[0001]The present invention relates to a method and apparatus for manufacturing a pressed part. Specifically, the present invention relates to a method and apparatus for manufacturing a pressed part having a part or the whole of the L-shape by having a curved portion which is curved in the longitudinal direction in plan view and has a hat cross-section.
BACKGROUND
[0002]Body of an automobile is composed of a plurality of frame members obtained by by press forming (taking the case blank is steel example is later described) blank. These frame components, in order to secure the vehicle collision safety, a very important component. For example, the side sill, cross members, front pillars and the like are known as skeletal member.
[0003]
　Many of the skeletal member has a hat cross-section to partially or entirely. Hat cross-section, a top plate, and two longitudinal walls, two 凹稜 line, constituted by two flanges. Two vertical walls leads to both sides of the top plate. Two 凹稜 line leads to two vertical walls. Two flanges leads to two 凹稜 line. High strength is, in order to improve and body weight of the collision safety performance, required for the frame member.
[0004]
　Figure 16 is a perspective view illustrating with an example of the skeleton member 0 which has a straight shape in the longitudinal direction in a plan view and a side view (e.g., side sill) has a hat cross-section. Figure 17 is an explanatory view of a front pillar 0-1 is an example of a frame member having a hat section, FIG. 17 (a) a perspective view, FIG. 17 (b) is a plan view. Further, FIG. 18 (also referred to as "L-pressing part" in this specification) part having a L-shape by having a curved portion which is curved in the longitudinal direction in plan view and has a hat cross-sectional perspective showing a 1 it is a diagram.
[0005]
　By "in plan view" as used herein, means that the view frame member in a direction orthogonal to the top plate is the widest planar portion in member. Specifically, means to see the frame member 0-1 from white arrow direction in FIG. 17 (a), the watching frame member 0-1 from a direction perpendicular to the paper surface in FIG. 17 (b) It means.
[0006]
　Frame member 0 illustrated in FIG. 16 has a substantially straight shape in the longitudinal direction. In contrast, the front pillar 0-1, as shown in FIG. 17 (a), FIG. 17 (b), the having an L-like shape by having a curved portion which is curved in the longitudinal direction in plan view.
[0007]
　Front pillars 0-1, as shown in FIG. 18, includes a curved shape in an L-type longitudinally in plan view and has a hat cross-section in its lower 0-2. Specifically, the front pillar 0-1, the top plate 11, and two vertical walls 12, 14 leading to opposite sides of the top plate 11, the two leading to each of the two vertical walls 12, 14 凹稜 lines 16 and 17 When, having a hat-shaped cross-section formed by the two flanges 13 and 15 leading to each of the two 凹稜 lines 16,17. The front pillar 0-1 has a partially curved shape to the L-type in plan view by a curved portion 1a curving in the longitudinal direction.
[0008]
　Frame member 0, since it has a substantially straight shape in the longitudinal direction can be produced by primarily performing bending the blank. Frame member 0, the circumferential length of the cross section does not change significantly in the longitudinal direction. Thus, the skeletal member 0, be composed of a low high-strength steel sheet blank elongation properties, cracking and wrinkles are hardly generated at the time of press working, molding is relatively easy.
[0009]
　Patent Document 1, a method of bending a pressed part having a hat section is disclosed. The method disclosed by Patent Document 1, for manufacturing a pressed part having a substantially straight shape in the longitudinal direction of which has a hat cross-section.
　Figure 19 is a perspective view showing a produced by bending the L-shaped pressed parts 1.
[0010]
　When the method disclosed in Patent Document 1 bent L-pressing component 1 shown in FIG. 18 is molded, as shown in FIG. 19, wrinkles on the outside of the flange portion of the curved portion 1a (A portion). Therefore, L-pressing part 1 is formed by pressing a generally drawing. In the draw-forming, in order to suppress the generation of wrinkles by controlling the inflow of the blank, forming the blank with a blank holder in addition to the die and punch.
[0011]
　Figure 20 is an explanatory view showing an L-shaped pressed parts 2, FIG. 20 (a) a perspective view, FIG. 20 (b) is a plan view. Figure 21 is a plan view showing a wrinkle in the shape of the blank 3 in the case of drawing the blank 3 holding region B. Figure 22 (a) ~ FIG 22 (d) are cross-sectional views showing the process of construction and drawing of the die for drawing. Further, FIG. 23 is a perspective view of a diaphragm panel 5 which is drawing.
[0012]
　For example, for molding by draw forming an L-shaped pressed parts 2 shown in FIG. 20, as shown in FIG. 22 (a) ~ FIG 22 (d), the die 41, using the punch 42 and the blank holder 43.
　First, as shown in FIG. 22 (a), placing the blank 3 between the punch 42 and the blank holder 43 and die 41.
[0013]
　Next, as shown in FIG. 22 (b), a holding region wrinkles around the blank 3 B (hatched portion in FIG. 21) to hold strongly sandwich the blank holder 43 and die 41. Next, as shown in FIG. 22 (c), to move the die 41 in the direction of the relative punch 42.
[0014]
　Then, as shown in FIG. 22 (d), the blanks 3 at a final die 41 is pressed against the punch 42 for processing the blank 3. In this way, molded to the aperture panel 5 shown in FIG. 23.
[0015]
　During drawing, the periphery of the wrinkle holding region B of the blank 3 is held strongly sandwiched by the blank holder 43 and die 41. Therefore, the region inside the wrinkle holding region B in the blank 3 is stretched in a state in which tension loaded at the time of molding.
[0016]
　This allows forming the aperture panel 5 while suppressing the occurrence of wrinkles. Aperture panel 5 which is formed is cut off the unnecessary portion of the periphery, L-pressing component 2 shown in FIGS. 20 (a) and 20 (b) is manufactured.
[0017]
　According to the press working by drawing, it can be molded to complex shapes with the L-pressing part 2. However, as shown in FIG. 21, it is necessary to provide a large wrinkle holding region B around the blank 3. Therefore, after the molding to the panel 5 stop blanks 3, increased the portion removed by cutting as unnecessary portions, the manufacturing cost decreases the yield of the material is increased.
[0018]
　Further, in the process of molding the diaphragm panel 5, a vertical wall 2-2 and 2-4 shown in FIG. 20 (a) is molded simultaneously. Therefore, without the blank 3 is too inflow portion which is formed in the top plate 2-1 in the course of molding, the vertical wall as shown in FIG. 22 (b) ~ Figure 22 (d) 2-2 and 2-4 blank 3 from both sides of the top plate 2-1 by flowing, is molded.
[0019]
　In particular, the inner flange of the curved portion 5a which is curved in an L-shape in plan view in the diaphragm panel 5 (D portion of FIG. 23) will molding condition so-called stretch flangeability. Thus, cracking, when the blank 3 is made of low elongation and high-strength steel sheet occurs. In particular, since the tensile strength is small high-strength steel sheet elongation of at least 590 MPa, it not can be processed without generating a crack in the D portion.
[0020]
　On the other hand, the corner portion and an outer vertical wall 2-2 and the top plate 2-1 is associated curved portion 2a (C portion in FIG. 23) in FIG. 20 (a), the order is larger flared shape outward, blank 3 is extended greatly, thereby generating a low high-strength steel sheet elongation property cracking.
　It will be described in more detail. Figure 24 is a plan view for explaining the flow of material in the drawing.
[0021]
　In forming the aperture panel 5 forming the outer vertical wall 12 and an inner vertical wall 14 of the curved portion 1a at the same time. Thus, the blank 3 portions to be formed in the top plate 11 is not so much inflow, as shown in FIG. 24, the vertical wall 12 and 14, by which the material flows from both sides of the top plate 11 is molded .
[0022]
　In particular, the blank 3 portions to be formed on the inside of the curved portion 1a (D portion of FIG. 23 and 24) is moved from the inside of the curved portion 1a to the outside, it stretched larger in the radial direction of the curved portion 1a. A molded state called "stretch-flange molding". Therefore, it occurs at low high-strength steel sheet having elongation properties cracking.
[0023]
　On the other hand, C portion of FIG. 23, since it has a large overhang shape to the outside in the outer corner portion of the curved portion 1a, the blank 3 is extended significantly. Thus, as in the D portion in part C, produced at low high-strength steel sheet having elongation properties cracking.
[0024]
　For the above reason, conventionally, it can not be used less high-strength steel sheet having elongation properties, the blank 3, especially tensile strength made of a high strength steel sheet of more than 590MPa to L-shaped pressed parts 2 material excellent in stretchability the steel plate of relatively low intensity was used in the blank 3. Therefore, it is inevitable to increase the thickness of the blank 3 in order to secure a predetermined strength, it was contrary to the demands of weight reduction of the vehicle body.
[0025]
　Patent Document 2, after forming the excess thickness portion protruding to the plate thickness direction to a portion that is formed on the inside of the curved portion of the L-shaped in the blank, by performing press molding a blank formed the excess metal portion while crushing the excess thickness portion, the method for producing the L-pressing component is disclosed.
