JP2015128793A - Press-forming apparatus, press-forming method, and press-formed part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press-forming apparatus that can prevent occurrence of a buckling and a folding and appropriately thicken a vertical wall portion and a corner portion.SOLUTION: The press-forming apparatus for pressing a work piece to form a press-formed part. The work piece has a hat-shaped cross section or a U-shaped cross section that includes an upper wall portion having a first thickness, a vertical wall portion, and a curved corner portion connected to the vertical wall portion. The press-forming apparatus includes: a punch member that performs press work so as to reduce a height of the vertical wall portion and thicken the vertical wall portion and the corner portion to a second thickness larger than the first thickness; a pad member that faces a first bearing member across the vertical wall portion and holds a space between the pad member and the first bearing member equal to or less than the second thickness during pressing; and a thickening regulation part that is provided in at least one of the punch member and the bearing member, and touches the corner portion being thickened to regulate a thickness of the corner portion equal to or less than the second thickness.

Description

  The present invention relates to a press molding apparatus, a press molding method, and a press molded product.

  2. Description of the Related Art A press molding apparatus that presses a workpiece to form a press-formed product having a hat-shaped cross section or a U-shaped cross section is used. The formed press-molded product is used as a vehicle part such as an automobile.

  In a press-molded product used as a vehicle part, it is required to increase the strength of a part of the molded product from the viewpoint of ensuring collision safety, vehicle body rigidity, and the like. Therefore, as in Patent Document 1 below, when press-molding a press-formed product from a work material having a hat-shaped cross section, a technique is used in which the material of the work material is flowed to partially increase the thickness. Yes. Specifically, the height of the vertical wall portion of the workpiece is reduced to increase the thickness of the vertical wall portion.

JP 2008-296252 A

  By the way, when press-molding so as to reduce the height of the vertical wall portion, buckling tends to occur in the vertical wall portion. When buckling occurs, it becomes difficult to form the vertical wall portion that has been increased in thickness to an appropriate shape. In Patent Document 1 described above, the buckling of the vertical wall portion during press molding is not sufficiently studied.

  Further, when press molding is performed so as to reduce the height of the vertical wall portion, the corner portion connected to the vertical wall portion is likely to be folded. When the folding occurs, it becomes difficult to form a corner portion appropriately thickened. In addition, in patent document 1, it is not fully examined about the folding of the corner part at the time of press molding.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to appropriately increase the thickness of the vertical wall portion and the corner portion while preventing the occurrence of buckling and folding. An object of the present invention is to provide a press molding apparatus that can perform the above-described process.

  In order to solve the above-described problem, according to one aspect of the present invention, there is provided a press molding apparatus for pressing a workpiece to form a press-molded product, wherein the workpiece is an upper wall portion having a first thickness. A first wall supporting a workpiece from the inside of the hat-shaped cross section or the U-shaped cross section having a hat-shaped cross section or a U-shaped cross section including a curved wall portion connected to the vertical wall section. The height of the vertical wall portion is reduced by lowering the member, the second support member that supports the workpiece at the lower end of the vertical wall portion, and the second support member together with the first support member. On the other hand, the punch member that performs press working to increase the thickness of the vertical wall portion and the corner portion to the second thickness larger than the first thickness, and the first support member across the vertical wall portion, are being pressed. In addition, the gap between the first support member and the first support member is kept equal to or smaller than the second thickness. Press forming comprising: a member, and a thickening restricting portion that is provided on at least one of the punch member and the support member and that contacts the corner portion during thickening to restrict the thickness of the corner portion to a second thickness or less. An apparatus is provided.

  In the press molding apparatus, the workpiece is a long member, and the punch member reduces the overall height of the longitudinal wall portion in the longitudinal direction, while the entire longitudinal wall portion. May be increased to the second thickness.

  In order to solve the above-described problem, according to one aspect of the present invention, there is provided a press molding method for molding a press-molded product by press-working a work material, wherein the work material has an upper wall portion having a first thickness. A hat-shaped cross section including a vertical wall portion and a curved corner portion connected to the vertical wall portion, or a U-shaped cross section, and the workpiece is applied to the first support member from the inside of the hat-shaped cross section or the U-shaped cross section. A step of supporting, a step of supporting the workpiece on the second support member at a lower end portion of the vertical wall portion, a lowering of the punch member together with the first support member relative to the second support member, A step of performing press working to reduce the height of the vertical wall portion sandwiched between the support member and the pad member while increasing the thickness of the vertical wall portion to a second thickness larger than the first thickness; Pad member and first support portion facing the first support member across the portion The step of maintaining the distance between the second thickness and the second thickness during press working, and the thickening restricting portion provided on at least one of the punch member and the support member in contact with the corner portion during thickening Thereby, a step of regulating the thickness of the corner portion to the second thickness or less is provided.

  In order to solve the above-described problems, according to one aspect of the present invention, there is provided a press-formed product having a hat-shaped cross section or a U-shaped cross section, which is formed by pressing a workpiece having a first thickness. The upper wall portion of the first thickness is connected to both end portions of the upper wall portion, and is connected to the increased thickness vertical wall portion of the second thickness larger than the first thickness and the increased thickness vertical wall portion. And a press-molded product provided with a thickened corner portion having a second thickness.

  As described above, according to the present invention, it is possible to appropriately increase the thickness of the vertical wall portion and the corner portion while preventing the occurrence of buckling and folding.

