamping. For the inner panel 14, a steel plate member having a tensile strength equal to or smaller than the tensile strength of the center pillar RF12 is used. In this embodiment, a 590 MPa steel plate member is used. Then, the inner panel 14 is molded by cold pressing.

Next, the hinge RF20 arranged in the closed space of the center pillar 10 will be explained. As best shown in FIG. 2, the hinge RF20 is disposed along the inner surface of the center pillar RF12 of the center pillar 10. As shown in FIG. The hinge RF20 is composed of a second top plate portion 20A, which is a bent central portion, and a pair of second vertical wall portions 20B on both sides (front and rear of the vehicle) of the second top plate portion 20A. The second top plate portion 20A in this embodiment corresponds to the “top plate portion” of the present invention, and the second vertical wall portion 20B in this embodiment corresponds to the “vertical wall portion” of the present invention.

As described above, the hinge RF20 is disposed along the inner surface of the center pillar RF12 of the center pillar 10, and therefore has a generally U-shaped cross section. The second top plate portion 20A is arranged inside the first top plate portion 12A of the center pillar RF12. The left and right second vertical wall portions 20B as viewed in FIG. 2 are arranged inside the first vertical wall portion 12B of the center pillar RF12, and are located upward as viewed in FIG. 2 from the ridge line L1 at both ends of the second top plate portion 20A. It is formed by being integrally connected towards. Similar to the first vertical wall portion 12B, the left and right second vertical wall portions 20B are arranged so as to be inclined in a direction in which the distance between them widens upward as viewed in FIG.

As described above, the U-shaped cross section of the hinge RF20 is bent and extended from the second top plate part 20A at the center position in the width direction and the ridge line L1 at both widthwise ends of the second top plate part 20A. It is formed to have a pair of second vertical wall portions 20B.

FIG. 3 shows the overall configuration of the hinge RF20. FIG. 3 shows the second top plate portion 20A of the hinge RF20 viewed from the outside in the vehicle width direction. As clearly shown in FIG. 3, the hinge RF20 is formed in an elongated shape, and similarly to the center pillar 10, it is formed in a curved shape that gently protrudes outward in the vehicle width direction in the bending region BE. That is, it is formed with a curved portion in a partial range in the longitudinal direction.

Hinge RF20 is formed by press molding. In order to improve side collision performance, high-strength steel plates are used as press-forming materials. Its tensile strength is 590 MPa or more. In this embodiment, a high tensile strength steel plate of 1180 MPa was used. The thickness of the pressed steel plate is about 1 mm to 2 mm, and a single high-tensile steel plate is press-formed by room temperature pressing or hot stamping. The direction indicated by the white arrow P in FIG. 3 is the press forming direction. When a high-tensile steel plate is press-formed as in this embodiment, extra thickness is generated in the second vertical wall portion 20B subjected to the bending process during the press-forming process, and wrinkles are likely to occur. In particular, wrinkles are likely to occur in the second vertical wall portion 20B of the curved portion of the hinge RF20 having the bending region BE.

As shown in FIGS. 2 and 3, the second top plate portion 20A is welded to the inner surface of the first top plate portion 12A in the center pillar RF12 of the center pillar 10 by spot welding. Therefore, a plurality of welding protrusions 22 are formed on the second top plate portion 20A so as to protrude outward in the vehicle width direction by a predetermined height (for example, a height of 2 mm). Each welding protrusion 22 is arranged intermittently along the vehicle vertical direction.

The outer surface of the welding protrusion 22, that is, the welding seat 23, has a planar shape as shown in FIG. is formed. Moreover, the shape of each welding protrusion 22 is circular in this embodiment, as shown in FIG. However, the shape of each welding protrusion 22 can be various shapes such as a rectangle, a triangle, an ellipse, and a hexagon.

Note that welding between the center pillar 10 and the hinge RF20 is also performed between the first vertical wall portion 12B of the center pillar RF12 and the second vertical wall portion 20B of the hinge RF20, as shown by the cross in FIG. ing. Therefore, a plurality of welding protrusions 25 are formed on the pair of second vertical wall portions 20B shown in FIGS. 2 and 3. Each welding protrusion 25 is formed to protrude toward the pair of first vertical wall portions 12B of the center pillar RF12, and is disposed intermittently in the vehicle vertical direction. The welding seat surface 26 is welded to the inner surface of the first vertical wall portion 12B by spot welding.

