Patent Publication Number: US-9889486-B2

Title: Manufacturing method of press-formed article and press forming apparatus

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a manufacturing method of press-formed article and a press forming apparatus. 
     Description of the Related Art 
     Hitherto, there is known a technology of manufacturing a metal plate used for a frame component of a vehicle such as a motor vehicle by means of the press forming. In this application, a need for a metal plate constant in the plate thickness as well as a metal plate having a difference in the plate thickness by partially forming a thickened portion is increasing. JP 2014-166645A, JP 2007-14978A, and JP 2008-296252A disclose apparatuses and methods for manufacturing a metal plate on which a thickened portion is formed by means of the press forming. 
     In the press forming apparatuses disclosed in JP 2014-166645A and JP 2007-14978A, a metal plate is arranged between a pair of upper and lower dies, and the metal plate is pressed in a direction parallel with a main surface in this state. As a result, a part of a material of the metal plate becomes fluid, flows into a recess provided in the die, and a thickened portion in a shape corresponding to a shape of the recess is formed. Moreover, according to JP 2008-296252A, protrusions are partially provided in a lengthwise direction in a metal plate bent in a U shape, and a thickened portion is partially formed in the lengthwise direction by pressing the protrusions in a horizontal direction. 
     According to JP 2014-166645A and JP 2007-14978A, upper and lower dies are arranged so that opposing surfaces opposing main surfaces of a metal plate align with the horizontal direction, and both ends of the metal plate are pressed in the horizontal direction. These press forming apparatuses placed in the horizontal direction require a wide space for placing the dies, and possesses such a problem that space saving is difficult. 
     Moreover, according to JP 2008-296252A, a top die is moved downward, thereby bringing the top die in contact with a pair of lower lateral dies, and the metal plate is pressed by moving the pair of lateral dies in the horizontal direction so as to approach each other. In other words, there is provided such a structure that a driving force for moving the top die in the vertical direction is converted into driving forces for moving the lateral dies in the horizontal direction, and a special die structure and a gimmick are thus necessary. As a result, the die structure becomes complex, which possesses a problem of an increased cost. 
     SUMMARY OF THE INVENTION 
     The present invention is made in view of the above-mentioned problem, and has an object to provide a manufacturing method of press-formed article and a press forming apparatus enabling a decrease in the complexity of the die structure, thereby decreasing the cost as well as the space. 
     (1) A manufacturing method of press-formed article according to one aspect of the present invention is a manufacturing method of press-formed article by forming a flat plate member. The method includes a step of placing the flat plate member between a first die and a second die so that a first main surface of the flat plate member opposes a first opposing surface, and a second main surface, which is a main surface directing opposite to the first main surface of the flat plate member, opposes a second opposing surface, and a step of causing a first press portion opposing a first end of the flat plate member and a second press portion opposing a second end on an opposite side of the first end of the flat plate member to approach each other, thereby pressing the flat plate member. In the step of the placing the flat plate member, the flat plate member is placed so that the first main surface and the second main surface align with a vertical direction. In the step of pressing, the flat plate member is pressed in the vertical direction by causing the first press portion and the second press portion to approach each other in the vertical direction. Moreover, in the step of pressing, a thick portion is formed on the flat plate member by causing a part of a material of the flat plate member in the vertical direction to flow into a thickened portion-forming section formed at least one of the first opposing surface and the second opposing surface. 
     In the above-mentioned method, the flat plate member is pressed by the first press portion and the second press portion, and the thickened portion, which is a thick portion, is formed on the flat plate member by causing a part of the material of the flat plate member in the vertical direction to flow into the thickened portion-forming section. Moreover, the flat plate member is arranged in a vertically placed state so that the first main surface and the second main surface align with the vertical direction, the dies can be placed in a narrow space compared with the conventional case where the flat plate member is placed in a horizontally placed state so that the first main surface and the second main surface align with the horizontal direction, resulting in a saved space. Moreover, both the direction in which the first press portion and the second press portion approach each other, and the direction in which the flat plate member is pressed are the same vertical direction. Thus, a driving force for causing the first press portion and the second press portion to approach each other can be directly used as a force for pressing the flat plate member, the conventional special die structure and the gimmick are thus no longer necessary, and the die structure can be simplified, thereby decreasing the cost. 