It is a perspective view showing an example of composition of a press-formed product concerning a 1st embodiment of the present invention. It is a schematic diagram which shows an example of the manufacturing process of the press-formed product which concerns on 1st Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on 1st Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on 1st Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on 1st Embodiment. It is a schematic diagram for demonstrating the conditions of the 3 point | piece bending simulation regarding a press molded product. It is a graph which shows the analysis result of 3 point | piece bending simulation in case a support space | interval is 200 mm. It is a graph which shows the analysis result of 3 point | piece bending simulation in case a support space | interval is 300 mm. It is a graph which shows the analysis result of 3 point | piece bending simulation in case a support space | interval is 600 mm. It is a graph which shows the analysis result of 3 point | piece bending simulation. It is a graph which shows the analysis result of 3 point | piece bending simulation. It is a perspective view which shows an example of a structure of the press-formed product which concerns on the modification of 1st Embodiment. It is a schematic diagram which shows an example of the manufacturing process of the press-formed product which concerns on the modification of 1st Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on the modification of 1st Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on the modification of 1st Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on the modification of 1st Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on 2nd Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on 2nd Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on 2nd Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on the modification of 2nd Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on the modification of 2nd Embodiment. It is a schematic diagram for demonstrating an example of a structure of the press molding apparatus which concerns on the modification of 2nd Embodiment. It is a perspective view which shows an example of a structure of the press-formed product which concerns on other embodiment. It is a perspective view which shows an example of a structure of the press-formed product which concerns on other embodiment. It is a perspective view which shows an example of a structure of the press-formed product which concerns on other embodiment. It is a perspective view which shows an example of a structure of the press-formed product which concerns on other embodiment. It is a perspective view which shows an example of a structure of the press-formed product which concerns on other embodiment. It is a perspective view which shows an example of a structure of the press-formed product which concerns on other embodiment.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

<1. First Embodiment>
(1-1. Overview of press-formed product)
An example of the configuration of the press-formed product 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a perspective view showing an example of the configuration of a press-formed product 10 according to the first embodiment.

  The press-formed product 10 can be used as a part of various devices, but here, it will be described as being used as a part of a vehicle such as an automobile. For example, the press-formed product 10 is used as a center pillar of an automobile that requires high rigidity. In such a case, in order to ensure the safety of the impact on the side surface of the center pillar, it is necessary to increase the rigidity and strength of the portion of the press-formed product 10 on which the impact acts.

  The press-formed product 10 is formed by applying a process such as bending or drawing to a flat plate (also referred to as a blank) with a press-forming device. In the first embodiment, the press-molded product 10 is a long molded product extending in a so-called hat-shaped cross section as shown in FIG. Specifically, the press-molded product 10 includes an upper wall portion 12, a thickened vertical wall portion 13, and a flange portion 14.

  The upper wall portion 12 is formed to have the same thickness t1 (for example, 1.6 mm) as the plate thickness of the blank (see the blank 70 shown in FIG. 2). The upper wall portion 12 is a flat rectangular surface along the longitudinal direction of the press-formed product 10 (Y direction in FIG. 1).

  The vertical wall portion 13 is a pair of wall portions formed substantially perpendicular to the upper wall portion 12. The vertical wall portions 13 are respectively connected to both end portions in the width direction (X direction in FIG. 1) of the upper wall portion 12. The thickness t2 (for example, 2.0 mm) of the vertical wall portion 13 is increased by a press molding apparatus to be described later, and is larger than the thickness t1 of the upper wall portion 12. Thereby, the rigidity and intensity | strength of the vertical wall part 13 in the press molded product 10 become high. Further, since the vertical wall portion 13 becomes hard due to strain (work hardening) when the thickness is increased by the press molding apparatus, the rigidity and strength are further increased. The thickness t1 corresponds to the first thickness, and the thickness t2 corresponds to the second thickness.

  The flange portion 14 is connected to the lower end portion of the vertical wall portion 13. The flange portion 14 is formed to have the same thickness t1 as that of the upper wall portion 12. For example, a fastening hole (not shown) for fastening the press-formed product 10 to the vehicle body is formed in the flange portion 14.

  In the press-formed product 10, as shown in FIG. 1, the corner portion 15 between the upper wall portion 12 and the vertical wall portion 13 and the corner portion 16 between the vertical wall portion 13 and the flange portion 14 are also increased in thickness. ing. Specifically, the corner portions 15 and 16 are thickened so as to be flush with the vertical wall portion 13 in the width direction (X direction shown in FIG. 1) of the press-formed product 10. Thereby, the rigidity of the corner parts 15 and 16 also becomes high.

  Next, an example of a method for manufacturing the press-formed product 10 having the above-described configuration will be described with reference to FIG. The press-molded product 10 is molded by subjecting the blank 70 to press processing twice.

  FIG. 2 is a schematic diagram illustrating an example of a manufacturing process of the press-formed product 10 according to the first embodiment. The manufacturing process of the press-formed product 10 shown in FIG. 2 is started from the place where the blank 70 is prepared as the preparation process S1. Here, it is assumed that the blank 70 is a flat plate having a plate thickness t1.

  Next, in the first molding step S <b> 2, a first press process is performed on the blank 70. The first press work is bending or drawing by a press forming apparatus having a die or a punch. The primary molded product 80 subjected to the first press work is a long molded product having a hat-shaped cross section with a plate thickness t1. That is, the primary molded product 80 includes an upper wall portion 82 corresponding to the upper wall portion 12 of the press molded product 10, a vertical wall portion 83 corresponding to the vertical wall portion 13, and a flange portion 84 corresponding to the flange portion 14. Have. Here, the height of the vertical wall portion 83 is h1. Moreover, the corner part 85 of the upper wall part 82 and the vertical wall part 83, and the corner part 86 of the vertical wall part 83 and the flange part 84 are each curved surfaces (so-called R surface).

  Next, in the second molding step S3, a second press process is performed on the primary molded product 80, which is a workpiece. The second press work is performed by a press molding apparatus 100 described later. By performing the second press work, the press-formed product 10 which is a secondary molded product in which the vertical wall portion 83 is increased in thickness to t2 is formed.

