JP2010201459A - Method for manufacturing metallic member having closed section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a metallic member having a closed section for manufacturing the partially reinforced metallic member having the closed section with high precision by a relatively simple method. <P>SOLUTION: A metallic plate-like workpiece W1 is press-formed in a projecting shape, and a projecting part projecting in the opposing direction is formed on a projecting top face part W2. The projecting part of the plate-like workpiece W1 is squeezed by press-forming the projecting part of the plate-like workpiece W1 in the projecting direction of the plate-like workpiece W1, and projecting side face parts W3, W4 are displaced inwardly respectively to form a closed section to manufacture the member of the closed section from the plate-like workpiece W1. A part in which at least any one of the thickness, the strength and the proof stress thereof is larger than that of other parts is formed on the projecting part of the plate workpiece W1. In the part in which at least any one of the thickness, the strength and the proof stress of the projecting part is larger than that of other parts of the projecting part, the squeezing amount when the projecting part is press-formed and squeezed is set to be larger than that of other parts of the projecting part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a metal closed cross-section member that manufactures a closed cross-section member formed in a closed cross-section shape from a metal plate-shaped material (plate-shaped workpiece).

  As is well known, body members such as pillar members that form part of the basic structure of a vehicle body in a vehicle such as an automobile, front and rear side frames, and a dash cross member that is located in the lower front portion of a dash panel include: From the viewpoint of securing strength and rigidity and improving safety, high strength and high rigidity are required, and weight reduction is required for improving fuel efficiency.

  In order to meet these demands, the vehicle body member as described above is often configured as a metal closed cross-section member. As a method of manufacturing such a metal closed cross-section member, for example, a cross-sectional hat shape in which a flange portion that projects a metal plate-like workpiece such as a steel plate to the outside at both ends of a U-shaped cross section by pressing is integrally formed In general, a method for manufacturing a closed cross-section member is generally known in which a flange portion of two plate-like workpieces formed in a cross-sectional hat shape is overlapped with each other to form a closed cross-section shape, and then the flange portion is welded. It has been.

  Further, for example, in Patent Document 1, a triangular tube as a closed cross-section member is manufactured, and a first bending step of bending the vicinity of both end portions of a steel plate cut into a predetermined shape in advance with a predetermined curvature, and a first bending A second bending step in which the central portion of the steel plate bent in the process is pushed and bent at a predetermined curvature, and the both ends are moved upward while pressing the central portion of the steel plate formed in the second bending step from the left and right in the longitudinal direction. A manufacturing method of a triangular tube having a constraining molding process of pressing and constraining and molding, and a welding process of welding the butted parts of both ends without unloading after the constraining molding process is disclosed. .

JP 2000-51932 A

  In recent years, in vehicles such as automobiles, further reduction in weight has been demanded in order to improve fuel efficiency, and further reduction in weight has also been demanded for body members that occupy a relatively large weight. For this reason, about the vehicle body member comprised as a metal closed cross-section member, manufacturing without providing a flange part is desired.

  Although Patent Document 1 describes a manufacturing method of a triangular tube formed in a closed cross-sectional shape without providing a flange portion, a vehicle body member used in a vehicle such as an automobile has a complicated shape, Since the cross-sectional shape can change in a complicated manner in the longitudinal direction, when the manufacturing method described in Patent Document 1 is applied, a plurality of plates having cutout portions having the same shape as the molded cross-section of the closed cross-section member are produced. It is necessary and can be difficult to apply to a body member used in a vehicle such as an automobile.

  Further, in vehicles such as automobiles, as described above, there is a demand for higher strength and higher rigidity as well as lighter weight. For vehicle body members configured as metal closed cross-section members, it is possible to effectively increase strength and rigidity while reducing weight by reinforcing only those parts that require higher strength and higher rigidity. However, in such a case, since it becomes difficult to form the partially reinforced portion, it is difficult to accurately manufacture the metal closed cross-section member.

  Accordingly, the present invention has been made in view of the above technical problem, and a metal closed cross-section member capable of accurately manufacturing a partially closed metal closed cross-section member by a relatively simple method. It aims at providing the manufacturing method of.

  For this reason, in the manufacturing method of the metal closed cross-section member according to claim 1 of the present application, the metal plate-like workpiece is sandwiched between the blank holder and the die of the first mold, By relatively moving the punch into the forming space of the die, the plate-like workpiece is protruded in the moving direction of the punch with respect to the die and press-formed into a convex shape, and the convex shape of the plate-like workpiece is formed. A first press molding step of molding a convex portion protruding in a direction opposite to the convex direction of the plate-like workpiece on the convex top surface portion to be molded, and the press-molded plate-like workpiece as a second By press-molding the convex part of the press-molded plate-shaped workpiece in a direction protruding into the convex shape of the plate-shaped workpiece by the core mold of the second mold, while being held by the die of the molding die Crushing the convex part of the plate-like workpiece Forming a press molding surface and displacing the convex side surface portions on both sides of the convex top surface portion of the plate-shaped workpiece formed in the first press molding step inwardly to form a closed cross section. And a press forming step of manufacturing a closed cross-section member formed in a closed cross-section shape from a metal plate-shaped workpiece, wherein the projecting portion of the plate-shaped workpiece is A portion where at least one of the plate thickness, strength and proof stress is larger than the other portion of the convex portion, and in the second press molding step, at least one of the plate thickness, strength and proof strength of the convex portion is provided. However, the portion larger than the other portion of the convex portion is characterized in that the crushing amount by which the convex portion is pressed and crushed is set larger than the other portion of the convex portion. .

  Further, the invention according to claim 2 of the present application is the invention according to claim 1, wherein at least one of the thickness, strength, and proof stress of the convex portion is larger than the other portion of the convex portion, the closed portion is closed. The reinforcing member for reinforcing the cross-sectional member is a portion that is firmly attached so as to cover the convex portion.

  Furthermore, the invention according to claim 3 of the present application is the invention according to claim 2, wherein the reinforcing member has a joint portion with the plate-like workpiece, and the plate-like workpiece is press-molded in the first press-molding step. It is characterized in that it is fixedly attached so as to be provided in a portion excluding the bent ridge line portion of the plate-like workpiece that is bent when being done.

  Still further, the invention according to claim 4 of the present application is the invention according to claim 2 or 3, wherein the reinforcing member is the convex side surface of the plate-like workpiece that is closed in the second press molding step. It is characterized by being fixedly attached so that it may be provided along the said plate-shaped workpiece | work to the edge part on the opposite side to the said convex top surface part side of a part.

  Still further, the invention according to claim 5 of the present application is the invention according to claim 1, wherein the plate-like workpiece has a first plate material and at least one of plate thickness, strength, and proof stress is greater than that of the first plate material. Is a tailored blank that is welded to a second plate material that is larger than the other portion of the convex portion, and the thickness, strength, and proof strength of the convex portion are larger than those of the other portions of the convex portion. It is characterized by comprising.

  Still further, the invention according to claim 6 of the present application is the invention according to any one of claims 1 to 5, wherein, in the first press molding step, the convex portion is continuous in a longitudinal direction of the plate-like workpiece. A portion in which at least one of the thickness, strength and proof stress of the convex portion is larger than the other portion of the convex portion is formed such that the height of the convex portion is higher than the other portion of the convex portion. In the second press molding step, at least one of the thickness, strength, and proof stress of the convex portion is larger than the other portion of the convex portion, and the other portion of the convex portion is substantially in the same position. The portion where the thickness, strength and proof stress of the convex portion is greater than the other portion of the convex portion is such that the amount of crushing by which the convex portion is pressed and crushed is the convex portion. It is characterized by being set larger than other parts Those were.

  Furthermore, the invention according to claim 7 of the present application is press-molded between the first press-molding process and the second press-molding process in the invention according to any one of claims 1 to 6. The method further comprises a bending step of bending the end of the convex side surface portion of the plate-shaped workpiece opposite to the convex top surface portion side toward the inner side of the plate-shaped workpiece. It is.

  Furthermore, the invention according to claim 8 of the present application is the invention according to any one of claims 1 to 7, wherein the plate-shaped workpiece that has been press-molded is closed in cross section after the second press-molding step. In addition, the method further comprises a press-molding step in which the end portions of the convex side surface portions are pressed against a surface portion opposite to a surface portion that presses the convex portion of the core mold to determine and mold. It is a thing.

  Furthermore, the invention according to claim 9 of the present application is the invention according to any one of claims 1 to 8, wherein after the second press molding step, the press-molded plate-like workpiece is closed. The method further comprises a welding step of welding ends of the convex side portions.

  According to the method for manufacturing a metal closed cross-section member according to claim 1 of the present application, the plate-like workpiece is press-formed into a convex shape and protrudes in the direction opposite to the direction in which the convex shape of the plate-like workpiece protrudes on the convex top surface portion. The first press molding step for forming the convex part to be pressed, and the convex part of the plate-like work is crushed by press-molding the convex part of the plate-like work in a direction projecting into the convex shape of the plate-like work. And a second press molding step in which each of the convex side portions is displaced inward to make a closed cross section, and in the second press molding step, at least the plate thickness, strength and proof stress of the convex portion are included. A part that is larger than the other part of the convex part is set so that the amount of crushing by pressing and crushing the convex part is set larger than the other part of the convex part. Without complicating the board in a relatively simple way Is the intensity and at least one is partly greater yield strength, partially reinforced metal closed-section member can be accurately produced.

  According to the invention of claim 2 of the present application, a portion in which at least one of the plate thickness, strength and proof stress of the convex portion is larger than the other portion of the convex portion is a reinforcing member for reinforcing the closed cross-section member When the metal closed cross-section member partially reinforced by the reinforcing member for reinforcing the closed cross-section member is manufactured, the above effect is effectively obtained. Can play.

  Furthermore, according to the invention according to claim 3 of the present application, the reinforcing member is a portion excluding the bent ridge line portion of the plate-like workpiece that is bent when the plate-like workpiece is press-molded. When the plate-like workpiece is press-molded, the plate-like workpiece can be prevented from cracking from the joint portion between the reinforcing member and the plate-like workpiece.

  Furthermore, according to the invention according to claim 4 of the present application, the reinforcing member is an end opposite to the convex top surface side of the convex side surface portion of the plate-like workpiece to be closed in the second press molding step. Even in the case of manufacturing a metal closed cross-section member provided with a reinforcing member so as to suppress the collapse of the cross-section of the closed cross-section member by being firmly contacted so as to be provided along the plate-like workpiece to the portion, An effect can be produced effectively.

  Still further, according to the invention according to claim 5 of the present application, the plate-shaped workpiece includes the first plate material and the second plate material in which at least one of the plate thickness, strength, and proof stress is larger than that of the first plate material. The tailored blank is a welded tailored blank, and at least one of the thickness, strength, and proof strength of the convex part is larger than the other part of the convex part. In the case of manufacturing a reinforced metal closed cross-section member, the above effect can be effectively achieved.