Since the hinge RF20 includes a curved portion (bending region BE) as described above, wrinkles are likely to occur in the second vertical wall portion 20B due to press molding. If the shape of each welding protrusion 25 is affected by these wrinkles, there is a possibility that the surfaces cannot be joined together when the welding seat surface 26 is joined to the inner surface of the first vertical wall section 12B. Therefore, in this embodiment, the welding seat surface 26 is a control surface portion that requires high forming accuracy in press forming. The second vertical wall portion 20B located between the respective welding protrusions 25 or the second vertical wall portion 20B located around the respective welding protrusions 25 is a control surface external portion 27 that does not require molding precision. There is.

As described above, the welding protrusion 25 serves to weld and join the center pillar RF12 and the hinge RF20, and also prevents or suppresses the occurrence of wrinkles that occur in the second vertical wall portion 20B when the hinge RF20 is press-formed. act. On the other hand, the second vertical wall portion 20B, which serves as the external management surface 27, is provided as a member that plays a role in absorbing, through deformation, excess thickness that causes wrinkles during press molding.

<One embodiment of press device>
5 to 7 show the steps of press-forming the above-mentioned hinge RF20 using the press device 40. Note that in FIGS. 5 to 7, only the part of the press die that performs press forming is shown, and peripheral parts such as the drive part that operates the press die and the fixed part that supports and fixes the entire press apparatus are omitted. These peripheral parts have the same structure as a general press device. Further, FIG. 4 shows a blank product B that is input into the press device 40 as a workpiece W. As shown in FIG. The blank product B is formed into the rough shape of the hinge RF20 by drawing a flat plate material (not shown). That is, in the blank product B, a portion 20AB that will become the top plate portion 20A of the hinge RF20 and a portion 20BB that will become the vertical wall portion 20B on the top plate portion 20A side of the hinge RF20 are formed in this drawing process. On the other hand, in the blank product B, the portion of the hinge RF20, which is a U-shaped cross-sectional member, on the side opposite to the top plate portion 20A, which will become the second vertical wall portion 20B, is not drawn and left as a flange portion 20CB. Therefore, the blank B has a hat-shaped cross section. Further, in the blank product B, an area BE corresponding to the bending area BE of the hinge RF20 is bent in advance. Here, explanation of the drawing process is omitted. In addition, in the following description, the description about the shaping|molding of the welding protrusion part 22 formed in 20 A of 2nd top plate parts of hinge RF20 is abbreviate|omitted.

FIG. 5 shows a process in which a blank B, which will become a workpiece W, is put into a die 50 (corresponding to the first mold of the present invention) which is the lower mold of the press device 40. Here, the pad 61 and bending blade 62 of the upper die (corresponding to the second die of the present invention) 60 are at the top dead center position. The bending blades 62 are disposed line-symmetrically on both sides of the pad 61, and are slidable relative to the pad 61 in the vertical direction in FIG. FIG. 6 shows a step from the step of FIG. 5 in which the pad 61 of the upper die 60 sandwiches the workpiece W on the top molding part 51 of the die 50. The top molding portion 51 is a portion formed at the center of the die 50 to protrude toward the upper mold 60. Then, the bending blade 62 of the upper mold 60 moves relative to the pad 61, and the protrusion 64A of the molding surface exterior 64, which is the lower end of the bending blade 62, is in contact with the flange portion 20CW of the workpiece W. Further, in FIG. 7, the flange portion 20CW of the workpiece W, which is a blank product B, is shaped by the bending blade 62 from a bent state to a state extending approximately straight with respect to the second vertical wall portion 20B. At this time, the welding protrusion 25 is formed on the second vertical wall portion 20B of the hinge RF20 by the vertical wall forming portion 52 of the die 50 and the vertical wall forming portion 63 of each bending blade 62. In this way, the open side surface of the open cross-section member that is the hinge RF20 is molded by the die 50, and the closed side surface opposite to the open side surface is molded by the upper mold 60.

<One embodiment of press mold>
FIG. 9 shows the molding surface portion 61A of the pad 61, the vertical wall molding portion 63 of each bending blade 62, and the outside molding surface 64 in a transparent state. FIG. 11 shows an enlarged view of one management surface molding section 63A in the vertical wall molding section 63 and its surroundings. In FIG. 11, a dashed line indicates the outline of the vertical wall molded portion 63. Moreover, FIG. 10 shows the top plate forming part 51, the vertical wall forming part 52, and the outside forming surface 53 of the die 50. FIG. 12 shows an enlarged view of one management surface molding section 52A in the vertical wall molding section 52 and its surroundings. In FIG. 12 , a dashed line indicates the outline of the vertical wall molding portion 52 . As shown in FIGS. 10 and 9, the outer molding surfaces 53 and 64 are formed extending to both outer sides of the vertical wall molding parts 52 and 63. The outside molding surfaces 53 and 64 are surfaces facing each other in the pressing direction.