[0026]
　In the method disclosed by Patent Document 2, it is necessary to crush the excess thickness portion protruding to the plate thickness direction of the blank by press molding. Therefore, when a steel sheet of a relatively low intensity blanks and excellent elongation property is susceptible molded without causing cracking, high-strength steel sheet lower blank elongation properties, especially tensile strength or high 590MPa cracks unavoidably occur during press forming in the case of strength steel.
[0027]
　The present inventors have, by Patent Document 3, even if the press forming blank 3 tensile strength is from the above high strength steel sheet 590 MPa, a high yield without causing wrinkles and cracks, can be produced L-pressed parts invention have been disclosed. The present invention, as shown in FIG. 1 to be described later (a) ~ FIG 1 (e), through the first to third steps below, to produce an L-shaped pressed parts 1.
[0028]
　The first step: the punch 72 and the blank holder 73, the pad 74, after placing the blank 8 between the die 71 and the bending die 75, a portion to be formed in the top plate 11 in the blank 8, the pad 74 and the punch while sandwiched therebetween held by 72, to sandwich and hold the portion to be outside of the curved portion 1a than the portion to be molded in the top plate 11 in the blank 8 in the blank holder 73 and die 71 (FIGS. 1 (a) and 1 ( b)).
[0029]
　Step 2: After the first step, by processing the blank 8 by relatively moving the bending tool 75 in the direction of the punch 72 is located, an inner vertical wall 14 of the curved portion 1a, shaping the 凹稜 lines 17 and flange 15 (see FIG. 1 (c)).
[0030]
　Third step: after the second step, the blank 8 while maintaining across the blank holder 73 and die 71, the die 71 and the blank holder 73 in the direction of the blank holder 73 against a blank 8 is arranged by processing the blank 8 by relatively moving the outer vertical wall 12 of the curved portion 1a, forming the 凹稜 line 16 and the flange 13 (see FIG. 1 (d)). Then, the pad 74, by increasing the die 71 and the bending die 75 is taken out of the press part 1 which has been formed (see FIG. 1 (e)).
[0031]
　In the second step, the inside of the vertical wall 14 of the curved portion 1a, although molding a 凹稜 line 17 and the flange 15, the outer vertical wall 12 of the curved portion 1a, 凹稜 lines 16 and the flange 13 is not formed. Therefore, the blank 8 in the molded pulled only from the inside of the curved portion 1a, the portion to be formed on the top plate 11 in the blank 8 flows into the inside of the curved portion 1a.
[0032]
　Therefore, in the second step, unlike the drawing shown in FIG. 22, the portion to be molded to the inside of the curved portion 1a of the blank 8 will not move too large from the inside to the outside of the curved part 1a in the process of molding .
[0033]
　Furthermore, since the whole of the blank 8 is bent by the longitudinal direction of the distal end of the blank 8 to flow into the inside of the curved portion 1a, the inner flange 15 of the curved portion 1a is in a state of being compressed. Therefore, elongation of the inner flange 15 of the curved portion 1a at the time of molding, as compared to the drawing, is greatly reduced.
[0034]
　The inner vertical wall 14 of the curved portion 1a, in the molding process of 凹稜 lines 17 and flange 15, since the flow into the inside of the curved portion 1a portion molded to the portion and the flange 13 which is formed on the top plate 11, a state where compressive stress remained contracts in the longitudinal direction.
[0035]
　Therefore, the corner portion is a juncture of the outer vertical wall 12 and the top plate 11 of the curved portion 1a is also compressive stresses are formed from the state remaining. Thus, as compared with the drawing to be molded from the absence of compressive stress, it is small elongation of the blank is required.
[0036]
　Therefore, the metal plate of high strength at drawing the inside of the flange 15 of the curved portion 1a (e.g. tensile strength high-tensile steel plate of more than 590 MPa) which is the cracking occurs and an outer vertical wall 12 of the curved portion 1a, a top plate elongation of the blank 8 can be a small depression in the corners is a juncture between 11. Therefore, it can be formed without cracking even by using a metal plate having a low elongation and high-strength as a blank 8.
[0037]
　Moreover, inside the vertical wall 14 of the curved portion 1a, 凹稜 lines 17 and the flange 15 is bent by the bending die 75 and the punch 72. Therefore, the portion to be formed on the inner side and the longitudinal direction of the distal end portion of the curved portion 1a, the blank-holder area always provided in draw forming, it is not necessary to provide. This amount can only reduce the blank 8 may also enhance the yield of material.
CITATION
Patent Document
[0038]
Patent Document 1: JP 2006-015404 Patent Publication
Patent Document 2: JP 64-66024 Patent Publication
Patent Document 3: WO 2014/106932 pamphlet
Summary of the Invention
Problems that the Invention is to Solve
[0039]
　The present inventors have, L-pressing component formability result of intensive studies in order to further enhance, be subjected to press working by bending the blank 8 by a second step which is disclosed by Patent Document 3, that it may without causing molding defects can not be produced L-pressing part 1 has been found.
[0040]
　As such a case, for
example, (a) if the blank 8 having the above tensile strength 1180MPa ultra high-tensile steel
plate, (b) L-shaped pressed parts 1 height (the product heightwise direction of the vertical wall 12, 14 If the projection distance) 70mm or more and
high, (c) the radius of curvature R of the L-shaped pressed parts 1凹稜line 16, 17 1 if and is 10mm or less small
or curved portion in (d) L-pressing component 1 the radius of curvature R in a plan view of 1a 2 may less than 100mm and less
include. In these cases, cracks occur inside the flange 15 of the curved portion 1a in the second step disclosed in Patent Document 3.
[0041]
　Further, (e) the blank 8 may consist of more than tensile strength 1180MPa ultra high-tensile steel plate, the height of the L-shaped pressed parts 1 is 55mm or more, the radius of curvature of the L-pressing component 1凹稜line 16,17 R 1 that is 15mm or less, or, the curvature radius R inner of the curved portion 1a of the L-pressing component 1 2 even if the to satisfy at least two of things is 140mm or less, the Patent Document 3 cracks occur inside the flange 15 of the curved portion 1a in the second step disclosed.
[0042]
　The present invention enhances the forming limit of the invention disclosed in Patent Document 3, it has been made in order to solve the novel problems in the second step of the patent document 3. The present invention, if either of the above (a) ~ (e), the be subjected to press working by the second step, L-type without cracking in the inner flange 15 of the curved portion 1a and to provide a manufacturing method and a manufacturing apparatus capable of producing stamped parts 1.
Means for Solving the Problems
[0043]
　The present inventors have conducted extensive studies to solve the above problems, the following finding A ~ D of the listed is obtained, and accomplished the present invention by overlapping a further study.
　(A) during molding of the second step of forming the inner vertical wall 14 of the curved portion 1a is in the blank 8, located below the site (L type that is molded into an end portion of the extending direction of the top plate 11 portion) flows towards the site to be molded on the inside of the vertical wall 14 of the curved portion 1a. Thus, it supplied to the site where the blank 8 is formed inside the flange 15 of the curved portion 1a.
[0044]
　Therefore, in the blank 8, to the site to be molded on the inside of the vertical wall 14 of the curved portion 1a, in the blank 8, by increasing the flow rate of the portion is molded on the end of the extending direction of the top plate 11 , cracking in the inner flange 15 of the curved portion 1a can be suppressed, it is possible to improve the forming limit of the second step.
[0045]
　(B) at the time of press working, limits the amount of inner vertical wall 14 can flow to the site to be molded into a blank 8 of the curved portion 1a is a cross-sectional circumference of the flange 15 in the molding before and after the inflow direction of the cross-section of the blank 8 the amount of change in length, is determined geometrically. The limit amount is forming limit of the second step of forming a vertical wall 14 of the inner curved portion 1a.
[0046]
　(C) in the blank 8, along the portion to be molded to the inside of the flange 15 of the curved portion 1a of the L-shaped pressed parts 1 (preferably the region outside the region in the blank 8, which is molded in a press part 1), for example by both molded material inflow promoting portion such beads during the second processing, in the blank 8, portions that are formed on the end portion of the extending direction of the top plate 11 (L-shaped portion located below the) is, in the blank 8 can increase the amount flowing to the site to be molded on the inside of the flange 15 of the curved portion 1a.
[0047]
　The shape of the (D) material inflow promoting portion, by a shape that can ensure a line length difference of the material inflow direction (maximum principal strain direction deformation of the inner flange 15 of the curved portion 1a of the press part 1), the material can increase the flux amount, it is possible to increase the forming limit of the second step.
　The present invention is as listed below.