  Furthermore, according to the invention according to claim 6 of the present application, in the first press molding step, the convex portions are continuously provided in the longitudinal direction of the plate-like workpiece, and the plate thickness, strength, and proof stress of the convex portions are increased. At least one part larger than the other part of the convex part is formed so that the height of the convex part is higher than the other part of the convex part, and in the second press molding process, the plate thickness, strength and proof strength of the convex part A portion corresponding to the convex portion of the plate-like workpiece of the closed cross-section member is formed by press-molding a portion where at least one of the convex portion is larger than the other portion of the convex portion and the other portion of the convex portion to substantially the same position. It can be manufactured by flattening, and the effect can be more effectively exhibited.

  Still further, according to the invention according to claim 7 of the present application, the convex top surface side of the convex side surface portion of the plate-shaped workpiece press-molded between the first press molding step and the second press molding step. When the plate-shaped workpiece is made to have a closed cross-section, the convex shape of the press-molded plate-shaped workpiece is further provided with a bending process of bending the end opposite to the inner side of the plate-shaped workpiece. A metal closed cross-section member can be manufactured with higher accuracy by reducing the inward displacement of the side surface portion.

  Still further, according to the invention according to claim 8 of the present application, after the second press molding step, the end portions of the convex side surface portions of the press-formed plate-like workpiece having a closed cross section are formed into a core mold. Is further provided with a pressing process that presses and presses the convex part against the surface part opposite to the surface part to be pressed. Molding accuracy can be obtained.

  Still further, according to the invention according to claim 9 of the present application, a welding step of welding the ends of the convex side portions having a closed cross-section of the press-formed plate-like workpiece after the second press-forming step. Further, the bonding strength of the closed cross-section member can be increased, and a stronger closed cross-section member can be manufactured.

It is a side view showing typically the body structure of a car provided with the metal closed section member concerning this embodiment. It is a perspective view showing the front side frame as a metal closed section member concerning this embodiment. FIG. 3 is a cross-sectional view of the front side frame taken along a line Y3a-Y3a, a line Y3b-Y3b, and a line Y3c-Y3c in FIG. It is a figure which shows the plate-shaped workpiece | work for manufacturing a front side frame. It is a perspective view which shows the draw shaping | molding die of the draw shaping | molding apparatus for draw-molding a plate-shaped workpiece. FIG. 6 is a cross-sectional view of a draw mold along line Y6-Y6 in FIG. It is explanatory drawing for demonstrating a draw molding process. It is a perspective view which shows the plate-shaped workpiece shape | molded by drawing. It is sectional drawing which shows the plate-shaped workpiece shape | molded by drawing along the Y9-Y9 line | wire in FIG. It is sectional drawing which shows the bending mold of the bending apparatus for bending and forming the edge part of the convex side part of the plate-shaped workpiece shape | molded by drawing. It is explanatory drawing for demonstrating a bending process. It is explanatory drawing for demonstrating a bending process. It is explanatory drawing for demonstrating a press molding process. It is a principal part enlarged view which expands and shows the A section of Fig.13 (a). It is explanatory drawing for demonstrating a press molding process about the cross section corresponding to the cross section shown in FIG.3 (c) of a front side frame. It is explanatory drawing for demonstrating a press molding process about the cross section corresponding to the cross section shown in FIG.3 (b) of a front side frame. It is explanatory drawing for demonstrating a final pressing molding process. It is explanatory drawing for demonstrating the method to manufacture the front side frame as another metal closed cross-section member which concerns on this embodiment. It is explanatory drawing for demonstrating the method to manufacture another metal closed cross-section member which concerns on this embodiment. FIG. 20 is a cross-sectional view showing a state where the plate-like workpiece shown in FIG. 19 is held by a die of a press mold.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, terms indicating a specific direction and position (for example, “up”, “down”, “right”, “left” and other terms including those terms) are used as necessary. These terms are used for easy understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms.

  FIG. 1 is a side view schematically showing a vehicle body structure of an automobile provided with a metal closed cross-section member according to the present embodiment. As shown in FIG. 1, the manufacturing method of the metal closed cross-section member according to the present embodiment forms the front side frame 20 coupled to the side body 10 of the automobile with a metal plate-like workpiece in a closed cross-sectional shape. However, the present invention is not limited to this, and may be applied to the manufacture of other vehicle body members such as the rear side frame 30 coupled to the side body 10. Furthermore, the present invention is not limited to the vehicle body member, and can be applied to the manufacture of other metal closed cross-sectional members formed in a closed cross-sectional shape.

  FIG. 2 is a perspective view showing a front side frame as a metal closed section member according to the present embodiment. 3 is a cross-sectional view of the front side frame taken along the lines Y3a-Y3a, Y3b-Y3b, and Y3c-Y3c in FIG. 2, and FIG. 3 (a), FIG. 3 (b), and FIG. 3 (c) is a cross-sectional view of the front side frame taken along lines Y3a-Y3a, Y3b-Y3b, and Y3c-Y3c in FIG.

  As shown in FIG. 2, the front side frame 20 as a metal closed section member according to the present embodiment is configured as a closed section member that extends in the longitudinal direction and is formed in a closed section shape, The lower surface portion 22, the right side surface portion 23, the left side surface portion 24, the first inclined side surface portion 25 that is inclined obliquely downward to the right from the upper surface portion 21 toward the right side surface portion 23, and the upper surface portion 21 toward the left side surface portion 24. A second inclined side surface portion 26 inclined obliquely downward to the left, a third inclined side surface portion 27 inclined obliquely upward and rightward from the lower surface portion 22 toward the right side surface portion 23, and from the lower surface portion 22 toward the left side surface portion 24. Thus, the fourth inclined side surface portion 28 inclined obliquely upward to the left is formed into an octagonal cross section having a hollow portion 29.

  In the front side frame 20, the upper surface portion 21 and the lower surface portion 22 are formed in parallel along the longitudinal direction and the cross-sectional length in the short side direction is formed substantially the same, but as shown in FIG. The cross-sectional shape is changed in the longitudinal direction. In the cross section shown in FIG. 3A, the front side frame 20 includes a left side surface portion 24, a first inclined side surface portion 25, and a third inclined side surface portion 27, the left side surface portion 24 in the cross section shown in FIG. The right inclined surface portion 23, the second inclined side surface portion 26, and the fourth inclined surface are formed so as to have shorter cross-sectional lengths than the first inclined side surface portion 25 and the third inclined side surface portion 27. The side surface portion 28 is formed to have a cross-sectional length longer than the cross-sectional lengths of the right side surface portion 23, the second inclined side surface portion 26, and the fourth inclined side surface portion 28 in the cross section shown in FIG. ing. In addition, the inclination angle of the third inclined side surface portion 27 with respect to the lower surface portion 22 and the inclination angle of the fourth inclined side surface portion 28 with respect to the lower surface portion 22 are each formed at a substantially constant predetermined angle in the longitudinal direction. The front side frame 20 is also formed with a plurality of beads 31 that are recessed inward of the hollow portion 29 in the right side surface portion 23 and the first inclined side surface portion 25.

  In the present embodiment, the front side frame 20 as a metal closed cross-section member is also made of a metal for partially reinforcing the plate thickness of the front side frame 20 as shown in FIG. A reinforcing member 35 is fixedly attached to the inner surface. As shown in FIGS. 2 and 3C, the reinforcing member 35 is formed in a substantially flat plate shape, and is formed from a substantially central portion of the lower surface portion 22 of the front side frame 20 in a part in the longitudinal direction of the front side frame 20. 3 is provided along the front side frame 20 across the three inclined side surface portions 27 and the right side surface portion 23. As shown in FIG. 3 (c), the inner surface shape of the portion of the lower surface portion 22 and the third inclined side surface portion 27 of the front side frame 20 to which the reinforcing member 35 is attached substantially matches the longitudinal direction of the front side frame 20. In this manner, the front side frame 20 is formed so as to protrude outward.

  As described above, the reinforcing member 35 is fixedly attached to the front side frame 20, whereby the front side frame 20 can be partially reinforced, and the front side frame 20 can be reduced in weight while reducing the weight of the front side frame 20. Strength and rigidity can be partially increased.

Next, a method for manufacturing the front side frame 20 as a metal closed cross-section member according to this embodiment configured as described above will be described.
In the present embodiment, when the front side frame 20 is manufactured, first, a metal plate material (plate work) formed in a substantially flat plate shape such as a steel plate is prepared, and the front side frame is provided on the plate work. A reinforcing member for reinforcing 20 is fixed and joined.

  4A and 4B are diagrams showing a plate-like workpiece for manufacturing the front side frame. FIG. 4A is a top view of the plate-like workpiece, and FIG. 4B is a diagram in FIG. It is sectional drawing of the plate-shaped workpiece | work along the Y4b-Y4b line. 4A and 4B show a state in which the reinforcing member is fixed and joined to the plate-like workpiece.

  As shown in FIGS. 4A and 4B, a metal reinforcing member R1 formed in a substantially flat plate shape such as a steel plate is applied to the plate-like workpiece W1 using a joining method such as laser welding. It is fixedly joined and attached to the plate-like workpiece W1 corresponding to the portion of the front side frame 20 to be reinforced. The reinforcing member R1 is partly joined to the plate-like workpiece W1, and the joined portion with the plate-like workpiece W1 excludes the bent ridge line portion of the plate-like workpiece W1 that is bent when the plate-like workpiece W1 is press-molded. Provided in the part. Note that the reinforcing member R1 and the plate-like workpiece W1 may be fixed and joined by welding the entire circumference of the reinforcing member R1 to the plate-like workpiece W1.

  In the present embodiment, the reinforcing member R1 is firmly attached to the plate-like workpiece W1 in this way, and the plate-like workpiece W1 is press-molded into a convex shape in a state where the plate thickness of the plate-like workpiece W1 is partially increased. Specifically, it is formed by drawing (drawing) and is formed into a predetermined shape corresponding to the shape of the front side frame 20.

  FIG. 5 is a perspective view showing a draw forming die of a draw forming apparatus for drawing a plate-like workpiece, and FIG. 6 is a cross-sectional view of the draw forming die taken along line Y6-Y6 in FIG. In FIG. 5, only the lower surface of the draw mold die is shown, and only the upper surface of the draw mold blank holder is shown.

  As shown in FIGS. 5 and 6, a draw forming die (first forming die) 40 used in a draw forming apparatus for drawing a plate-like workpiece W1 is a blank holder 41 for holding the plate-like workpiece W1. The punch 42 is configured so that the outer peripheral surface portion 42 a is fitted to the inner peripheral surface portion 41 a of the blank holder 41 and is movable in the vertical direction with respect to the blank holder 41, and is disposed to face the blank holder 41 and the punch 42. And a die 45 configured to be movable in the vertical direction.

