Technical field
[0001]
　The present invention is an automobile, various vehicles other than automobiles, home appliances, marine, process for producing the press molded product to be used in building materials, and apparatus.
Background technique
[0002]
　For example, the vehicle body of an automobile, various structural members: including (eg floor cross member, side sills, side members, etc.). The structural member, press-molded article to the material a metal plate such as a steel plate or the like is frequently used. Press molding time of the material breaking, shape fixability, and the advantage over production costs, often press-molded product is obtained by pressing by forming bending a metal plate is subjected. Press-molded product, for example, has a groove-shaped or hat-shaped cross-sectional shape. Press-molded product of the channel section includes a top plate portion and a pair of vertical wall portions extending from the top plate. Press-molded product of the hat-shaped cross-section further includes a pair of flanges extending from each longitudinal wall.
[0003]
　1 is a configuration example of a press forming apparatus that performs common bending an explanatory view schematically showing. As shown in FIG. 1, the press molding apparatus 1 is an apparatus for producing a channel section or hat-shaped cross section of the press-molded product. FIG 1 illustrates a case of manufacturing hat-shaped cross section of the press-formed article (see dashed line in the figure). Press forming apparatus 1 comprises a punch 2 as the lower mold includes a die 3 and the pad 5 to be punch 2 and the counter as an upper mold. Pad 5, the die 3, or the upper holder or slide operates in the die 3 and integrally, is supported via a pressure member 4. Pad 5 is receivable in the die 3, constituting a part of the die 3 while being accommodated in the die 3.
[0004]
　Forming bent shaped by such press forming apparatus 1 of the metal plate 6 to the press-molded product is performed as follows. Before molding, sandwich the metal plate 6 by the punch 2 and the pad 5. That is, before starting the pushing of the third metal plate 6 by the punch 2, to restrain the portion to be formed in the top plate portion of the press-molded article in the metal plate 6 by the punch 2 and the pad 5. Down the die 3 to the bottom dead center in this state. Thus, the top plate portion of the press-molded product is molded along the upper surface of the punch 2 (distal end surface) 2a. Vertical wall portion is formed along the side surface 2b of the punch 2. Ridge portion is formed between the top plate portion and the vertical wall portion. Ridge portion connecting the top plate portion and the vertical wall portion is formed along the punch shoulder part 2c of the punch 2. Hereinafter referred to as such bending to bend the forming pad shaping.
[0005]
　Recently, the automobile, in order to improve the contributing fuel to the prevention of global warming, weight reduction of the vehicle body is required. In addition, the improvement of safety at the time of collision accident is required. These requirements, as a metal plate 6 which is a material of the structural member, tensile strength or high strength steel sheet 440MPa is employed. For example, there is also a high strength steel sheet 590MPa grade is used, in some cases high-strength steel sheet 980MPa grade, even the high-strength steel sheet of the 1180MPa class is used.
[0006]
　The shape of the structural member may be relatively complicated. This interference prevents the structural member and the other member, bonding between the structural member and the other members, by design constraints such as securing the desired space.
[0007]
　FIGS. 2-8 are perspective views showing an example of the press-molded product having a relatively complicated shape. Of these figures, FIG. 2, the tensile strength of the first example is formed from the above high strength steel sheet 590MPa (DP (Dual Phase) galvannealed steel sheet thickness made of steel is 1.2 mm) It shows the press-molded product 7. 3 to 8 are respectively, a tensile strength of more high-strength steel sheet (sheet thickness galvannealed steel sheet of about 1.2 mm, the non-plated steel plate, etc.) 440 MPa second example to seventh example molded from shows the of the press-molded product 7.
[0008]
　Sectional shape of the press-molded product 7 of the first embodiment to seventh embodiment are all hat-shaped. That is, any of the press-molded product 7 is also a top plate portion 7a, a vertical wall portion 7c extending from each of the left and right ends of the top plate portion 7a, and the ridge portion 7b located between the top plate portion 7a and a vertical wall portion 7c , and a flange portion 7d extending from the lower end of each vertical wall portion 7c. Moreover, the press molded article 7 has a shape changing unit 9 in a part of the ridge portion 7b.
[0009]
　In the press-molded product 7 of the first example shown in FIG. 2, the shape changing part 9 is provided in both the ridge portion 7b at both ends of the top plate portion 7a. These shape changes section 9, approximately in the middle of the local longitudinal press-formed product 7, it is to change the height of the ridge portion 7b. In this case, the top plate portion 7a, the stepped portion 8 is formed in a region that connects the shape changing unit 9 to each other.
[0010]
　In the second example of the press-molded product 7 shown in FIG. 3, the shape changing part 9 is provided in both the ridge portion 7b at both ends of the top plate portion 7a. These shape changes section 9, a wide range approximately in the middle of the longitudinal direction of the press-molded product 7, in which the height of the ridge portion 7b is changed. In this case, corresponding to the position of the shape change unit 9, the height of the top plate portion 7a is changed gradually.
[0011]
　In the third example of the press-molded product 7 shown in FIG. 4, the shape change unit 9 to one of the ridge portion 7b at both ends of the top plate portion 7a is provided. The shape change unit 9, approximately in the middle of the local longitudinal press-formed product 7, in which a change in the arc length in the cross section of the ridge portion 7b. In this case, corresponding to the position of the shape changing portion 9, the angle of the top plate portion 7a and a vertical wall portion 7c changes.
