Technical field
[0001]
　The present invention is, for example, hat-shaped cross section or channel-shaped cross section such as a high strength of the press-molded product having a press forming method and press can be produced with excellent dimensional accuracy by suppressing the occurrence of the mouth opening after press molding on the molding apparatus.
　The present application, to March 3, 2015, claiming priority based on Japanese Patent Application No. 2015-041701, filed in Japan, the contents of which are incorporated here.
Background technique
[0002]
　High-tensile steel sheet, in order to reduce the fuel efficiency of the prevention of global warming, and the improvement further safety at the time of collision accident, is widely used as automotive body components. For example, the strength members and the reinforcing member such as a side sill and side members of the motor vehicle body components, since it is considerably received by design constraints such as interference preventing or desired spatial secured with other components, require tight dimensional accuracy it is often.
[0003]
　However, the formability of the steel sheet decreases as the strength of the steel sheet is increased. Therefore, by performing the press forming high strength steel sheet, an attempt to manufacture for example the side sill inner panel having a cross-section of the hat, the spring back is liable to occur in the resulting press-molded article. Results in a decrease of the defects and yield in a subsequent step the spring back occurs (e.g. welding process). Thus, the press molded product of springback suppression consisting of high-strength steel sheet is strongly demanded.
[0004]
　Figure 15A ~ FIG. 15D, as the first conventional example performs pressing by bent along the work plate 1001 which is a high-strength steel sheet using a press-forming device 1000, the press-molded product having a cross-sectional shape of the hat 1005 is an explanatory view schematically showing a situation of manufacturing a.
[0005]
　First, a top surface 1002a of the work plate 1001 punch 1002 as illustrated in FIG 15A, the nip pressure by positioning the die pad 1004 provided in the die 1003. Next, as shown in FIG. 15B, pushing relatively punch 1002 to die 1003, further by closest the punch 1002 and die 1003, as shown in FIG. 15C, it is press-molded to be processed plate 1001. Thereafter, by releasing the die 1003 as shown in FIG. 15D, the press-molded product 1005 having a cross-sectional shape of the hat is manufactured. However, this is a press molded product 1005 that is shaped to, sometimes the angular change of the ridge line 1005b which lead to the top plate 1005a, spring back of wall warping of the vertical wall 1005c leading to ridge 1005b is generated.
[0006]
　Figure 16A ~ FIG. 16F, as a second conventional example is an explanatory view showing the suppressing press molding method the wall warp using press forming apparatus 2000A, the 2000B.
[0007]
　In this molding process, the first step shown in FIGS. 16A and 16B, by performing the press forming on the target plate 2001 using a pre processing punch 2006 and pre processing die 2007 is formed into a flange 2005d of the press-molded product 2005 to mold the portion 2001a that. Then, the second step shown in FIG. 16C ~ FIG 16E, portions 2001a, clamping pressure is positioned by a top surface 2002a of the punch 2002 and the work plate 2001 which is molded 2001a, a die pad 2004 provided in the die 2003 pushed relatively punch 2002 to die 2003 Te. In this way, the target plate 2001 when press molding, it is possible to suppress the wall warping of the press-molded product 2005 obtained. However, even in this molding method, the angle change of the ridge line 2005b in the press molded article 2005 is not resolved.
[0008]
　The applicant has Patent Document 1, the Patent Document 2, by using a die having a out freely arranged die pad, and a punch having a punch pad and out freely arranged, the angle of the vertical wall of the press-molded product the mouth opening due to the change have been disclosed suppresses invention. Figure 17A ~ FIG. 17D as a third conventional example is an explanatory view showing a press-molding method disclosed in Patent Document 2.
[0009]
　In this press molding method, as shown in FIG. 17A, a die 3009 having a die pad 3008 that is out freely arranged, the press-forming device 3000 constituted by a punch 3011 having a punch pad 3010 that is out freely arranged used. Then, as shown in FIG. 17B and FIG. 17C, the die pad 3008 and the punch pad 3010, a target plate 3001 portion 3001a is shaped corresponding to the flange at the narrow pressed state, formed into an end of the top plate 3005a to start the press molding while generating a predetermined amount of initial deflection in the portion that. Moreover, crushing the deflection in a state where the die 3009 and punch 3011 is closest (molding bottom dead center) as shown in FIG. 17D. According to such a press-molding method, it is possible to suppress the mouth opening of the vertical wall 3005c by angular variation of the ridge line 3005b of the press-molded product 3005.
[0010]
　Figure 18 is an explanatory diagram for explaining the principle of suppressing the mouth opening of the vertical wall 3005c by angular variation of the ridge line 3005b of the press-molded product 3005 by a press molding method using a press-forming device 3000 shown in FIGS. 17A ~ FIG 17D it is.
[0011]
　As shown in FIG. 18, in this press-molding process, the deflection imparted to the target plate 3001 in the press forming by the die pad 3008 and the punch pad 3010, it is crushed to the forming end (molding bottom dead center). Accordingly, (A portion in FIG. 18) sites flowing to the portion to be formed from the portion to be molded into ridge 3005b vertical wall 3005c in target plate 3001, and, B unit at a site granted deflection (FIG. 18 ) to, it is possible to generate a mouth closing direction moment. Therefore, the mouth open moment is offset occurring ridge, it is possible to suppress the mouth opening of the vertical wall 3005C.
CITATION
Patent Literature
[0012]
Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-82660
Patent Document 2: Japanese Laid-Open Patent Publication No. 2012-51005
Summary of the Invention
Problems that the Invention is to Solve
[0013]
　Figure 19 is an explanatory diagram showing an example of the cross-sectional shape of the patent document disclosed press-forming method by 2 (third conventional example) press-molded product 3005 produced by.
[0014]
　The present inventors have found that in the disclosed press-molding method in Patent Document 2, the height h of the press-molded article 3005 is high, the initial to keep the dimensional accuracy of the bore opening of the vertical wall 3005c in the tolerance amount of deflection setting the allowable range becomes narrow (e.g. 0.5 mm), the management of the initial deflection amount in the field of actual production was found that sometimes becomes practically difficult.
[0015]
　Further, the present inventors have found that in the disclosed press-molding method in Patent Document 2, a predetermined initial deflection amount by the die pad 3008 and a punch pad 3010 (Distance from the punch shoulder and upper work boards 3001; for example 10 mm) by bending a portion to be molded to the end portion of the top plate 3005a for performing press forming, as shown in FIG. 19, a top plate 3005a of the press-molded product 3005 in target plate 3001 in the press-forming gives, habit bending due to the deflection in the molding 3005e, 3005e may remain, the dimensional accuracy of the top plate 3005a has found that it may not fall within the tolerance.
[0016]
　An object of the present invention, Patent Document 1, as in the invention disclosed in Patent Document 2, while generating a deflection of a predetermined amount of the top plate from the molding initial press-molding, press molding squeezing the deflection molding Late in the method, to expand the initial deflection amount of the allowable setting range for dimensional accuracy securing the mouth opening of the vertical wall, and further, the size of the top plate surface due to deflection to be generated by the end of the top plate in the press forming to improve the accuracy, it is to provide a technique for realizing a simple method.