  Specifically, the height of the vertical wall portion 83 of the primary molded product 80 is reduced from h1 to h2, while the vertical wall portion 83 is increased in thickness to t2. At this time, the corner portion 85 of the upper wall portion 82 and the vertical wall portion 83 and the corner portion 86 of the vertical wall portion 83 and the flange portion 84 are also thickened. As a result, the press-formed product 10 in which the vertical wall portion 13 and the corner portions 15 and 16 are increased in thickness is formed.

  A press having a hat-shaped cross section in which the vertical wall portion 13 is thickened to a plate thickness t2 using a flat blank 70 having a plate thickness t1 by the manufacturing method of the press-formed product 10 according to the first embodiment described above. The molded product 10 can be molded.

  By the way, a tailored blank is known as a manufacturing method for increasing the thickness of a part of a molded product. A tailored blank is obtained by welding two plates having different plate thicknesses before press molding to form one blank. A thick plate of the two plates is applied to a portion where rigidity and strength are required. However, in the above tailored blank, a welded portion in which two plates are welded to the molded product remains.

Tailored rolled blanks are also known. Tailored rolled blanks
It is a blank using a roll-shaped coil (thickness wound with a steel plate) having a partly different thickness. However, this method requires a custom coil.

  Furthermore, a method of providing a stiffener called a stiffener at a site where the blank needs rigidity or strength is also known. However, in the case of this method, since the stiffener is provided, the number of parts increases.

  On the other hand, in the case of the manufacturing method of the press-formed product 10 according to the first embodiment, no weld is generated, there is no need to use a custom-made coil, and the number of parts does not increase. That is, by a simple manufacturing method, it is possible to form the press-molded product 10 in which the vertical wall portion 13 that may be subjected to an impact when used in a center pillar of an automobile is thicker than the plate thickness t1 of the blank 70.

(1-2. Configuration Example of Press Molding Device)
An example of the configuration of the press forming apparatus 100 according to the first embodiment will be described with reference to FIGS. The press molding apparatus 100 forms the press molded product 10 in which the vertical wall portion 13 which is a secondary molded product is thickened by performing press processing of the primary molded product 80 which is a workpiece.

  3-5 is a schematic diagram for demonstrating an example of a structure of the press molding apparatus 100 which concerns on 1st Embodiment. 3 shows the state of the press molding apparatus 100 immediately before the start of press processing for increasing the thickness, FIG. 4 shows the state of the press molding apparatus 100 during press processing, and FIG. Shows the state of the press molding apparatus 100 (located at the bottom dead center).

  As illustrated in FIGS. 3 to 5, the press molding apparatus 100 includes a die 110, a cushion 120, a punch 130 that is an example of a punch member, and a pad 140 that is an example of a pad member. The die 110 and the cushion 120 are an example of a support member that supports the primary molded product 80. More specifically, the cushion 120 is an example of a first support member that supports the primary molded product 80 inside the hat-shaped cross section, and the die 110 supports the primary molded product 80 at the lower end portion of the vertical wall portion 83. It is an example of 2 support members.

  The die 110 is fixed to a lower holder (not shown) of the press molding apparatus 100. The die 110 is formed with a flange support recess 112 that supports the flange portion 84 (including the lower end portion of the vertical wall portion 83) of the primary molded product 80 when the primary molded product 80 is set. The die 110 has a pad moving surface 114 on which the pad 140 can be moved.

  The cushion 120 is movably supported by the lower holder of the press molding apparatus 100. The cushion 120 supports the set primary molded product 80 from the inside of the hat-shaped cross section. Specifically, the cushion 120 supports the inside of the upper wall portion 82 and the vertical wall portion 83 of the primary molded product 80. The cushion 120 is biased upward (direction D1) by a biasing member 122 such as a spring.

  The punch 130 is movably supported by an upper holder (not shown) of the press molding apparatus 100. The punch 130 is located above the upper wall portion 82 of the set primary molded product 80 and descends downward (direction D2; the direction opposite to the direction D1) during press working. The punch 130 is lowered in the direction D2 between the two pads 140 as shown in FIGS. 4 and 5 in a state where the upper wall 82 is sandwiched between the punch 120 and the cushion 120 as shown in FIG. The primary molded product 80 is press-molded. At this time, the punch 130 is lowered relative to the die 110 together with the cushion 120 to reduce the height of the vertical wall portion 83 of the primary molded product 80 from h1 to h2, while the vertical wall portion 83 is reduced. Is pressed so as to increase the thickness from t1 to t2. When the vertical wall portion 83 is thickened, the corner portions 85 and 86 are also thickened. In addition, since the vertical wall part 83 is thickened, producing distortion, it becomes hard (work hardening). The punch 130 performs such press processing for the entire longitudinal direction of the primary molded product 80.

  The pad 140 is located outside the vertical wall portion 83 of the primary molded product 80 and faces the cushion 120 with the vertical wall portion 83 interposed therebetween. The pad 140 is provided on the pad moving surface 114 of the die 110 so as to be movable in the left-right direction (direction D3 or direction D4). The pad 140 is urged in a direction D3 toward the vertical wall portion 83 by an urging member 142 such as a spring. The biasing member 142 has one end connected to the pad 140 and the other end connected to the die 110.

  The pad 140 urged in this way is held at a distance from the cushion 120 during the press working so as to be equal to or less than the thickness after the thickening of the vertical wall portion 83 (that is, the thickness t2). Specifically, the vertical wall portion during thickening while the pad 140 urged by the urging member 142 moves in the direction opposite to the urging direction of the urging member 142 during press processing by the punch 130. Since it keeps contacting 83, buckling of the vertical wall part 83 can be prevented.