     On this occasion, “the first end and the second end” mean ends on both sides in the press direction of the flat plate member. 
     (2) In the above-mentioned manufacturing method of press-formed article, at least one of the first die and the second die may be arranged so that the bottom end is positioned in a recess formed on a mount surface of a support member. 
     As a result, positioning can be promoted by positioning the bottom end of the die is in the recess. 
     (3) In the above-mentioned manufacturing method of press-formed article, the first die and the second die may be arranged so as to be positioned between portions of a supporting member in the step of pressing. 
     As a result, even if the dies are vertically placed, the dies can be prevented from falling down in the press step. 
     (4) In the above-mentioned manufacturing method of press-formed article, the step of placing the flat plate member may include a first placing step of placing the flat plate member so that the first main surface opposes the first opposing surface, and a second placing step of placing the second die so that the second main surface opposes the second opposing surface after the first placing step. The flat plate member may be supported by a temporarily supporting member so that the first main surface and the second main surface align with the vertical direction in the first placing step. 
     As a result, even before the flat plate member is arranged between the first die and the second die, the flat plate member can be stably supported so as not to fall down. 
     (5) In the above-mentioned manufacturing method of press-formed article, the flat plate member may be formed by means of hot press. 
     In the above-mentioned method, the thickened portion can easily be formed even in the case of the hot press by controlling the fluid so that a part of the material of the flat plate member flows into the thickened portion-forming section. 
     (6) A press forming apparatus according to another aspect of the present invention is a press forming apparatus for forming a flat plate member. The press forming apparatus includes a first press portion that opposes a first end of the flat plate member, a second press portion that opposes a second end, which is an end on an opposite side with respect to the first end of the flat plate member, a first die that includes a first opposing surface opposing a first main surface of the flat plate member, a second die that includes a second opposing surface opposing a second main surface, which is a main surface directing opposite to the first main surface of the flat plate member, and a driving section that causes the first press portion and the second press portion to approach each other in a vertical direction so as to press the flat plate member. A thickened portion-forming section is formed on at least one of the first opposing surface and the second opposing surface so that a part of a material of the flat plate member flows into the thickened portion-forming section, thereby forming a thick portion on the flat plate member. The first die and the second die are respectively arranged so that the first opposing surface and the second opposing surface align with the vertical direction. 
     In the above-mentioned press forming apparatus, the flat plate member is pressed by the first press portion and the second press portion, and the thickened portion, which is a thick portion, is formed on the flat plate member by causing a part of the material of the flat plate member in the vertical direction to flow into the thickened portion-forming section. Moreover, the first die and the second die are arranged in the vertically placed state where the first opposing surface and the second opposing surface align with the vertical direction, and the dies can thus be placed in a narrow space compared with the conventional case where the first opposing surface and the second opposing surface are arranged in a horizontally placed state so as to align with the horizontal direction, resulting in a saved space. Moreover, both the direction in which the first press portion and the second press portion approach each other, and the direction in which the flat plate member is pressed are the same vertical direction. Thus, a driving force for causing the first press portion and the second press portion to approach each other is directly used as a force for pressing the flat plate member, the conventional special die structure and the gimmick are thus no longer necessary, and the die structure can be simplified, thereby decreasing the cost. 
     (7) The above-mentioned press forming apparatus may include a support member that includes a mount surface on which the first die and the second die are placed. A recess in which a bottom end of at least one of the first die and the second die is positioned may be formed on the mount surface. 
     As a result, positioning can be promoted by positioning the bottom end of the die is in the recess. 
     (8) In the above-mentioned press forming apparatus, the first die may have a first side surface directing opposite to the first opposing surface. The second die may have a second side surface directing opposite to the second opposing surface. The above-mentioned press forming apparatus may include a supporting member that has portions positioned outside in the horizontal direction of the first side surface and the second side surface. 
     As a result, even if the dies are vertically placed, the dies can be prevented from falling down during the pressing. 