Means for Solving the Problems
[0017]
　The present invention is summarized as follows.
[0018]
(1) the first aspect of the present invention, a punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed; disposed opposite to the punch, the punch shoulder part and corresponding die bottom end shoulder, the die bottom end Kataren portion, wherein the die pad accommodating portion provided at the die bottom end Kataren portion and the dies formed; is disposed in the punch pad accommodating portion, the punch a punch pad plate pressing surface is formed; press forming to produce a press-molded product from the target plate using a press molding apparatus comprising a; is disposed in the die pad accommodating portion, and the die pad die plate pressing surface is formed a method, when nipped the target plate by said and said die punch, the die side of the section between the point where the are in contact with the die pad and the die bottom end shoulder portion of the work plate faces the die and the Ipaddo and a non-contact, and the end surface adjacent to the punch shoulder part of the punch plate pressing surface is in the punch inside side of the punch shoulder part flush or the punch shoulder.
(2) In the press molding method according to (1), when nipped the target plate by said and said die punch, the end surface adjacent to the punch shoulder part of the punch plate pressing surface is the it may be a punch shoulder flush.
(3) In the press molding method according to (2), said die and from a state in which nipped the target plate by said punch, may push further the die pad to the punch side.
(4) In the press molding method according to (1), when nipped the target plate by said and said die punch, the end surface adjacent to the punch shoulder part of the punch plate pressing surface is the it may be the punch inner side than the punch shoulder.
(5) above (1) press-molding method according to any one of - (4) may be bent.
[0019]
(6) A second aspect of the present invention includes a punch punch shoulder and the punch Kataren portion and the punch pad accommodating portion is formed; die disposed opposite to the punch, corresponding to the punch shoulder part a bottom end shoulder, the die bottom end Kataren portion, wherein the die pad accommodating portion provided at the die bottom end Kataren portion and the dies formed; is disposed in the punch pad accommodating portion, the punch plate pressing surface There punch pad formed; disposed on the die pad accommodating portion, and the die pad die plate pressing surface is formed; equipped with, in the punch in a section from the punch shoulder to the edge of the punch pad accommodating portion a press forming apparatus having a recess formed on the inner side of the punch than the punch shoulder.
[0020]
(7) A third aspect of the present invention, a punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed; disposed opposite to the punch, the punch shoulder part and corresponding die bottom end shoulder, the die bottom end Kataren portion, wherein the die pad accommodating portion provided at the die bottom end Kataren portion and the dies formed; is disposed in the punch pad accommodating portion, the punch a punch pad plate pressing surface is formed; disposed on the die pad accommodating portion, and the die pad die plate pressing surface is formed; equipped with, the die bottom end Kataren portion of the die, the die bottom in the section from Tankata portion to the edge of the die pad receiving portion, a press-molding apparatus recess is formed on the inner side of the die than the die bottom end shoulder.
[0021]
(8) a fourth aspect of the present invention, a punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed; disposed opposite to the punch, the punch shoulder part and corresponding die bottom end shoulder, the die bottom end Kataren portion, wherein the die pad accommodating portion provided at the die bottom end Kataren portion and the dies formed; is disposed in the punch pad accommodating portion, the punch a punch pad plate pressing surface is formed; disposed on the die pad accommodating portion, and the die pad die plate pressing surface is formed; wherein the punch pad accommodating portion in the punch as the edge of the punch shoulder part provided, the width of the punch plate pressing surface is narrower than the width of the punch pad accommodating portion, the end portion of the punch plate pressing surface is on a plane perpendicular to the pressing direction, and an end portion of the die plate pressing surface pre-located in the same position It is a molding apparatus.
[0022]
(9) A fifth aspect of the invention, a punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed; disposed opposite to the punch, the punch shoulder part and corresponding die bottom end shoulder, the die bottom end Kataren portion, wherein the die pad accommodating portion provided at the die bottom end Kataren portion and the dies formed; is disposed in the punch pad accommodating portion, the punch a punch pad plate pressing surface is formed; disposed on the die pad accommodating portion, and the die pad die plate pressing surface is formed; wherein the die pad accommodating portion in the die of the die bottom end shoulder end the provided as edge, the width of the die plate pressing surface is narrower than the width of the die pad receiving portion, an end portion of the die plate pressing surface is on a plane perpendicular to the pressing direction, the end of the punch plate pressing surface press in the same position as the part It is in the form equipment.
[0023]
(10) (6) In the press forming apparatus according to any one of - (9), in a state in which said said punch die is closest, the die plate pressing surface of the die pad from the punch shoulder to deflection residual of the work plate corresponding to the area to the end (expanded portion), the die and the die pad may be a non-contact.
(11) above (6) in a press molding apparatus according to any one of - (10), from a state where said die and said punch is closest, further driver pushing toward the die pad to said punch it may have.
(12) above (6) in a press molding apparatus according to any one of - (11), the width of the die plate pressing surface may be substantially equal to the width of the punch plate pressing surface.
(13) above (6) press-forming apparatus according to any one of - (12) may be a cold press forming apparatus.
Effect of the invention
[0024]
　According to the present invention, in a state in which the punch and die is closest deflection residual at the site deflection is formed on the end portion of the top plate of the work plate in press forming (bulge having a small curvature shape) because it is not crushed, it is possible to suppress the generation of moment occurs when the crushed residue deflection.
　That is, the R blind parts to be molded on the top plate in the target plate, in until a position in contact with the die pad and the end portion of the punch pad, punch, that a gap is provided between the die and the work plate can, regardless of the initial deflection amount, it is possible to suppress variation in the mouth closing direction moment generated in the portion to be molded on the top plate of the target plate, it is possible to widen the allowable setting range of the initial deflection amount.
　Accordingly, to expand the initial deflection amount of the allowable setting range to ensure the dimensional accuracy by suppressing mouth opening in the vertical wall within the tolerance can be realized by a simple method.
　Further, when the nipped the target plate by the die and punch, if the end surface adjacent to the punch shoulder part of the punch plate pressing surface is pressed to the punch inner side than the punch shoulder, the bending habit of the top plate can be eliminated, it is possible to ensure the dimensional accuracy of the top plate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025]
[1] is an explanatory diagram showing a cross-sectional shape of the press-molded product to manufacture in the embodiment of the present invention.
[Figure 2A] is a schematic diagram for explaining a press-forming method according to a first embodiment of the present invention, showing a state in which nipped the steel sheet by the die pad and the punch pad.
[Figure 2B] is a schematic diagram for explaining a press-forming method according to the embodiment, showing a state of an initial stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[Figure 2C] is a schematic diagram for explaining a press-forming method according to the embodiment, showing the state of the late stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[FIG 2D] is a schematic diagram for explaining a press-forming method according to the embodiment, showing a state immediately before the die and punch are closest together.
[FIG 2E] is a schematic diagram for explaining a press-forming method according to the embodiment, showing a state in which the die and punch was closest.
[Figure 3A] is a schematic diagram for explaining a press-forming method according to a second embodiment of the present invention, showing a state in which nipped the steel sheet by the die pad and the punch pad.