[0012]
　In the fourth example of the press-molded product 7 shown in FIG. 5, the shape changing unit 9 is provided in both the ridge portion 7b at both ends of the top plate portion 7a. These shape changes section 9, a wide range approximately in the middle of the longitudinal direction of the press-molded product 7, in which the ridge line portion 7b is twisted. In this case, corresponding to the position of the shape change unit 9, the top plate portion 7a and the vertical wall portion 7c is twisted.
[0013]
　In the fifth example of the press-molded product 7 shown in FIG. 6, the shape changing part 9 is provided in both the ridge portion 7b at both ends of the top plate portion 7a. These shape changes section 9, a wide range approximately in the middle of the longitudinal direction of the press-molded product 7, in which the ridge line portion 7b is bent in the width direction of the press-molded product 7. In this case, corresponding to the position of the shape change unit 9, the top plate portion 7a and the vertical wall portion 7c is bent in the width direction of the press-molded product 7.
[0014]
　In a sixth example of the press-molded product 7 shown in FIG. 7, the shape change unit 9 to one of the ridge portion 7b at both ends of the top plate portion 7a is provided. Shape changing unit 9, approximately in the middle of the local longitudinal press-formed product 7, the ridge portion 7b is of recessed in the width direction of the press-molded product 7. In this case, corresponding to the position of the shape change unit 9, the top plate portion 7a and the vertical wall portion 7c is recessed in the width direction of the press-molded product 7.
[0015]
　In a seventh example of the press-molded product 7 shown in FIG. 8, the shape change unit 9 to one of the ridge portion 7b at both ends of the top plate portion 7a is provided. The shape change unit 9, a range of up to one end from substantially the center of the longitudinal direction of the press-molded product 7, in which a change in the radius of curvature in the cross section of the ridge portion. In this case, corresponding to the position of the shape change unit 9, the height of the width and the vertical wall portion 7c of the top plate portion 7a is changed.
[0016]
　The pad bending shown in FIG. 1, a high strength steel sheet, a press-molded article 7 of the first example shown in FIG. 2 when producing cold, the following problems occur. The press-molded product 7, wrinkle is generated in the area of ​​the shape change portion 9 of the ridge portion 7b, and the region near its (vertical wall portion 7c, etc.).
[0017]
　Such wrinkles can be a press-molded article 7 in the second example to seventh example shown in FIGS. 3 to 8, similarly occurs.
[0018]
　If an attempt suppress the occurrence of such wrinkles, it decreases the degree of freedom in design of the structural member. Depending on the press formability of high-strength steel sheet according to the material, because the dimensions of the shape-changing portion 9 of the ridge portion 7b is constrained.
[0019]
　The prior art to reduce the wrinkles of prevention in the press molded article, for example, disclosed in JP-A-2010-115674 (Patent Document 1) and JP 2012-024837 (Patent Document 2).
[0020]
　Patent Document 1 discloses a technique for imparting a bead of uneven vertical wall portion and the flange portion. The bead of imparting, line length difference generated in the end portion of the material before and after the bending is reduced. Thus, wrinkles are suppressed.
[0021]
　Patent Document 2, the cross-sectional shape intended for the manufacture of a press molded article is bent and the width direction is hat-shaped, discloses a technique of suppressing wrinkles occurring on the outside of the vertical wall portion or the like of the bent portion of the press-molded product. In this technique, excess thickness portion is provided is limited to the outside of the bend. During pressing, the excess thickness portion with bent in the opposite direction to the pressing direction by the upper and lower molds are sandwiched between the molds. Thus, tension is applied to the outer side of the bent portion, wrinkles can be suppressed.
CITATION
Patent Literature
[0022]
Patent Document 1: JP 2010-115674 Patent Publication
Patent Document 2: JP 2012-024837 JP
Summary of the Invention
Problems that the Invention is to Solve
[0023]
　According to the technique disclosed in Patent Document 1, the uneven shape of the bead appear in the press-molded product. Therefore, application of the technique is limited to the production of special press-molded product.
[0024]
　Disclosed in Patent Document 2 technology can not be applied to a press-molded article 7 all manufacturing the first example to seventh example described above. Further, according to the technique, since there is excess thickness portion, inevitably a decrease in yield.
[0025]
　Thus, in the prior art, the tensile strength, for example, 440MPa or more high strength steel sheet, when forming the press-molded product having a shape change in a part of the ridge portion, in the region and its vicinity of the shape-changing region it is not possible to reduce the occurrence of wrinkles in.
[0026]
　An object of the present invention, even when used in molding the press-formed product of channel section or hat-shaped cross-section having a shape changing portion in a part of the ridge portion, for example, a high strength steel sheet as a material, the shape change the method of manufacturing a press molded article that can reduce the occurrence of wrinkles in parts region and the region in the vicinity thereof, and to provide a manufacturing apparatus.
Means for Solving the Problems
[0027]
　(1) manufacturing method according to an embodiment of the present invention is a method for manufacturing a press molded article from the material.