  The die 45 of the draw mold 40 is provided with a concave portion 45b that is recessed in the lower surface 45a, and a molding space 45c for drawing the plate-like workpiece W1 to which the reinforcing member R1 is attached is provided in the concave portion 45b. Is formed. The recess 45b provided on the die 45 of the draw mold 40 is formed in a predetermined shape according to the shape of the front side frame 20, and as shown in FIG. A first inclined wall portion 45e inclined obliquely downward to the right from 45d, a first right vertical wall portion 45f extending downward in the vertical direction from the first inclined wall portion 45e, and horizontal from the first right vertical wall portion 45f A right horizontal portion 45g extending rightward in the direction, a second right vertical wall portion 45h extending substantially downward in the vertical direction from the right horizontal portion 45g, a second inclined wall portion 45i inclined obliquely downward to the left from the bottom surface portion 45d, A first left vertical wall portion 45j extending vertically downward from the second inclined wall portion 45i, a left horizontal portion 45k extending leftward in the horizontal direction from the first left vertical wall portion 45j, and substantially vertical from the left horizontal portion 45k. Second left vertical wall 4 extending downward in the direction And a l. Further, the bottom surface portion 45d of the concave portion 45b provided in the die 45 is provided with a convex portion 45m that protrudes in a circular arc shape from the bottom surface portion 45d toward the inner side of the molding space 45c. As shown in FIG. 5, the bottom surface 45d is provided continuously in the longitudinal direction.

  On the other hand, the punch 42 of the draw mold 40 is formed in a predetermined shape according to the shape of the front side frame 20 in order to form the plate-like workpiece W1 with the die 45 of the draw mold 40, as shown in FIG. As shown, the head of the punch 42 includes an upper surface portion 42d formed in a substantially planar shape, a first inclined wall portion 42e inclined obliquely downward to the right from the upper surface portion 42d, and a first inclined wall portion 42e. A right vertical wall portion 42f extending downward in the vertical direction, a right horizontal portion 42g extending rightward in the horizontal direction from the right vertical wall portion 42f, a second inclined wall portion 42i inclined obliquely downward to the left from the upper surface portion 42d, and a second The left vertical wall portion 42j extending vertically downward from the inclined wall portion 42i and the left horizontal portion 42k extending leftward in the horizontal direction from the left vertical wall portion 42j are provided. The upper surface portion 42d of the punch 42 is provided with a concave portion 42m that is recessed from the upper surface portion 42d in a circular arc shape, and the concave portion 42m is provided continuously in the longitudinal direction on the upper surface portion 42d.

  The punch 42 of the draw mold 40 is also formed with a groove 42n for press-molding the reinforcing member R1 corresponding to the reinforcing member R1 attached to the plate-like workpiece W1. According to the shape of the reinforcing member R1, the groove 42n is formed on the reinforcing member R1 from the substantially central portion of the concave portion 42m provided in the upper surface portion 42d of the punch 42 to the second inclined wall portion 42i as shown in FIG. It is formed to be recessed substantially equal to the thickness.

  In the draw forming apparatus including the draw forming die 40 configured as described above, the punch 42 is moved into the forming space 45c of the die 45 in a state where the plate-like workpiece W1 is sandwiched between the blank holder 41 and the die 45. By drawing the plate-like workpiece W1, the plate-like workpiece W1 is press-molded into a predetermined shape according to the shape of the front side frame 20. Note that the die 45 of the draw mold 40 protrudes toward the inner side of the molding space 45c on the second inclined wall portion 45i and the first left vertical wall portion 45j of the recess 45b according to the shape of the bead 31. A bead forming protrusion (not shown) is formed, and the punch 42 of the draw mold 40 has a bead that is recessed in the second inclined wall portion 42 i and the left vertical wall portion 42 j in accordance with the shape of the bead 31. A forming groove (not shown) is formed.

  When the plate-like workpiece W1 is drawn using the draw mold 40, as shown in FIG. 6, the blank holder 41 and the die 45 are spaced apart from each other, and the upper surface portion 42d of the punch 42 is used as the blank holder 41. The plate-like workpiece W <b> 1 is held on the upper surface 41 b of the blank holder 41 in a state of being disposed below the upper surface 41 b of the blank holder 41. Then, the die 45 of the draw mold 40 is moved downward, the both ends in the short direction of the plate-like workpiece W1 are sandwiched by the blank holder 41 and the die 45, and then the punch 42 is moved upward, and the punch 42 Moves into the forming space 45c of the die 45, and the plate-like workpiece W1 is drawn.

  FIG. 7 is an explanatory diagram for explaining the draw forming process. FIG. 7A shows a plate-shaped workpiece in which a punch is moved upward after the plate-shaped workpiece is sandwiched between a blank holder and a die. FIG. 7B shows a state where the punch is further moved upward and the plate-like workpiece is further drawn. FIG. 7 shows a cross section that does not include the reinforcing member R1 attached to the plate-like workpiece W1 and the groove 42n provided in the punch 42 for forming the reinforcing member R1.

  As shown in FIG. 7A, the upper surface of the punch 42 is moved by moving the punch 42 into the molding space 45 c of the die 45 in a state where the plate-like workpiece W <b> 1 is sandwiched between the blank holder 41 and the die 45. The plate-like workpiece W1 is drawn into a trapezoidal cross section by 42d. When the punch 42 is further moved upward, as shown in FIG. 7B, the plate-like workpiece W1 is further drawn, and the plate-like workpiece W1 is formed into a predetermined shape by the punch 42 and the die 45. FIG. 7 shows a cross section that does not include the reinforcing member R1 attached to the plate-like workpiece W1 and the groove portion 42n provided in the punch 42 for forming the reinforcing member R1. When the press molding is performed by the die 42 and the die 45, the reinforcing member R1 attached to the plate-like workpiece W1 is also molded into a predetermined shape by the punch 42 and the die 45.

  FIG. 8 is a perspective view showing a draw-formed plate-like workpiece, and FIG. 9 is a cross-sectional view showing the draw-formed plate-like workpiece along line Y9-Y9 in FIG. As shown in FIGS. 8 and 9, the draw-formed plate-like workpiece W <b> 1 is a central portion in the short-side direction excluding both ends in the short-side direction of the plate-like workpiece W <b> 1 sandwiched between the blank holder 41 and the die 45. Is protruded in the moving direction of the punch 42 with respect to the die 45 and is press-formed into a convex shape, and has a convex top surface portion W2 and convex side surface portions W3 and W4 formed on both sides of the convex top surface portion W2. ing.

  The draw-formed plate-like workpiece W1 has a convex top surface portion W2 formed by the bottom surface portion 45d of the concave portion 45b provided on the die 45 and the top surface portion 42d of the punch 42, and the convex top surface portion W2 has a bottom surface portion 45d. Convex portions W2a projecting in a circular arc shape in a direction opposite to the projecting shape of the plate-like workpiece W1 by the convex portions 45m provided on the upper surface portion 42d and the concave portions 42m provided on the upper surface portion 42d continuously in the longitudinal direction. Is provided. Further, as shown in FIG. 8, the convex top surface portion W2 includes a right convex top surface portion W2b located on the right side of the convex portion W2a and a left convex top surface portion W2c located on the left side of the convex portion W2a. The sections W2b and W2c divided by the convex portion W2a of the convex top surface portion W2 are shaped so that the cross-sectional length in the short direction changes in the longitudinal direction.

  On the right side of the convex top surface portion W2, the first inclined wall portion 45e, the first right vertical wall portion 45f, the right horizontal portion 45g and the second right vertical wall portion 45h of the recess 45b provided in the die 45 are punched. A convex side surface portion W3 is formed by the first inclined wall portion 42e, the right vertical wall portion 42f, the right horizontal portion 42g, and the outer peripheral surface portion 42a of the 42, and the convex side surface portion W3 is a first inclined wall of the concave portion 45b. A convex top surface portion W2, which is formed by the portion 45e and the first inclined wall portion 42e of the punch 42, specifically, a first right convex side surface portion W3a which is inclined obliquely downward to the right from the right convex top surface portion W2b. A second right convex side surface portion W3b formed by the first right vertical wall portion 45f of the recess 45b and the right vertical wall portion 42f of the punch 42 and extending vertically downward from the first right convex side surface portion W3a; The right horizontal portion 45g of the recess 45b and the right horizontal portion 42g of the punch 42 Molded by the third right convex side surface portion W3c that is molded and extends rightward in the horizontal direction from the second right convex side surface portion W3b, the second right vertical wall portion 45h of the concave portion 45b, and the outer peripheral surface portion 42a of the punch 42. And a fourth right convex side surface portion W3d extending substantially downward in the vertical direction from the third right convex side surface portion W3c.

  On the other hand, on the left side of the convex top surface portion W2, the second inclined wall portion 45i, the first left vertical wall portion 45j, the left horizontal portion 45k, and the second left vertical wall portion 45l of the concave portion 45b provided in the die 45 are provided. And the second inclined wall portion 42i, the left vertical wall portion 42j, the left horizontal portion 42k and the outer peripheral surface portion 42a of the punch 42 form a convex side surface portion W4, and the convex side surface portion W4 is a second portion of the concave portion 45b. A convex left surface portion W2 formed by the inclined wall portion 45i and the second inclined wall portion 42i of the punch 42, specifically, a first left convex side surface portion inclined obliquely downward and leftward from the left convex top surface portion W2c. A second left convex side surface portion formed by W4a, the first left vertical wall portion 45j of the recess 45b and the left vertical wall portion 42j of the punch 42 and extending vertically downward from the first left convex side surface portion W4a. W4b, left horizontal portion 45k of the recess 45b and left horizontal portion 42k of the punch 42 Formed by the third left convex side surface portion W4c extending from the second left convex side surface portion W4b to the left in the horizontal direction, the second left vertical wall portion 45l of the concave portion 45b, and the outer peripheral surface portion 42a of the punch 42. And a fourth left convex side surface portion W4d extending substantially downward in the vertical direction from the third left convex side surface portion W4c.