[0048]
　(1) and the punch and blank holder, the pad, the arrangement blanks between the die and the bending die, by performing press working includes first to third steps below, a top plate extending in the longitudinal direction , and two longitudinal walls leading to each side of the top plate, and two凹稜lines connected to each of the two longitudinal walls, which has a formed hat section by two flanges connected to each said two凹稜line, a method of manufacturing a pressed part having a part or the whole of the L-shape in the plan view by a curved portion which is curved in the longitudinal direction in a plan view perpendicular to the top plate,
　the following conditions 1 and 2 satisfies the method of manufacturing a pressed part;
　step 1: holds across by said pad and said punch portions are formed in the top plate in the blank, the bra The part to be molded on the outside of the curved portion than the portion that is molded into the top plate of the click pinching and holding by the blank holder and the die.
　Step 2: After the first step, by performing press working by bending a said bending tool to the blank moves relative to the direction in which the punch is placed, inside of the curved portion forming a vertical wall, and凹稜line connected to said longitudinal wall, and a flange connected to the concave ridge.
　Third step: after the second step, the blank while holding sandwich by the blank holder and the die, relatively moving the die and the blank holder in a direction in which the punch is located by performing press working by draw forming on the blank Te, the molding and the longitudinal wall of the outer of said curved portion, and凹稜line connected to said longitudinal wall, and a flange connected to the concave ridge.
　The condition 1 the second step, in the blank, along the portion to be molded to the inside of the flange of the curved portion of the press part, forming a material inlet promoting portion one or more. However, the material inflow promoting portion increases the amount that flows into the portion where the blank is formed into the inside of the flange of the bending portion.
　[Condition 2]
　The material inflow promoting unit is a sectional circumferential length in cross section along the direction perpendicular to the straight line and parallel to and the top plate in contact with the inner side of the center position of the curved portion in a plan view perpendicular to the top plate has a cross-sectional shape that increases with distance from the inner flange of the curved portion of the pressed part.
[0049]
　(2) satisfies the following condition 3 or 4, the manufacturing method of a press part according to item 1.
　[Condition 3] the blank that consists of tensile strength 1180MPa or more ultra-high-tensile steel plate, said projection distance to the press part of the height the longitudinal wall of the product height direction is 70mm or more, the pressed part radius of curvature of the凹稜line that is 10mm or less in a side view, or satisfy at least one of that inner radius of curvature of the curved portion in the pressed part is less than 100mm in the plan view of the .
　[Condition 4] the blank that consists of tensile strength 1180MPa or more ultra-high-tensile steel plate, said projection distance to the press part of the height the longitudinal wall of the product height direction is 55mm or more, the pressed part the radius of curvature of the凹稜line is 15mm or less in a side view, or, satisfies at least two or more of said inner of the curved portion in the press part curvature radius is 140mm or less in the plan view to.
[0050]
　(3) the material inflow promoting portion, in the blank, it said formed outside the region of the region to be formed into the press part, 1 or 2 manufacturing method of a press part according to paragraph.
[0051]
　(4) the material inflow promotion section, the manufacturing method of a press part according to any one of the cross-sectional circumference is partially constant 1-3 Section.
[0052]
　(5) the material inflow promoting portion, said flange and protruding bead tapering toward from the flange in the direction of arrangement of said top plate in a direction toward the top plate or the alignment direction of the flange and the top plate, in a concave bead tapering toward from said top plate in a direction towards the flange, the method of manufacturing a press part according to any one of 1-4, wherein.
[0053]
　(6) the material inflow promotion section, the manufacturing method of a press part according to any one of 1 to 5, wherein said cross-sectional peripheral length is increased stepwise.
[0054]
　(7) the material inflow promotion section, in vertical cross section including a straight line perpendicular straight lines and a horizontal plane in contact with the center of the inside of the bend at the end of the second step, the curved portion of the blank site and has an outer shape obtained by connecting the edges of the blank, method of manufacturing a pressed part according to any one of 1 to 6, wherein the inner 凹稜 lines and is shaped into association point of the flange.
[0055]
　(8) including said third following fourth step after step, 1 manufacturing method of a press part according to any one of 1-7, wherein:
　the fourth step; Molded articles obtained by the third step remaining part of the periphery of, to remove unnecessary portions comprising all or part of the material inflow promoting portion.
[0056]
　In the method of manufacturing a pressed part according to these present invention,
　punch, top plate, a vertical wall located inside the curved portion, of the leads to vertical wall凹稜lines and flange each having a thickness of the back surface side lead to the凹稜line to have the shape including the shape,
　the blank holder have a shape including a thickness back surface side of the shape of the flange leading to凹稜line and this凹稜line connected to the vertical wall positioned outside of the curved portion,
　pad, blank has a shape including a plate thickness front surface side of the shape of the top plate so as to face the holder,
　die, vertical wall located outside the curved portion, a flange, respectively leading to凹稜line and this凹稜line connected to the vertical wall of having a shape including a thickness surface of the shape,
　the bending type, vertical wall located inside the curved portion,凹稜lines connected to the vertical wall, and flanges respectively connected to the凹稜line It has a shape including a thickness surface side of the shape
is respectively preferable.
[0057]
　In the method of manufacturing a pressed part according to these present invention, the blank may be pre-processed metal plate.
　These manufacturing method of a press part according to the present invention, after completion of the third step of press parts, and fixed so as not to move relatively blank holder against the punch press part blank holder is molded the as no pressurized against the die, with respect to the blank holder and punch it may be taken out of the press part from the mold by separating relatively the pad and die and bending tool.
[0058]
　In the method of manufacturing a pressed part according to these present invention, the blank is desirably thickness is less than and at 0.8mm or 3.2 mm.
　In the method of manufacturing a pressed part according to these present invention, the width of the top plate in a plan view is a 30mm or 400mm or less, the projection distance of the height at which the vertical wall of the product height direction of the pressed parts is below 300mm be with, it is desirable that the inner radius of curvature of the curved portion in the press part is 5mm or more in plan view.
[0059]
　(9) and the punch and blank holder, pads disposed opposite to the punch and blank holder, and a die and bending tool, by performing press working includes the step of following first to third blank, longitudinal configuration and top plate extending in a direction, and two longitudinal walls leading to each side of the top plate, and two凹稜lines connected to each of the two vertical walls, the two flanges connected to each said two凹稜line Press for manufacturing a pressed part having a L-like shape in a part or the whole in the plan view by a curved portion which is curved in the longitudinal direction in a plan view perpendicular to the top plate and having a hat-shaped cross section to be the component of the manufacturing apparatus,
　satisfies the following conditions 1 and 2, the press part of the manufacturing apparatus;
　step 1: the pad, together with the punch, in the blank Holds across a portion to be formed into serial top plate, the blank holder, together with the die, across the portion which is formed on the outer side of the curved portion than the portion that is molded into the top plate of the blank holding to.
　Step 2: After the first step, the bending type, by processing the blank moves relative to the direction in which the punch is placed, a vertical wall of the inner side of the curved portion , molded and凹稜line connected to said longitudinal wall, and a flange connected to the concave ridge.
　Third step: after the second step, while the blank holder is retained across the blank with said die, said die and said blank holder and said blank holder is arranged with respect to the blank holder by processing the blank moves relative to have direction, by forming a凹稜line connected to the vertical wall and said longitudinal wall of the outer of said curved portion, a flange connected to the concave edge line, the pressed part molding a.
　[Condition 1] The bending die and the punch, by the second step, in the blank, the press part said side by side in the portion to be molded to the inside of the flange of the curved portion material inflow promoting portion one or more of comprises a material inlet promoting portion forming mechanism that forms. However, the material inflow promoting portion increases the amount that flows into the portion where the blank is formed into the inside of the flange of the bending portion.
　[Condition 2] The material inflow promoting portion forming mechanism, orthogonal the material inlet promoting portion, the straight line and the top plate are parallel in contact with the inner circumference of the center position of the curved portion in a plan view perpendicular to the top plate sectional circumference in cross section along the direction of the said to increase with increasing distance from the inner flange of the curved portion of the press part, is formed.
[0060]
　(10) further satisfies the following condition 3 or 4, the press parts manufacturing apparatus according to item 9.
　[Condition 3] the blank that consists of tensile strength 1180MPa or more ultra-high-tensile steel plate, said projection distance to the press part of the height the longitudinal wall of the product height direction is 70mm or more, the pressed part radius of curvature of the凹稜line that is 10mm or less in a side view, or satisfy at least one of that inner radius of curvature of the curved portion in the pressed part is less than 100mm in the plan view of the .
　[Condition 4] the blank that consists of tensile strength 1180MPa or more ultra-high-tensile steel plate, said projection distance to the press part of the height the longitudinal wall of the product height direction is 55mm or more, the pressed part the radius of curvature of the凹稜line is 15mm or less in a side view, or, satisfies at least two or more of said inner of the curved portion in the press part curvature radius is 140mm or less in the plan view to.
[0061]
　(11) the material inlet promoting portion forming mechanism, the material inflow promoting portion, in the blank, is formed in a region outside the region to be formed into the press part, the production of a press part according to 9 or paragraph 10 apparatus.