  In the above description, the vertical wall portion 83 and the corner portions 85 and 86 of the primary molded product 80 are increased in thickness. However, the present invention is not limited to this, and only the vertical wall portion 83 may be increased in thickness. In the above description, the vertical wall portion 83 is increased in thickness in the entire longitudinal direction of the primary molded product 80. However, the present invention is not limited to this, and only a portion in the longitudinal direction of the vertical wall portion 83 is increased in thickness. Also good.

(1-3. Example of operation of press molding apparatus)
Next, an example of the operation of the press molding apparatus 100 during press working will be described with reference to FIGS. As shown in FIG. 3, this operation example starts from a state in which the set primary molded product 80 is sandwiched between the cushion 120, the punch 130, and the pad 140.

  First, the punch 130 starts to descend in the direction D2, and a load is applied to the primary molded product 80. Accordingly, the cushion 120 also descends in the direction D2 against the urging force of the urging member 122 in the direction D1. As a result, as shown in FIG. 4, the vertical wall portion 83 of the primary molded product 80 that has received the load contracts in the direction D <b> 2 and expands in the direction D <b> 4 (the direction opposite to the direction D <b> 3).

  The pad 140 is urged in the direction D3 by the urging member 142, but when the vertical wall 83 swells in the direction D4, a force acts on the pad 140 from the vertical wall 83 in the direction D4. As a result, the pad 140 also moves in the direction D4 against the urging force of the urging member 142. At this time, since the pad 140 urged by the urging member 142 is kept in contact with the vertical wall portion 83, the vertical wall portion 83 can be prevented from being bent and buckled. As a result, the vertical wall portion 83 can be increased in thickness to a uniform thickness t2.

  As shown in FIG. 5, the cushion 120 and the pad 140 continue to move until the punch 130 reaches the bottom dead center. At this time, the urging force of the urging member 142 is adjusted so that the distance between the pad 140 and the cushion 120 does not become larger than t2. Thereby, the vertical wall part 83 is thickened to thickness t2. At this time, the corner portion 85 of the upper wall portion 82 and the vertical wall portion 83 and the corner portion 86 of the vertical wall portion 83 and the flange portion 84 are also increased in thickness. In addition, the vertical wall 83 is hardened because it increases in thickness while causing distortion (work hardening).

  On the other hand, the upper wall portion 82 and the flange portion 84 of the primary molded product 80 maintain the thickness t1 until the punch 130 reaches the bottom dead center. As a result, when the press molding is completed, a press molded product 10 which is a secondary molded product in which the vertical wall portion 13 and the corner portions 15 and 16 are increased in thickness as shown in FIG.

(1-4. Effectiveness)
The effectiveness of the press-formed product 10 formed by the above-described press-forming apparatus 100 will be described using an analysis result when a three-point bending simulation is performed on the press-formed product 10.

  FIG. 6 is a schematic diagram for explaining the conditions of the three-point bending simulation for the press-formed product 10. In the simulation, the press-formed product 10 is supported by sandwiching a back plate 520 between support members 510 located at both ends in the longitudinal direction as shown in FIG. At this time, the press-formed product 10 is fixed to the back plate 520 which is a flat plate in the flange portion 14 by welding. Then, a predetermined load is applied by the indenter 530 to the center in the longitudinal direction of the press-formed product 10 supported by the support member 510. Thereby, the part to which the load of the press-formed product 10 is applied is deformed and displaced.

  Below, referring to FIG. 7 to FIG. 9, the analysis result regarding the press-formed product 10 according to the present embodiment in which the vertical wall portion 13 is thickened and the comparative example 1 in which the vertical wall portion is not thickened. A description will be given by comparing the analysis results with respect to the press-formed product. The simulation is performed for each of cases where the support intervals between the two support members 510 that support the press-formed product are 200 mm, 300 mm, and 600 mm. Here, the plate thickness of the upper wall portion 12 and the flange portion 14 of the press-formed product 10 is 1.0 mm, and the plate thickness of the vertical wall portion 13 is increased (1.2 mm to 2.0 mm). The plate thickness of the upper wall portion, the vertical wall portion, and the flange portion of the molded product according to Comparative Example 1 is uniform, and is 1.0 mm here.

  FIG. 7 is a graph showing the analysis result of the three-point bending simulation when the support interval between the two support members 510 is 200 mm. FIG. 8 is a graph showing an analysis result of a three-point bending simulation when the support interval is 300 mm. FIG. 9 is a graph showing an analysis result of a three-point bending simulation when the support interval is 600 mm.

  The horizontal axes of the six graphs in FIGS. 7 to 9 indicate the plate thickness of the vertical wall portion 13. 7A, FIG. 8A, and FIG. 9A, the vertical axis indicates the maximum load at which the press-formed product is displaced, and FIG. 7B, FIG. 8B, and FIG. The vertical axis | shaft of each graph of (b) shows the absorbed energy which a press molded product absorbs. In addition, as an analysis result, the analysis result which does not reflect work hardening and the analysis result which reflected work hardening are shown. As can be seen from FIGS. 7 to 9, the greater the thickness of the vertical wall portion 13, the greater the maximum load and absorbed energy at which the press-formed product 10 is displaced. In addition, when work hardening is reflected, the maximum load and absorbed energy are further increased. That is, the press-formed product 10 according to the present embodiment is not easily deformed and has a large amount of energy absorption. Thereby, when the press-formed product 10 according to the first embodiment is used for a center pillar of an automobile, the collision performance can be improved.

  Next, with reference to FIG. 10 and FIG. 11, the analysis result of the three-point bending simulation regarding the press-formed product 10 according to the present example and the press-formed products according to Comparative Examples 2 and 3 having different tensile strengths will be described. To do. 10 and 11 are graphs showing the analysis results of the three-point bending simulation.