  In the present embodiment, the reinforcing member R1 attached to the plate-like workpiece W1 is also press-molded simultaneously with the plate-like workpiece W1, and the reinforcing member R1 press-molded by the groove 42n of the punch 42 is the convex portion of the plate-like workpiece W1. A portion R2 formed in a circular arc shape with a quarter cross section along W2a and covering the convex portion W2a of the plate-like workpiece W1, a portion R3 molded along the left convex top surface portion W2c of the plate-like workpiece W1, and 1 and a portion R4 formed along the left convex side surface portion W4a. The convex part of the plate-like workpiece W1 is provided with a part (a part where W2a is covered by the reinforcing member R1) having a larger plate thickness than the other part of the convex part (the part having only the convex part W2a) by the reinforcing member R1. . As described above, the reinforcing member R1 has a bent ridge line portion of the plate-like workpiece W1 that is bent when the plate-like workpiece W1 is press-molded, that is, the convex portion W2a and the left convex portion. The plate-like workpiece W1 is fixedly contacted so as to be provided in a portion excluding the bent ridge line portion with the top surface portion W2c and the bent ridge line portion between the left convex top surface portion W2c and the first left convex side surface portion W4a. Yes. Thereby, when the plate-like workpiece W1 is press-molded, the plate-like workpiece W1 can be prevented from cracking from the joint portion between the reinforcing member R1 and the plate-like workpiece W1.

  Further, the draw-formed plate-like workpiece W1 has a second inclined wall portion 45i and a second inclined portion of the punch 42 formed on the first left vertical wall portion 45j and the second inclined portion of the punch 42. The bead forming groove formed on the wall 42i and the left vertical wall 42j forms a bead W4f on the convex side surface W4, specifically, the first and second left convex side surfaces W4a and W4b. Is done.

  The convex portion W2a, the right convex top surface portion W2b, and the left convex top surface portion W2c provided on the convex top surface portion W2, respectively, are the lower surface portion 22, the fourth inclined side surface portion 28, and the third inclined side surface of the front side frame 20. The first right convex side surface portion W3a of the convex side surface portion W3 is molded according to the shape of the left side surface portion 24 of the front side frame 20, and the second side surface of the convex side surface portion W3 is molded. The right convex side surface portion W3b is formed according to the shape of the second inclined side surface portion 26 and the upper surface portion 21 of the front side frame 20, and the first left convex side surface portion W4a of the convex side surface portion W4 is the front side. It is molded according to the shape of the right side surface portion 23 of the frame 20, and the second left convex side surface portion W 4 b of the convex side surface portion W 4 is according to the shapes of the first inclined side surface portion 25 and the upper surface portion 21 of the front side frame 20. Molded

  In the present embodiment, when the plate-like workpiece W1 is draw-molded, as shown in FIG. 7, the both ends of the plate-like workpiece W1 in the short direction are drawn with the blank holder 41 and the die 45 sandwiched therebetween. By doing so, wrinkles are prevented from occurring in the draw-formed plate-like workpiece W1.

  The punch 42 of the first mold 40 is moved into the molding space 45c of the die 45 in a state where the metal plate-like workpiece W1 is sandwiched between the blank holder 41 of the first mold 40 and the die 45. Although the plate-like workpiece W1 is press-molded, the blank holder 41 holding the plate-like workpiece W1 and the die 45 are moved relative to the punch 42 in a state where the punch 42 is fixed. You may do it.

  After the plate-like workpiece W1 to which the reinforcing member R1 is attached is drawn by the draw-forming device having the draw-molding die 40, the draw-formed plate-like workpiece W1 is shown in FIG. 9 by blanking means (not shown). The portion located below the blanking line L1 is blanked, and both ends W5 in the short direction of the plate-like workpiece W1 sandwiched between the blank holder 41 and the die 45, the third right convex side surface portion W3c, The fourth right convex side surface portion W3d, the third left convex side surface portion W4c, and the fourth left convex side surface portion W4d are cut off.

  Next, the plate-like workpiece W1 is an end portion of the convex side surface portions W3 and W4, specifically, the convex top surface portion W2 of the second right convex side surface portion W3b of the convex side surface portion W3 shown in FIG. The end W3e opposite to the side and the end W4e opposite to the convex top surface W2 side of the second left convex side surface W4b of the convex side surface W4 are bent inward. FIG. 10 is a cross-sectional view showing a bending mold of a bending apparatus for bending an end portion of a convex side surface portion of a draw-formed plate-like workpiece.

  As shown in FIG. 10, a bending mold 50 used in a bending apparatus for bending the end portions W3e and W4e of the convex side portions W3 and W4 of the plate-like workpiece W1 is a draw-formed plate-like workpiece W1. A first die 51 for holding the second die 52, a second die 52 fitted to the outer peripheral surface 51 a of the first die 51, a third die 53 for supporting the second die 52, A fourth die 54 disposed below the die 51 and a punch 55 disposed to face the first die 51 and configured to be movable in the vertical direction are provided.

  The first die 51 of the bending mold 50 is urged upward by urging means (not shown) and is arranged in a state of being separated from the fourth die 54. As shown in FIG. 10, the upper surface 51b of the first die 51 has a right side portion of the convex side surface portion W4 of the plate-shaped workpiece W1 formed by drawing, specifically, the second left convex side surface portion W4b. In order to bend the end W4e, the plate-like workpiece W1 is formed by drawing in a state where the end W4e to be bent of the second left convex side surface W4b is positioned above the second die 52. Are formed according to the shape of the convex top surface portion W2 and the convex side surface portion W4. Further, the left side portion of the upper surface 51b of the first die 51 is formed by bending the convex side surface portion W3 of the draw-formed plate-like workpiece W1, specifically, the end portion W3e of the second right convex side surface portion W3b. Therefore, the second right convex side surface portion W3b is bent so that the end portion W3e to be bent is positioned above the second die 52 so as to hold the draw-formed plate-like workpiece W1. It is formed according to the shape of the shape top surface portion W2 and the convex side surface portion W3.

  On the other hand, the punch 55 of the bending die 50 includes a right punch 55a for pressing the draw-formed plate-like workpiece W1 held on the right portion of the upper surface 51b of the first die 51, and the first die 51. And a left punch 55b for pressing the plate-like workpiece W1 held on the left portion of the upper surface 51b.

  It should be noted that the punch 55 of the bending mold 50 has a thickness approximately equal to the thickness of the reinforcing member R1 in accordance with the shape of the reinforcing member R1 below the right punch 55a in order to press the reinforcing member R1 attached to the plate-like workpiece W1. Although a groove portion that is equally depressed is formed, in FIG. 10 and FIGS. 11 and 12 described later, the reinforcing member R1 attached to the plate-like workpiece W1 and the groove portion formed below the punch 55 are not provided. A cross section is shown.

  When using the bending mold 50 to bend and form the end portions W3e and W4e of the convex side portions W3 and W4 of the plate-like workpiece W1, the first die 51 is biased as shown in FIG. In a state of being biased upward by the means, the draw-formed plate-like workpiece W1 is held on the right side portion of the upper surface 51b of the first die 51 with the first left convex side surface portion W4a on the lower side. . Then, the punch 55 of the bending mold 50 is moved downward, and bending is performed by the punch 55 and the second die 52.

  11 and 12 are explanatory views for explaining a bending process, in which FIG. 11 shows a state in which the punch is lowered and the punch and the plate-shaped workpiece formed by drawing are in contact with each other. The punch is further lowered so that the first die and the fourth die are in contact with each other, and the end of the convex side surface portion of the draw-formed plate-like workpiece is bent.

  As shown in FIG. 11, when the punch 55 is lowered while the plate-like workpiece W1 is held on the upper surface 51b of the first die 51, the right punch 55a of the punch 55 comes into contact with the plate-like workpiece W1. . When the punch 55 is further moved downward from this state, the right punch 55a and the second die 52 of the punch 55 are sandwiched between the right workpiece 55a of the punch 55 and the first die 51. Thus, the end W4e of the second right convex side surface portion W4b of the convex side surface portion W4 is bent inward, and the first die 51 contacts the fourth die 54 as shown in FIG. Then, the downward movement of the punch 55 is stopped, and the bending is finished. In the portion where the reinforcing member R1 is attached to the plate-like workpiece W1, the reinforcing member R1 comes into contact with the groove provided in the lower portion of the right punch 55a of the punch 55 and is pressed downward by the right punch 55a of the punch 55. The

  When the bending of the end W4e of the convex side surface portion W4 of the plate-like workpiece W1 is completed, the punch 55 is moved upward, and the plate-like workpiece W1 held by the first die 51 and the first die 51 is moved upward. Is moved back to the initial position. Then, as shown by a two-dot chain line in FIG. 12, the draw-formed plate-like workpiece W1 is rotated 90 degrees so that the plate-like workpiece W1 is first with the first right convex side portion W3a on the lower side. In the same manner, the end W3e of the second left convex side W3b of the convex side W3b is inward by the left punch 55b and the second die 52. Bent to the side.

  In this way, the end portions W3e and W4e opposite to the convex top surface portion W2 side of the convex side surface portions W3 and W4 of the plate-like workpiece W1 to which the reinforcing member R1 is attached are both bent inward. Thereafter, the plate-like workpiece W1 is press-molded in a direction in which the projection W2a provided on the convex top surface portion W2 protrudes into the projection of the plate-like workpiece W1, which is opposite to the projection direction of the projection W2a. The convex side surface portions W3 and W4 on both sides of the top surface portion W2 are displaced inward, respectively, so that the plate-like workpiece W1 is closed.

  FIG. 13 is an explanatory diagram for explaining the press molding process, and FIG. 13A is a drawing process in a press molding die of a press molding apparatus for press-molding a plate-like work to make a closed cross section. FIG. 13B shows a state in which the convex portion of the convex top surface portion of the plate-like workpiece is pressed by the core die of the press mold, and FIG. (C) shows a state in which the convex portion of the convex top surface portion of the plate-like workpiece is press-molded by the core die of the press-molding die and the end portions of the convex side surface portions are brought into contact with each other to form a closed cross section. . In FIGS. 13B and 13C, the punch of the press mold is omitted. FIG. 13 shows a cross section corresponding to the cross section shown in FIG. 3A of the front side frame 20 in order to explain the press molding process. In FIG. 15 and FIG. FIG. 3C shows a cross section corresponding to the cross section shown in FIG.

  As shown in FIG. 13 (a), a press mold (second mold) 60 used in a press molding apparatus for press-molding a plate-shaped workpiece W1 that has been molded into a closed section is drawn. A die 61 for holding the plate-like workpiece W1, a core die 65 disposed above the die 61 and configured to be movable in the vertical direction, and disposed above the core die 65 in the vertical direction. And a punch 67 configured to be movable.

  As shown in FIG. 13A, the die 61 of the press mold 60 is provided with a recess 62 that is recessed in a top surface 61a for holding the convex top surface portion W2 of the plate-like workpiece W1. FIG. 14 is an enlarged view of the main part showing the A portion of FIG. 13A in an enlarged manner. As shown in FIG. 14, the concave portion 62 provided in the die 61 of the press mold 60 includes a bottom surface portion 62a. Side wall portions 62b and 62c, specifically, a right side wall portion 62b located on the right side in FIG. 14 and a left side wall portion 62c located on the left side, are extended in the longitudinal direction.