[Figure 3B] is a schematic diagram for explaining a press-forming method according to the embodiment, showing a state of an initial stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[Figure 3C] is a schematic diagram for explaining a press-forming method according to the embodiment, showing the state of the late stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
It is a schematic diagram for explaining a press-forming method according to FIG. 3D] the same embodiment, showing a state in which the die and punch was closest.
[Figure 4A] is a schematic diagram for explaining a press-forming method according to a third embodiment of the present invention, showing a state in which nipped the steel sheet by the die pad and the punch pad.
[Figure 4B] is a schematic diagram for explaining a press-forming method according to the embodiment, showing a state of an initial stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[Figure 4C] is a schematic diagram for explaining a press-forming method according to the embodiment, showing the state of the late stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[Figure 4D] is a schematic diagram for explaining a press-forming method according to the embodiment, showing a state immediately before the die and punch are closest together.
It is a schematic diagram for explaining a press-forming method according to FIG. 4E] the same embodiment, showing a state in which the die and punch was closest.
[Figure 5A] is a schematic diagram for explaining a press-forming method according to a fourth embodiment of the present invention, showing a state in which nipped the steel sheet by the die pad and the punch pad.
[Figure 5B] is a schematic diagram for explaining a press-forming method according to the embodiment, showing a state of an initial stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[Figure 5C] is a schematic diagram for explaining a press-forming method according to the embodiment, showing the state of the late stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[Figure 5D] is a schematic diagram for explaining a press-forming method according to the embodiment, showing a state immediately before the die and punch are closest together.
It is a schematic diagram for explaining a press-forming method according to FIG. 5E] the same embodiment, showing a state in which the die and punch was closest.
[Figure 6A] is a schematic diagram for explaining a press-forming method according to a first modification of the present invention, showing a state in which nipped the steel sheet by the die pad and the punch pad.
[Figure 6B] is a schematic diagram for explaining a press-forming method according to the modified example, showing a state of an initial stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[Figure 6C] is a schematic diagram for explaining a press-forming method according to the modified example, showing a state of a later stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
It is a schematic diagram for explaining a press-forming method according to FIG. 6D] the modification, showing a state in which the die and punch was closest.
It is a schematic diagram for explaining a press-forming method according to FIG. 6E] the modification, from a state in which the die and punch is closest, showing a further state pushed the die pad to the punch side.
[Figure 7A] is a schematic diagram for explaining a press-forming method according to a second modification of the present invention, showing a state in which nipped the steel sheet by the die pad and the punch pad.
[Figure 7B] is a schematic diagram for explaining a press-forming method according to the modified example, showing a state of an initial stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[Figure 7C] is a schematic diagram for explaining a press-forming method according to the modified example, showing a state of a later stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
It is a schematic diagram for explaining a press-forming method according to FIG. 7D] the modification, showing a state in which the die and punch was closest.
It is a schematic diagram for explaining a press-forming method according to FIG. 7E] the modification, from a state in which the die and punch is closest, showing a further state pushed the die pad to the punch side.
8 is an explanatory view showing the dimensions of the press-molded product having a cross-sectional shape of the hat-analyzed in the Examples and Comparative Examples.
It is an explanatory diagram for illustrating the dimensions of each part of the press-forming device according to [9] The present invention analyzed in Examples.
It is a graph showing the results of numerical analysis of [10] Examples 1 and 2 and Comparative Example 1.
11 is an explanatory diagram showing an analysis result of Comparative Example 1 and Example 2.
FIG. 12 is an explanatory diagram showing an analysis result of Comparative Example 1 and Example 1 and Example 2.
FIG. 13 is an explanatory diagram showing an analysis result of Example 1 and Example 2.
FIG. 14 is an explanatory diagram showing an analysis result of Example 1 and Example 2.
[Figure 15A] is a schematic diagram for explaining a press-forming method according to the first conventional example, showing a state in which nipped the steel sheet by the die pad and the punch.
[Figure 15B] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state in which lowering the die while nipped the steel sheet by the die pad and the punch.
[Figure 15C] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state in which the die and punch was closest.
[FIG 15D] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state in which release of the die.
[Figure 16A] is a schematic diagram for explaining a press-forming method according to the second conventional example, showing a state where the steel sheet by a punch pad of the pre processing die and pre processing punch are nipped.
[Figure 16B] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state where the pre-processing die and pre processing punch by closest steel is pre processed.
[Figure 16C] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state in which nipped by the die pad and the punch pre-processed steel sheet.
[FIG 16D] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state in which lowering the die while nipped the pre-processed steel sheet by the die pad and the punch.
[FIG 16E] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state in which the die and punch was closest.
FIG. 16F] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state in which release of the die.
[Figure 17A] is a schematic diagram for explaining a press-forming method according to the third conventional example, showing a state in which nipped the steel sheet by the die pad and the punch pad.
[Figure 17B] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state of an initial stage of lowering the die while nipped the steel sheet by the die pad and the punch pad. .
[Figure 17C] is a schematic diagram for explaining a press-forming method according to the prior art, showing a state of a later stage of lowering the die while nipped the steel sheet by the die pad and the punch pad.
[FIG 17D] is a schematic diagram for explaining a press-forming method according to the conventional example, illustrating a state in which closest to the die and punch.
FIG. 18 is an explanatory diagram for explaining the principle of suppressing the mouth opening of the vertical wall of the third conventional example prepared by press molding method according to the press-molded product shown in FIGS. 17A ~ FIG 17D.
19 is an explanatory diagram showing an example of a third conventional example cross-sectional shape of the press-molded article produced by a press molding method according to the shown in FIG. 17A ~ FIG 17D.
DESCRIPTION OF THE INVENTION
[0026]
　The present inventors have made intensive studies in order to solve the above problems, with the listed findings (A) ~ (C) below, and have completed the present invention.
[0027]
(A) to the direction deflection is generated in the portion which is molded into the top plate of the work plate in press forming adversely direction pushing shape molding bottom dead center, and the portion that is formed on the top plate of the work plate end from R blind, during the period until a position in contact with the end portion of the die pad, by providing a gap between the die and the die pad and the target plate, regardless of the initial deflection amount of the top plate in the work plate the portion to be molded can suppress the fluctuation of the mouth closing direction moments occurring part, it is possible to widen the allowable setting range of the initial deflection amount.
[0028]
(B) moiety by the die pad and the punch pad during press molding start keep the target plate pressed narrow at a position close to the die than the punch shoulder part, during press molding to be molded to the end portion of the top plate in the work plate perform molding giving the deflection of the predetermined amount, a predetermined in a press molding method to collapse the deflection in the press molding end, the interior of the top surface of the facing punch portion to be molded to the end portion of the top plate in the work plate may be provided a deep recess, by pushing a predetermined amount to offset the curl of the top plate in the press-in depth of the recess in the molding bottom dead center, can eliminate the curl of the top plate, the dimensional accuracy of the top plate can be ensured, it is possible to provide a gap between the die and the die pad and the target plate mentioned in (a).
[0029]
When pushed by the die pad in the depth direction of the recess in the molding bottom dead center portion that is formed on the top plate of the (C) target plate, the target plate during the molding die and the punch narrow pressed by a predetermined pressure by loading it can be pushed while applying tension to the work plate. Therefore, it is possible to reduce the deflection remaining at the end of the top plate, can be secured dimensional accuracy of the top plate.