　The press molded product is provided with a top plate portion, a vertical wall portion extending from both ends of the top plate portion, and a ridgeline portion in between said vertical wall portion and the top plate portion, the ridge portion some have a shape changing portion.
　The manufacturing method includes
　a preparation step of preparing a metal plate as the material,
　comprising a punch, as well as using the pads and the die becomes the punch pair, and a press working step of performing press working on said material.
　Said pressing step,
　by said punch and said pad, a region adjacent to at least the shape changing portion of the areas of the top plate portion, at least the shape change of the area in the region of the respective ridge portions and, a first step of forming the region from the boundary between the ridge portion and at least the shape-changing the vertical wall a region adjacent to the portion of the areas of each of the vertical wall portion to a predetermined height,
　the first Following step, in a state sandwiched with the material by the punch and the pad, and a second step of forming the remaining regions by the punch and the die.
[0028]
　In the manufacturing method of the above (1), wherein the predetermined height is, the vertical wall portion and 2mm or more from the boundary between the ridge portion is preferably less than half the total height of the vertical wall portion.
[0029]
　Manufacturing method (1) can adopt the following configuration.
　In the first step, by said punch and said pad, the whole area of the top plate portion, the entire area of the respective ridge portions, and the between the ridge portion and the vertical wall portion of the areas of the vertical wall portion shaping the region up to the predetermined height from the boundary.
　In the second step, by said punch and said die, for forming a region exceeding the predetermined height of the areas of the respective vertical wall portions.
[0030]
　Manufacturing method (1) can adopt the following configuration.
　Wherein the shape changing portion of the ridge portion is at least one of the following (a) ~ (f).
　(A) the height of the ridge portion is changed,
　the arc length is changed in (b) the ridge portion of the cross-section,
　the ridge portion is twisted (c),
　the ridge portion is bent in the width direction (d),
　(e) or recessed the ridge portion protrudes in the width direction,
　a change in radius of curvature at (f) the ridge portion of the cross section.
[0031]
　(2) manufacturing apparatus according to an embodiment of the present invention is an apparatus for manufacturing a press molded article from the material.
　The press molded product is provided with a top plate portion, a vertical wall portion extending from both ends of the top plate portion, and a ridgeline portion in between said vertical wall portion and the top plate portion, the ridge portion some have a shape changing portion.
　The manufacturing apparatus includes a punch, and the pad and the die becomes the punch pair.
　The punch tip surface corresponding to the region of the top plate, a side corresponding to the region of the respective vertical wall portions, and a punch shoulder part corresponding to a region of the respective ridge line portions.
　The pad, at least the shape-changing portion bottom surface corresponding to the region adjacent to the corner portion corresponding to a region of at least the radius variations of the area of each ridge portion of the areas of the top plate portion, and having an inner surface corresponding to the region from the boundary between the vertical wall a region adjacent to at least the shape changing portion and the ridge portion of the areas of each of the vertical wall portion to a predetermined height.
[0032]
　(3) press-molded product manufacturing apparatus according to an embodiment of the present invention includes a punch, a pad, and a die, the.
　Punch comprises front end surface, side surfaces, and a punch shoulder provided between said side surface and said tip surface. Wherein the punch shoulder portion shape changing portion is provided on part of the length of the punch.
　Pad bottom face facing the front end face of the punch, inner surface is opposed to a part of the side surface of the punch, and a corner portion opposite to the punch shoulder part is provided between the inner surface and the bottom surface provided.
　Die, in the region of the side surface of the punch comprises an inner surface facing the region except for the inner surface facing the area of the pad.
[0033]
　In the production apparatus of (2), wherein the predetermined height is, the vertical wall portion and 2mm or more from the boundary between the ridge portion is preferably less than half the total height of the vertical wall portion.
[0034]
　Manufacturing apparatus of (2) may adopt the following configuration.
　The bottom surface of the pad, corresponding to the entire area of the top plate. Wherein each corner of the pad, corresponding to the entire area of the respective ridge line portions. The inner surfaces of the pad, corresponding to the region from the boundary between the ridge portion and the vertical wall portion of the areas of the vertical wall portion to the predetermined height.
　The die has an inner surface corresponding to the area exceeding the predetermined height of the areas of the respective vertical wall portions.
[0035]
　In this manufacturing apparatus, it is preferable to employ the following configuration.
　The die is divided corresponding to the respective vertical wall.
　The manufacturing apparatus, after the pushing to the pad of the material by the punch is completed, and a die moving mechanism for moving toward the respective die to said each side of said punch.
Effect of the Invention
[0036]
　According to the present invention, even when used in molding the press-formed product of channel section or hat-shaped cross-section having a shape changing portion in a part of the ridge portion, for example, a high strength steel sheet as a material, the shape change it is possible to reduce the occurrence of wrinkles in parts region and the region in the vicinity thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037]
[1] Figure 1 is a configuration example of a press forming apparatus that performs common bending a cross-sectional view schematically showing.
FIG. 2 is a perspective view showing an example of the press-molded product having a relatively complicated shape.
FIG. 3 is a perspective view showing an example of the press-molded product having a relatively complicated shape.
[4] FIG. 4 is a perspective view showing an example of the press-molded product having a relatively complicated shape.
FIG. 5 is a perspective view showing an example of the press-molded product having a relatively complicated shape.