     (9) The above-mentioned press forming apparatus may include a press member on which the first press portion is provided. The press member may be integrally formed with the supporting member. 
     As a result, the structure of the press forming apparatus can be more simplified compared with a case where the press member and the supporting member are constructed independently of each other. 
     (10) The above-mentioned press forming apparatus may comprise a temporarily supporting member that is attached to the support member, and supports the flat plate member so that the first main surface and the second main surface are aligned with the vertical direction. 
     As a result, even before the flat plate member is arranged between the first die and the second die, the flat plate member can be stably supported so as not to fall down. 
     With the above-mentioned press forming apparatus, the thickened portion can easily be formed even in the case of the hot press by controlling the fluid so that a part of the material of the flat plate member flows into the thickened portion-forming section. 
     EFFECTS OF INVENTION 
     The present invention can provide the manufacturing method of press-formed article and the press forming apparatus enabling a decrease in the complexity of the die structure, thereby decreasing the cost as well as the space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing a configuration of a press forming apparatus according to a first embodiment of the present invention. 
         FIG. 2  is a flowchart showing procedures of a manufacturing method of press-formed article according to the first embodiment of the present invention. 
         FIG. 3  is a diagram describing the manufacturing method of press-formed article. 
         FIG. 4  is a diagram describing the manufacturing method of press-formed article. 
         FIGS. 5A and 5B  are diagrams showing the configuration of a press forming apparatus according to a second embodiment of the present invention. 
         FIG. 6  is a diagram showing the configuration of a press forming apparatus according to a third embodiment of the present invention. 
         FIG. 7  is a diagram describing the manufacturing method of press-formed article according to the third embodiment of the present invention. 
         FIG. 8  is a diagram describing the manufacturing method of press-formed article according to the third embodiment of the present invention. 
         FIG. 9  is a diagram showing the configuration of a press forming apparatus according to another embodiment of the present invention. 
         FIG. 10  is a diagram showing the configuration of a press forming apparatus according to another embodiment of the present invention. 
         FIG. 11  is a diagram showing the configuration of a press forming apparatus according to another embodiment of the present invention. 
         FIG. 12  is a schematic diagram describing partial electric heating. 
         FIG. 13  is a schematic diagram describing press forming of a flat plate member to which the partial electric heating is applied. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described in detail with reference to drawings. 
     First Embodiment 
     [Configuration of Press Forming Apparatus] 
     First, a description is given of a configuration of a press forming apparatus  1  according to a first embodiment of the present invention with reference to  FIGS. 1, 3, and 4 . 
     The press forming apparatus  1  is an apparatus that carries out press forming so that a partially thick portion (thickened portion) is formed on a flat plate member  10  such as a metal plate constant in a plate thickness. The press forming apparatus  1  includes a first die  11 , a second die  12 , a support member  15 , a supporting member  13 , a press member  14 , and a driving section  23 . The flat plate member  10  is a metal plate made of a material such as hard steel, soft steel, or aluminum, and includes a first main surface  10 C, a second main surface  10 D, which is a main surface opposing the first main surface  10 C, a first end  10 A, and a second end  10 B, which is an end on an opposite side of the first end  10 A. 
     The first die  11  is in an approximately rectangular parallelepiped shape, and includes a first opposing surface  11 A opposing the first main surface  10 C of the flat plate member  10 , and a first side surface  11 B directing opposite to the first opposing surface  11 A in the horizontal direction. The first die  11  is placed on its bottom surface on a support member  15 , and is arranged so that the first opposing surface  11 A aligns with the vertical direction (is parallel with the vertical direction) as illustrated in  FIGS. 1, 3 , and  4 . 
     A thickened portion-forming section  16  in a recessed groove shape is formed at a portion approximately at the center in the vertical direction on the first opposing surface  11 A. The thickened portion-forming section  16  is provided so that a part of the material of the flat plate member  10  in the vertical direction flows into the thickened portion-forming section  16  during the press forming, thereby forming a thickened portion, which is a thick portion on the flat plate member  10 . The thickened portion-forming section  16  is a portion surrounded by a pair of sidewall surfaces formed by horizontal surfaces extending in the horizontal direction, a flat bottom wall surface connecting ends on an inner side of the pair of the side wall surfaces with each other, and is recessed toward a direction departing from the flat plate member  10 . 