  The bottom surface portion 62a of the concave portion 62 provided in the die 61 of the press mold 60 is formed according to the shape of the lower surface portion 22 of the front side frame 20, and is provided on the convex top surface portion W2 of the plate-like workpiece W1. The section W2a is formed to have a cross-sectional length L21 that is substantially the same as the cross-sectional arc length L11. Further, the side wall portions 62b and 62c of the concave portion 62 are formed so as to have substantially the same cross-sectional length as the shortest cross-sectional length of the convex top surface portion W2 that changes in the longitudinal direction. The right wall 62b of the recess 62 is formed to have a cross-sectional length L22 that is substantially the same as the shortest cross-sectional length L12 of the left convex top surface W2c, and the left wall 62c of the recess 62 is The right convex top surface portion W2b is formed to have the same cross-sectional length L23 as the shortest cross-sectional length of the cross-sectional length L13, and the inclination angle of the side wall portions 62b and 62c of the concave portion 62 with respect to the bottom surface portion 62a is the front. Depending on the shape of the side frame 20, it is formed at a substantially constant predetermined angle in the longitudinal direction.

  In the present embodiment, as shown in FIG. 3C, the portion to which the reinforcing member 35 is attached in the lower surface portion 22 and the third inclined side surface portion 27 of the front side frame 20 extends in the longitudinal direction of the front side frame 20. As shown in FIG. 15A, which will be described later, the die 61 of the press mold 60 has a plate shape so as to protrude outward from the front side frame 20 so that the inner surface shapes substantially coincide. Corresponding to the portion of the workpiece W1 to which the reinforcing member R1 is attached, a groove portion 62d is formed that is recessed from the substantially central portion of the bottom surface portion 62a to the right side wall portion 62b. The groove 62d is formed to have substantially the same depth D1 as the plate thickness of the reinforcing member R1 at the bottom surface 62a and the right side wall 62b.

  The core die 65 of the press mold 60 is formed above the die 61 so as to press-mold the convex portion W2a provided on the convex top surface portion W2 of the plate-like workpiece W1 in a direction protruding in the convex shape of the plate-like workpiece W1. Is arranged. The core die 65 is formed longer in the longitudinal direction than the plate-like workpiece W1, and as shown in FIG. 13 (a), an upper surface portion 65a, a lower surface portion 65b, a right side surface portion 65c, a left side surface portion 65d, A first inclined side surface portion 65e inclined obliquely downward to the right from the upper surface portion 65a toward the right side surface portion 65c; a second inclined side surface portion 65f inclined obliquely downward to the left toward the left side surface portion 65d from the upper surface portion 65a; A third inclined side surface portion 65g inclined obliquely upward to the right from the lower surface portion 65b toward the right side surface portion 65c; a fourth inclined side surface portion 65h inclined obliquely upward to the left toward the left side surface portion 65d from the lower surface portion 65b; It has. The lower surface portion 65b, the third inclined side surface portion 65g, and the fourth inclined side surface portion 65h of the core mold 65 are the lower surface portion 22, the third inclined side surface portion 27, and the fourth inclined side surface portion of the front side frame 20, respectively. 28, the upper surface portion 65a, the first inclined side surface portion 65e, and the second inclined side surface portion 65f of the core mold 65 are respectively the upper surface portion 21 of the front side frame 20 and the first inclined side surface. It is formed according to the shape of the portion 25 and the second inclined side surface portion 26.

  Further, the core die 65 of the press mold 60 has a narrower cross-sectional width than that of the front side frame 20 when the plate-like workpiece W1 is closed, specifically, FIG. As shown in (c), a draw-molded plate in which the cross-sectional width L31 between the right side surface portion 65c and the left side surface portion 65d of the core mold 65 corresponds to the right side surface portion 23 and the left side surface portion 24 of the front side frame 20 It is formed so as to have a cross-sectional width narrower than the cross-sectional width L32 between the first left convex side surface portion W4a and the first right convex side surface portion W3a. Further, the cross-sectional width in the short direction of the lower surface portion 65b of the core mold 65 is set to be substantially the same as the cross-sectional length L11 of the convex portion W2a of the plate-like workpiece W1. The core die 65 is configured so that it can be removed in the longitudinal direction of the closed cross-section member formed in the closed cross-section after the plate-like workpiece W1 is closed.

  As will be described later, the punch 67 of the press mold 60 is abutted after the convex side portions W3 and W4e of the draw-formed plate-like workpiece W1 are abutted to form a closed cross section. The end portions W3e and W4e of the convex side surface portions W3 and W4 are connected to the convex top surface portion W2 of the core 65, more specifically, the surface portion opposite to the surface portion (lower surface portion) 65b that presses the convex portion W2a. (Upper surface portion) A punch for pressing and molding by pressing to 65a. The punch is disposed above the core die 65 and configured to be movable in the vertical direction.

  In the press molding apparatus provided with the press mold 60 configured as described above, the draw-formed plate-like workpiece W1 is formed into a plate shape on the die 61 of the press mold 60 and on the recess 62 provided on the die 61. In a state where the convex portion W2a of the workpiece W1 is disposed, the press-molding die together with the reinforcing member R1 fixed so as to cover the convex portion W2a of the plate-like workpiece W1 with the convex portion W2a of the plate-like workpiece W1. 60 is pressed in the concave portion 62 in the direction in which the plate-like workpiece W1 protrudes in a convex shape by the core die 65, and the convex side portions W3 and W4 on both sides of the convex top surface portion W2 of the plate-like workpiece W1 are respectively inside. It is possible to make a closed cross-section by displacing to the side.

  In the present embodiment, the reinforcing member R1 attached so as to cover the convex portion W2a of the plate-like workpiece W1 is provided with a portion where the plate thickness of the plate-like workpiece W1 is larger than other portions of the convex portion. The portion where the plate thickness is larger than the other portion of the convex portion is harder to mold than the other portion of the convex portion when press forming the convex portion, and the portion where the plate thickness is larger than the other portion of the convex portion The convex side surface portion W3 that is continuous to the inner surface is less likely to be displaced inward, but the convex portion is press-molded in the portion where the plate thickness is larger than the other portions of the convex portion by the groove portion 62d formed in the bottom surface portion 62a. Such a problem is avoided by setting the amount of crushing to be larger than the other portions of the convex portion.

  When the convex part W2a of the draw-formed plate-like workpiece W1 is press-molded in the concave portion 62 using the press-molding die 60, the plate-like workpiece W1 is pressed into the press-molding die as shown in FIG. A plate-shaped workpiece in which the convex portion W2a of the plate-like workpiece W1 is arranged on the concave portion 62 provided in the die 61 so that the central axes thereof in the short direction substantially coincide with each other, and is draw-formed. The convex top surface portion W2 of W1 is held on the upper surface 61a of the die 61.

  When the plate-like workpiece W1 is held by the die 61, the core die 65 is moved downward, and the convex portion W2a of the plate-like workpiece W1 is plate-like by the core die 65 as shown in FIG. The left convex top surface portion W2c and the convex side surface portion W4 are pressed downward in the direction in which the workpiece W1 protrudes in a convex shape, so that the right side wall portion 62b of the concave portion 62 and the upper surface 61a With the shoulder portion 62e as a fulcrum, the draw-formed plate-like workpiece W1 is displaced inward in the closing direction, and the right convex top surface portion W2b and the convex side surface portion W3 are the left side wall portion 62c and the upper surface 61a of the concave portion 62. With the shoulder 62f of the die 61, which is the intersection with the fulcrum, as a fulcrum, the draw-formed plate-like workpiece W1 is displaced inward in the closing direction.

  Further, when the core die 65 is moved downward and the convex portion W2a of the plate-like workpiece W1 is press-molded in the concave portion 62 of the die 61 by the core die 65, as shown in FIG. The portion W2a is crushed and the punch 65 and the die 61 form a press-formed surface W2d on the plate-like workpiece W1, and the convex side portions W3 and W4 on both sides of the convex top surface portion W2 are further displaced inward. The end portions W3e and W4e of the convex side portions W3 and W4 are brought into contact with each other to form a closed cross section.

  FIG. 13 shows a cross section corresponding to the cross section shown in FIG. 3A of the front side frame 20 in order to explain the press molding process, but FIG. 3B and FIG. Other cross sections such as the cross section corresponding to the cross section shown in c) are simultaneously press-molded to form a closed cross section.

  FIG. 15 is an explanatory diagram for explaining a press molding process for a cross section corresponding to the cross section shown in FIG. 3C of the front side frame, and FIG. 15A is a drawing mold in a press mold. FIG. 15B shows a state in which the plate-shaped workpiece is held, and FIG. 15B shows a convex top surface portion in which the convex portion formed on the convex top surface portion of the plate-shaped workpiece is press-molded by the core mold of the press mold. 2 shows a state in which the ends of the convex side portions on both sides are abutted to form a closed cross section.

  As shown in FIG. 15A, the core die 65 is moved downward in a state where the plate-like workpiece W1 is held by the die 61, and the convex portion W2a of the plate-like workpiece W1 is plate-like by the core die 65. When the reinforcing member R1 is provided so as to cover the convex portion W2a of the plate-like workpiece W1 when pressed downward in the direction in which the workpiece W1 protrudes in a convex shape, the reinforcing member provided along the convex portion W2a The portion R2 of R1 is pressed downward together with the convex portion W2a, and the left convex side surface portion W2c and the convex side surface portion W4 close together the reinforcing member R1 and the plate-shaped workpiece W1 formed by drawing with the shoulder portion 62e of the die 61 as a fulcrum. In the portion where the reinforcing member R1 is not provided so as to cover the convex portion W2a of the plate-like workpiece W1, the convex portion W2a is pressed downward, the right convex top surface portion W2b and the convex shape. The side surface W3 is formed of the die 61. Parts 62f displaced in a direction to close the draw-formed plate workpiece W1 to the inner side as a fulcrum.

  When the convex portion W2a formed on the convex top surface portion W2 of the plate-like workpiece W1 is press-molded by the core die 65 of the press-molding die 60, as shown in FIG. In the portion where the reinforcing member R1 is provided so as to cover the portion W2a, the portion R2 of the reinforcing member R1 provided along the convex portion W2a is pressed together with the convex portion W2a to the groove portion 62d provided in the bottom surface portion 62a of the concave portion 62. In a portion where the reinforcing member R1 is not provided so as to cover the convex portion W2a of the plate-like workpiece W1, it is press-formed to the bottom surface portion 62a of the concave portion 62, and the plate-like workpiece W1 and the reinforcement are formed by the punch 65 and the die 61. Press forming surfaces W2d and R2d are respectively formed on the member R1, and the convex side surfaces W3 and W4 on both sides of the convex top surface portion W2 are respectively displaced inward to form convex side surfaces. 3, W4 end W3e, and what W4e is closed grained butted.