[0030]
　Hereinafter, the present invention has been made based on new knowledge of the above, based on the embodiment will be described in detail.
　Note that the following embodiments, by pressing in a cold press forming apparatus steel plate S as the target plate, the cross section of the hat, as shown in Figure 1 the shape of the press-molded product (hereinafter, press-molded product 1 It will be described for producing a referred to as).
　The press-molded product 1 includes a top plate 1a, a pair of ridge lines 1b continuous with the top plate 1a, a 1b, two vertical walls 1c contiguous to the pair of ridge lines 1b, 1b, and 1c, two vertical walls 1c has a flange 1d for each successive 1c, and a 1d.
[0031]
(First Embodiment)
　With reference to FIGS. 2A ~ Figure 2E described molding press method according to the first embodiment of the present invention. In the present embodiment, by pressing a steel plate S by using the press forming apparatus 100, to produce a press-molded product 1. The steel sheet S, using pre-processed steel sheet by press molding shown in FIGS. 16A and 16B. Figure 2A ~ 2E are explanatory views over time showing a process of manufacturing a press molded article 1 from the steel plate S by press forming apparatus 100. In the figure, Y-direction is press-molding direction, X direction is the width direction.
[0032]
(Press forming apparatus 100)
　as shown in FIG. 2A, the press molding apparatus 100 includes a punch 110, the die 120, a punch pad 130, composed of a die pad 140.
[0033]
(Punch 110)
　punch 110 is arranged opposite the die 120 so as to sandwich the steel sheet S, has a pair of punch shoulder portion 111, a punch Kataren portion 113, a punch pad accommodating portion 115.
　A pair of punch shoulder part 111 is a portion corresponding to the R portion of the inner surface of the ridge 1b, 1b of the press-molded product 1 (the surface of the punch 110 side).
　Punch Kataren portion 113 of the upper surface of the punch 110, is a site formed so as to connect between the punch shoulder part 111 and the punch pad accommodating portion 115. In the present embodiment, the punch Kataren portion 113 has a concave shape over the punch shoulder 111 on the punch pad housing portion 115.
　Punch pad accommodating portion 115, at least in part between a pair of punch shoulder part 111, is a depression housed movable around a punch pad 130.
[0034]
(Die 120)
　die 120 is disposed opposite to the punch 110 so as to sandwich the steel sheet S, a pair of die bottom end shoulder 121, and the die bottom end Kataren portion 123, a die pad accommodating portion 125 having.
　Die bottom end shoulder 121 is a portion corresponding to the outer surface of the ridge 1b, 1b of the press-molded product 1 (the surface of the die 120 side). In the example shown in this embodiment, the die bottom end shoulder portion 121 is formed on the R portion having a predetermined radius of curvature, even if the die bottom end shoulder 121 is formed at the corner portion having a predetermined angle good. If the die bottom end shoulder 121 is formed at the R portion having a predetermined radius of curvature, the die bottom end shoulder 121 is a portion between the R blind two points in the R unit.
　Die bottom end Kataren portion 123 is a portion which is formed so as to connect between the die bottom end shoulder 121 and the die pad accommodating portion 125.
　Die pad accommodating portion 125, at least in part between a pair of die bottom end shoulder 121, is a depression which is capable of accommodating formation of the die pad 140.
[0035]
(Punch pad 130)
　punch pad 130 is capable of accommodating disposed punch pad accommodating portion 115 formed on the punch 110. Punch pad 130 has a shaft fixing surface 133 to which one end of the movable shaft 130A in the press forming direction is fixed, and a punch plate pressing surface 135 of nipping the steel sheet S with the die pad 140. The other end of the shaft 130A is supported by the punch 110 through the pressure support mechanism of the gas cushion, not shown. Or cushion mechanism installed in the not shown pressing machine bolsters may be supported using.
　In the state where the shaft fixing surface 133 is in contact with the bottom surface of the punch pad accommodating portion 115, the punch plate pressing surface 135 is positioned below the punch shoulder 111.
[0036]
(Die pad 140)
　the die pad 140 is disposed on the die pad accommodating portion 125 formed in the die 120. Die pad 140 includes a shaft fixing surface 143 to which one end of the movable shaft 140A in the press forming direction is fixed, and a die plate pressing surface 145 nipping the steel sheet S with a punch pad 130.
　The other end of the shaft 140A is supported by the die 120 through the pressure support mechanism of the gas cushion, not shown. Or cushion mechanism installed in the not shown pressing machine slide may be supported using.
[0037]
　The width of the die plate pressing surface 145 is preferably is set substantially equal to the width of the punch plate pressing surface 135, a wide following range of 6mm than the width of the width of the punch plate pressing surface 135 of the die plate pressing surface 145 it, that is, the one end face of the die plate pressing surface 145 protrudes to within 3mm from one end surface of the punch plate pressing surface 135 in the width direction is allowed.
　The width of the die plate pressing surface 145 and the punch plate pressing surface 135 is narrower than the width between the pair of punches Kataren portions 113 and 113, it is preferred that the difference is not less than the thickness of the steel sheet S on one side . Preferably it is desirable that the above 5mm on one side (ensuring higher side 5mm width of the gap provided between the die 120 and the steel plate S). And 5mm smaller, since the thickness becomes thin strength of the punch shoulder part 111 is insufficient, there is a possibility that punch 110 is broken by applying pressure at a molding bottom dead center (a state where the punch 110 and die 120 are closest to each other) .
[0038]
　In the press molding method according to this embodiment, using the above press forming apparatus 100, to produce a press-molded article 1 from the steel sheet S through the following steps.
[0039]
(Step 1)
　First, as shown in FIG. 2A, the punch pad 130 and the die pad 140 is sandwiched and pressed at a position close to the die 120 than the punch shoulder part 111 of the steel plate S.
[0040]
(Step 2)
　Next, as shown in FIG. 2B, FIG. 2C, in the state in which nipped the steel sheet S, the die 120 while forming a deflection on the steel sheet S between the punch shoulder part 111 and the punch plate pressing surface 135 It was lowered, to approach the die 120 and the punch 110 to each other. Figure 2B illustrates an initial stage of lowering the die 120, FIG. 2C shows a later stage to lower the die. At the time shown in FIG. 2C, a state where the shaft fixing surface 143 of the die pad 140 is in contact with the upper surface of the die pad accommodating portion 125. Therefore, after this point would die pad 140 along with the descent of the die 120 is also lowered at the same rate of descent.
　As shown in FIGS. 2A ~ Figure 2C, the position of the die 120 is push amount to the internal side of the punch 110 than the portion of the initial deflection amount + punch shoulder 111 which is formed on the end portion of the top plate of the steel plate S minute up to a position above the bottom dead center by the die pad 140 and the punch pad 130, hold pressure narrow steel plate S, does not move relative to the punch 110. Meanwhile, molded to the steel sheet S by the die 120 and the punch 110 is advanced.