FIG. 6 is a perspective view showing an example of the press-molded product having a relatively complicated shape.
[7] FIG. 7 is a perspective view showing an example of the press-molded product having a relatively complicated shape.
[8] FIG. 8 is a perspective view showing an example of the press-molded product having a relatively complicated shape.
[9] FIG. 9 is a perspective view showing an example of a configuration of a manufacturing apparatus used for manufacturing a press molded article according to the first embodiment of the present invention.
[10] FIG 10 is a perspective view showing an example of a configuration of a manufacturing apparatus used for manufacturing a press molded article according to the first embodiment of the present invention.
[11] FIG 11 is a perspective view showing an example of a configuration of a manufacturing apparatus used for manufacturing a press molded article according to the first embodiment of the present invention.
FIG 12A] FIG 12A is a diagram showing a state of stamping by the manufacturing apparatus of the first embodiment, showing a state before starting the molding.
[Figure 12B] Figure 12B is a diagram showing a state of stamping by the manufacturing apparatus of the first embodiment, showing the molding initial state.
[FIG. 12C] FIG 12C is a view showing a state of stamping by the manufacturing apparatus of the first embodiment, showing a state during molding completed.
FIG 13A] FIG 13A is a diagram showing a state of stamping by the manufacturing apparatus of the second embodiment, showing a state before starting the molding.
FIG 13B] FIG 13B is a diagram showing a state of stamping by the manufacturing apparatus of the second embodiment, showing the molding initial state.
[FIG. 13C] FIG 13C is a view showing a state of stamping by the manufacturing apparatus of the second embodiment, illustrating a state during molding completed.
[Figure 14A] Figure 14A is a diagram showing a state of stamping by the manufacturing apparatus of the third embodiment, showing a state before starting the molding.
FIG 14B] FIG 14B is a diagram showing a state of stamping by the manufacturing apparatus of the third embodiment, showing the molding initial state.
FIG 14C] FIG 14C is a view showing a state of stamping by the manufacturing apparatus of the third embodiment, illustrating a state during molding completed.
[15] FIG 15 is a diagram showing the investigation results of Example.
DESCRIPTION OF THE INVENTION
[0038]
　The present inventors have made intensive studies in order to solve the above problems, we found the following findings.
[0039]
　The pad bending, when molding the channel section or hat-shaped cross section of the press-molded product having a shape change in a part of the ridge portion, a region is formed in the top plate portion of the press-molded product out of the material metal sheet It is throughout, is restrained by the punch and the pad. Meanwhile, areas that are molded into the ridge portion, and a region to be molded into the vertical wall portion, the area of ​​the top plate portion after being restrained by the punch and the pad, is processed in the order in accordance with the pushing of the punch to the die. Then, when the pushing of the punch to the die has reached a bottom dead center, the area of ​​the ridge portion and the vertical wall portion is restrained by the punch and the die. Then, when pressing a ridge portion which includes a shape changing part, the area of ​​the region and its vicinity of the shape-changing portion, the material is gathered from the surrounding areas, more than the excess meat tends to occur. The excess meat too causes wrinkles in the area of ​​the region and its vicinity of the shape-changing portion.
[0040]
　Therefore, if suppressed too excessive meat in the area of ​​the region and its vicinity of the shape-changing portion, it said that it is possible to reduce the generation of wrinkles. For this purpose, a region that restrains the initial pressing by the punch and the pad (hereinafter, also referred to as "restraining region") may be larger. Its restraint region not only the region of the top plate portion, which is a part of the region of the vertical wall portion adjacent region of the wrinkles are easily generated shape changing portion, and the shape change unit. Thus, during the press working, there is no room for the meat more than occurs in the region of the region and its vicinity of the shape-changing portion, wrinkles are reduced.
[0041]
　The present invention has been completed based on the above findings. Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0042]
　First Embodiment
　FIGS. 9 to 11 are perspective views showing an example of a configuration of a manufacturing apparatus used for manufacturing a press molded article according to the first embodiment of the present invention. Manufacturing apparatus 10 shown in FIGS. 9 to 11 are all press-molding apparatus. Press forming apparatus 10 shown in FIG. 9 is an apparatus for manufacturing a press molded article 7 of the first example of the hat-shaped cross-section shown in FIG. 2. Press forming apparatus 10 shown in FIG. 10 is an apparatus for manufacturing a press molded article 7 of the second example of the hat-shaped cross section shown in FIG. 3. Press forming apparatus 10 shown in FIG. 11 is an apparatus for manufacturing a press molded article 7 of the sixth example of the hat-shaped cross-section shown in FIG. 7.
[0043]
　Figure 12A ~ 12C are a view showing a state of stamping by the manufacturing apparatus of the first embodiment. Of these figures, FIG. 12A shows a state before start forming. Figure 12B illustrates the forming initial state. Figure 12C shows a state at the time of molding is complete. These figures show a cross-section area shape change unit.
[0044]
　As shown in FIGS. 9 to 12C, the press molding apparatus 10 includes a punch 11 as a lower die includes a die 12 and pad 13 as the upper die. That is, forming a punch 11, a die 12 and pad 13, but the pair. In order to facilitate understanding of the structure, in FIGS. 9 to 11 show a die 12 by a one-dot chain line.