[0062]
　(12) the material inlet promotion section, the press part of the manufacturing apparatus of according to any one of the cross-sectional circumferential length of 9-11, wherein a partially constant.
[0063]
　(13) the material inlet promoting portion, said flange and protruding bead tapering toward from the flange in the direction of arrangement of said top plate in a direction toward the top plate or the alignment direction of the flange and the top plate, in a concave bead tapering toward from said top plate in a direction towards the flange, the press parts manufacturing apparatus according to any of 9-12, wherein.
[0064]
　(14) the material inlet promoting portion forming mechanism, at least, the said blank at the end of the first step is provided in a region in contact, pressed parts of the manufacturing apparatus according to any of 9-13, wherein.
[0065]
　(15) the material inlet promoting portion forming mechanism, the material inflow promotion section, so that the cross-sectional circumferential length increases stepwise formed, pressed parts of the manufacturing apparatus according to any one of 9-14, wherein .
[0066]
　(16) the material inlet promoting portion forming mechanism, a vertical cross section including a straight line perpendicular to the material inlet promoting portion, with the second contact in a central position inside the curved portion at the end of step lines and the horizontal plane in order to have a portion to be molded into Junction inner 凹稜 lines and the flange of the curved portion of the blank, the outer shape obtained by connecting the edges of the blank is molded, 9-15 stamping parts manufacturing apparatus according to any one of Items.
[0067]
　(17) comprising a device for performing the following fourth step after the third step, the press parts manufacturing apparatus according to any of 9-16, wherein:
　the fourth step; obtained by the third step and remaining part of the periphery of the molded article, to remove unnecessary portions comprising all or part of the material inflow promoting portion.
[0068]
　In the manufacturing apparatus pressed part according to these present invention, when the release after molding completion, it is desirable to provide a locking mechanism for fixing immovably relative blank holder against the punch.
　In the manufacturing apparatus pressed part according to these present invention, it is desirable to have the bending die and the sub-base formed integrally with supporting the pad and die vertically movably, and a die base for supporting the sub-base to freely enter and exit .
　In the manufacturing apparatus pressed part according to these present invention, the bending die and the sub-base formed integrally with supporting the die vertically movably supports the sub-base freely out to support the pad liftably die base it is desirable to have and.
Effect of the invention
[0069]
　The present invention, even if the second processing disclosed in Patent Document 3 in the case of satisfying the condition 3 or 4, forming limit increases than invention the inflow of material disclosed in Patent Document 3 can be enhanced, thereby, the L-pressing component, with good yield without causing cracks on the inside of the flange of the curved portion can be manufactured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0070]
[1] Figure 1 (a) ~ FIG 1 (e) is a cross-sectional view schematically showing a configuration and the molding process of the manufacturing apparatus according to an embodiment of the present invention.
[2] Figure 2 (a) ~ FIG. 2 (e) is a cross-sectional view showing another mold configuration example and molding step according to the embodiment of the present invention.
[Figure 2A] Figure 2A is an explanatory diagram of the configuration example shown partially manufacturing apparatus according to an embodiment of the present invention.
[Figure 2B] Figure 2B is an explanatory view showing an example of a second step of forming the inner vertical wall of the bending portion of the intermediate molded article which is press-formed partially by the production apparatus according to an embodiment of the present invention is there.
[Figure 2C] FIG 2C is an explanatory diagram showing the formation of the material inlet promoting portion forming mechanism and凹稜line in the production apparatus according to an embodiment of the present invention, the positional relationship between the blank.
FIG 2D] FIG 2D is in the conventional punch material inflow promoting portion forming mechanism is not provided, is an explanatory diagram showing a cross section corresponding to the A-A cross section in Figure 2A.
FIG 2E] FIG 2E is a positional relationship between the material inlet promoting portion forming mechanism and凹稜line forming portion and the blank in the manufacturing apparatus according to the embodiment of the present invention, B, C, in explanatory view showing a position of D cross-section is there.
FIG 2F] FIG 2F is, B, C, the flange forming portion of the punch in the D section, is a graph showing the cross-sectional circumferential length difference for a conventional punch.
[Figure 2G] Figure 2G is an explanatory diagram showing an A-A cross section in a punch material inflow promoting portion forming mechanism is provided.
FIG 2H] Figure 2H, the positional relationship between the material inlet promoting portion forming mechanism and凹稜line forming portion and the blank in the manufacturing apparatus according to the embodiment of the present invention, B, C, in explanatory view showing a position of D cross-section is there.
FIG 2I] FIG. 2I, the bending die and punch, by providing the material inlet promoting portion forming mechanism constituted by the recess and the protrusion, in illustration showing why the cracks in a portion of the blank is prevented is there.
FIG 2J] FIG. 2J (a) ~ FIG 2J (f) is formed in the punch is an explanatory diagram showing an example of the shape of the components of various materials inflow promoting portion forming mechanism.
[3] FIG. 3 (a) is a plan view showing the shape before shaping the blank, FIG. 3 (b) is a plan view showing the shape of the molding process of the blank.
[4] FIG. 4 is a plan view showing the flow of material in the embodiment of the present invention.
[5] FIG. 5 (a) ~ FIG. 5 (d) is an explanatory diagram showing an example of a mold used in the present invention.
[6] FIG. 6 (a) ~ FIG. 6 (d) is a diagram showing another example of a mold used in the present invention.
[7] FIG. 7 (a) ~ FIG. 7 (d) are explanatory views showing another example of a mold used in the present invention.
[8] FIG. 8 is an exploded perspective view of a mold shown in FIG.
[9] FIG. 9 (a) ~ FIG. 9 (c) shows the press parts for molding in the present invention Examples 1-7 and Comparative Examples 1-7, respectively, a front view, a plan view, is a right side view .
[10] FIG 10 is a plan view showing the shape of the blank used in Comparative Examples 1-7, the present invention Examples 1-7.
[11] FIG 11 is a perspective view showing the configuration of a mold used in Comparative Example 1-7.
[12] FIG 12 is a plan view showing the shape of the blank used in the present invention Examples 8 and 9.
[13] FIG. 13 (a) ~ FIG. 13 (c) shows the molded intermediate molded article shape in the present invention Examples 8 and 9, respectively, a front view, right side view, a plan view.
[14] FIG. 14 (a) ~ FIG. 14 (c) shows the shape of the pressed parts molded in the present invention Examples 8 and 9, respectively, a front view, right side view, a plan view.
[15] FIG 15 is a perspective view showing a structure of a mold for forming is carried out by the present invention in the present invention Examples 8 and 9.
[16] FIG 16 is a perspective view of an example frame member having a straight shape in the longitudinal direction in a plan view and a side view and has a hat cross-section.
[17] FIG 17 is an explanatory view of a front pillar is skeletal member having a hat section, FIG. 17 (a) a perspective view, FIG. 17 (b) is a plan view.
[18] FIG 18 is a perspective view showing an L-shaped pressed parts.
[19] FIG 19 is a perspective view showing a bent L-shaped pressed parts manufactured by molding.
FIG. 20 is an explanatory view showing an L-shaped pressed parts, FIG. 20 (a) a perspective view, FIG. 20 (b) is a plan view.
[21] FIG 21 is a plan view showing the shape of the blank in the case of drawing a blank holding area within the blank.
[22] FIG. 22 (a) ~ FIG 22 (d) are cross-sectional views showing the structure and stop the process of forming the mold for drawing.
[23] FIG 23 is a perspective view of the diaphragm panels draw forming.
[24] FIG 24 is a plan view for explaining the flow of material in the drawing.
DESCRIPTION OF THE INVENTION
[0071]
　As an example of L-shaped stamped parts produced by the present invention, an example of a method and apparatus for manufacturing a L-pressing component according to the present invention will be sequentially described.
[0072]
　1. L-pressing part 1
　to illustrate the shape in FIG. 18, L-pressing part 1 has a hat cross-section, and a curved portion 1a which is curved in L-type longitudinally in plan view.
[0073]
　Hat cross-section, a top plate 11, a vertical wall 12, and 凹稜 lines 16, 17, constituted by a flange 13, 15. Vertical wall 12 and 14 leads on each side of the top plate 11. 凹稜 lines 16 and 17 connected to each vertical wall 12,14. Flanges 13 and 15 respectively leading to 凹稜 lines 16,17. L-pressing component 1, by having a curved portion 1a, has a L-shape in plan view.
[0074]
　L-pressing component 1, and the plate thickness plate thickness less 0.8mm or 3.2 mm, or 590 MPa, the blank and the material made of high-tensile steel sheet having particularly a 1800MPa tensile strength below or 1180 MPa. The high-tensile steel plate is generally used as a frame member for an automobile.
[0075]
　The tensile strength of the blank, in order to ensure the performance such as strength as a frame member for an automobile, not less than 200 MPa, preferably 1800MPa or less. In particular, the tensile strength of the blank, 500 MPa or higher, preferably at least 590 MPa, further preferably is not less than 1180 MPa, it is possible to reduce the thickness of the blank, can reduce the weight of the L-shaped pressed parts 1.