  The analysis results of the press-formed product 10 according to this example shown in FIGS. 10 and 11 are the same as those in FIGS. 8A and 8B. About the molded product of the comparative example 2 and the comparative example 3, the plate | board thickness of an upper wall part, a vertical wall part, and a flange part is uniform, and is analyzing about the case where it is 1.0 mm and 1.2 mm here. . Here, the molded product of Comparative Example 2 is made of a material having a tensile strength of 980 MPa. The molded product of Comparative Example 3 is made of a material having a tensile strength of 1180 MPa class.

  As can be seen from FIG. 10 and FIG. 11, the press-formed product 10 of the present example exhibits characteristics superior to those of the comparative example 2 having a tensile strength of 980 MPa class. Moreover, when the plate | board thickness of the vertical wall part of the press-molded product 10 is 1.2 mm, the characteristic equivalent to the molded product of the comparative example 3 of the tensile strength 1180 Mpa class with a plate thickness of 1.2 mm is shown. For this reason, according to the press molding apparatus 100 according to the first embodiment, by performing press molding using a material having low tensile strength, it is possible to ensure the same characteristics as a molded product related to a material having high tensile strength. . For this reason, the characteristics of the press-formed product 10 can be maintained while reducing the weight of the material.

(1-5. Modification)
A configuration example of the press-formed product 20 and the press-forming device 150 according to the modification of the first embodiment will be described with reference to FIGS.

(1-5-1. Configuration example of press-formed product)
An example of the configuration of the press-formed product 20 according to the modification of the first embodiment will be described with reference to FIGS. 12 and 13. FIG. 12 is a perspective view showing an example of the configuration of a press-formed product 20 according to a modification of the first embodiment. FIG. 13 is a schematic diagram illustrating an example of a manufacturing process of the press-formed product 20 according to the modification of the first embodiment.

  The press molded product 20 is also a long molded product extending in a so-called U-shaped cross section as shown in FIG. Specifically, the press-formed product 20 has an upper wall portion 22 and a vertical wall portion 23, but does not have the flange portion 14 of the press-formed product 10 shown in FIG. For this reason, a fastening hole for fastening the press-formed product 20 to the vehicle body is formed in the upper wall portion 22 or the vertical wall portion 23.

  Also in the press-formed product 20, the vertical wall portion 23 is thickened to a thickness t 2 that is larger than the thickness t 1 of the upper wall portion 22. Further, the corner portion 25 between the upper wall portion 22 and the vertical wall portion 23 is also thickened so as to be flush with the vertical wall portion 23. Thereby, the rigidity of the vertical wall part 23 and the corner part 25 becomes high.

  As shown in FIG. 13, the press-formed product 20 having the above-described configuration is also subjected to two press operations on the blank 70 that is a flat plate having a thickness t <b> 1 prepared in the preparation step S <b> 11, similarly to the press-formed product 10. It shape | molds by giving (1st shaping | molding process S12 and 2nd shaping | molding process S13 shown in FIG. 13). That is, by the first molding step S12, the primary molded product 80 having a hat-shaped cross section with a plate thickness t1 is formed. Then, in the second molding step S13, the press-molded product 20 which is a secondary molded product whose thickness is increased to the thickness t2 by the amount the vertical wall portion has shrunk to the height h2 is molded.

(1-5-2. Configuration example and operation example of press molding apparatus)
An example of the configuration and operation of a press forming apparatus 150 according to a modification of the first embodiment will be described with reference to FIGS. The press molding apparatus 150 also molds the press-molded product 20 in which the vertical wall portion 23 which is a secondary molded product is thickened by performing press processing of the primary molded product 80.

  14 to 16 are schematic views for explaining an example of the configuration of a press forming apparatus 150 according to a modification of the first embodiment. 14 shows the state of the press molding device 150 immediately before the start of press processing for increasing the thickness, FIG. 15 shows the state of the press molding device 150 during press processing, and FIG. Shows the state of the press molding apparatus 150 (located at the bottom dead center).

  As shown in FIGS. 14 to 16, the press forming apparatus 150 includes a die 160, a cushion 120, a punch 130, and a pad 140. The die 160 has the same configuration as that of the die 110 of the press forming apparatus 100 shown in FIGS. 3 to 5 except that the flange support recess 112 is not formed. The configurations of the cushion 120, the punch 130, and the pad 140 of the press molding apparatus 150 are the same as those of the press molding apparatus 100. For this reason, the main functions of the die 160, the cushion 120, the punch 130, and the pad 140 of the press molding apparatus 150 are the same as those of the press molding apparatus 100.

Next, an example of operation during press working of the press forming apparatus 150 will be described.
In this operation example, the punch 130 and the cushion 120 start to descend in the direction D2 from the state shown in FIG. 14, and a load is applied to the primary molded product 80. As a result, as shown in FIG. 15, the vertical wall portion 83 of the primary molded product 80 contracts in the direction D2, while expanding in the direction D4. At this time, since the pad 140 urged by the urging member 142 is kept in contact with the vertical wall portion 83, the vertical wall portion 83 can be prevented from being bent and buckled. As a result, the vertical wall portion 83 can be increased in thickness to a uniform thickness t2.

  Then, as shown in FIG. 16, the cushion 120 and the pad 140 continue to move until the punch 130 reaches the bottom dead center. At this time, the urging force of the urging member 142 is adjusted so that the distance between the pad 140 and the cushion 120 does not become larger than t2. Thereby, the vertical wall part 83 is thickened to thickness t2. The corner portions 85 of the upper wall portion 82 and the vertical wall portion 83 are also increased in thickness. In addition, the vertical wall part 83 becomes hard because it increases in thickness while generating distortion.

  On the other hand, the upper wall portion 82 of the primary molded product 80 maintains the thickness t1 until the punch 130 reaches the bottom dead center. As a result, when the press molding is completed, a press molded product 20 which is a secondary molded product in which the vertical wall portion 23 and the corner portion 25 are increased in thickness as shown in FIG. 12 is molded.