[0045]
　Punch 11 has an upper surface 11a (front end face), and a punch shoulder part 11c provided between the pair of side surfaces 11b, and the upper surface 11a and side surface 11b. Punch shoulder 11c is a portion that connects the top surface 11a and side surface 11b. The shape of the upper surface 11a has a shape corresponding to the region of the top plate portion 7a of the press-molded product 7. The shape of the side surface 11b has a shape corresponding to the region of the vertical wall portion 7c of the press-molded product 7. The shape of the punch shoulder part 11c has a shape corresponding to the region of the ridge portion 7b of the press-molded product 7 (including a shape change portion 9). The punch shoulder 11c, a portion in the longitudinal direction of the punch 11, the shape changing portion is provided. The shape of the shape changing portion of the punch shoulder part 11c has a shape corresponding to the region of the shape-changing portion 9 present in the portion of the ridge portion 7b of the press-molded product 7. That is, the punch shoulder part 11c is provided with a portion where the cross-sectional shape in the longitudinal direction of the punch 11 or changes are bent extending direction of the punch shoulder part 11c.
[0046]
　Pad 13 is disposed opposite to the upper surface 11a of the punch 11. Pad 13 includes a bottom surface 13a, a pair of inner surfaces 13b, and a corner portion 13c. Corners 13c is a portion connecting the bottom surface 13a and the inner side surface 13b. The shape of the bottom surface 13a has a shape corresponding to the region of the top plate portion 7a of the press-molded product 7. That is, the bottom surface 13a faces the upper surface 11a of the punch 11, the shape is a shape to match the shape of the upper surface 11a of the punch 11. The shape of the corner portion 13c has a shape corresponding to the region of the ridge portion 7b of the press-molded product 7 (including a shape change portion 9). That is, the corner portion 13c is punched shoulder and 11c facing, its shape is a shape according to the shape of the punch shoulder part 11c. The "combined shape" means that the shape of the uneven locations facing each other across a material metal sheet has been inverted. Its inner surface 13b is opposed to a part of the side surface 11b of the punch 11. Specifically, the shape of the inner surface 13b, in a shape corresponding to the region from the boundary between the vertical wall portion 7c and the edge line portion 7b of the areas of the vertical wall portion 7c of the press-molded product 7 to a predetermined height h there (see FIG. 12C).
[0047]
　Pad 13, the upper holder operating slide integrally, are supported via a pressure member. Pressure member, a hydraulic cylinder, a gas cylinder, spring, a rubber or the like, to impart a downward force (force toward the punch 11) on the pad 13. Pad 13, as long as it is supported via a pressure member, may be supported on a slide which operates integrally with the upper holder.
[0048]
　In the first embodiment, the die 12 is divided into two, each die 12 is arranged on the outside of both sides of the pad 13. Each die 12 includes an inner surface 12a. Shape of the inner surface 12a has a shape corresponding to the region exceeding predetermined height h of the areas of the vertical wall portion 7c of the press-molded product 7. In other words, the inner surface 12a, of the area of ​​the side surface 11b of the punch 11, facing the region excluding the inner surface 13b opposite to the area of ​​the pad 13. Each die 12 may be connected to the upper holder or slide through the die moving mechanism such as a cam. Die moving mechanism, pushing the punch 11 against the pad 13 reaches the bottom dead center, after the pushing of the pad 13 of the metal plate 14 by the punch 11 has been completed, each die 12 toward each side 11b of the punch 11 obliquely moving downward (refer to the outlined arrow in FIG. 12B).
[0049]
　Method for producing a press-molded article 7 using the press forming apparatus 10 of such first embodiment includes the following preparatory steps and stamping.
[0050]
　[Preparation Step]
　As shown in FIGS. 9 to 12A, as a material, to prepare the metal plate 14. As the metal plate 14, for example, tensile strength or more can be used in high-strength steel sheet 440 MPa. The metal plate 14 may be a high-strength steel sheet 590MPa grade high-strength steel sheet 980MPa grade, or even high-strength steel sheet of 1180MPa class. Further, as the metal plate 14, a stainless steel plate, aluminum plate, it is also possible to use a copper plate or the like.
[0051]
　[Stamping]
　As shown in FIGS. 9 to 12C, the pressing process is subjected to press working by bending a metal plate 14 using a press molding apparatus 10, to produce a press-formed product 7. Hereinafter, detailed explanation of the situation in the pressing step.
[0052]
　As shown in FIG. 12A, after placing the metal plate 14 on the punch 11 lowers the slide. Thus, the pad 13 and the die 12 is lowered. Then, the pushing begins to pad 13 of the metal plate 14 by the punch 11, the bending of the metal plate 14 starts.
[0053]
　Further continuing the descent of the slide, pushing the punch 11 reaches the bottom dead center with respect to the pad 13, the processing by the punch 11 and the pad 13 is completed. Thus, as shown in FIG. 12B, the entire area of ​​the top plate portion 7a is formed. Together with this, the entire region of the ridge portion 7b including the shape-changing portion 9 is formed. Furthermore, the area up to a predetermined height h of the areas of the vertical wall portion 7c is formed.