     It should be noted that the shape of the thickened portion-forming section  16  is not limited to this shape, and can be appropriately changed depending on the shape of the thickened portion formed on the flat plate member  10 . For example, the cross sectional shape may be semicircular or triangular. Moreover, multiple thickened portion-forming sections  16  may be formed on the first opposing surface  11 A. Moreover, the position at which the thickened portion-forming section  16  is formed is not limited to the center of the first opposing surface  11 A, and may be formed on an end side. 
     The second die  12  is in a rectangular parallelepiped shape more in the width in the vertical direction than the first die  11 , and includes a second opposing surface  12 A opposing the second main surface  10 D of the flat plate member  10 , and a second side surface  12 B directing opposite to the second opposing surface  12 A in the horizontal direction. As illustrated in  FIG. 3 , the second die  12  is arranged next to the first die  11  on the support member  15  so that the second opposing surface  12 A opposes the first opposing surface  11 A across the flat plate member  10 , and the top surface is parallel with the top surface of the first die  11 . As a result, the flat plate member  10  can be arranged between the first die  11  and the second die  12 . The second die  12  is placed on its bottom surface on the support member  15  as the first die  11 , and is arranged so that the second opposing surface  12 A aligns with the vertical direction (is parallel with the vertical direction). 
     In the press forming apparatus  1  according to this embodiment, the first die  11  and the second die  12  are arranged in the vertically placed state so that the first opposing surface  11 A and the second opposing surface  12 A align with the vertical direction in this way. Therefore, the apparatus can be placed in a narrower space compared with a case where the first die  11  and the second die  12  are arranged in a horizontally placed state so that the first opposing surface  11 A and the second opposing surface  12 A align with the horizontal direction. In other words, the press forming apparatus  1  has a structure advantageous in the space saving. 
     The support member  15  is a metal member in a rectangular parallelepiped shape, and includes a mount surface  15 A on which bottom surfaces of the first die  11  and the second die  12  are placed. The support member  15  is arranged on a bottom side in the vertical direction of the first die  11  and the second die  12  in a state where the support member  15  is in a horizontally placed state so that the mount surface  15 A aligns with the horizontal direction (is parallel with the horizontal direction). 
     A flat surface  15 D and a recess  15 B recessed from the flat surface  15 D are formed on the mount surface  15 A. The first die  11  is placed on a portion adjacent to the recess  15 B on the flat surface  15 D. The recess  15 B is formed in a groove shape corresponding to a shape of a bottom end of the second die  12 . The recess  15 B is a portion surrounded by a pair of flat side wall surfaces extending in the vertical direction and a flat bottom wall surface connecting bottom sides of the pair of the sidewall surfaces with each other. As shown in  FIG. 3 , the second die  12  is positioned by arranging the bottom end so as to be placed in the recess  15 B (bringing the bottom end in contact with the bottom wall surface of the recess  15 B). Moreover, a portion  15 C adjacent to the recess  15 B of the flat surface  15 D opposes the second end  10 B of the flat plate member  10 , and functions as a second press portion for pressing the flat plate member  10  from the second end  10 B side as described later. 
     The supporting member  13  is a member for supporting the first die  11  and the second die  12  arranged in the vertically placed state as described above so as not to fall down. The supporting member  13  includes a first supporting portion  18 , a second supporting portion  19 , and a main body portion  17 B for connecting the supporting portions with each other, and these portions are integrally formed as shown in  FIGS. 1, 3, and 4 . A cross section of the supporting member  13  cut on a plane including the left/right direction and the vertical direction of  FIG. 1  has a U shape inverted upside down. 