[0076]
　When using a high-tensile steel plate of the blank, the width of the top plate 11 in a plan view is too wide, when forming the inner vertical wall 14 and the flange portion 15 of the curved portion 1a, the inflow resistance of the blank 8 increased, flows to the inside of the curved portion 1a of the blank 8 is insufficient. Therefore, it is desirable width of the top plate 11 in plan view is 400mm or less. On the other hand, if the width of the top plate 11 in a plan view is too narrow, it can not be secured pressure pad 74 to have to reduce the pressure device pad 74 such as a gas cushion. Therefore, the width of the top plate 11 is desirably 30mm or more.
[0077]
　When products projection distance in the height direction of the height of the vertical walls 12, 14 of the vertical wall 12, 14 in side view is too high, the inside of the vertical wall 14 of the curved portion 1a, 凹稜 lines 17 and the flange portion 15 inflow resistance of the blank 8 at the time of molding increases the inflow of the blank 8 into the inside of the curved portion 1a becomes insufficient. Therefore, it is desirable the height of the vertical wall 12, 14 is less than 300 mm.
[0078]
　The height of the vertical wall 12, 14 is desirably 70mm or more. If the height of the vertical wall 12, 14 is less than 70 mm, since the molding method disclosed by Patent Document 3 irrespective of the present invention can be molded L-shaped pressed parts 1 without cracking of the flange 15 .
[0079]
　The radius of curvature of the L-shaped pressed parts 1 凹稜 line 16, 17 is too small, when forming the inner side of the flange portion 15 of the curved portion 1a, the inflow of the blank 8 will be insufficient to inside of the curved portion 1a . Therefore, the radius of curvature of 凹稜 lines 16 and 17 is desirably 5mm or more in side view.
[0080]
　It is desirable in plan view a radius of curvature of the inner vertical wall 14 of the curved portion 1a is less than 100mm. If the radius of curvature is 100mm greater, by a molding method disclosed by Patent Document 3 irrespective of the present invention is because it forming an L-shaped pressed parts 1 without cracking of the flange 15.
[0081]
　The radius of curvature of 凹稜 lines 16 and 17 is desirably 10mm or less. The radius of curvature of 凹稜 line 17 is 10mm greater than the molding method disclosed by Patent Document 3 irrespective of the present invention is because it forming an L-shaped pressed parts 1 without cracking of the flange 15.
[0082]
　The blank 8 is formed of a tensile strength 1180MPa or more ultra-high tensile steel, that the product projected distance in the height direction of the vertical wall 12, 14 is the height of the L-shaped pressed parts 1 is 55mm or more, L-pressing radius of curvature of 凹稜 lines 16, 17 of the component 1 is 15mm or less in a side view, or at least of that inner radius of curvature of the curved portion 1a of the L-pressing part 1 is 140mm or less in a plan view it is preferable to satisfy two or more. This any one or if neither satisfied, because the by molding method disclosed by Patent Document 3 irrespective of the present invention can be molded L-shaped pressed parts 1 without cracking of the flange 15 .
[0083]
　Furthermore, the reduction rate of thickness of the L-shaped pressed parts 1: {(thickness maximum value - thickness minimum value) / plate thickness maximum value} × 100 is 15% or less. L-pressing part 1 having such low thickness reduction rate is not present so far. From a thickness reduction rate of the L-shaped pressed parts 1 is a structural member of the automobile body to be such low, the tensile strength of more than 200MPa steel as a blank, preferably a tensile strength of more than 590MPa high tensile steel plate, more preferably by tensile strength using the above ultra-high-tensile steel plate 1180 MPa, can be reduced thickness of the blank, it is possible to reduce the weight of the L-pressing part 1 having excellent collision safety performance. The tensile strength of the L-shaped pressed parts 1 is practically is less 1800 MPa.
[0084]
　2. L-pressing part 1 of the manufacturing method and manufacturing apparatus
　Figure 1 (a) ~ FIG 1 (e) is a cross-sectional view schematically showing a configuration and the molding process of the manufacturing apparatus according to an embodiment of the present invention.
[0085]
　In an embodiment of the present invention, in order to mold the L-shaped stamped parts 1 by performing press forming on the blank 8, using a mold shown in FIG. 1 (a) ~ FIG 1 (e).
　The mold comprises a punch 72 and a blank holder 73, the pad 74 is disposed opposite to the punch 72 and the blank holder 73, the die 71 and the bending die 75.
[0086]
　Punch 72 has a shape including an L-shaped top plate 11 of the press part 1, inside the vertical wall 14,凹稜lines 17 and flange 15 each having a thickness of the back surface side of the shape of the curved portion 1a.
　Blank holder 73 has a shape including an outer vertical wall 12, the thickness back surface side of the shape of凹稜line 16 and the flange 13 of the curved portion 1a.
[0087]
　Pad 74 has a shape including a thickness surface side of the shape of the top plate 11 so as to face the blank holder 73.
　Die 71 has a shape including an outer vertical wall 12 and flange 13 each having a thickness of the surface side of the shape of the curved portion 1a.
[0088]
　Furthermore, the bending mold 75 has a shape including an inner vertical wall 14,凹稜lines 17 and flange 15 each having a thickness of the surface side of the shape of the curved portion 1a.
　Figure 2 (a) ~ FIG. 2 (e) is a cross-sectional view showing another mold configuration and the molding step according to the embodiment of the present invention.
　The difference with the mold shown in FIG. 1 in that the locking mechanism 76 to be described later to the punch 72 is mounted.
[0089]
　Locking mechanism 76 is constituted by a freely arranged pin out against the punch 72. Locking mechanism 76 to the forming bottom dead center from the start molding (FIG. 2 (a) ~ FIG 2 (c)) is completely housed in the punch 72. Locking mechanism 76 is moved to the blank holder 73 side protrudes to secure the blank holder 73 to the punch 72 in the molding bottom dead center shown in Figure 2 (d).
[0090]
　Lock mechanism 76 releasing raise the die 71, the pad 74 and the bending die 75 in a state of fixing the blank holder 73 on the punch 72 during the release. In this way, the locking mechanism 76 prevents the molded L-pressing component 1 is damaged by pressure of a pad 74.
[0091]
　As the locking mechanism 76, the positional relationship between a molding bottom dead center after the completion of the forming and bending die 75 and the die 71 pads 74 (diaphragm type) fixed may be used a mechanism for (held) to release. For example,
　fixed bending mold 75 (a) a pad 74, also releasing fixed die 71 (aperture type) and the pad 74 or the bending die 75 at the same time,
　the blank by inserting a (b) spacer by fixing the distance between the molding bottom dead center of the holder 73 and the pad 74 is released,
　and (c) stationary the relationship with the molding bottom dead center of the pad 74 and the die 71 (diaphragm type) (holding) to release
it is exemplified.
[0092]
　Shaping the blank into L-shaped pressed parts 1 using these molds.
　Locking mechanism 76, the main body of the press, for example, lead to the blank holder 73, a control to stop the rise of the cushion pins of the press side is possible, since it is possible to stop the rise of the blank holder -73, it may not be provided in a mold such as a punch 72.
[0093]
　Figure 2A is an explanatory diagram an example of the configuration of a manufacturing apparatus 20 partially illustrated in accordance with an embodiment of the present invention. In FIG. 2A ~ Figure 2J, but give them different sign than the code attached in FIGS to mold components and blanks are for convenience of description, the configuration of the mold elements and the blank are the same It shows things.
[0094]
　As shown in FIG. 2A, the manufacturing apparatus 20 includes a bending die 21, the die 22, the blank holder 27, a punch 23 disposed opposite the bending die 21 and the die 22.
　Manufacturing apparatus 20, the die 22, the bending die 21 and the die pad 26, the arrangement blanks 24 or preformed blank between the punch 23 and the blank holder 27 (not shown), cold or warm in by performing press working to produce an L-shaped pressed parts 1 or intermediate product 1-1 thereof having an outer shape as shown in FIG. 18. As used herein, "intermediate product" means a previous press molded product to remove material inflow promoting portion which will be described later. L-type press-molded product is obtained by removing an unnecessary portion of such material inflow promoting portion from the intermediate molded article.
[0095]
　Manufacturing apparatus 20 is preferably used in the case of satisfying the above conditions 1 or 2. When satisfying the above conditions 1 or 2, when the second processing in the Patent Document 3, to produce a crack on the inside of the flange 15 of the curved portion 1a of the L-pressing component 1 obtained using the production apparatus 20 because efficacy is obtained.
[0096]
　Figure 2B is an explanatory diagram showing an example of the intermediate molded article 1-1 by the manufacturing apparatus 20 is press-molded part. Further, FIG. 2C is an explanatory view showing the material inflow promoting portion forming mechanism 25 and 凹稜 line forming portion 23b in the manufacturing apparatus 20, the positional relationship between the blank 24.