[0054]
　After such processed by the punch 11 and the pad 13 is completed, subsequently, in a state where the constraining sandwich the metal plate 14 by the punch 11 and the pad 13, to continue the descent of the slide to the bottom dead center. Then, each die 12, the die moving mechanism, it moves obliquely downward toward the respective side faces 11b of the punch 11 so that narrows each other (refer to the outlined arrow in FIG. 12B). Thus, starts processing by the punch 11 and the die 12, the region exceeding predetermined height h of the areas of the vertical wall portion 7c is formed (see FIG. 12C). That is, the remaining area is formed by the punch 11 and the die 12. In the present embodiment, the flange portion 7d connected to the vertical wall portion 7c is also formed by the punch 11 and the die 12. Press-molded product 7 In this way, can be obtained.
[0055]
　According to the press working process using such press forming apparatus 10, the area of ​​the wrinkles are easily generated shape changing unit 9, and a part of the region of the vertical wall portion 7c adjacent to the shape-changing portion 9, the punch 11 bound from the initial processing by the pad 13 and. Therefore, when the pressing, there is no room for the meat more than occurs in the region of the region and its vicinity of the shape-changing portion 9. As a result, even when using a high-strength steel sheet as a material, it is possible to reduce the occurrence of wrinkles in the area of ​​the region and its vicinity of the shape-changing portion 9. Therefore, when manufacturing a press molded article having a relatively complicated shape, it is possible to promote the high strength, it also becomes possible to increase the degree of freedom in designing.
[0056]
　As described above, the area of ​​each longitudinal wall portion 7c adjacent to the shape-changing portion 9 is first regions forming up to a predetermined height h by the pad 13 and the punch 11, the remaining regions by subsequent die 12 and the punch 11 It is molded. The predetermined height h, the vertical wall portion 7c and the boundary between the ridge portion 7b 2 mm or more and less than half of the total height H of the vertical wall portion 7c (H / 2). The reason for this is as follows. If the predetermined height h is less than 2mm from the boundary between the vertical wall portion 7c and the ridge portion 7b, at the time of processing by the die 12 and the punch 11 after the machining region of the vertical wall portion 7c becomes wide, wrinkles It tends to occur. Wrinkle On the other hand, if the predetermined height h exceeds half of the total height H of the vertical wall portion 7c, during processing by the previous pad 13 and the punch 11, the processing region of the vertical wall portion 7c becomes extensive, also in this case There tends to occur. However, the lower limit of the predetermined height h is preferably set to 3 mm, more preferably from 5 mm. The upper limit of the predetermined height h is preferably set to 40 mm, more preferably from 20 mm.
[0057]
　Press-molded product 7, prepared target in the first embodiment, FIG. 2, a first example of the hat-shaped cross section shown in FIGS. 3 and 7, is not limited to press-molded article 7 of the second example and the sixth example. In other words, the press-molded product 7, as long as it has a shape changing unit 9 in a part of the ridge portion 7b, a third example to fifth example shown in FIG. 4 to 6, and 8, and the press molding of the seventh embodiment it may be a goods 7. In short, the shape changing portion 9 of the ridge portion 7b of the press-molded product 7 is at least one of the following (a) ~ (f).
　Height varying (a) the ridge line portion,
　the arc length is changed in (b) the ridge line portion of the cross section,
　(c) ridge portion is twisted,
　it bends in the width direction (d) ridge portion,
　(e) ridge part is recessed or protruding in the width direction,
　a change in radius of curvature at (f) the ridge line part of the cross section.
[0058]
　In the first example of the press-molded product 7 shown in FIG. 2, a crack in the area of ​​the region and its vicinity of the shape-changing portion 9 also liable to occur. According to the first embodiment, it is possible to suppress such a crack.
[0059]
　Further, the pair of ridge portions of the press-molded product may not be a parallel. For example, a pair of ridge portions may together meet at the end. The cross-sectional shape of the press-molded article, may be a groove shape with no flange portion.
[0060]
　[Second Embodiment]
　FIGS. 13A ~ FIG 13C is a diagram showing the status of the stamping operation by the manufacturing apparatus of the second embodiment. Of these figures, FIG. 13A shows a state before start forming. Figure 13B illustrates the forming initial state. Figure 13C shows a state at the time of molding is complete. These figures as well as FIG. 12A ~ FIG 12C, showing a cross section in the region of the shape-changing portion.
[0061]
　The second embodiment for a base of the above-described first embodiment, is a modification of the part. In the second embodiment, the height of the inner surface 13b of the pad 13 is higher as compared with the first embodiment. Each die 12 is arranged adjacent to both sides of the pad 13, is fixed directly to the upper holder. In other words, exceptional die moving mechanism is not provided. In the case of the second embodiment, the die 12 may be integral without being divided into two.
[0062]
　Similar to the first embodiment described above, the step of pressing the second embodiment, with the lowering of the upper die holder, first processed by the punch 11 and the pad 13 is completed (see FIG. 13B). And, to continue the descent of the upper die holder continue. Then, each die 12 is lowered as it reaches the bottom dead center (refer to the outlined arrow in FIG. 13B). Thus, by the punch 11 and the die 12, the region exceeding predetermined height h of the areas of the vertical wall portion 7c is formed (see FIG. @ 13 C). Press-molded product 7 In this way, can be obtained.