     The main body portion  17 B extends outward with respect to the first side surface  11 B and the second side surface  12 B in a state where the flat plate member  10  is arranged between the first die  11  and the second die  12  ( FIG. 3 ). The first supporting portion  18  and the second supporting portion  19  extend downward in the vertical direction from both ends in the horizontal direction of the main body portion  17 B toward the support member  15 . The first supporting portion  18  is positioned outside the first side surface  11 B in the horizontal direction, and the second supporting portion  19  is positioned outside the second side surface  12 B in the horizontal direction in a state where the supporting member  13  is moved down ( FIG. 3 ) as shown in  FIG. 3 . In other words, the first supporting portion  18  is a portion that can be in contact with the first side surface  11 B, and the second supporting portion  19  is a portion that can be in contact with the second side surface  12 B. 
     A first inner surface  13 A opposing the first side surface  11 B is formed inside the first supporting portion  18 , and a second inner surface  13 B opposing the second side surface  12 B is formed inside the second supporting portion  19 . On this occasion, a horizontal distance between the first inner surface  13 A and the second inner surface  13 B is slightly longer than a horizontal distance between the first side surface  11 B and the second side surface  12 B. As a result, the first die  11  and the second die  12  can be placed between the first supporting portion  18  and the second supporting portion  19  as shown in  FIG. 3 . 
     The press member  14  is a member for pressing the flat plate member  10 . The press member  14  is provided, at a tip, with a first press portion  14 A opposing the first end  10 A of the flat plate member  10 , and is attached to a portion approximately the center in the horizontal direction of the main body portion  17 B. More specifically, the press member  14  is integrally formed with the supporting member  13  so that the first press portion  14 A is positioned on a lower side in the vertical direction with respect to the bottom surface  17 A of the main body portion  17 B. 
     The driving section  23  is a unit for moving the press member  14  in the vertical direction. The driving section  23  includes a reciprocally movable hydraulic or electric piston, and is arranged on a top surface of the supporting member  13  (main body portion  17 B). According to this embodiment, the press member  14  is fixed to the supporting member  13 , and the press member  14  can thus indirectly be moved by the driving section  23  pressing the supporting member  13 . As a result, the first press portion  14 A can be caused to approach the second press portion  15 A, and the flat plate member  10  can be pressed in the direction parallel with the main surfaces  10 C and  10 D by the first press portion  14 A and the second press portion  15 A. It should be noted that the press member  14  and the supporting member  13  may be provided independently of each other, and, in this case, the driving section  23  may be configured to move only the press member  14 . 
     The first press portion  14 A and the second press portion  15 A can be caused to approach each other in the vertical direction in this way, thereby pressing the flat plate member  10  in the vertical direction in the press forming apparatus  1  according to this embodiment. In other words, both the direction in which the first press portion  14 A and the second press portion  15 A are caused to approach each other and the direction in which the flat plate member  10  is pressed are the vertical direction, and are thus the same with each other. Therefore, a driving force by the driving section  23  for causing the first and second press portions  14 A and  15 A approach each other can be directly used as a force for pressing the flat plate member  10 . Therefore, a special die structure and a gimmick are not necessary for changing the driving force in the vertical direction of the driving section  23  to a different direction, and the structure of the first and second dies  11  and  12  can thus be simplified. 
     [Manufacturing Method of Press-Formed Article] 
     A description is now given of a manufacturing method of press-formed article according to this embodiment by using the press forming apparatus  1  with reference to a flowchart shown in  FIG. 2 . First, a step S 10  of preparing for the flat plate member  10  is carried out. In the step S 10 , a metal plate constant in the plate thickness is prepared as the flat plate member  10 , and the flat plate member  10  is heated at a predetermined temperature in an electric furnace or the like. As a result, the entire flat plate member  10  is brought into a softened state. The press-formed article is manufacturing method by means of the hot press of applying press forming to the flat plate member  10  in the softened state by the heating in this way according to this embodiment. It should be noted that the present invention is not limited to the case of the hot press, and the step S 10  may be omitted in a case of the cold working. 
     Then, a step S 20  of placing the flat plate member  10  is carried out. In the step S 20 , a first placement step S 21  and a second placement step S 22  described later are sequentially carried out, thereby placing the flat plate member  10  between the first die  11  and the second die  12  while the first main surface  10 C and the second main surface  10 D align with the vertical direction (are parallel with the vertical direction) as shown in  FIG. 3 . 