<2. Second Embodiment>
A second embodiment will be described. The press-formed product according to the second embodiment is the same as the press-formed product 10 except that the thickness of the corner portion (see FIG. 19) is different from that of the press-formed product 10 according to the first embodiment. On the other hand, the press molding apparatus according to the second embodiment is different from the press molding apparatus 100 according to the first embodiment. Therefore, in the following, a configuration example and an operation example of the press molding apparatus according to the second embodiment will be described.

(2-1. Configuration Example of Press Molding Device)
An example of the configuration of the press molding apparatus 200 according to the second embodiment will be described with reference to FIGS. 17 to 19. The press molding apparatus 200 performs the press processing of the primary molded product 80 that is a workpiece, thereby molding the press molded product 10 in which the vertical wall portion 13 that is a secondary molded product is thickened.

  FIGS. 17-19 is a schematic diagram for demonstrating an example of a structure of the press molding apparatus 200 which concerns on 2nd Embodiment. 17 shows the state of the press molding apparatus 200 immediately before the start of press processing for increasing the thickness, FIG. 18 shows the state of the press molding apparatus 200 during press processing, and FIG. Shows the state of the press molding apparatus 200 (which is located at the bottom dead center).

  As shown in FIGS. 17 to 19, the press molding apparatus 200 includes a die 210, a cushion 220, a punch 230 that is an example of a punch member, and a pad 240 that is an example of a pad member. The die 210 and the cushion 220 are an example of a support member that supports the primary molded product 80. More specifically, the cushion 220 is an example of a first support member that supports the primary molded product 80 inside the hat-shaped cross section, and the die 210 supports the primary molded product 80 at the lower end portion of the vertical wall portion 83. It is an example of 2 support members.

  The die 210 is fixed to a lower holder (not shown) of the press molding apparatus 200. The die 110 is formed with a flange support recess 212 that supports the flange portion 84 (including the lower end portion of the vertical wall portion 83) of the primary molded product 80 when the primary molded product 80 is set. The top surface 114 of the die 210 is in contact with the pad 240.

  The cushion 220 is movably supported by the lower holder of the press molding apparatus 200. The cushion 220 supports the set primary molded product 80 from the inside of the hat-shaped cross section. Specifically, the cushion 220 supports the inside of the upper wall portion 82 and the vertical wall portion 83 of the primary molded product 80. The cushion 220 is biased upward (direction D1) by a biasing member 222 such as a spring.

  The punch 230 is movably supported by an upper holder (not shown) of the press molding apparatus 200. The punch 230 is located above the upper wall portion 82 of the set primary molded product 80 and descends downward (direction D2; the direction opposite to the direction D1) during press working. As shown in FIG. 3, the punch 230 moves down between the two pads 240 in the direction D <b> 2 to press-mold the primary molded product 80.

  The pad 240 is located outside the vertical wall portion 83 of the primary molded product 80 and faces the cushion 220 with the vertical wall portion 83 interposed therebetween. The pad 240 is biased in the direction D2 (that is, along the moving direction of the punch 230) by a biasing member 242 such as a spring and is in contact with the upper surface 214 of the die 210. The biasing member 242 has one end connected to the pad 240 and the other end connected to the punch 230.

  In the press molding apparatus 200, the gap between the pad 240 urged by the urging member 242 and the cushion 220 is maintained at the same size as the thickness t <b> 2 of the vertical wall portion 83 after the thickness increase. For this reason, since the vertical wall part 83 thickened in the press work by the punch 230 contacts the pad 240, the buckling of the vertical wall part 83 can be prevented.

  Further, a restriction convex portion 216 that restricts the amount of increase in the thickness of the vertical wall portion 83 of the primary molded product 80 and the corner portion 86 of the flange portion 84 is formed in a portion adjacent to the flange support concave portion 212 of the die 210. Similarly, on the end portion adjacent to the pad 240 of the punch 230, a restriction convex portion 236 for restricting the increase in the thickness of the upper wall portion 82 of the primary molded product 80 and the corner portion 85 of the vertical wall portion 83 is formed. . The restricting convex portion 216 and the restricting convex portion 236 are formed so that the thicknesses of the thickened corner portions 85 and 86 are t2. Thereby, the space in which the corner portions 85 and 86 are thickened is restricted, so that the corner portions 85 and 86 can be prevented from being folded during the thickening.

  Note that the restriction convex portion may be provided only on one of the die 210 and the punch 230. Further, the restriction convex portion may be formed in the press molding apparatus 100 according to the first embodiment. Even in such a case, it is possible to prevent the corner portions 85 and 86 from being folded when the thickness is increased.

(2-2. Example of operation of press molding apparatus)
Next, an operation example of the press molding apparatus 200 will be described with reference to FIGS.

  In this operation example, the punch 230 starts to descend in the direction D2 from the state shown in FIG. 17, and a load is applied to the primary molded product 80. Accordingly, the cushion 220 also descends in the direction D2 against the urging force of the urging member 222 in the direction D1. As a result, as shown in FIG. 18, the vertical wall portion 83 of the primary molded product 80 that has received a load contracts in the direction D2, while expanding in the direction D4.

  Then, as shown in FIG. 19, the cushion 220 continues to move until the punch 230 reaches the bottom dead center, while the position of the pad 240 is urged by the urging member 242 so that the distance from the cushion 220 is constant. Is held to be. For this reason, the vertical wall portion 83 that has not been in contact with the pad 240 before the patch 230 descends swells so as to fill the space between the cushion 220 and the pad 240 and comes into contact with the pad 240.