[0097]
　Manufacturing apparatus 20 performs the press working by shaping the bending of the second step disclosed by Patent Document 3, further, as shown in FIG. 2A, 2C, the bending die 21, the punch 23, the material flows promoting portion the formation mechanism 25, the recess 21a for forming the material inflow promoting unit 19 in the blank 24, the convex portions 23a are formed. Thus, material inflow promoting portion forming mechanism 25 is constituted by the convex portion 23a provided in the recess 21a and the punch 23 provided in the bending die 21.
[0098]
　Manufacturing apparatus 20, as shown in Figure 2B, during the press working by shaping the bending of the second step disclosed by Patent Document 3, in the blank 24, the curved portion 1a of the L-shaped pressed parts 1 inner flange It arranged in the vicinity of the portion to be molded to 15 to form a material inflow promoting portion 19.
[0099]
　Figure 2B, as shown in 2C, material inflow promoting portion forming mechanism 25, the material inflow promoting portion 19, in the blank 24, outside the region (hatched region in FIG. 2C) which is formed into a L-shaped pressed parts 1 it is preferably formed in a region. Thus, it becomes possible to leave no trace of material inflow promoting unit 19 in the L-shaped pressed parts 1.
[0100]
　However, when the trace of the material inlet promoting portion 19 is permitted to remain in L-pressing component 1, the area (drawing a material inflow promoting portion 19, in the blank 24 is formed into L-shaped pressed parts 1 it may be provided toward the inside of the hatched area) in 2C.
[0101]
　Next, the material inflow promoting portion forming mechanism 25 in detail.
　Figure 2D is an explanatory diagram showing a conventional punch 23-1 material inflow promoting portion forming mechanism 25 is not provided, the cross section corresponding to the A-A cross section in Figure 2A.
[0102]
　Figure 2E is an explanatory view showing the material inflow promoting portion forming mechanism 25 and 凹稜 line forming portion 23b in the manufacturing apparatus 20, the positional relationship between the blank 24, B, C, the position of D cross-section.
[0103]
　Figure 2F, B, C, the flange forming portion of the punch 23 in the D section, is a graph showing the cross-sectional circumferential length difference for a conventional punch. B in the graph of FIG. 2F, C, shows the case left of the conventional method in D section, showing a case where the right side of an embodiment of the present invention. Also, the cross section of the bottom of the graph in FIG. 2F illustrates B, C, the shape of the blank 24 in the D section.
[0104]
　Further, FIG. 2G shows the A-A cross section of the punch 23 the material flowing promoting portion forming mechanism 25 is provided.
[0105]
　When satisfying the above conditions 1 or 2, when the pressing blank 24 by the second machining for forming the vertical wall 14 of the inner peripheral side of the curved portion 1a using a conventional punch 23-1, in Figure 2D crack occurs in a portion shown.
[0106]
　FIG. 2E, as shown in 2F, in the embodiment of the present invention, by providing a material composed inflow promoting portion forming mechanism 25 by the convex portion 23a provided in the recess 21a and the punch 23 provided in the bending die 21 to form the material inflow promoting unit 19 in the intermediate product 1-1 which is press-molded.
[0107]
　Material inflow promoting portion 19, B, C, so that the cross section circumference of D cross-section increases gradually with distance from the inner surface of the curved portion 1a, is formed. Here, B, C, D cross-section, the center of increasing distance from the curved portion 1a of the inner flange 15 of the L-shaped pressed parts 1, with the inwardly curved circumferential direction of the curved part 1a in plan view perpendicular to the top plate 11 position (a portion) parallel to the line tangent to a and cross section along the direction perpendicular to the top plate (material inflow cross section: maximum principal strain direction cross section of the deformation of the inner flange 15 of the curved portion 1a of the L-shaped pressed parts 1 ) it is. This central location is not intended to be limited to the exact center position may be a predetermined area including the exact center position of the curved circumferential direction.
[0108]
　Cross-sectional shape of the material inflow promoting portion 19, moves away from the inner flange 15 of the curved portion 1a of the L-shaped pressed parts 1, not limited to the shape of a monotonically increasing, a cross-sectional circumference partially constant it may be.
[0109]
　As shown in FIG. 2F, as compared with the conventional method without the material inflow promoting portion forming mechanism 25, in the embodiment of the present invention, B, C, the flange forming portion of the punch 23 in the D section, conventional punch sectional circumferential length difference are both increased relative.
[0110]
　Furthermore, in embodiments of the present invention, the material inflow promoting portion forming mechanism 25, the cross-sectional circumferential length difference in the C section is increased than the cross section circumferential length difference in the B section, and sectional circumferential length difference in the D cross section C section to increase than the cross-section circumferential length difference in the provided.
[0111]
　In other words, in embodiments of the present invention, B, C, section line length difference D cross-section the material inflow promoting portion forming mechanism 25 having a shape which is section line length difference to increase (inflow), bending die 21 and as the recess 21a and the convex portion 23a in the punch 23, provided.
[0112]
　Material inflow promoting unit 19, for example as shown in FIG. 2G, the vertical cross section including a straight line perpendicular at the straight line and the horizontal plane in contact with the inner side of the center position of the curved portion 1a at the end of the second step, the blank 24 , a site to be molded into Junction inner 凹稜 line 17 and the flange 15 of the curved portion 1a, so as to have an outer shape obtained by connecting the edge portion 24a of the blank 24, it is illustrated to be formed.
[0113]
　Figure 2H is an explanatory view showing the material inflow promoting portion forming mechanism 25 and 凹稜 line forming portion 23b in the manufacturing apparatus 20, the positional relationship between the blank 24, B, C, the position of D cross-section.
[0114]
　As described above, for the inflow by material inflow amount of change difference of the material by the inflow promoting portion forming mechanism 25 (inflow increase in Figure 2F (without the material inflow promoting portion forming mechanism conventional method, it flows according to the method of the present invention means the increase) in the amount) is, (B sectional ⇒C sectional ⇒D section with distance from a portion of the blank 24, as indicated by the thick arrow in FIG. 2H), increases. The change difference in a portion of the blank 24 may be hardly provided for easily occurs more cracks. The area providing the change difference between inflow of material may be up to the position of the edge of the blank 24 prior to molding in a plan view.
[0115]
　Next, the function of the material inflow promoting portion forming mechanism 25.
　Figure 2I is a bending die 21 and the punch 23, by providing a material composed inflow promoting portion forming mechanism 25 by the recess 21a and the convex portion 23a, indicating the reason why the cracks in a portion of the blank 24 is prevented described it is a diagram.
[0116]
　Cause of cracks in a portion of the blank 24, the blank 24, a high tensile force F in the circumferential direction of the 凹稜 line 17 located at the top of a section. In an embodiment of the present invention, by performing the press working is provided a material inlet promoting portion forming mechanism 25, to increase the inflow of the material in the outer side than a portion. Thereby, the inflow of material from the surrounding a portion is increased, the flow amount of the material into a portion is increased.
[0117]
　That is, the material inflow promoting portion forming mechanism 25, the inflow of material into portions to be formed into a curved portion 1a of the blank 24 is increased. Therefore, although the main stress direction of deformation of this portion does not significantly change, the amount of deformation of this portion is reduced.
[0118]
　In this manner, than the case without the material inflow promoting portion forming mechanism 25, in the blank 24, the inflow of material into portions to be formed on the inner side of the flange 17 of the curved portion 1a of the L-shaped pressed parts 1 increases to.
[0119]
　Therefore, in the blank 24, the tension F in the circumferential direction of the 凹稜 line 17 located at the top of a portion can be reduced. Thus, deformation load of the part to be molded into a curved portion 1a of the blank 24 is reduced, cracks in a portion of the blank 24 can be prevented.
[0120]
　Figure 2J (a) ~ FIG 2J (f) is formed in the punch 23 is an explanatory diagram showing an example of the shape of the components of various materials inflow promoting portion forming mechanism 25.
　As the convex portion 23a which is a component of the material inflow promoting portion forming mechanism 25 provided on the punch 23, as shown in FIG. 2J (a), has been described with reference to FIG. 2G, the top plate 11 in the L-pressing component 1 it can be used a convex portion that protrudes toward the same side.
[0121]
　As shown in FIG. 2J (b), instead of the protrusions 23a shown in FIG. 2J (a), it may be used recesses 23c tapering toward the top plate 11 of the L-shaped pressed parts 1 to the other side. In this case, the bending die 21, it is needless to say that forms the convex portions corresponding to the recess 23c.
[0122]
　When the blank 24 is small, as shown in FIG. 2J (c), may be formed a convex portion 23a in a range blank 24 is in contact.
　Further, as described above with FIG. 2J (d), when a trace of material inflow promoting portion 19 is permitted to remain in L-pressing component 1, is material inflow promoting portion 19, the blank 24 , as provided over the inner region (hatched region in FIG. 2C) which is formed into a L-shaped pressed parts 1, it may be formed convex portions 23a.