     First, the flat plate member  10  is placed so that second end  10 B is in contact with the mount surface  15 A, and the first main surface  10 C opposes the first opposing surface  11 A in a state where the first die  11  is placed on the mount surface  15 A so that the first opposing surface  11 A aligns with the vertical direction in the first placement step S 21  as shown in  FIG. 1 . Then, the second die  12  is placed on the support member  15  so that the bottom end is placed in the recess  15 B in the second placement step S 22  as shown in  FIG. 3 . As a result, a state where the second main surface  10 D is opposing the second opposing surface  12 A is brought about, and the flat plate member  10  is arranged between the first die  11  and the second die  12  in the state where the first main surface  10 C and the second main surface  10 D are aligned with the vertical direction. 
     Then, a step S 30  of pressing the flat plate member  10  is carried out. The press member  14  is moved down toward the support member  15  by operating the driving section  23  while the flat plate member  10  is arranged between the first die  11  and the second die  12  as shown in  FIG. 3  in the step S 30  (arrow in  FIG. 3 ). As a result, the first press portion  14 A approaches the second press portion  15 A, and comes in contact with the first end  10 A of the flat plate member  10 . Then, the flat plate member  10  is pressed by the first press portion  14 A and the second press portion  15 A from the both ends  10 A and  10 B in the direction parallel with the main surfaces  10 C and  10 D by further moving down the press member  14  as shown in  FIG. 4 . 
     The first press portion  14 A and the second press portion  15 A can be caused to approach each other in the vertical direction in this way, thereby pressing the flat plate member  10  in the vertical direction by the driving section  23  according to this embodiment. As a result, a fluid of the material is generated in the direction parallel with the main surfaces  10 C and  10 D in the softened flat plate member  10 , and a part of the material flows into the thickened portion-forming section  16 . As a result, a thickened portion, which is a thick portion, is formed on a first main surface  10 C side of the flat plate member  10 . 
     Moreover, the supporting member  13  moves down toward the support member  15  along with the press member  14  in the step S 30 , the flat plate member  10  can be pressed in a state where the first and second dies  11  and  12  are placed between the portions of the supporting member  13  as shown in  FIG. 4 . As a result, the first die  11  and the second die  12  can be prevented from falling down by an impact during the press. 
     Finally, a step S 40  of taking out the press-formed article is carried out. After the forming of the flat plate member  10  is completed in the step S 30 , the press member  14  is moved up by operating the driving section  23  in the step S 40 . Then, the second die  12  is removed from the support member  15 , and the press-formed article is removed from the first die  11 . The manufacturing method of press-formed article according to this embodiment is completed by the steps S 10  to S 40 . 
     Operations and Effects 
     A description is now given of features and operations/effects of the press forming apparatus  1  according to the embodiment. 
     The press forming apparatus  1  includes the first press portion  14 A, the second press portion  15 A, the first die  11  including the first opposing surface  11 A, the second die  12  including the second opposing surface  12 A, and the driving section  23  for causing the first press portion  14 A and the second press portion  15 A to approach each other. The thickened portion-forming section  16  for forming the thick portion on the flat plate member  10  is formed on the first opposing surface  11 A. The first die  11  and the second die  12  are respectively arranged so that the first opposing surface  11 A and the second opposing surface  12 A align with the vertical direction. The press forming apparatus  1  is configured so that a part of the material of the flat plate member  10  in the vertical direction flows into the thickened portion-forming section  16  by causing the first press portion  14 A and the second press portion  15 A to approach each other in the vertical direction, thereby pressing the flat plate member  10  in the vertical direction. 
     In the above-mentioned press forming apparatus  1 , the flat plate member  10  is pressed by the first press portion  14 A and the second press portion  15 A, and the thickened portion, which is the thick portion, is formed on the flat plate member  10  by causing a part of the material of the flat plate member  10  in the vertical direction to flow into the thickened portion-forming section  16 . Moreover, the first die  11  and the second die  12  are arranged in the vertically placed state where the first opposing surface  11 A and the second opposing surface  12 A align with the vertical direction, and the dies can thus be placed in a narrow space compared with the conventional case where the first opposing surface  11 A and the second opposing surface  12 A are arranged in the horizontally placed state so as to align with the horizontal direction, resulting in a saved space. Moreover, both the direction in which the first press portion  14 A and the second press portion  15 A approach each other, and the direction in which the flat plate member  10  is pressed are the same vertical direction. Thus, the driving force of the driving section  23  for causing the first press portion  14 A and the second press portion  15 A to approach each other is directly used as the force for pressing the flat plate member  10 , the conventional special die structure and the gimmick are thus no longer necessary, and the die structure can be simplified, thereby decreasing the cost. 