In order to form the welding protrusion 25 and the external management surface 27, which are management surface parts, on the second vertical wall part 20B of the hinge RF20, the vertical wall molded parts 52 on both sides of the top plate molded part 51 of the die 50 are provided with management surfaces. A plurality of (six in this embodiment) management surface molding portions 52A are formed to protrude toward the vertical wall molding portion 63 of the bending blade 62 compared to the external molding portion 52B and the management surface external molding portion 52B. There is. In addition, the portion of the outside management surface molded portion 52B that is sandwiched between the respective management surface molded portions 52A has an excess wall that is recessed in the direction away from the vertical wall molded portion 63 of the bending blade 62 compared to the outside management surface molded portion 52B. A receiving portion 52C is formed. Furthermore, the vertical wall molding portion 63 of each bending blade 62 has a management surface that is recessed in the direction away from the vertical wall molding portion 52 of the die 50 compared to the non-management surface molding portion 63B and the non-management surface molding portion 63B. A molded portion 63A is formed. Furthermore, a plurality of protrusions 64A are formed on the outer molding surface 64, which is the lower surface of each bending blade 62, and protrude toward the die 50 compared to the surrounding area. Each protrusion 64A extends on the outside molding surface 64 in a direction intersecting the vertical wall molding part 63, and is formed one by one between each management surface molding part 63A. Furthermore, a plurality of recesses 53A are formed on the upper surface of the outer molding surface 53 of the die 50, which are depressed in a direction away from the outer molding surface 64 of the bending blade 62 compared to the surrounding area. Each recessed portion 53A extends in a direction intersecting the vertical wall molded portion 52 on the molded surface exterior 53, and is provided between each management surface molded portion 52A at a position corresponding to each excess thickness receiving portion 52C. It is formed. The protrusions 64A and the recesses 53A are formed in such a shape and position that they fit into each other when the upper die 60 is at the bottom dead center.

FIG. 13 shows that the upper mold 60 is at the bottom dead center as shown in FIG. 13 shows how each welding protrusion 25 (25W in FIG. 13) having a surface portion) 26 (26W in FIG. 13) is formed. The welding protrusion 25 (25W in FIG. 13) is formed by being sandwiched between each control surface forming section 52A of the die 50 and the control surface forming section 63A of each bending blade 62. The upper management surface exterior 27 (27W in FIG. 13) is formed by being sandwiched between each management surface outside molding section 52B of the die 50 and the management surface outside molding section 63B of each bending blade 62. Further, the second top plate portion 20A (20AW in FIG. 13) is molded by being sandwiched between the top plate molding portion 51 of the die 50 and the molding surface portion 61A of the pad 61. In this embodiment, the distance between each control surface forming part 52A of the die 50 and the control surface forming part 63A of each bending blade 62 in the opposing direction is approximately equal to the plate thickness T of the workpiece W. That is, during molding of the workpiece W, the gaps in the plate thickness T direction between each management surface molding section 52A and each management surface molding section 63A and the workpiece W are approximately zero.

FIG. 14 shows that when the upper die 60 is at the bottom dead center as shown in FIG. 14, 27W) is shown being molded. In the upper part of FIG. 14, the management surface outside 27 (27W in FIG. 14) is formed by being sandwiched between each management surface outside molding part 52B of the die 50 and the management surface outside molding part 63B of each bending blade 62. . On the other hand, in the lower part of FIG. 14, the workpiece W is sandwiched between each extra-thickness receiving part 52C of the die 50 and the outside-of-management-surface molding part 63B of each bending blade 62 and is molded.

In this embodiment, the interval in the opposing direction between each of the molded parts 52B outside the management surface of the die 50 and the molded parts 63B outside the management surface of each bending blade 62 is approximately equal to the thickness T of the workpiece W. That is, during molding of the workpiece W, the gaps in the plate thickness T direction between each of the molded parts 52B outside the control surface and the molded parts 63B outside the management surface and the workpiece W are approximately zero. However, compared to the plate thickness T of each second vertical wall portion 20BW of the workpiece W, each gap between each excess thickness receiving portion 52C of the die 50 and the outside-of-control-surface forming portion 63B of each bending blade 62 in the plate thickness T direction. C is set larger than the plate thickness T of the workpiece W. That is, each gap C=plate thickness T+gap CE. Therefore, the external control surface 27W of each second vertical wall part 20BW can be freely deformed within the gap C during press forming, and the welding protrusion 25W of each second vertical wall part 20BW (see FIG. 13) ) is absorbed by the deformation of the outer management surface 27W within the gap C. In this embodiment, the plate thickness T of each second vertical wall portion 20BW of the workpiece W is approximately 1 to 2 mm, the gap C is the plate thickness T + 0.1 mm or more, and the gap CE is 0.1 mm or more. . Further, the second top plate portion 20AW is formed by sandwiching the workpiece W between the top plate molding portion 51 of the die 50 and the molding surface portion 61A of the pad 61.