[0123]
　As shown in FIG. 2J (e), the convex portion 23a may be provided two or more.
　Furthermore, as shown in FIG. 2J (f), the convex portion 23a is the thickness of the plate parallel to the direction of the blank 12 may be formed stepwise.
[0124]
　Thus, material inflow promoting portion forming mechanism 25, in the blank 24, the portion to be formed into a longitudinal end 1b of the L-pressing part 1, in the blank 24, the inner side of the curved portion 1a of the L-shaped pressed parts 11 the material inflow promoting portion 19 to increase the inflow of material into portions to be formed into the flange 15, to form one or more.
[0125]
　In FIG 2J (a) ~ FIG 2 (f), the convex portion 23a in order to clarify the components, but the recess 23c is drawn to have an edge, so that in practice does not interfere with the flow of material it goes without saying protrusion 23a, the edge of the recess 23c is to smooth R (curve) to.
[0126]
　L-pressing component 1 embodiment of the present invention is to manufacture the subject is to satisfy the condition 1 or 2 above, in the method described in the conventional patent document 3, resulting in cracks in the part a.
[0127]
　3 (a) is a plan view showing the shape before molding the blank 8, FIG. 3 (b) is a plan view showing the shape of the molding process of the blank 8. Further, FIG. 4 is a plan view showing the flow of material in the embodiment of the present invention. In FIGS. 3 and 4, is omitted material inflow promoting portion 19 and the material inflow promoting portion forming mechanism 25.
[0128]
　As shown in FIG. 1 (a), the blank 8 having the shape shown in FIG. 3 (a), the punch 72 and the blank holder 73, is disposed between the pad 74 and the die 71 and the bending tool 75.
[0129]
　Next, as shown in FIG. 1 (b), as well as sandwiched therebetween pressure and retained by the pad 74 and the punch 72 a portion to be molded in the top plate 11 in the blank 8 is formed in the top plate 11 in the blank 8 the become outer portion of the curved portion 1a than the portion to sandwich in pressure and held by a blank holder 73 and die 71.
[0130]
　Next, as shown in FIG. 1 (c), the bending tool 75 to move relatively in the direction in which the punch 72 is disposed, inside the vertical wall 14 of the curved portion 1a by working the blank 8,凹稜line by molding 17 and the flange 15, forming a blank 8 into the shape shown in FIG. 3 (b).
　At this time, the blank 8 for Hippareru from only the inside of the curved portion 1a, part is also molded flows into the inner peripheral side of the curved portion 1a sandwiched punch 72 and the blank holder 73 and the pad 74 and the die 71.
[0131]
　Therefore, unlike the case of the drawing being pulled from both outside and inside of the curved portion 1a (see FIG. 24), as shown in FIG. 4, the inner flange of the curved portion 1a (D unit), the blank 8 It does not move so large from the inside to the outside of the curved part 1a in the process of molding, further, the whole of the blank 8 is bent by the longitudinal direction of the distal end of the blank 8 flows into the inside of the curved portion 1a. Then, the inside of the flange 15 (D portion) of the curved portion 1a made on the inside of the bend is compressed. Therefore, elongation of the inner flange 15 of the curved portion 1a at the time of molding (D unit) is significantly reduced compared to drawing.
[0132]
　Furthermore, as shown in FIG. 1 (d), the inside of the vertical wall 14 of the curved portion 1a, after the end of the molding 凹稜 line 17 and the flange portion 15, the pressure across the blank 8 by the blank holder 73 and die 71 and while holding the die 71 and the blank holder 73 is moved relatively in the direction of the blank holder 73 against a blank 8 is disposed outside of the vertical wall 12 of the curved portion 1a by working the blank 8, concave forming a ridge 16 and the flange 13. In this manner, forming a L-pressing component 1 shown in FIG. 18.
[0133]
　At this time, in the molding process of the inner vertical wall 14 and the flange 15 of the curved portion 1a, since the flow into the inside of the curved portion 1a portion molded to the portion and the flange 13 which is formed in the top plate 11, the longitudinal direction squashed compressive stress become remained state. Therefore, the outer vertical wall 12 and the corner portion is a juncture between the top plate 11 of the curved portion 1a is extended significantly in the course of the molding (C portion in FIG. 4), projecting from a state in which compressive stress is remained outside It is molded into shape.
[0134]
　Therefore, as compared with the case of draw forming to be molded from the absence of compressive stress, elongation of the material required is reduced. As a result, it is possible to be used with low elongation properties high strength material (e.g. high-tensile steel sheet or 590 MPa) as the blank 8, satisfactorily molded by suppressing the occurrence of cracks.
[0135]
　During molding of the inner vertical wall 14 and the flange 15 of the curved portion 1a is to be bent by the bending die 75, there is no need to provide a wrinkle holding region on the inner peripheral side portion and the longitudinal direction of the distal end portion of the curved portion 1a . Therefore, it is possible to reduce the blank 8 can be molded with a high material yield.
[0136]
　Furthermore, as shown in FIGS. 2A ~ 2C, by pressing by the bending die 21 and the material inflow promoting portion forming mechanism 25 provided on the punch 23, the intermediate molded article 1-1, the inner flange 15 of the curved portion 1a is material inflow promoting portion 19 to increase the inflow of material into portions to be formed into the at least one form.
[0137]
　Therefore, according to the embodiment of the present invention, as described with reference to FIG. 2I, in the blank 24, material of the part to be molded on the inside of the flange 15 of the curved portion 1a of the L-shaped pressed parts 1 the amount of inflow is increased. Therefore, it is possible to reduce the tension F in the circumferential direction of the 凹稜 line 17 located at the top of a portion of the blank 24, thereby, cracks in a portion of the blank 24 can be prevented.
[0138]
　Finally, as shown in FIG. 1 (e), after the molding of the L-shaped pressed parts 1 has been completed, when taking out the L-shaped pressed parts 1 after molding from the mold, for example by locking mechanism 76, the blank holder 73 is fixed so as not to move relative to the punch 72.
[0139]
　Then, the blank holder 73 so as not pressurized by pressing the L-pressing component 1 after the forming die 71, relative to the blank holder 73 and the punch 72, the pad 74 and the die 71 and the bending die 75 and the from away in, take out. Thus, the intermediate product 1-1 after molding without damaging deformed by the pad 74 and the blank holder 73 under pressure, can be extracted.
[0140]
　Then, the retrieved remaining part of the periphery of the intermediate molded article 1-1, all or unnecessary portion including a portion of the material inflow promoting unit 19, a suitable removal device (e.g. cutting device such as this type of removal device by removing using a device) which is conventionally used as it is possible to produce L-pressing part 1 of a high strength having a desired shape.
[0141]
　The above is an outline of an apparatus for producing L-pressing component 1 will be described in more detail the structure of the mold.
　Figure 5 (a) ~ FIG. 5 (d) is an explanatory diagram showing an example of a mold used in the present invention. Locking mechanism 76 is omitted in FIGS. 5-7.
[0142]
　The mold, causes supported directly on the bending die 75 and the die (iris) 71 and the pad 74 and the respective die base 77, each driven independently relative to the die base 77. The mold can be downsized in its entirety for not using a frame or the like for supporting the bending die 75 and the drawing die 73.
[0143]
　FIG 6 (a) ~ FIG. 6 (d) is a diagram showing another example of a mold used in the present invention.
　This mold has a structure facing the pad 74 and the die 71 (diaphragm type) in the sub-base 75. The eccentric load of the pad 74 and the die 71 (diaphragm type), by receiving a sub-base 75 of the bending die and integrally, improve the deformation of the mold than the die shown in FIG. 5 (a) ~ FIG 5 (d) it can.
[0144]
　Figure 7 (a) ~ FIG. 7 (d) are explanatory views showing another example of a mold used in the present invention, FIG 8 is an exploded perspective view of the mold.
　The mold, by incorporating pad 74 to the die base 77, rather than the sub-base 75, can be avoided loadbearing putting 74 applied to the sub-base 75. For vertical load on the sub-base consisting only receive from integral bending die, it can improve the deformation of the sub-base of the mold than the die shown in FIG. 6 (a) ~ FIG 6 (d).
[0145]
　Figure 5 (a) ~ FIG 5 (d), FIG. 6 (a) ~ FIG 6 (d), the mold illustrated in FIG. 7 (a) ~ FIG. 7 (d), both, according to the present invention prepared the method is a mold having a particularly effective structure for carrying out the. However, suppressing structure deformation of the mold affects the cost and size of the mold. Therefore, part of the size and shape to be produced, further may be suitably determined whether in consideration of such intensity blank considering necessary rigidity to the mold, using a mold having any structure used.