     The press forming apparatus  1  includes the support member  15  including the mount surface  15 A on which the first die  11  and the second die  12  are placed. The recess  15 B in which the bottom end of the second die  12  is positioned is formed on the mount surface  15 A. As a result, the second die  12  can easily be positioned by positioning the bottom end of the second die  12  in the recess  15 B as shown in  FIG. 3 . 
     The press forming apparatus  1  includes the supporting member  13  including the first and second supporting portions  18  and  19  positioned outside, in the horizontal direction, the first side surface  11 B and the second side surface  12 B. As a result, even if the first die  11  and the second die  12  are vertically placed, the first die  11  and the second die  12  can be prevented from falling down during the press forming. 
     The press forming apparatus  1  includes the press member  14  on which the first press portion  14 A is provided, and the press member  14  is integrally formed with the supporting member  13 . As a result, the structure of the press forming apparatus  1  can be more simplified compared with the case where the press member  14  and the supporting member  13  are constructed independently of each other. 
     Second Embodiment 
     A description is now given of a press forming apparatus  2  and a manufacturing method of press-formed article according to a second embodiment of the present invention. The press forming apparatus  2  according to the second embodiment basically has the same configuration as that of the press forming apparatus  1  according to the first embodiment, and provides the same effect, but is different in a point that the press forming apparatus  2  further includes temporarily supporting members  21  for supporting the flat plate member  10 . 
     The press forming apparatus  2  includes the pair of temporarily supporting members  21  each in a thin plate shape as shown in  FIGS. 5A and 5B . The temporarily supporting members  21  are attached outside, in the widthwise direction, an arrangement area (portion indicated by broken lines) of the second die  12  as illustrated in  FIG. 5B . It should be noted that a state before the temporarily supporting members  21  are attached to the support member  15  is shown in  FIG. 5A . 
     The temporarily supporting members  21  have an elongate shape extending from a bottom end to a top end, the top end is bent so as to depart from the flat plate member  10 , and the bottom end is fixed by a fixing tool  22  to a side wall surface  15 H on the first die  11  side of the recess  15 B. The temporarily supporting members  21  are in contact with the second main surface  10 D on both ends of the flat plate member  10 , thereby supporting the flat plate member  10  so that the state where the first main surface  10 C and the second main surface  10 D align with the vertical direction is maintained. 
     The flat plate member  10  is first arranged between the first die  11  and the temporarily supporting members  21  in the first placement step S 21  of the manufacturing method using the press forming apparatus  2 . On this occasion, the flat plate member  10  is supported by the contact of the second main surface  10 D with the temporarily supporting members  21 , and the first main surface  10 C and the second main surface  10 D are maintained in the state where the first main surface  10 C and the second main surface  10 D align with the vertical direction. In other words, the flat plate member  10  can be prevented from falling down by the temporarily supporting members  21 . The second die  12  is then arranged, and the flat plate member  10  is thus arranged between the first die  11  and the second die  12  as in the first embodiment. The flat plate member  10  can be stably supported by using the temporarily supporting members  21  so as not to fall down even before the flat plate member  10  is arranged between the first die  11  and the second die  12  in this way according to the second embodiment. 
     Third Embodiment 
     A description is now given of a press forming apparatus  3  and a manufacturing method of press-formed article according to a third embodiment of the present invention with reference to  FIGS. 6 to 8 . The press forming apparatus  3  according to the third embodiment has the same configuration as that of the press forming apparatus  1  according to the first embodiment, and provides the same effect, but is different in a point that thickened portion-forming sections  16  and  17  are respectively formed both on the first opposing surface  11 A and the second opposing surface  12 A. 