[0041]
(Step 3)
　Figure 2D, from the state shown in Figure 2C, further showing a state in which the die 120 and the punch 110 is lowered die 120 and the die pad 140 until just before the closest approach. At this point, the height position of the punch shoulder part 111, comprising a height position of the end surface of the punch plate pressing surface 135 and is approximately the same. That is, FIG. 2B, the initial was formed in the state shown in FIG. 2C deflection is almost eliminated state, while the residual deflection (bulge having a small curvature shape) of the punch shoulder part 111 and the punch plate pressing surface 135 It is formed on.
[0042]
　(Step 4)
　Next, as shown in FIG. 2E, from the state shown in FIG. 2D, further lowering the die 120 and the die pad 140, adjacent spaced apart from the punch shoulder part 111 of the punch plate pressing surface 135 an end face, a predetermined amount of the inner side of the punch 110 than the punch shoulder part 111 (e.g., the pressing direction 1mm) can be pushed.
[0043]
　In press forming apparatus 100 according to the present embodiment, in a section from a punch shoulder 111 on the punch 110 to the edge of the punch pad accommodating portion 115, the recess in the interior side of the punch 110 is formed than the punch shoulder 111 . Thus, when nipped the steel sheet S by the die 120 and the punch 110, of the steel sheet S, the section between the points in contact with the end portion and the die pad 140 of die bottom end shoulder portion 121 of the die 120 side the surface may be a non-contact state with the die 120 and the die pad 140.
　Therefore, since the portion corresponding to the section in the steel sheet S is not crushed, with the change of the initial deflection amount, the variation of the moment B the deflection deposition unit described with reference to FIG. 18 is suppressed, the vertical wall 1c, 1c by variation of the moment a only, it is possible to control the dimensional accuracy of the press-molded product 1. In other words, regardless of the initial deflection amount, variation in the mouth closing direction moment generated in the portion to be molded to the end portion of the top plate 1a can be suppressed, it is possible to expand the allowable setting range of the initial deflection amount.
[0044]
　Furthermore, according to this embodiment, the end surface adjacent apart from the punch shoulder part 111 of the punch plate pressing surface 135, since the internal side of the punch 110 than the punch shoulder part 111, the press molding of Patent Document 2 the degree of magnitude how it is possible to eliminate the residual bend any, were inevitably occur.
[0045]
(Second Embodiment)
　for press-molding method will be described with reference to FIGS. 3A ~ Figure 3D according to the second embodiment of the present invention. In the present embodiment, by pressing a steel plate S by using the press forming apparatus 200, to produce a press-molded product 1. The steel sheet S, using pre-processed steel sheet by press molding shown in FIGS. 16A and 16B. Figure 3A ~ FIG 3D is an explanatory diagram over time showing a process of manufacturing a press molded article 1 from the steel plate S by press-forming device 200. In the figure, Y-direction is press-molding direction, X direction is the width direction.
[0046]
(Press forming apparatus 200)
　as shown in FIG. 3A, the press molding apparatus 200 includes a punch 210, the die 220, a punch pad 230, composed of a die pad 240.
[0047]
(Punch 210)
　punch 210 is arranged opposite the die 220 so as to sandwich the steel sheet S, has a pair of punch shoulder portion 211, a punch Kataren portion 213, a punch pad accommodating portion 215.
　A pair of punch shoulder portion 211 is a portion corresponding to the R portion of the ridge 1b of the press-molded product 1, the inner surface of the 1b (the surface of the punch 210 side).
　Punch Kataren portion 213 of the upper surface of the punch 210, is a site formed so as to connect between the punch shoulder part 211 and the punch pad accommodating portion 215. In other words, the upper surface of the punch 210, is a portion except for the punch shoulder 211 and the punch pad accommodating portion 215.
　Punch pad accommodating portion 215, at least in part between a pair of punch shoulder 211, is a depression housed movable around a punch pad 230.
[0048]
(Die 220)
　die 220 is disposed opposite to the punch 210 so as to sandwich the steel sheet S, a pair of die bottom end shoulder 221, and the die bottom end Kataren portion 223, a die pad accommodating portion 225 having.
　Die bottom end shoulder 221 is a portion corresponding to the outer surface of the ridge 1b, 1b of the molded article (the surface of the die 220 side). In the example shown in this embodiment, the die bottom end shoulder portion 221 is formed on the R portion having a predetermined radius of curvature, even if the die bottom end shoulder 221 is formed at the corner portion having a predetermined angle good. If the die bottom end shoulder 221 is formed at the R portion having a predetermined radius of curvature, the die bottom end shoulder 221 is a portion between the R blind two points in the R unit.
　Die bottom end Kataren portion 223 is a portion which is formed so as to connect between the die bottom end shoulder 221 and the die pad accommodating portion 225. The die bottom end Kataren portion 223, from the end of the die pad side of the die bottom end shoulder 221, in the section to the edge of the die pad accommodating portion 225, the inner side of the die 220 than the die bottom end shoulder 221 recess is formed.
　Die pad accommodating portion 225, at least in part between a pair of die bottom end shoulder 221, is a depression which is capable of accommodating formation of the die pad 240.
[0049]
(Punch pad 230)
　punch pad 230 is capable of accommodating disposed punch pad accommodating portion 215 formed on the punch 210. Punch pad 230 has a shaft fixing surface 233 to which one end of the movable shaft 230A in the press forming direction is fixed, and a punch plate pressing surface 235 nipping the steel sheet S with the die pad 240. The other end of the shaft 230A is supported by the punch 210 through the pressure support mechanism of the gas cushion, not shown. Or cushion mechanism installed in the not shown pressing machine bolsters may be supported using.
[0050]
(Die pad 240)
　the die pad 240 is disposed on the die pad accommodating portion 225 formed in the die 220. Die pad 240 includes a shaft fixing surface 243 to which one end of the movable shaft 240A in the press forming direction is fixed, and a die plate pressing surface 245 nipping the steel sheet S with a punch pad 230.
　The other end of the shaft 240A is supported by the die 220 through the pressure support mechanism of the gas cushion, not shown. Or cushion mechanism installed in the not shown pressing machine slide may be supported using.
[0051]
　In the press molding method according to this embodiment, using the press forming apparatus 200 described above, to produce a press-molded article 1 from the steel sheet S through the following steps.
[0052]
(Step 1)
　First, as shown in FIG. 3A, by a punch pad 230 and the die pad 240 is sandwiched and pressed at a position close to the die 220 than the punch shoulder 211 steel sheet S.
[0053]
(Step 2)
　Next, as shown in FIG. 3B, FIG. 3C, in a state in which nipped the steel sheet S, the die 220 while forming a deflection on the steel sheet S between the punch shoulder part 211 and the punch plate pressing surface 235 It was lowered, to approach the die 220 and the punch 210 to each other. Figure 3B shows an initial step of lowering the die 220, FIG. 3C shows a later stage of lowering the die 220. At the time shown in FIG. 3C, a state where the shaft fixing surface 243 of the die pad 240 is in contact with the upper surface of the die pad accommodating portion 225. Therefore, after this point would die pad 240 along with the descent of the die 220 is also lowered at the same rate of descent.