claims

And the punch and blank holder, the pad, the arrangement blanks between the die and the bending die, by performing press working includes first to third steps below, a top plate extending in the longitudinal direction, the top panel and two longitudinal walls connected to both sides of the plate, and two凹稜lines connected to each of the two longitudinal walls, which has a formed hat section by two flanges connected to each said two凹稜line, the top plate in a plan view perpendicular to a method of manufacturing a pressed part having a L-like shape in a part or the whole in the plan view by a curved portion which is curved in the longitudinal direction,
　satisfies the following conditions 1 and 2 the method of manufacturing a pressed part;
　step 1: holds across by the top plate the pad and the punch portions being formed on in the blank, the blank The kick portion that is formed on the outside of the curved portion than the portion that is molded into the top plate pinching and holding by the blank holder and the die.
　Step 2: After the first step, by performing press working by bending a said bending tool to the blank moves relative to the direction in which the punch is placed, inside of the curved portion forming a vertical wall, and凹稜line connected to said longitudinal wall, and a flange connected to the concave ridge.
　Third step: after the second step, the blank while holding sandwich by the blank holder and the die, relatively moving the die and the blank holder in a direction in which the punch is located by performing press working by draw forming on the blank Te, the molding and the longitudinal wall of the outer of said curved portion, and凹稜line connected to said longitudinal wall, and a flange connected to the concave ridge.
　The condition 1 the second step, in the blank, along the portion to be molded to the inside of the flange of the curved portion of the press part, forming a material inlet promoting portion one or more. However, the material inflow promoting portion increases the amount that flows into the portion where the blank is formed into the inside of the flange of the bending portion.
　[Condition 2]
　The material inflow promoting unit is a sectional circumferential length in cross section along the direction perpendicular to the straight line and parallel to and the top plate in contact with the inner side of the center position of the curved portion in a plan view perpendicular to the top plate has a cross-sectional shape that increases with distance from the inner flange of the curved portion of the pressed part.
[Requested item 2]
　Satisfies the following condition 3 or 4, the manufacturing method of a press part according to claim 1.
　[Condition 3] the blank that consists of tensile strength 1180MPa or more ultra-high-tensile steel plate, said projection distance to the press part of the height the longitudinal wall of the product height direction is 70mm or more, the pressed part radius of curvature of the凹稜line that is 10mm or less in a side view, or satisfy at least one of that inner radius of curvature of the curved portion in the pressed part is less than 100mm in the plan view of the .
　[Condition 4] the blank that consists of tensile strength 1180MPa or more ultra-high-tensile steel plate, said projection distance to the press part of the height the longitudinal wall of the product height direction is 55mm or more, the pressed part the radius of curvature of the凹稜line is 15mm or less in a side view, or, satisfies at least two or more of said inner of the curved portion in the press part curvature radius is 140mm or less in the plan view to.
[Requested item 3]
　The material inflow promoting portion, in the blank, said formed outside the region of the region to be formed into the press part, a manufacturing method of a press part according to claim 1 or 2.
[Requested item 4]
　The material inflow promotion section, the manufacturing method of a press part according to any one of claims 1 to 3, wherein the cross-sectional circumference is partially constant.
[Requested item 5]
　The material inflow promoting portion, said flange and protruding bead tapering toward from the flange in the direction of arrangement of said top plate in a direction toward the top plate or the top in the arrangement direction of the flange and the top plate, a concave bead is convex toward the direction from the plate to the flange, the manufacturing method of a press part according to any one of claims 1-4.
[Requested item 6]
　The material inflow promotion section, the manufacturing method of a press part according to any one of claims 1 to 5, wherein the cross-sectional circumferential length increases stepwise.
[Requested item 7]
　The material inflow promotion section, in vertical cross section including a straight line perpendicular at the contact with the inner side of the center position of the curved portion straight line and the horizontal plane at the end of the second step, concave inner side of the curved portion of the blank site and has an outer shape obtained by connecting the edges of the blank, method of manufacturing a pressed part according to any one of claims 1 to 6, which is molded into the Junction of edges and the flanges.
[Requested item 8]
　Including the third following fourth step after step, the method of manufacturing a press part according to any one of claims 1 to 7:
　the fourth step; around the third molded article obtained by the process remaining part of, to remove unnecessary portions comprising all or part of the material inflow promoting portion.
[Requested item 9]
　And the punch and blank holder, pads disposed opposite to the punch and blank holder, and a die and bending tool, by performing press working including the blanks shown in the following 1-3 step, extending longitudinally hat comprised a top plate for standing, and two longitudinal walls leading to each side of the top plate, and two凹稜lines connected to each of the two vertical walls, the two flanges connected to each said two凹稜line manufacturing of stamped parts for manufacturing a pressed part having a L-like shape in a part or the whole in the plan view by a curved portion which is curved in the longitudinal direction in a plan view perpendicular to the top plate and having a type of cross-section an apparatus,
　satisfies the following conditions 1 and 2, the press part of the manufacturing apparatus;
　step 1: the pad, together with the punch, the top of the blank It holds across the part to be molded, the blank holder, together with the die to hold across the part to be molded on the outside of the curved portion than the portion that is molded into the top plate of the blank.
　Step 2: After the first step, the bending type, by processing the blank moves relative to the direction in which the punch is placed, a vertical wall of the inner side of the curved portion , molded and凹稜line connected to said longitudinal wall, and a flange connected to the concave ridge.
　Third step: after the second step, while the blank holder is retained across the blank with said die, said die and said blank holder and said blank holder is arranged with respect to the blank holder by processing the blank moves relative to have direction, by forming a凹稜line connected to the vertical wall and said longitudinal wall of the outer of said curved portion, a flange connected to the concave edge line, the pressed part molding a.
　[Condition 1] The bending die and the punch, by the second step, in the blank, the press part said side by side in the portion to be molded to the inside of the flange of the curved portion material inflow promoting portion one or more of comprises a material inlet promoting portion forming mechanism that forms. However, the material inflow promoting portion increases the amount that flows into the portion where the blank is formed into the inside of the flange of the bending portion.
　[Condition 2] The material inflow promoting portion forming mechanism, orthogonal the material inlet promoting portion, the straight line and the top plate are parallel in contact with the inner circumference of the center position of the curved portion in a plan view perpendicular to the top plate sectional circumference in cross section along the direction of the said to increase with increasing distance from the inner flange of the curved portion of the press part, is formed.
[Requested item 10]
　Further, to satisfy the following condition 3 or 4, the press parts manufacturing apparatus according to claim 9.
　[Condition 3] the blank that consists of tensile strength 1180MPa or more ultra-high-tensile steel plate, said projection distance to the press part of the height the longitudinal wall of the product height direction is 70mm or more, the pressed part radius of curvature of the凹稜line that is 10mm or less in a side view, or satisfy at least one of that inner radius of curvature of the curved portion in the pressed part is less than 100mm in the plan view of the .
　[Condition 4] the blank that consists of tensile strength 1180MPa or more ultra-high-tensile steel plate, said projection distance to the press part of the height the longitudinal wall of the product height direction is 55mm or more, the pressed part the radius of curvature of the凹稜line is 15mm or less in a side view, or, satisfies at least two or more of said inner of the curved portion in the press part curvature radius is 140mm or less in the plan view to.
[Requested item 11]
　The material inflow promoting portion forming mechanism, the material inflow promoting portion, in the blank, is formed in a region outside the region to be formed into the press part, a press part of a manufacturing apparatus according to claim 9 or 10.
[Requested item 12]
　The material inflow promotion section, the press part of the manufacturing apparatus of according to any of claims 9-11 wherein the cross-sectional circumference is partially constant.
[Requested item 13]
　The material inflow promoting portion, said flange and protruding bead tapering toward from the flange in the direction of arrangement of said top plate in a direction toward the top plate or the top in the arrangement direction of the flange and the top plate, a concave bead is convex toward the direction from the plate to the flange, the press parts manufacturing apparatus according to any one of claims 9-12.
[Requested item 14]
　The material inflow promoting portion forming mechanism, at least, the first of said blank at the end of step is provided in the region contacting the press part of the manufacturing apparatus according to any one of claims 9-13.
[Requested item 15]
　The material inflow promoting portion forming mechanism, the material inflow promotion section, so that the cross-sectional circumferential length increases stepwise formed, pressed parts of the manufacturing apparatus according to any one of claims 9-14.
[Requested item 16]
　The material inflow promoting portion forming mechanism, the material inflow promotion section, in a vertical cross section including a straight line perpendicular straight lines and a horizontal plane in contact with the center of the inside of the bend at the end of the second step, the a portion to be molded to the Junction of the inner 凹稜 lines and the flange of the bending portion in the blank, so as to have an outer shape obtained by connecting the edges of the blank is molded, according to claim 9-15 stamping parts manufacturing apparatus according to any.
[Requested item 17]
　Comprising a device for performing the third following fourth step after the step, the manufacturing apparatus of a press part according to any one of claims 9 to 16:
　the fourth step; molding obtained by the third step remaining part of the periphery of goods, to remove unnecessary portions comprising all or part of the material inflow promoting portion.