  In this way, the convex portions W2a formed on the convex top surface portion W2 of the plate-like workpiece W1 are press-molded in a direction protruding in the convex shape of the plate-like workpiece W1, and both sides of the convex top surface portion W2 of the plate-like workpiece W1. When the convex side surface portions W3 and W4 are displaced inward to make a closed cross section, the thickness of the portion where the reinforcing member R1 is provided so as to cover the convex portion W2a of the plate-like workpiece W1 Since it is larger than the other part of the convex part, it becomes difficult to mold, and the convex side surface part that is continuous with the part larger than the other part of the convex part is difficult to be displaced inward, but in this embodiment, Set the amount of crushing the portion where the plate thickness is larger than the other portion of the convex portion by pressing and molding the convex portion to be larger than the other portion of the convex portion, and the plate thickness is larger than the other portion of the convex portion The convex side surface that continues to the part stands up like the convex side surface that continues to the other part of the convex part. Strain is displaced to the inner side, it can be closed roughened plate workpiece.

  FIG. 16 is an explanatory diagram for explaining a press molding process for a cross section corresponding to the cross section shown in FIG. 3B of the front side frame 20, and FIG. 16A is a drawing-molded plate. FIG. 16B shows a state in which the convex portion of the convex top surface portion of the plate-like workpiece is pressed by the core die of the press mold, and FIG. 16B shows the convex portion of the convex top surface portion of the draw-formed plate workpiece. Shows a state in which the end portions of the convex side portions are abutted with each other and the closed cross-section is formed by pressing with a core die of the press mold.

  Also for the cross section corresponding to the cross section shown in FIG. 3B of the front side frame 20, the plate-like workpiece W 1 is arranged so that the convex portion W 2 a of the plate-like workpiece W 1 is disposed on the concave portion 62 provided on the die 61. When the core die 65 is moved downward while being held by the die 61, the convex portion W2a of the plate-like workpiece W1 is moved to the plate-like workpiece W1 by the core die 65 as shown in FIG. The left convex top surface portion W2c and the convex side surface portion W4 are pressed downward in the direction protruding in a convex shape, whereby the draw-formed plate-like workpiece W1 is closed with the shoulder portion 62e of the die 61 as a fulcrum. The right convex top surface portion W2b and the convex side surface portion W3 are displaced inward in the direction of closing the draw-formed plate-like workpiece W1 with the shoulder portion 62f of the die 61 as a fulcrum. .

  When the core die 65 is further moved downward and the convex portion W2a of the plate-like workpiece W1 is press-molded in the concave portion 62 of the die 61 by the core die 65, as shown in FIG. W2a is crushed and a press molding surface W2d is formed by the punch 65 and the die 61, and the convex side surface portions W3 and W4 on both sides of the convex top surface portion W2 are further displaced inward, respectively. The end portions W3e and W4e of the portions W3 and W4 are brought into contact with each other to form a closed cross section.

  In the present embodiment, the sections W2c and W2b into which the convex top surface W2 is divided by the convex W2a are formed so that the cross-sectional lengths L12 and L13 change in the longitudinal direction, but the die 61 of the press mold 60 is used. The cross-sectional lengths L22 and L23 of the side wall portions 62b and 62c of the concave portion 62 provided in the concave portion 62 are set substantially the same as the shortest portions of the cross-sectional lengths L12 and L13 of the divided portions W2c and W2b of the convex top surface portion W2, respectively. The convex top surface portions W2c and W2b corresponding to the third inclined side surface portion 27 and the fourth inclined side surface portion 28 of the front side frame 20 are substantially equal in the longitudinal direction by being press-formed using the formed die 61. The press molding can be started up at the timing, and the press molding can be performed stably.

  As shown in FIGS. 13 (c), 15 (b) and 16 (b), the convex portion W2a of the plate-like workpiece W1 is reinforced at the portion where the reinforcing member R1 is firmly attached so as to cover the convex portion W2a. Along with the member R1, by pressing in the concave portion 62 in the direction of projecting the plate-like workpiece W1 by the core die 65, the convex portion W2a is crushed to form a press-molded surface and the convex top surface portion W2. After the convex side portions W3 and W4 on both sides of the two are displaced inward to make a butted closed cross section, the end portions W3e and W4e of the butted convex side portions W3 and W4 are core-shaped. The convex portion W2a of 65 is pressed against the surface portion 65a opposite to the surface portion 65b to be pressed, and is pressed and molded.

  FIG. 17 is an explanatory diagram for explaining the final press molding process. FIG. 17A shows a state before final press molding, and FIG. 17B shows a state after final press molding. Show. In addition, in FIG. 17, about the plate-shaped workpiece | work W1, the cross section corresponding to the cross section shown to Fig.3 (a) of the front side frame 20 is shown. As shown in FIG. 17 (a), when the end faces W3e and W4e of the projecting side faces W3 and W4 that are abutted against the plate-like workpiece W1 are pressed against the core mold 65 and determined. A punch 67 that is arranged above the core mold 65 and configured to be movable in the vertical direction is used.

  When the punch 67 of the press mold 60 is moved downward so as to press the projected side surfaces W3 and W4 of the plate-like workpiece W1 against each other, the ends W3e and W4e are pressed downward, as shown in FIG. As described above, the end portions W3e and W4e of the projecting side surface portions W3 and W4 that are abutted to each other of the plate-like workpiece W1 are pressed by the punch 67 and are opposite to the surface portion 65b that presses the projecting portion W2a of the core die 65. The surface portion W6 is pressed against the surface portion 65a and is formed by pressing, and the surface portion W6 corresponding to the upper surface portion 21 of the front side frame 20 is formed by the punch 67 and the core die 65. FIG. 17 shows a cross section corresponding to the cross section shown in FIG. 3A of the front side frame 20, but the cross section corresponding to the cross sections shown in FIGS. 3B and 3C of the front side frame 20. Other cross sections such as the above are also pressed at the same time and determined.

  In this way, the end portions W3e and W4e of the projecting side surface portions W3 and W4 that are abutted with each other on the plate-like workpiece W1 are pressed against the surface portion 65a opposite to the surface portion 65b that presses the convex portion W2a of the core die 65. By further including a definite press molding step for deterministic press molding, high molding accuracy can be obtained by a relatively simple method for the surface opposite to the press molding surface W2d.

  After the end portions W3e and W4e of the projecting side surfaces W3 and W4 of the plate-like workpiece W1 are pressed and formed by the punch 67 and the core die 65, the projecting side surfaces W3 and W4 of the abutted surfaces are formed. The end portions W3e and W4e are joined to each other by welding such as laser welding, and the front side frame 20 as a closed cross-sectional member formed in a closed cross-sectional shape without providing a flange portion is manufactured. As shown in FIG. 3C, a reinforcing member 35 is attached to the front side frame 20 from the lower surface portion 22 of the front side frame 20 to the third inclined side surface portion 27 and the right side surface portion 23.

  In the present embodiment, the plate-like workpiece W1 is sandwiched between the blank holder 41 of the draw mold 40 and the die 45 by draw molding, and the punch 42 is moved into the molding space 45c of the die 45 to obtain a plate shape. The workpiece W1 is protruded in the direction of movement of the punch 42 with respect to the die 45 and is formed into a convex shape, and the convex shape of the plate-shaped workpiece W1 is projected to the convex top surface portion W2 formed into a convex shape of the plate-shaped workpiece W1. The convex portion W2a protruding in the direction opposite to the direction to be formed is formed, but may be formed using other press forming such as overhang forming, for example.

  In addition, the side surfaces W3e and W4e opposite to the convex top surface portion W2 side of the convex side surface portions W3 and W4 of the plate-shaped workpiece W1 formed by drawing are bent and formed into a closed cross section. Further, only one of the end portions W3e and W4e of the convex side surface portions W3 and W4 of the plate-like workpiece W1 may be bent inward, and then the closed cross section may be formed. It is also possible to make a closed cross-section without doing.

  Further, the concave portion 62 provided on the die 61 of the press mold 60 in the direction in which the convex portion W2a of the plate-shaped workpiece W1 formed by drawing is protruded into the convex shape of the plate-shaped workpiece W1 by the core die 65 of the press mold 60. The end portions W3e and W4e of the plate-like workpiece W1 are brought into contact with each other to form a closed cross-section by press-molding, but the convex side portions W3 and W4 of the plate-like workpiece W1 are formed. The end portions W3e and W4e may be overlapped to form a closed cross section. In such a case, preferably, in the welding process, the convex side surface portion of the plate-like workpiece W1 that is overlapped and has a closed cross section is provided. The ends W3e and W4e of W3 and W4 are welded by lap welding or fillet welding.

  In addition, in the present embodiment, the reinforcing member R1 is provided along the plate-like workpiece W1 from the substantially central portion in the short direction of the projection W2a of the plate-like workpiece W1 to the first convex side surface portion W3. The plate-like workpiece W1 that is closed in the second press molding step so that the reinforcing member is provided along the front side frame 20 from the lower surface portion 22 of the front side frame 20 to the upper surface portion 21 of the front side frame 20. The reinforcing member is fixedly brought into contact with the plate-like workpiece W1 so as to be provided along the plate-like workpiece W1 up to the end portions W3e, W4e opposite to the convex top surface portion W2 side of the convex side portions W3, W4. Also good.

  Thus, in the manufacturing method of the front side frame 20 as a metal closed cross-section member according to the present embodiment, the plate-like workpiece W1 is press-formed into a convex shape, and the convex shape of the plate-like workpiece W1 is formed on the convex top surface portion W2. A first press molding step of forming a convex portion projecting in a direction opposite to the direction projecting in the direction opposite to the first convex shape, and a plate shape by pressing the convex portion of the plate-like workpiece W1 in a direction projecting into the convex shape of the plate-like workpiece W1. A second press forming step of crushing the convex portion of the work W1 to form a press molding surface and displacing the convex side portions W3 and W4 to the inner side to make a closed cross section. In the molding step, the portion where the thickness of the convex portion is larger than that of the other portion of the convex portion is set such that the amount of crushing by the convex portion being pressed and crushed is larger than that of the other portion of the convex portion. Accordingly, it is possible to accurately manufacture a metal closed cross-section member whose thickness is partially increased and partially reinforced by a relatively simple method without complicating a molding apparatus such as a mold. it can.

  Further, the portion where the plate thickness of the convex portion is larger than the other portion of the convex portion is a portion in which the reinforcing member R1 for reinforcing the closed cross-section member 20 is firmly attached so as to cover the convex portion, thereby reinforcing In the case of manufacturing a metal closed cross-section member partially reinforced by the member R1, the above-described effect can be effectively achieved.