[0054]
(Step 3)
　Next, as shown in FIG. 3D, from the state shown in FIG. 3C, further lowering the die 220 and the die pad 240, the die 220 and the punch 210 is in a state of being closest. In press-molding method according to the present embodiment, at this point, the height position of the punch shoulder part 211, comprising a height position of the end surface of the punch plate pressing surface 235 and is approximately the same. That is, of the punch plate pressing surface 235, the end surface adjacent apart from the punch shoulder part 211 is a punch shoulder part 211 and the flush (flush). That is, FIG. 3B, the initial was formed in the state shown in FIG. 3C deflection is almost eliminated state, and the residual deflection (bulge having a small curvature shape) and a die bottom end shoulder 221 die plate pressing surface 245 It is formed between the.
[0055]
　In press forming apparatus 200 according to this embodiment, the die bottom end Kataren portion 223 of the die 220, in the interval from the end of die bottom end shoulder 221 to the edge of the die pad accommodating portion 225, the die bottom end shoulder recess inside side of the die 220 is formed than part 221. Thus, when nipped the steel sheet S by the die 220 and the punch 210, of the steel sheet S, the die surface of the die 220 side of the section between the points in contact with the die bottom end shoulder 221 and the die pad 240 it can be 220 and die pad 240 and a non-contact state.
　Therefore, since the portion corresponding to the section in the steel sheet S is not crushed, with the change of the initial deflection amount, the variation of the moment B the deflection deposition unit described with reference to FIG. 18 is suppressed, the vertical wall 1c, 1c by variation of the moment a only, it is possible to control the dimensional accuracy of the press-molded product 1. In other words, regardless of the initial deflection amount, variation in the mouth closing direction moment generated in the portion to be molded to the end portion of the top plate 1a can be suppressed, it is possible to expand the allowable setting range of the initial deflection amount.
[0056]
(Third Embodiment)
　For press forming method according to a third embodiment of the present invention with reference to FIGS. 4A ~ Figure 4E will be described. In the present embodiment, by pressing a steel plate S by using the press forming apparatus 300, to produce a press-molded product 1. The steel sheet S, using pre-processed steel sheet by press molding shown in FIGS. 16A and 16B. FIGS. 4A ~-4E are explanatory views over time showing a process of manufacturing a press molded article 1 from the steel plate S by press-forming device 300. In the figure, Y-direction is press-molding direction, X direction is the width direction.
[0057]
(Press forming apparatus 300)
　as shown in FIG. 4A, the press molding apparatus 300 includes a punch 310, the die 320, a punch pad 330, composed of a die pad 340.
[0058]
(Punch 310)
　punch 310 is arranged opposite the die 320 so as to sandwich the steel sheet S, has a pair of punch shoulder portion 311, a punch Kataren portion 313, a punch pad accommodating portion 315.
　A pair of punch shoulder portion 311 is a portion corresponding to the R portion of the inner surface of the ridge 1b, 1b of the press-molded product 1 (the surface of the punch 310 side).
　Punch Kataren portion 313 of the upper surface of the punch 310, is a site formed so as to connect between the punch shoulder part 311 and the punch pad accommodating portion 315. In the present embodiment, since the punch pad accommodating portion 315 is formed as an edge a pair of punch shoulder portion 311 as described later, the punch tip of the punch shoulder 311 (steel sheet S and the first contact end) Kataren portion 313 and be considered. In the example shown in FIG. 4A ~ 4E, but the tip of the punch Kataren portion 313 is a pointed shape, the punch pad 330 side may be rounded by providing the R portion.
　Punch pad housing portion 315, as the edges of the pair of punch shoulder 311, is a depression housed movable around a punch pad 330.
[0059]
(Die 320)
　die 320 is disposed opposite to the punch 310 so as to sandwich the steel sheet S, a pair of die bottom end shoulder 321, and the die bottom end Kataren portion 323, a die pad accommodating portion 325 having.
　Die bottom end shoulder 321 is a portion corresponding to the outer surface of the ridge 1b, 1b of the molded article (the surface of the die 320 side).
　In the example shown in this embodiment, the die bottom end shoulder portion 321 is formed on the R portion having a predetermined radius of curvature, even if the die bottom end shoulder 321 is formed at the corner portion having a predetermined angle good. If the die bottom end shoulder 321 is formed at the R portion having a predetermined radius of curvature, the die bottom end shoulder 321 is a portion between the R blind two points in the R unit.
　Die bottom end Kataren portion 323 is a portion which is formed so as to connect between the die bottom end shoulder 321 and the die pad accommodating portion 325.
　Die pad accommodating portion 325, at least a portion between the pair of die bottom end shoulder 321, is a depression which is capable of accommodating formation of the die pad 340.
[0060]
(Punch pad 330)
　punch pad 330 is capable of accommodating disposed punch pad accommodating portion 315 formed on the punch 310. Punch pad 330 has a shaft fixing surface 333 to which one end of the movable shaft 330A in the press forming direction is fixed, and a punch plate pressing surface 335 nipping the steel sheet S with the die pad 340. The other end of the shaft 330A is supported by the punch 310 through the pressure support mechanism of the gas cushion, not shown. Or cushion mechanism installed in the not shown pressing machine bolsters may be supported using.
　In the state where the shaft fixing surface 333 is in contact with the bottom surface of the punch pad accommodating portion 315, the punch plate pressing surface 335 is positioned lower than the punch shoulder 311.
　The width of the punch plate pressing surface 335 is set smaller than the width of the punch pad accommodating portion 315. That is, the punch pad 330 in this embodiment has a convex shape protruding in the die 320 side.
　The end portion of the punch plate pressing surface 335, on a plane perpendicular to the pressing direction, it is in the same position as the edge of the die plate pressing surface 345 which will be described later.
[0061]
(Die pad 340)
　the die pad 340 is disposed on the die pad accommodating portion 325 formed in the die 320. The die pad 340 has a shaft fixing surface 343 to which one end of the movable shaft 340A in the press forming direction is fixed, and a die plate pressing surface 345 nipping the steel sheet S with a punch pad 330.
　The other end of the shaft 340A is supported by the die 320 through the pressure support mechanism of the gas cushion, not shown. Or cushion mechanism installed in the not shown pressing machine slide may be supported using.
[0062]
　In the press molding method according to this embodiment, using the press forming apparatus 300 described above, to produce a press-molded article 1 from the steel sheet S through the following steps.
[0063]
(Step 1)
　First, as shown in FIG. 4A, the punch pad 330 and the die pad 340 is sandwiched and pressed at a position close to the steel sheet S to the die 320 than the punch shoulder 311.
[0064]
(Step 2)
　Next, FIG. 4B, as shown in FIG. 4C, in a state in which nipped the steel sheet S, while forming a deflection on the steel sheet S between the punch shoulder part 311 and the punch plate pressing surface 335 die 320 It was lowered, to approach the die 320 and the punch 310 to each other. Figure 4B shows an initial step of lowering the die 320, FIG. 4C shows a later stage of lowering the die 320. At the time shown in FIG. 4C, a state where the shaft fixing surface 343 of the die pad 340 is in contact with the upper surface of the die pad accommodating portion 325. Therefore, after this point would die pad 340 along with the descent of the die 320 is also lowered at the same rate of descent.