FIG. 8 shows the shape of the workpiece W formed in the process of FIG. In the process shown in FIG. 6, the workpiece W is held between the pad 61 of the upper mold 60 and the top molding part 51 of the die 50. In the process of FIG. 6, the bending blade 62 of the upper mold 60 is in contact with the flange portion 20CW of the work W. Therefore, the flange portion 20CW of the workpiece W is pressed and deformed by the protrusion 64A of the outer forming surface 64, which is the lower end surface of the bending blade 62. As a result, in the workpiece W, an external management surface 27W corresponding to the external management surface 27 of the hinge RF20 is formed. This external management surface 27W becomes the trigger for forming the external management surface 27 of the hinge RF20 in the process shown in FIG. Therefore, by forming the control surface exterior 27W in the process of FIG. 6, when the welding protrusion 25 of the hinge RF20 is formed in the process of FIG. It is deformed and absorbed. Therefore, it is possible to suppress wrinkles and deformation from occurring in the welding protrusion 25 of the hinge RF20.
<Other embodiments>
Although specific embodiments have been described above, the present invention is not limited to their appearance and configuration, and various changes, additions, and deletions are possible.

In the above embodiment, an example of the center pillar hinge reinforcement is shown as the open cross-section member, but other members of the vehicle structural member may be used as the open cross-section member. Further, in the above embodiment, the pressing direction of the press device is the vertical direction, but it is not limited to the vertical direction. Further, in the above embodiment, each vertical wall portion of the open cross-section member is provided with a plurality of management surface portions, but the number can be set to any number, including a single number, as necessary.

In the above embodiment, the recess and the protrusion were formed to extend over the entire outside of each molding surface of the first mold and the second mold, but adjacent to the molding surface of the first mold and the second mold. It may be partially formed only in the area where the However, as in the above embodiment, forming the entire outside of each molding surface of the first mold and the second mold improves the formability of bending the outside of the control surface with respect to the workpiece, rather than forming it partially. is good.

<Operations and effects of the above embodiments corresponding to each invention>
Finally, the effects of the above-mentioned embodiments corresponding to each invention after the first invention in the above-mentioned "Means for Solving the Problems" will be additionally described.

According to the first invention, when the open cross-section member is press-molded, the control surface forming portions of the first mold and the second mold mold the management surface portion of the vertical wall portion of the open cross-section member. At this time, the excess thickness receiving part of the first mold and the outside-of-control-surface forming part of the second mold do not apply press pressure to the plate material, which is the workpiece, due to the gap between them. Therefore, the excess thickness that is generated due to the molding of the control surface part of the vertical wall section causes the plate material sandwiched between the excess thickness receiving part of the first mold and the molded part outside the control surface of the second mold to be deformed within the above-mentioned gap. It is absorbed by Therefore, the press working load when press forming the outside of the control surface of the vertical wall portion of the open cross section member is small, and the press working load of the entire press forming can be suppressed. Moreover, it is possible to suppress wrinkles caused by press forming on the management surface portion of the vertical wall portion of the open cross-section member.

According to the second invention, the protrusion is provided at a portion corresponding to the outside of the management surface outside the molding surface of the second mold. Therefore, during press molding, the protrusion of the second mold first contacts the plate material and deforms it toward the molded portion outside the control surface of the first mold. Thereby, it is possible to create an opportunity for deformation of the plate material toward the final shape of the vertical wall portion of the open cross-section member after press forming, and it is possible to suppress the generation of excess thickness that causes wrinkles.

According to the third invention, a plurality of management surfaces can be formed over a wide range in the longitudinal direction of the open cross-section member.

According to the fourth invention, it is possible to form a center pillar hinge reinforcement having a wrinkle-free management surface without increasing the press working load. Further, by using the welded portion as the management surface, the joining strength of the center pillar hinge reinforcement to the center pillar reinforcement can be increased.

According to the fifth invention, the part to be welded and joined to other members is used as a control surface, thereby improving molding accuracy. Therefore, the bonding strength with other members can be increased.