  At this time, since the bulge in the direction D4 of the vertical wall portion 83 is restricted by the pad 240 and is not greatly bent, it is possible to prevent the vertical wall portion 83 from buckling. As a result, the vertical wall 83 is increased in thickness to a uniform thickness t2. At the same time, the corner portion 85 of the upper wall portion 82 and the vertical wall portion 83 and the corner portion 86 of the vertical wall portion 83 and the flange portion 84 are also thickened. At this time, the corners 85 and 86 are not bent by the restricting convex portions 216 and 236, and the corner portions 85 and 86 are also thickened to the thickness t2.

  On the other hand, the upper wall portion 82 and the flange portion 84 of the primary molded product 80 maintain the thickness t1 until the punch 230 reaches the bottom dead center. As a result, when the press molding is completed, a press molded product 10 which is a secondary molded product in which the vertical wall portion 13 and the corner portions 15 and 16 are increased in thickness is generated. The press-formed product 10 generated in this way also exhibits the same characteristics as the press-formed product 10 described with reference to FIGS. 7 to 11 described above, and can improve the collision performance when used for the center pillar of an automobile. .

(2-3. Modifications)
A modification of the second embodiment will be described. Hereinafter, an example of the configuration and operation of a press forming apparatus 250 according to a modification of the second embodiment will be described with reference to FIGS. 20 to 22. The press-formed product formed by the press-forming device 250 is the same as the press-formed product 20 except that the corner thickness (see FIG. 22) is different from the press-formed product 20 according to the modification of the first embodiment. Is the same.

  20-22 is a schematic diagram for demonstrating an example of a structure of the press molding apparatus 250 which concerns on the modification of 2nd Embodiment. 20 shows the state of the press molding apparatus 250 immediately before the start of press processing for increasing the thickness, FIG. 21 shows the state of the press molding apparatus 250 during press processing, and FIG. Shows the state of the press forming apparatus 250 (located at the bottom dead center).

  As shown in FIGS. 20 to 22, the press forming apparatus 250 includes a die 260, a cushion 220, a punch 230, and a pad 240. The die 260 has the same configuration as that of the die 210 of the press molding apparatus 200 shown in FIGS. 17 to 19 except that the flange support concave portion 212 and the restriction convex portion 216 are not formed. The configurations of the cushion 220, the punch 230, and the pad 240 of the press molding apparatus 250 are the same as those of the press molding apparatus 200. For this reason, the main functions of the die 260, the cushion 220, the punch 230, and the pad 240 of the press molding apparatus 250 are the same as those of the press molding apparatus 200.

Next, an example of operation during press working of the press molding apparatus 250 will be described.
In this operation example, the punch 230 and the cushion 220 start to descend in the direction D2 from the state shown in FIG. 20, and a load is applied to the primary molded product 80. As a result, as shown in FIG. 21, the vertical wall portion 83 of the primary molded product 80 contracts in the direction D2, while expanding in the direction D4.

  Then, as shown in FIG. 22, while the cushion 220 continues to move until the punch 230 reaches the bottom dead center, the position of the pad 240 is urged by the urging member 242 so that the distance from the cushion 220 is constant. Is held to be. For this reason, the vertical wall portion 83 that has not been in contact with the pad 240 before the patch 230 descends swells so as to fill the space between the cushion 220 and the pad 240 and comes into contact with the pad 240.

  At this time, since the bulge in the direction D4 of the vertical wall portion 83 is restricted by the pad 240 and is not greatly bent, it is possible to prevent the vertical wall portion 83 from buckling. As a result, the vertical wall 83 is increased in thickness to a uniform thickness t2. At the same time, the corner portion 85 of the upper wall portion 82 and the vertical wall portion 83 is also thickened. At this time, the corner portion 85 is not bent by the restricting convex portion 216, and the corner portion 85 is also thickened to the thickness t2.

  On the other hand, the upper wall portion 82 of the primary molded product 80 maintains the thickness t1 until the punch 230 reaches the bottom dead center. As a result, when the press molding is completed, a press molded product 20 that is a secondary molded product in which the vertical wall portion 23 and the corner portion 25 are increased in thickness is generated.

  In the above description, the example in which the press-formed products 10 and 20 have a hat-shaped cross section or a U-shaped cross section having the flat upper wall portions 12 and 22 has been described. However, the cross-sectional shape of the press-formed product is not limited to these examples. For example, as shown in FIG. 23, the upper wall portion may be a hat-shaped cross section or a U-shaped cross section having a curvature.

  FIG. 23 is a perspective view showing an example of the configuration of a press-formed product 50 according to another embodiment. The press-molded product 50 is a long molded product extending in a U-shaped cross section. The press-formed product 50 includes an upper wall portion 52 having a curvature and a vertical wall portion 53. The press-formed product 50 has a U-shaped cross section, and the vertical wall portion 53 is increased in thickness to the plate thickness t2 by the press-forming device in the same manner as the press-formed products 10 and 20 with respect to the primary formed product having the thickness t1. So that it is pressed.

  In the above description, the example in which the press-formed products 10 and 20 have a straight longitudinal section (a section in a direction perpendicular to a hat-shaped section or a U-shaped section) has been described. However, the vertical cross-sectional shape of the press-formed product is not limited to these examples, and may have a curved vertical cross section as shown in FIGS. 24, 25, and 26, for example.

  FIG. 24 is a perspective view showing an example of the configuration of a press-formed product 10b having a hat-shaped cross section having a longitudinal section curved upward. Also in the press-formed product 10b, the vertical wall portion 13 is thickened to the plate thickness t2 with respect to the plate thickness t1 of the upper wall portion 12 and the flange portion 14 as in the press-formed product 10.

  FIG. 25 is a perspective view showing an example of a configuration of a press-formed product 20b having a U-shaped cross section having a longitudinal section curved upward. Also in the press-formed product 20b, the vertical wall portion 23 is increased in thickness to the plate thickness t2 with respect to the plate thickness t1 of the upper wall portion 22 as in the press-formed product 20.