[0065]
(Step 3)
　Figure 4D, from the state shown in FIG. 4C, further showing a state in which lowering the die 320 and the die pad 340 until just before the die 320 and the punch 310 are closest together. At this point, the height position of the punch shoulder part 311, comprising a height position of the end surface of the punch plate pressing surface 335 and is approximately the same. That is, FIG. 4B, the initial was formed in the state shown in FIG. 4C deflection is almost eliminated state, while the residual deflection (bulge having a small curvature shape) of the punch shoulder part 311 and the punch plate pressing surface 335 It is formed on.
[0066]
　(Step 4)
　Next, as shown in FIG. 4E, from the state shown in FIG. 4D, further lowering the die 320 and the die pad 340, adjacent spaced apart from the punch shoulder part 311 of the punch plate pressing surface 335 an end face, a predetermined amount of the inner side of the punch 310 than the punch shoulder part 311 (e.g., the pressing direction 1mm) can be pushed.
　That is, the end face adjacent apart from the punch shoulder part 311 of the punch plate pressing surface 335, the inner side of the punch 310 than the punch shoulder 311.
[0067]
　In press forming apparatus 300 according to the present embodiment, a punch pad accommodating portion 315 in the punch 310 is provided with a punch shoulder part 311 as the edge, the width of the punch plate pressing surface 335 is narrower than the width of the punch pad accommodating portion 315, end of the punch plate pressing surface 335, on a plane perpendicular to the pressing direction, is in the same position as the edge of the die plate pressing surface 345. That is, when nipped the steel sheet S by the die 320 and the punch 310, of the steel sheet S, the section between the points in contact with the end portion and the die pad 340 of die bottom end shoulder portion 321 of the die 320 side it can be a plane as die 320 and the die pad 340 and a non-contact state.
　Therefore, since the portion corresponding to the section in the steel sheet S is not crushed, with the change of the initial deflection amount, the variation of the moment B the deflection deposition unit described with reference to FIG. 18 is suppressed, the vertical wall 1c, 1c by variation of the moment a only, it is possible to control the dimensional accuracy of the press-molded product 1. In other words, regardless of the initial deflection amount, variation in the mouth closing direction moment generated in the portion to be molded to the end portion of the top plate 1a can be suppressed, it is possible to expand the allowable setting range of the initial deflection amount.
[0068]
　Furthermore, according to this embodiment, the end surface adjacent apart from the punch shoulder part 311 of the punch plate pressing surface 335, since the internal side of the punch 310 than the punch shoulder part 311, the press molding of Patent Document 2 it can be eliminated unavoidably generated curl in the process.
　In the present embodiment, since the punch pad accommodating portion 315 is formed as an edge a pair of punch shoulder 311, a thickness capable of ensuring the strength of the punch shoulder 311, i.e., the R shape of the punch shoulder 311 large press it is desirable to apply to the forming device. The large R-shape, for example, a radius of 10mm or more.
[0069]
(Fourth Embodiment)
　The press-forming method with reference to FIGS. 5A ~ FIG 5E will be described according to a fourth embodiment of the present invention. In the present embodiment, by pressing a steel plate S by using the press forming apparatus 400, to produce a press-molded product 1. The steel sheet S, using pre-processed steel sheet by press molding shown in FIGS. 16A and 16B. FIGS. 5A ~-5E are explanatory diagrams over time showing a process of manufacturing a press molded article 1 from the steel plate S by press-forming device 400. In the figure, Y-direction is press-molding direction, X direction is the width direction.
[0070]
(Press forming apparatus 400)
　as shown in FIG. 5A, press forming apparatus 400 includes a punch 410, the die 420, a punch pad 430, composed of a die pad 440.
[0071]
(Punch 410)
　punch 410 is arranged opposite the die 420 so as to sandwich the steel sheet S, has a pair of punch shoulder portion 411, a punch Kataren portion 413, a punch pad accommodating portion 415.
　A pair of punch shoulder portion 411 is a portion corresponding to the R portion of the inner surface of the ridge 1b, 1b of the press-molded product 1 (the surface of the punch 410 side).
　Punch Kataren portion 413 of the upper surface of the punch 410, is a site formed so as to connect between the punch shoulder part 411 and the punch pad accommodating portion 415. In other words, the upper surface of the punch 410, is a portion except for the punch shoulder 411 and the punch pad accommodating portion 415. In the present embodiment, the punch Kataren portion 413 has a concave shape over the punch shoulder 411 on the punch pad housing portion 415.
　Punch pad accommodating portion 415, at least in part between a pair of punch shoulder 411, is a depression housed movable around a punch pad 430.
[0072]
(Die 420)
　die 420 is disposed opposite to the punch 410 so as to sandwich the steel sheet S, a pair of die bottom end shoulder 421, and the die bottom end Kataren portion 423, a die pad accommodating portion 425 having.
　Die bottom end shoulder 421 is a portion corresponding to the outer surface of the ridge 1b, 1b of the molded article (the surface of the die 420 side). In the example shown in this embodiment, the die bottom end shoulder portion 421 is formed on the R portion having a predetermined radius of curvature, even if the die bottom end shoulder 421 is formed at the corner portion having a predetermined angle good. If the die bottom end shoulder 421 is formed at the R portion having a predetermined radius of curvature, the die bottom end shoulder 421 is a portion between the R blind two points in the R unit.
　Die bottom end Kataren portion 423 is a portion which is formed so as to connect between the die bottom end shoulder 421 and the die pad accommodating portion 425. In the present embodiment, since the die pad housing portion 425 as will be described later is formed as an edge a pair of die bottom end shoulder 421, the end portion of the die bottom end shoulder 421 (the boundary portion between the die pad accommodating portion 425) the regarded and die bottom end Kataren portion 423.
　Die pad housing portion 425, as the edges of the pair of die bottom end shoulder 421, is a depression which is capable of accommodating formation of the die pad 440.
[0073]
(Punch pad 430)
　punch pad 430 is disposed on the punch pad accommodating portion 415 formed punch 410. Punch pad 430 has a shaft fixing surface 433 to which one end of the movable shaft 430A in the press forming direction is fixed, and a punch plate pressing surface 435 nipping the steel sheet S with the die pad 440. The other end of the shaft 430A is supported by the punch 410 through the pressure support mechanism of the gas cushion, not shown. Or cushion mechanism installed in the not shown pressing machine bolsters may be supported using.
　In the state where the shaft fixing surface 433 is in contact with the bottom surface of the punch pad accommodating portion 415, the punch plate pressing surface 435 is positioned below the punch shoulder 411.
[0074]
(Die pad 440)
　the die pad 440 is disposed on the die pad accommodating portion 425 formed in the die 420. The die pad 440 has a shaft fixing surface 443 to which one end of the movable shaft 440A in the press forming direction is fixed, and a die plate pressing surface 445 nipping the steel sheet S with a punch pad 430.
　The other end of the shaft 440A is supported by the die 420 through the pressure support mechanism of the gas cushion, not shown. Or cushion mechanism installed in the not shown pressing machine slide may be supported using.
　The width of the die plate pressing surface 445 is set smaller than the width of the die pad accommodating portion 425. That is, the die pad 440 in this embodiment has a convex shape protruding the punch 410 side.
　The end portion of the die plate pressing surface 445, on a plane perpendicular to the pressing direction, is in the same position as the end of the punch plate pressing surface 435.