10 Center pillar 12 Center pillar reinforcement 12A First top plate portion 12B First vertical wall portion 12C Flange portion 14 Inner panel 14C Both side edges 16 T-shaped mounting portion 17 T-shaped mounting portion 18 Roof side rail 19 Side sill 20 Center pillar hinge reinforcement (pressed product, open cross-section member)
20A, 20AB, 20AW 2nd top plate part (top plate part)
20B, 20BB, 20BW 2nd vertical wall part (vertical wall part)
20CB, 20CW Flange portion 22 Welding protrusion 23 Welding seat 25, 25W Welding protrusion 26, 26W Welding seat (management surface)
27, 27W Management surface external 40 Press device 50 Die (first mold, lower mold)
51 Top plate molding section 52 Vertical wall molding section 52A Management surface molding section 52B Outside management surface molding section 52C Excess metal receiving section 53 Outside molding surface 53A Hollow section 60 Upper mold (second mold)
61 Pad (top plate molding part)
61A Molding surface part 62 Bending blade (vertical wall molding part)
63 Vertical wall forming part 63A Control surface forming part 63B Control surface outside forming part 64 Forming surface outside 64A Projection B Blank product W Work BE Bending area

Claims (5)

A press mold for press-forming a long open cross-section member formed by bending a plate material as a work into a U-shaped cross-section as a press-formed product,
a first mold for press-molding the open side surface of the open cross-section member;
a second mold for press-molding a closed side surface of the open cross-section member opposite to the open side surface with the plate material sandwiched between the second mold and the first mold;
The first mold and the second mold are
a top plate forming part that forms a top plate part that is a bent central part of the open cross-section member;
vertical wall forming portions forming vertical wall portions on both sides of the top plate portion of the open cross-section member;
Each of the vertical wall molding parts of the first mold and the second mold,
a management surface forming part that molds a management surface part that requires molding accuracy in the vertical wall part of the open cross-section member;
a management surface outside molding part for molding a management surface outside that does not require molding precision compared to the management surface part in the vertical wall part of the open cross-section member;
In each of the vertical wall forming portions of the first mold,
The control surface outside molding section includes an excess thickness receiving section adjacent to the control surface forming section that forms a space capable of receiving excess thickness generated in the workpiece due to the press forming,
The management surface molding part is formed with its molding surface protruding toward the management surface molding part of the second mold compared to the outside management surface molding part,
The excess metal receiving part is formed by recessing its molding surface in a direction away from the molding part outside the management surface of the second mold compared to the molding part outside the management surface other than the excess metal receiving part,
In each of the vertical wall forming portions of the second mold,
The management surface molding portion is formed by recessing its molding surface in a direction away from the management surface molding portion of the first mold compared to the outside management surface molding portion,
The gaps between the control surface molding parts in the vertical wall molding parts of the first mold and the second mold, and the gaps between the control surface molding parts during press molding, The plate material is sized to be formed by sandwiching the plate material between the surface molding parts and between the management surface molding parts,
The gap during press molding between the excess thickness receiving part of the first mold and the outside-of-control-surface molding part of the second mold in the vertical wall molding parts of the first mold and the second mold is , a press mold having a size that exceeds the thickness of the plate material in the thickness direction when the plate material is sandwiched between the two. The press mold according to claim 1,
The first mold and the second mold are
Both outsides of the vertical wall molding part for molding each vertical wall part of the open cross-section member are provided with molding surface exteriors that are surfaces facing each other in the pressing direction,
On the outside of the molding surface of the first mold, a surface facing the outside of the molding surface of the second mold is recessed in a portion corresponding to the excess thickness receiving part of the first mold compared to the surrounding area. Equipped with a recessed part,
On the outside of the molding surface of the second mold, a surface facing the outside of the molding surface of the first mold is compared to the surrounding area in a part corresponding to the molding part outside the management surface of the second mold. Equipped with a protruding protrusion,
A press mold, wherein the protrusion and the recess are shaped and positioned so that they fit into each other at the bottom dead center during press molding. The press mold according to claim 1 or 2,
A plurality of the management surface molding portions of the first mold and the second mold are arranged along the longitudinal direction of the open cross-section member, and the excess thickness receiving portion of the first mold is , a press mold disposed between the respective control surface molding parts. The press mold according to any one of claims 1 to 3,
The press molded product is a press mold that is a center pillar hinge reinforcement for vehicles. A press-molded product formed by the press mold according to any one of claims 1 to 4,
The control surface portion is a surface portion that is welded to another member. Press-formed product.

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