  FIG. 26 is a perspective view showing an example of the configuration of a press-formed product 50b having a U-shaped cross section having an upper wall portion 52 having a longitudinal section curved upward and having a curvature. Also in the press-formed product 50b, the vertical wall portion 53 is thickened to the plate thickness t2 with respect to the plate thickness t1 of the upper wall portion 52 as in the press-formed product 50.

  Moreover, the above demonstrated the example in which the press molded products 10 and 20 have a linear longitudinal shape. However, the longitudinal shape of the press-formed product is not limited to these examples, and may have a curved longitudinal shape as shown in FIGS. 27 and 28, for example.

  FIG. 27 is a perspective view showing an example of the configuration of a press-formed product 10c having a hat-shaped cross section having a curved longitudinal shape. Also in the press-formed product 10c, the vertical wall portion 13 is thickened to the plate thickness t2 with respect to the plate thickness t1 of the upper wall portion 12 and the flange portion 14 as in the press-formed product 10.

  FIG. 28 is a perspective view showing an example of the configuration of a press-formed product 20c having a U-shaped cross section having a curved longitudinal shape. Also in the press-formed product 20 c, the vertical wall portion 23 is thickened to the plate thickness t 2 with respect to the plate thickness t 1 of the upper wall portion 22, as in the press-formed product 20.

<3. Summary>
In the first and second embodiments described above, the punches 130 and 230 are lowered relative to the second support member (die 110 and 210) together with the first support member (cushion 120 and 220). Thus, press working is performed to increase the thickness of the vertical wall portion 83 to the second thickness (thickness t2) while reducing the height of the vertical wall portion 83 of the workpiece (primary molded product 80). The pads 140 and 240 facing the cushions 120 and 220 across the vertical wall portion 83 to be thickened are urged by urging members 142 and 242 as shown in FIGS. The distance between 120 and 220 is kept below the thickness t2.

  In the case of such a configuration, the vertical wall portion 83 of the primary molded product 80 which is increased in thickness from the thickness t1 to the thickness t2 by press working contacts the pads 140 and 240 biased by the biasing members 142 and 242. Will do. For this reason, since it can suppress that the vertical wall part 83 in the thickness increase bends, it can also prevent that the buckling generate | occur | produces in the vertical wall part 83 during press work. As a result, the vertical wall portion 83 of the primary molded product 80 can be appropriately increased in thickness.

  Further, the thickening restricting portion (the restricting convex portion 236, the restricting convex portion 216) provided on at least one of the punches 130 and 230 and the second support member (die 110, 210) is a corner portion 85 during thickening, In contact with 86, the thickness of the corners 85, 86 is regulated to the second thickness (thickness t2) or less. Thereby, the space in which the corner portions 85 and 86 are thickened is restricted, so that the corner portions 85 and 86 can be prevented from being folded during the thickening.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

10, 20 Press-formed product 12, 22 Upper wall portion 13, 23 Vertical wall portion 14 Flange portion 15, 16, 25 Corner portion 70 Blank 80 Primary molded product 82 Upper wall portion 83 Vertical wall portion 84 Flange portion 85, 86 Corner portion 100, 150, 200, 250 Press forming apparatus 110, 160, 210, 260 Die 120, 220 Cushion 122 Biasing member 130, 230 Punch 140, 240 Pad 142 Biasing member

Claims (4)

A press molding apparatus for pressing a workpiece to form a press-molded product, wherein the workpiece is an upper wall portion, a vertical wall portion, and a curved corner connected to the vertical wall portion having a first thickness. Having a hat-shaped cross section or a U-shaped cross section including a
A first support member that supports the workpiece from the inside of the hat-shaped cross section or the U-shaped cross section;
A second support member that supports the workpiece at a lower end portion of the vertical wall portion;
The height of the vertical wall portion is reduced by lowering relative to the second support member together with the first support member, while the vertical wall portion and the corner portion are larger than the first thickness. A punch member that performs press working to increase the thickness to the second thickness;
A pad member that faces the first support member across the vertical wall portion, and the distance between the first support member and the second thickness during the pressing process is kept equal to or less than the second thickness,
A thickening restricting portion that is provided on at least one of the punch member and the second support member, and that contacts the corner portion during thickening to restrict the thickness of the corner portion to the second thickness or less; A press molding apparatus comprising: In the press molding apparatus according to claim 1,
The workpiece is a long member,
The punch member is a press molding apparatus that reduces the overall height of the vertical wall portion in the longitudinal direction while increasing the thickness of the entire vertical wall portion to the second thickness. A press molding method for pressing a workpiece to form a press-molded product, wherein the workpiece is a first wall having an upper wall portion, a vertical wall portion, and a curved corner connected to the vertical wall portion. Having a hat-shaped cross section or a U-shaped cross section including a
Supporting the work piece on the first support member from the inside of the hat-shaped cross section or the U-shaped cross section;
Supporting the workpiece on a second support member at the lower end of the vertical wall; and
While lowering the punch member together with the first support member relative to the second support member, the height of the vertical wall portion sandwiched between the first support member and the pad member is reduced. Performing a press work to increase the thickness of the vertical wall portion to a second thickness larger than the first thickness;
Maintaining the distance between the pad member facing the first support member and the first support member across the vertical wall portion to be equal to or smaller than the second thickness during the pressing process;
The thickness of the corner portion is regulated to be equal to or less than the second thickness by bringing a thickening regulating portion provided on at least one of the punch member and the second support member into contact with the corner portion being thickened. And a press forming method. A press-formed product having a hat-shaped cross section or a U-shaped cross section, which is formed by pressing a workpiece having a first thickness,
An upper wall portion of the first thickness;
Connected to both ends of the upper wall portion, and a thickened vertical wall portion having a second thickness larger than the first thickness;
A press-molded product, which is connected to the thickened vertical wall portion and includes the thickened corner portion having the second thickness.

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