  Further, the reinforcing member R1 has a plate shape up to end portions W3e and W4e opposite to the convex top surface portion W2 side of the convex side surface portions W3 and W4 of the plate-like workpiece W1 that is closed in the second press molding step. The above-mentioned effect is effective even in the case of manufacturing a metal closed cross-section member provided with a reinforcing member so as to suppress the collapse of the cross-section of the closed cross-section member by being firmly contacted so as to be provided along the workpiece W1. Can be played.

  Still further, during the first press molding step and the second press molding step, the end of the convex side surface portion of the press-molded plate workpiece opposite to the convex top surface portion side is placed inside the plate workpiece. By further comprising a bending process that bends in the direction of the side, when the plate-shaped workpiece is made to have a closed cross-section, the inward displacement of the convex side surface of the press-molded plate-shaped workpiece is reduced. The metal closed cross-section member can be manufactured with higher accuracy.

  Still further, after the second press forming step, a welding step of welding the end portions of the convex side portions having a closed cross section of the press-formed plate-like workpiece is provided, whereby the closed cross-section member The bonding strength can be increased, and a stronger closed section member can be manufactured.

  In this embodiment, the reinforcing member R1 is attached to the plate-like workpiece W1, and the convex portion of the plate-like workpiece W1 is provided with a portion where the plate thickness is larger than other portions of the convex portion. Even in the case where the reinforcing member is attached so that at least one of the plate thickness, strength, and proof stress is larger than the other portion of the convex portion, in the second press molding process, the plate thickness, strength, and An effect similar to that of the above-described embodiment can be obtained by setting a portion where at least one of the proof stress is larger than the other portion of the convex portion, and setting the amount of crushing of the convex portion larger than that of the other portion of the convex portion. .

  In the manufacturing method of the metal closed cross-section member described above, a portion having a plate thickness larger than the other portion of the convex portion is provided on the convex portion of the plate-like workpiece W1 by the reinforcing member R1, and the thickness of the convex portion of the convex portion is different from that of the convex portion. By increasing the amount of crushing at the time of press molding the larger part than the other part of the convex part, the convex side surface part that is continuous with the part where the plate thickness is larger than the other part of the convex part, The plate-like workpiece W1 is displaced inward to form a closed cross-section in the same manner as the convex side portion continuous with the other portions of the projection, but the portion to which the reinforcing member R1 of the plate-like workpiece W1 is attached is a plate. The present invention can also be applied to the case where a metal closed cross-section member is manufactured using a tailored blank made of another plate material having a plate thickness larger than that of the workpiece W1.

  FIG. 18 is an explanatory diagram for explaining a method of manufacturing another metal closed cross-section member according to the present embodiment, and in FIG. 18, a state where a plate-like workpiece that has been draw-formed in a press mold is held. Is shown. The front side frame as another metal closed cross-section member according to the present embodiment is made of another plate material in which the reinforcing member 35 is attached to the front side frame 20 with a large plate thickness. Similar components are denoted by the same reference numerals and description thereof is omitted.

  When manufacturing another metal closed cross-section member according to the present embodiment, as the plate-like workpiece W10, for example, a first plate material W11 formed in a substantially flat plate shape such as a steel plate, and a plate thickness from the first plate material W11. A tailored blank formed by welding a second plate material W15 formed in a substantially flat shape such as a steel plate, for example, is used, and the portion to which the reinforcing member R1 of the plate-like workpiece W1 in the above-described embodiment is attached is first. 2 plate materials W15. In FIG. 18, the first plate material W11 is represented by hatching, and the second plate material W15 is represented by cross hatching.

  Even in the case where the plate-like workpiece W10 is used, a convex top surface portion in which the plate-like workpiece W10 is drawn into a convex shape and is formed into the convex shape of the plate-like workpiece W10 by the draw molding device provided with the draw mold 40. A convex portion that protrudes in a circular arc shape in the direction opposite to the convex direction of the plate-like workpiece W10 is formed on W2. As shown in FIG. 18, the convex portion of the plate-like workpiece W10 is provided with a portion W15a made of the second plate material W15 having a plate thickness larger than the other portion W2a of the convex portion made of the first plate material W11. Yes.

  After the plate-like workpiece W10 is drawn, blanking is performed in the same manner as the plate-like workpiece W1 described above, and then the convex side surface portions W3 and W4 of the plate-like workpiece W10 and the convex top surface portion W2 side. The opposite end portions are each bent inward. Then, by the press molding apparatus provided with the press mold 60, the convex part of the plate-like workpiece W1 is pressed in the concave part 62 in the direction in which the core mold 65 projects into the convex shape of the plate-like work W1. Molded. The die 61 of the press mold 60 is provided with a groove 62d that is formed to be recessed from the substantially central portion of the bottom surface portion 62 to the right side wall portion 62b corresponding to the shape of the second plate material W15. The portion 62a and the right side wall portion 62b are formed to have a depth D2 that is substantially the same as the difference in plate thickness between the second plate member W15 and the first plate member W11.

  Thereby, even when the projection W of the plate workpiece W10 is provided with the portion W15a made of the second plate material W15 having a plate thickness larger than the other portion W2a of the projection made of the first plate material W11. When the convex portion of W1 is press-molded and crushed, the portion W15a whose plate thickness is larger than the other portion W2a of the convex portion is made larger in the crushing amount of the convex portion than the other portion W2a of the convex portion, and the convex portion Similarly to the convex side surface portion continuing to the other portion W2a, the convex side surface portion continuing to the portion where the plate thickness is larger than the other portion of the convex portion can be displaced inward to form a closed cross section. The front side frame can be manufactured with high accuracy.

  Thus, the plate-like workpiece W10 is a tailored blank formed by welding the first plate material W11 and the second plate material W15 having a plate thickness larger than the first plate material W11, and the plate thickness of the convex portion is Even in the case where the metal closed cross-section member is manufactured using the plate-like workpiece W10 made of the second plate material W15, the portion W15a larger than the other portion W2a of the convex portion is partially reinforced by the second plate material W15. In addition, the metal closed cross-section member can be manufactured with high accuracy.

  In addition, although the tailored blank formed by welding the 1st board | plate material W11 and the 2nd board | plate material W15 whose plate | board thickness is larger than the 1st board | plate material W11 is used as the plate-shaped workpiece W10, a 2nd board | plate material is used. A tailored blank having at least one of the plate thickness, strength and proof stress greater than the first plate material can be used, and at least any of the plate thickness, strength and proof stress than other portions of the convex portion made of the first plate material. By making the crushing amount of the portion made of the second plate material larger than that of the other portion of the convex portion made of the first plate material, the same effect as in the above embodiment can be obtained.

  In the above-described embodiment, by providing the groove 62d in the bottom surface 62a of the recess 62 provided in the die 61, a portion in which at least one of the plate thickness, strength, and proof stress of the convex portion is larger than the other portions of the convex portion. Although the amount of crushing is set larger than other portions of the convex portion, in the first press molding process, at least one of the plate thickness, strength and proof stress of the convex portion is larger than the other portions of the convex portion. The height of the convex part is formed higher than the other part of the convex part, and at least one of the thickness, strength and proof stress of the convex part is larger than the other part of the convex part and the other part of the convex part The part is press-molded to substantially the same position so that the crushing amount of the part where the thickness, strength and proof stress of the convex part is larger than the other part of the convex part is larger than that of the other part of the convex part. It is also possible to make it.

  FIG. 19 is an explanatory diagram for explaining a method for manufacturing still another metal closed cross-section member according to the present embodiment, and FIG. 19 shows a state in which a plate-like workpiece is drawn. The front side frame as another metal closed cross-section member according to the present embodiment is such that the portion to which the reinforcing member is attached in the front side frame 20 does not protrude outward, and the reinforcing member is the inner surface of the front side frame 20. The reinforcing member extends to the end of the lower surface portion 22 on the fourth inclined side surface portion 28 side, and the same reference numerals are given to the same configurations as those in the above-described embodiment. The description is omitted. In FIG. 19, the reinforcing member is omitted, but the portion to which the reinforcing member is attached is hatched.

  When manufacturing another metal closed cross-section member according to the present embodiment, a plate-like workpiece W20 formed in a substantially flat plate shape such as a steel plate is used as the plate-like workpiece, and the plate-like workpiece W20 includes a plate. A reinforcing member R10 (see FIG. 20) that partially increases at least one of the plate thickness, strength, and proof stress of the workpiece 20 is fixed and joined. Even in the case where the plate-like workpiece W20 is used, the plate-like workpiece W20 is formed into a convex shape and protrudes in a convex shape of the plate-like workpiece W20 to the convex top surface portion W2 formed into the convex shape of the plate-like workpiece W20. Convex portions W2a projecting in a substantially arc shape in cross section in the direction opposite to the direction are provided continuously in the longitudinal direction of the plate-like workpiece W20.

  As shown in FIG. 19, in the plate-like workpiece W20, a portion W2f having a predetermined length S1 in the longitudinal direction of the plate-like workpiece W20 and to which the reinforcing member R10 is attached is a convex portion in the convex portion W2a of the plate-like workpiece W20. The height of the convex portion is higher than that of the other portion W2a. In the portion W2f to which the reinforcing member R10 is attached and at least one of the plate thickness, strength, and proof stress is larger than the other portion W2a of the convex portion, the height of the convex portion is set to H2, as shown in FIG. The height of the convex portion is higher than that of the other portion W2a of the convex portion whose height is H1. In addition, in the convex portion W2a of the plate-like workpiece W20, in the portion W2f where the height of the convex portion W2a is formed high, the short length of the plate-like workpiece W20 is preferably such that the cross-sectional length of the convex portion W2a is substantially constant. The width in the hand direction is narrow.

  In the draw mold 40 shown in FIG. 6, the plate-like workpiece W <b> 20 protrudes in a curved shape by partially increasing the height of the convex portion 45 m provided on the die 45 so as to protrude in a circular arc shape in the longitudinal direction. While forming, it can shape | mold using what formed the depth of the recessed part 42m provided in the punch 42 so that it may become depressed in circular arc shape partially in the longitudinal direction, and was depressed in the cross-sectional curve shape.

  After the plate-like workpiece W20 is drawn, blanking is performed in the same manner as the above-described plate-like workpiece W1, and then the convex side surface portions W3 and W4 of the plate-like workpiece W20 are connected to the convex top surface portion W2 side. The opposite end portions are each bent inward. And the convex part W2a of the plate-shaped workpiece W20 is press-molded in the direction protruding in the convex shape of the plate-shaped workpiece W1.

  20 is a cross-sectional view showing a state where the plate-like workpiece shown in FIG. 19 is held by a die of a press mold, and FIG. 20 shows a cross-section of the plate-like workpiece along the line Y20a-Y20a in FIG. The cross section of the convex part of the plate-like workpiece along the line Y20b-Y20b in FIG. 19 is indicated by a two-dot chain line.