     The first thickened portion-forming section  16  is formed approximately at the center in the vertical direction on the first opposing surface  11 A, and the second thickened portion-forming section  17  is formed on the second opposing surface  12 A in the press forming apparatus  3  as shown in  FIGS. 6 to 8 . The first thickened portion-forming section  16  and the second thickened portion-forming section  17  have groove shapes in approximately the same size, and are formed at positions at approximately the same heights. It should be noted that the first thickened portion-forming section  16  and the second thickened portion-forming section  17  may have shapes different from each other, may be formed at heights different from each other, and can be appropriately designed depending on the shapes of a target press-formed article. 
     In the manufacturing method using the press forming apparatus  3 , a part of the material of the flat plate member  10  in the vertical direction can be caused to flow into both the first thickened portion-forming section  16  and the second thickened portion-forming section  17  by using the first press portion  14 A and the second press portion  15 A to press the flat plate member  10  as shown in  FIGS. 7 and 8 . As a result, the thickened portions, which are the thick portions, of the flat plate member  10  can be formed both on the first main surface  10 C and the second main surface  10 D of the flat plate member  10 . Manufacturing of a press-formed article in the complex shape in which the thickened portions are formed on both the main surfaces  10 C and  10 D can be handled by forming the thickened portion-forming sections  16  and  17  both on the first die  11  and the second die  12  in this way. It should be noted that the temporarily supporting members  21  according to the second embodiment may be used also in the third embodiment. 
     Other Embodiments 
     Finally, a description is given of other embodiments of the present invention. 
     In addition to the recess  15 B in which the bottom end of the second die  12  is placed, a recess  15 E in which the bottom end of the first die  11  is positioned may be formed so that the recesses  15 B and  15 E flank a wall portion  15 F on the mount surface  15 A of the support member  15  as illustrated in  FIG. 9 . As a result, the first die  11  as well as the second die  12  can be easily positioned. 
     Moreover, a recess  15 G wider than an area in which the bottom end of the first die  11  and the bottom end of the second die  12  are placed may be formed as shown in  FIG. 10 . In this case, the second end  10 B of the flat plate member  10  is in contact with a bottom wall surface of the recess  15 G. Moreover, the recess itself may be omitted on the mount surface  15 A. 
     Moreover, the supporting member and the press member  14  may be constructed individually in the press forming apparatuses  1  to  3 . A first supporting member  81  is arranged so as to be in contact with the first side surface  11 B of the first die  11 , and a second supporting member  82  is arranged so as to be in contact with the second side surface  12 B of the second die  12  in this case as shown in  FIG. 11 . Moreover, the press member  14  is directly fixed to the driving section  23 . It should be noted that the first supporting member  81  and the second supporting member  82  are connected with each other so as to be integrally formed, which is not shown in  FIG. 11 . Moreover, the supporting members  13 ,  81 , and  82  may be omitted. 
     The first thickened portion-forming section  16  may be omitted, and only the second thickened portion-forming section  17  may be formed in the press forming apparatus  3 . 
     The above-mentioned manufacturing method is not limited to the case where the entire flat plate member  10  is heated in the electric furnace, and multiple electrodes  101  may be arranged at an interval on the main surface of the flat plate member  10 , and temperature rising portion by heating  102  may be partially formed by supplying a current to the electrodes  101  as shown in  FIG. 12  (partial electric heating). Then, as shown in  FIG. 13 , the material in the temperature rising portion by heating  102  may be caused to flow into thickened portion-forming sections  95 , thereby forming the thickened portion by pressing in a direction (arrow in the diagram) parallel with the main surface in a state where the flat plate member  10  is arranged between dies  91  and  92 . If portions other than the temperature rising portion by heating  102  are not heated, and are maintained in a low temperature state in this way, the low temperature portions are not softened, and are maintained in a state where the strength is high, and a friction coefficient between the dies  91  and  92  and the flat plate member  10  can be reduced during the pressing. Moreover, the heating of the flat plate member  10  is not limited to partial electric heating, but the flat plate member  10  may be entirely heated by supplying a current through it.