[0063]
　By the step of pressing the second embodiment, like the first embodiment described above, it is possible to reduce the occurrence of wrinkles in the area of ​​the region and its vicinity of the shape-changing portion 9. Moreover, it is not necessary to provide any special die moving mechanism in the second embodiment. Therefore, the apparatus configuration is simple.
[0064]
　[Third Embodiment]
　FIGS. 14A ~ 14C are diagrams showing the status of the stamping operation by the manufacturing apparatus of the third embodiment. Of these figures, FIG. 14A shows a state before start forming. Figure 14B illustrates the forming initial state. Figure 14C shows a state at the time of molding is complete. These figures, FIGS. 12A ~ FIG 12C, and as in FIG. 13A ~ FIG 13C, showing a cross section in the region of the shape-changing portion.
[0065]
　The third embodiment is basically the second embodiment described above, is a modification of the part. In the second embodiment described above, substantial machining area of ​​the vertical wall portion 7c by the die 12 and the punch 11 is a distal end portion of the vertical wall portion 7c (a lower end), significantly narrow. Therefore, it may be necessary additional restrike process for fine adjustment of the shape. The third embodiment is intended to improve the disadvantages of such second embodiment (increase in the number of steps).
[0066]
　Each die 12 of the third embodiment are arranged on the outside of both sides of the punch 11. Each die 12 is connected to the lower die holder or bolster via a die moving mechanism such as a cam. Further, each die 12, similarly to the first embodiment described above, but may be connected to the upper holder or slide through the die moving mechanism such as a cam. However, the die moving mechanism of the third embodiment, pushing the punch 11 against the pad 13 reaches the bottom dead center, after the pushing of the pad 13 of the metal plate 14 by the punch 11 has been completed, the respective die 12 punches 11 It moved horizontally toward each side 11b (refer to the outlined arrow in FIG. 14B).
[0067]
　Similar to the first embodiment described above, the step of pressing the third embodiment, with the lowering of the upper die holder, first processed by the punch 11 and the pad 13 is completed (see FIG. 14B). Then, it continues to continue the downward movement of the upper die holder to the bottom dead center. Then, each die 12, the die moving mechanism to move horizontally toward each side 11b of the punch 11 so that narrows each other (refer to the outlined arrow in FIG. 14B). Thus, by the punch 11 and the die 12, the region exceeding predetermined height h of the areas of the vertical wall portion 7c is formed (see FIG. 14C). Press-molded product 7 In this way, can be obtained.
[0068]
　By the step of pressing the third embodiment, similarly to the first and second embodiments described above, it is possible to reduce the occurrence of wrinkles in the area of ​​the region and its vicinity of the shape-changing portion 9. In the third embodiment, since the substantial working region of the vertical wall portion 7c by the die 12 and the punch 11 is wide, it is possible to suppress the additional restrike step can occur in the second embodiment.
[0069]
　Others The invention is not limited to the above embodiments, without departing from the scope of the present invention, it is needless to say various modifications are possible. For example, in the press forming apparatus of the above embodiment, comprises a punch as a lower mold, but a configuration in which a die and a pad as an upper mold, may be configured such that the arrangement of the upper and lower molds are inverted in the vertical Absent.
[0070]
　Also, restraint region of the top plate portion by the punch and the pad may be any region adjacent to at least the shape changing portion of the areas of the top plate. Restraint region of the ridge portion by the punch and the pad may be any region of at least the shape changing portion of the area of ​​each ridge portion. Restraint region of the vertical wall portion by the punch and the pad may be any region up to a predetermined height h a region adjacent to at least the shape changing portion of the areas of each longitudinal wall. For example, a region not adjacent to the shape-changing portion of the areas of the top plate portion may be formed by the pad may be molded by a separate pad. Region excluding the shape changing portion of the areas of the ridge portion may be formed by the pad may be shaped by the die. Regions not adjacent to the shape-changing portion of the areas of the vertical wall portion may be formed by the pad may be shaped by the die.
Example
[0071]
　It was investigated degree of occurrence of wrinkles in the case of producing a press-molded article 7 of the second example shown in FIG. 3. As the present invention example, assuming a press working according to the first embodiment shown in FIG. 12A ~ FIG 12C, was performed FEM analysis. As a comparative example, assuming a pad bending shown in FIG. 1, it was subjected to FEM analysis. In both analyzes, as a material, a plate thickness tensile 1.2mm strength with 590MPa grade DP steel. Then, either of the present invention examples and comparative examples was calculated plate thickness increase rate in the shape changing portion which wrinkles are concerned. As the thickness increase rate is high, more than meat is large, it means that the easy wrinkles occur.
[0072]
　The term thickness increase rate A is represented by the following formula (1).
　A = (t1-t0) / t0 × 100 [%] ... (1)
　formula (1), t0 represents the thickness of the pre-pressing, t1 denotes the sheet thickness after pressing.
[0073]
　Figure 15 is a diagram showing the investigation results of Example. As shown in FIG. 15, in the comparative example, the thickness increase rate of a shape changing portion exceeds 15%, wrinkles are predicted. In contrast, in the present invention examples, the thickness increase rate of a shape changing portion is suppressed to about 4%, was at a level that wrinkles are not generated.