  As shown in FIG. 20, the press mold 70 used in the press molding apparatus for press molding the convex portion W2a of the plate-like workpiece W20 is the bottom surface 65b of the core mold 65 in the press mold 60 shown in FIG. In addition, a groove portion 65i is formed in the third inclined side surface portion 65g so as to be recessed substantially equal to the thickness of the reinforcing member R10 according to the shape of the reinforcing member R10, and a groove portion is formed in the bottom surface portion 62a of the concave portion 62 provided in the die 61. What 62d is not formed is used. In FIG. 20, in the press mold 70, the same components as those of the press mold 60 are denoted by the same reference numerals, and description thereof is omitted.

  When the convex portion W2a of the plate-like workpiece W20 is press-molded in the concave portion 62 in the direction protruding in the convex shape of the plate-like workpiece W20 by the core die 65 by the press molding apparatus including the press molding die 70. In the portion W2f where the reinforcing member R10 is provided so as to cover the convex portion W2a of the plate-like workpiece W20, the reinforcing member R10 is press-formed to the bottom surface portion 62a of the concave portion 62 together with the convex portion W2a. In the portion where the reinforcing member R10 is not provided so as to cover W2a, the convex portion W2a is press-molded to the bottom surface portion 62a of the concave portion 62, and the convex portion W2a of the plate-like workpiece W20 is press-molded to substantially the same position.

  The reinforcing member R10 is attached to the plate-like workpiece W20, and at least one of the plate thickness, strength, and proof strength of the convex portion W2a formed on the convex top surface portion W2 of the plate-like workpiece W20 is greater than the other portions of the convex portion W2a. Even in the case where the large portion W2f is provided, in the first press molding step, the height of the convex portion is convex for a portion in which at least one of the thickness, strength, and proof stress of the convex portion is larger than the other portion of the convex portion. In the second press molding process, at least one of the thickness, strength and proof stress of the convex portion is larger than the other portion of the convex portion and the other portion of the convex portion. Is pressed to approximately the same position, and the amount of crushing at the portion where the plate thickness, strength and proof stress of the convex portion is larger than the other portion of the convex portion is made larger than the other portion of the convex portion. , Convex side continuous with other parts of the convex part As with the part, the convex side face part that continues to the part where at least one of the plate thickness, strength and proof stress is larger than the other part of the convex part can be displaced inward to make a closed cross-section. The side frame can be manufactured with high accuracy.

  In the above-described embodiment, the reinforcing member R10 is attached to the plate-like workpiece W20, and the convex portion of the plate-like workpiece W20 is provided with any of the plate thickness, strength, and proof stress, but the first plate member, Using a tailored blank formed by welding a second plate material having at least one of the plate thickness, strength and proof stress greater than those of the first plate material, at least one of the plate thickness, strength and proof stress at the convex part of the plate-like workpiece Even when the portion larger than the other portion of the convex portion is made of the second plate material, the portion made of the second plate material in the convex portion of the plate-like work is made more than the other portion of the convex portion made of the first plate material. When the height is formed high and the convex portion is press-molded and crushed, the portion made of the second plate and the portion made of the first plate are press-molded to substantially the same position, so that the plate thickness is The larger part than the other part The convex side surface part that continues to the part where the plate thickness is larger than the other part of the convex part and the convex side part part that continues to the other part of the convex part It is possible to make a closed cross-section by displacing to the side.

  Thus, in the first press molding step, the convex portion W2a is continuously provided in the longitudinal direction of the plate-like workpiece W1, and at least one of the plate thickness, strength, and proof stress of the convex portion W2a is the convex portion W2a. The portion W2f that is larger than the other portion is formed such that the height of the convex portion is higher than that of the other portion of the convex portion, and in the second press molding process, at least one of the plate thickness, strength, and proof stress of the convex portion is convex. The part corresponding to the convex part of the plate-like workpiece of the closed cross-section member is flattened and manufactured by press-molding the part larger than the other part of the part and the other part of the convex part to substantially the same position. Can do.

  In the present embodiment, the recess 61 is provided in the die 61 of the press mold 60. However, the plate-like workpiece W1 formed by drawing on the flat surface provided in the die 61 without providing the recess in the die 61 is provided. With the plate-like workpiece W1 held by the die 61 so that the projection W2a is arranged, the projection W2a of the plate-like workpiece W1 is projected by the core die 65 of the press mold 60 into the convex shape of the plate-like workpiece W1. In this direction, the flat part provided on the die 61 of the press mold 60 is pressed to crush the convex part W2a of the plate-like workpiece W1 to form the press-molded surface, and the convex shape of the plate-like workpiece W1. It is also possible to displace the convex side portions W3 and W4 on both sides of the top surface portion W2 inwardly to make a closed cross section.

  Moreover, in this embodiment, the convex part W2a provided in the convex top surface part W2 of the plate-shaped workpiece W1 press-molded is shape | molded by cross-sectional arc shape, and plate-shaped workpiece W1 is carried out by press-molding this convex part W2a. The convex side surface portions W3 and W4 on both sides of the convex top surface portion W2 are respectively displaced toward the inner side of the plate-like workpiece W1 so as to have a closed cross section, but the convex top of the press-formed plate-like workpiece W1 is formed. You may make it shape | mold the convex part provided in the surface part W2 in cross-sectional trapezoid shape.

  As described above, the present invention is not limited to the illustrated embodiments, and it goes without saying that various improvements and design changes can be made without departing from the gist of the present invention.

  The present invention relates to a method for manufacturing a metal closed cross-section member that manufactures a closed cross-section member from a metal plate-shaped workpiece, and is effective in manufacturing a vehicle body member formed in a closed cross-section shape such as a front side frame and a rear side frame. Applicable.

20 Front Side Frame 23 Right Side 35, R1, R10 Reinforcing Member 40 Draw Mold 41 Draw Mold Blank Holder 42 Draw Mold Punch 45 Draw Mold Die 45c Draw Mold Die Mold Space 60 Press Mold 61 Die of the press mold 62 Recessed portion provided in the die of the press mold 62a Bottom portion 62b, 62c of the recess provided in the die of the press mold 62d Side wall portion of the recess provided in the die of the press mold 62d Die of the press mold Groove portion 65 provided in the core 65 press mold core 65a core upper surface 65b core lower surface W1, W10, W20 plate workpiece W2 convex top surface W2a, W15a provided on the convex top surface Convex part W2d, R2d Press molding surface W3, W4 Convex side face part W3e, W4e Convex side face Protruded top wall side and opposite end portions W11 first plate W15 second plate member

Claims (9)

The plate-like workpiece is moved by relatively moving the punch of the first molding die into the molding space of the die in a state where the metal plate-like workpiece is sandwiched between the blank holder and the die of the first molding die. Projecting the workpiece in the direction of movement of the punch relative to the die and press-molding it into a convex shape, and projecting the convex shape of the plate-shaped workpiece on the convex top surface portion formed into the convex shape of the plate-shaped workpiece; A first press-molding step of molding a convex portion projecting in the opposite direction; and the press-molded plate-shaped workpiece in a state where the press-molded plate-shaped workpiece is held in a die of a second mold. By pressing the convex part in a direction in which the convex part of the plate-like workpiece protrudes by the core mold of the second molding die, the convex part of the plate-like workpiece is crushed to form a press-molded surface. The first press molding step A metal plate-like workpiece comprising: a second press-molding step in which the convex side surface portions on both sides of the convex top surface portion of the plate-like workpiece formed in the above are displaced inward to make a closed cross-section. A manufacturing method of a metal closed cross-section member for manufacturing a closed cross-section member formed in a closed cross-sectional shape from
The convex part of the plate-like workpiece is provided with a portion in which at least one of the plate thickness, strength and proof stress is larger than the other part of the convex part,
In the second press molding step, a portion in which at least one of the plate thickness, strength, and proof stress of the convex portion is larger than the other portion of the convex portion is a crush amount by which the convex portion is pressed and crushed. Is set larger than the other part of the convex part,
A method for producing a metal closed cross-section member.   A portion where at least one of the plate thickness, strength, and proof stress of the convex portion is larger than the other portion of the convex portion is fixed so that a reinforcing member for reinforcing the closed cross-section member covers the convex portion. The method for manufacturing a metal closed section member according to claim 1, wherein the metal closed section member is a portion.   The reinforcing member is provided in a portion excluding a bent ridge line portion of the plate-like workpiece that is bent when the plate-like workpiece is press-molded in the first press molding step. The method for manufacturing a metal closed cross-section member according to claim 2, wherein the metal closed cross-section member is fixed.   The reinforcing member is provided along the plate-like workpiece up to an end opposite to the convex top surface side of the convex side portion of the plate-like workpiece which is closed in the second press molding step. The method for manufacturing a metal closed cross-section member according to claim 2 or 3, wherein the metal closed cross-section member is fixed in contact with each other.   The plate-like workpiece is a tailored blank formed by welding a first plate material and a second plate material in which at least one of plate thickness, strength, and proof stress is larger than that of the first plate material. 2. The method for manufacturing a metal closed cross-section member according to claim 1, wherein a portion in which at least one of plate thickness, strength, and proof stress is larger than the other portion of the convex portion is made of the second plate material. .   In the first press molding step, the convex portion is provided continuously in the longitudinal direction of the plate-like workpiece, and at least one of the thickness, strength, and proof stress of the convex portion is another portion of the convex portion. Is larger than the other part of the convex part, and in the second press molding step, at least one of the plate thickness, strength and proof stress of the convex part is A part larger than the other part of the convex part and the other part of the convex part are press-molded to substantially the same position, and at least one of the thickness, strength and proof stress of the convex part is the other part of the convex part. 6. The larger portion is set such that the amount of crushing by crushing the convex portion by press molding is set larger than the other portion of the convex portion. Manufacturing method of metal closed cross-section member.   Between the first press molding step and the second press molding step, the plate-like end portion of the plate-like workpiece opposite to the convex top surface side of the plate-like workpiece is plate-shaped. The method for producing a metal closed cross-section member according to any one of claims 1 to 6, further comprising a bending step of bending the workpiece toward the inner side of the workpiece.   After the second press molding step, the end portions of the convex side surface portions having a closed cross section of the press-molded plate-like workpiece are opposite to the surface portions that press the convex portions of the core mold. The method for producing a metal closed cross-section member according to any one of claims 1 to 7, further comprising a final press forming step of pressing and pressing to the surface portion.   The method further comprises a welding step of welding the end portions of the convex side portions having a closed cross-section of the plate-shaped workpiece that has been press-formed after the second press-forming step. The manufacturing method of the metal closed cross-section member as described in any one of 1-8.

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