DESCRIPTION OF SYMBOLS
[0074]
　　7: press-molded product, 7a: top plate portion, 7b: ridge
　　portion, 7c: vertical wall, 7d: flange
　　portion, 8: stepped portion, 9: shape-changing
　　portion, 10: press-forming
　　device, 11: punch, 11a : tip face, 11b:
　　side, 11c: punch
　　shoulder, 13: pad, 13a: bottom, 13b: inner
　　surfaces, 13c:
　　corner, 12: die, 12a: inner
　　surface, 14: material (metal plate)

The scope of the claims
[Claim 1]
　A method for manufacturing a press molded article from the material,
　the press molded article, a top plate portion, a vertical wall portion extending from both ends of the top plate portion, said vertical wall portion and the top plate and a ridge portion is between having some change in shape of the ridge portion,
　the manufacturing method includes
　a preparation step of preparing a metal plate as the material,
　punch, and the punch and the pair made using the pad and die, anda pressing step of performing press working on said material,
　said pressing step,
　by said punch and said pad, at least the shape changing portion of the areas of the top plate portion adjacent regions, said at least the region of the shape-changing portion, and wherein said vertical wall a region adjacent to at least the shape changing portion of the areas of the vertical wall portion of the area of each ridge portion away from the boundary between the ridge portion A first step of forming a region up to a height,
　following the first step, in a state sandwiched with the material by the punch and the pad, the shaping the remaining regions by the punch and the die 2 and a step, the method for producing a press-molded product.
[Claim 2]
　A method of press-molded product produced according to claim 1,
　wherein the predetermined height is, more than 2mm from the boundary between the ridge portion and the vertical wall portion, is less than half of the total height of the vertical wall portion, manufacturing method of the press-molded product.
[Claim 3]
　A method of press-molded product produced according to claim 1 or claim 2,
　wherein in the first step, by said punch and said pad, the whole area of the top plate portion, the entire area of the respective ridge portions and, the molding the region up to the predetermined height from the boundary between the ridge portion and the vertical wall portion of the areas of the vertical wall,
　and in the second step, by said punch and said die, each longitudinal wall portion the predetermined height forming a region exceeding manufacturing method of a press molded article of the region.
[Claim 4]
　A method of press-molded product produced according to any one of claims 1 to 3,
　wherein the shape changing portion of the ridge portion is at least one of the following (a) ~ (f) the method of the press-molded product.
　(A) the height of the ridge portion is changed,
　the arc length is changed in (b) the ridge portion of the cross-section,
　the ridge portion is twisted (c),
　the ridge portion is bent in the width direction (d),
　(e) or recessed the ridge portion protrudes in the width direction,
　a change in radius of curvature at (f) the ridge portion of the cross section.
[Claim 5]
　An apparatus for manufacturing a press molded article from the material,
　the press molded article, a top plate portion, a vertical wall portion extending from both ends of the top plate portion, said vertical wall portion and the top plate and a ridge portion is between having some change in shape of the ridge portion,
　the manufacturing apparatus, the punch and provided with a pad and a die becomes the punch pair,
　the punch, the the distal end surface corresponding to the region of the top plate, a side corresponding to the region of the respective vertical wall portions, and includes a punch shoulder part corresponding to a region of the respective ridge portions,
　the pad region of the top plate portion bottom surface corresponding to the area adjacent to at least the radius variations among, corners that correspond to the region of at least the radius variations of regions of the respective ridge portions, and of the areas of the respective vertical wall portions the vertical wall a region adjacent to at least the radius variations Having an inner surface corresponding to the region up to a predetermined height from the boundary between the ridge portion, the press-molded product manufacturing apparatus.
[Claim 6]
　The distal end surface, a punch having side surfaces, and a punch shoulder portion provided between the side surface and the tip surface, punch shape variation in a part of the longitudinal direction of the punch to the punch shoulder part is provided If,
　comprising a bottom surface opposed to the front end surface of the punch, inner surface is opposed to a part of the side surface of the punch, and a corner portion opposite to the punch shoulder part is provided between the inner surface and the bottom surface a pad,
　in the region of the side surface of the punch, including a die having an inner surface facing the region except for the inner surface facing the area of the pad, press molded product manufacturing apparatus.
[Claim 7]
　A press molded product manufacturing apparatus according to claim 5,
　wherein the predetermined height is, more than 2mm from the boundary between the ridge portion and the vertical wall portion, is less than half of the total height of the vertical wall portion, press-molded product of the manufacturing equipment.
[8.]
　A press molded product manufacturing apparatus according to claim 5 or claim 7,
　wherein the bottom surface of the pad corresponding to the entire area of the top plate portion, each corner of the pad of each ridge corresponding to the entire area corresponds to the area of said inner surfaces of said pad from the boundary between the ridge portion and the vertical wall portion of the areas of the vertical wall portion to the predetermined height,
　the die, having an inner surface corresponding to the area exceeding the predetermined height of the areas of the respective vertical wall portions, the press-molded product manufacturing apparatus.
[Claim 9]
　A press molded product manufacturing apparatus according to claim 8,
　wherein the die is divided in correspondence with the respective vertical wall portions,
　the manufacturing apparatus, the pushing to the pad of the material by the punch after completing comprises a die moving mechanism for moving toward the respective die to said each side of said punch, press molded product manufacturing apparatus.