[0075]
　In the press molding method according to this embodiment, using the press forming apparatus 400 described above, to produce a press-molded article 1 from the steel sheet S through the following steps.
[0076]
(Step 1)
　First, as shown in FIG. 5A, the punch pad 430 and the die pad 440 is sandwiched and pressed at a position close to the steel sheet S to the die 420 than the punch shoulder 411.
[0077]
(Step 2)
　Next, FIG. 5B, as shown in FIG. 5C, in a state in which nipped the steel sheet S, while forming a deflection on the steel sheet S between the punch shoulder part 411 and the punch plate pressing surface 435 die 420 It was lowered, to approach the die 420 and the punch 410 to each other. Figure 5B shows an early stage to lower the die 420, FIG. 5C shows a later stage of lowering the die 420. At the time shown in FIG. 5C, a state where the shaft fixing surface 443 of the die pad 440 is in contact with the upper surface of the die pad accommodating portion 425. Therefore, after this point would die pad 440 along with the descent of the die 420 is also lowered at the same rate of descent.
[0078]
(Step 3)
　Figure 5D, from the state shown in FIG. 5C, further showing a state in which lowering the die 420 and the die pad 440 until just before the die 420 and the punch 410 are closest together. At this point, the height position of the punch shoulder part 411, comprising a height position of the end surface of the punch plate pressing surface 435 and is approximately the same. That is, FIG. 5B, the initial was formed in the state shown in FIG. 5C deflection is almost eliminated state, while the residual deflection (bulge having a small curvature shape) of the punch shoulder part 411 and the punch plate pressing surface 435 It is formed on.
[0079]
　(Step 4)
　Next, as shown in FIG. 5E, from the state shown in FIG. 5D, further lowering the die 420 and the die pad 440, adjacent spaced apart from the punch shoulder part 411 of the punch plate pressing surface 435 an end face, a predetermined amount of the inner side of the punch 410 than the punch shoulder part 411 (e.g., the pressing direction 1mm) can be pushed.
　That is, the end face adjacent apart from the punch shoulder part 411 of the punch plate pressing surface 435, the inner side of the punch 410 than the punch shoulder 411.
[0080]
　In press forming apparatus 400 according to this embodiment, the die pad housing portion 425 to the die 420 is provided as the edge of the end of die bottom end shoulder 421, the width of the die plate pressing surface 445 than the width of the die pad accommodating portion 425 narrow end of the die plate pressing surface 445, on a plane perpendicular to the pressing direction, is in the same position as the end of the punch plate pressing surface 435. Thus, when nipped the steel sheet S by the die 420 and the punch 410, of the steel sheet S, between positions in contact with the die plate pressing surface 445 of the end portion and the die pad 440 of die bottom end shoulder 421 the face of the die 420 side of the section so that the state of non-contact with the die 420 and the die pad 440.
　Therefore, since the portion corresponding to the section in the steel sheet S is not crushed, with the change of the initial deflection amount, the variation of the moment B the deflection deposition unit described with reference to FIG. 18 is suppressed, the vertical wall 1c, 1c by variation of the moment a only, it is possible to control the dimensional accuracy of the press-molded product 1. In other words, regardless of the initial deflection amount, variation in the mouth closing direction moment generated in the portion to be molded to the end portion of the top plate 1a can be suppressed, it is possible to expand the allowable setting range of the initial deflection amount.
[0081]
　Furthermore, according to this embodiment, the end surface adjacent apart from the punch shoulder part 411 of the punch plate pressing surface 435, since the internal side of the punch 410 than the punch shoulder part 411, the press molding of Patent Document 2 it can be eliminated unavoidably generated curl in the process.
[0082]
　As described above, according to the press-molding method according to the fourth embodiment from the first embodiment of the present invention, a punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed ; wherein disposed opposite to the punch, and a die bottom end shoulder portion having a shape corresponding to the punch shoulder part, and the die bottom end Kataren portion, the die bottom end Kataren die pad accommodating portion provided in portion Doo is die and formed; is disposed in the punch pad accommodating portion, and a punch pad punch plate pressing surface is formed; comprises; is disposed in the die pad accommodating portion, and the die pad die plate pressing surface is formed when manufacturing a press molded article from the work plate using a press forming apparatus, when nipped the target plate by said and said die punch, the die bottom end shoulder portion of the work plate of the die pad die side plates press The die-side surface of the section between the points in contact with example surface is said die and die pad and a non-contact, and the end surface adjacent to the punch shoulder part of the punch plate pressing surface is the punch shoulder it can be a punch inner side of the parts and flush or the punch shoulder.
　Therefore, regardless of the initial deflection amount, it is possible to suppress variation in the mouth closing direction moment generated in the portion to be molded on the top plate of the target plate, it is possible to widen the allowable setting range of the initial deflection amount.
　The first embodiment, the third embodiment, as in the fourth embodiment, the end surface adjacent apart from the punch shoulder part of the punch plate pressing surface is a state in which the punch inner side than the punch shoulder case, it is possible to eliminate the prior art curl has occurred (patent document 2) in inevitably.
[0083]
　The first modification of the following, when using the press-forming method according to the second modified example, possible to realize a push to the punches side while applying a tension to the portion to be molded to the end portion of the top plate 1a of the steel makes it possible to reduce the deflection remaining at the end of the top plate 1a, it is possible to increase the dimensional accuracy of the top plate 1a.
[0084]
(First Modification)
　for press-molding method will be described with reference to FIGS. 6A ~ FIG 6E according to a first modification of the present invention.
　FIGS. 6A ~ FIG. 6E are explanatory views showing a process of manufacturing a press molded article of a steel plate S by press forming apparatus 100 'over time.
[0085]
　In the present embodiment, among the press forming apparatus 100 described in the first embodiment, die 120 die 120 using 'press forming apparatus 100 is replaced with'.
　Die 120 'includes a die body 120A, a die holder 120B supporting the die body 120A, is provided between the die body 120A and the die holder 120B, pressurized toward the die body 120A on the steel sheet S pressing the support mechanism and 120C, by composed. Incidentally, the pressure support mechanism 120C may be any spring or gas cushions.
　Omitted punch, punch pad, and the die pad a press forming apparatus 100 are basically the same as that for given the same reference numerals and detailed description described in the first embodiment.
[0086]
　In the press molding method according to this first modification, as shown in FIG. 6D, from a state in which the die body 120A and the punch 110 is closest, further, by lowering the die holder 120B and the die pad 140, in Figure 6E pushing the portion to be formed in the top plate 1a of the steel sheet S as shown in the punch 110 side.
　According to the press-molding method, the two edges 1b of the steel sheet S in the press-forming, 1b and two ridge 1b, two vertical walls 1c respectively continuous to 1b, and 1c, two vertical walls 1c, and 1c each successive flanges 1d, 1d it is possible to narrow pressure in a die body 120A and the punch 110 to implement the push by the die pad 140 while loading the predetermined pressure.
　Accordingly, it is possible to realize a push to the punches side while applying a tension to the portion to be molded to the end portion of the top plate 1a of the steel sheet S, it is possible to increase the dimensional accuracy of the top plate 1a.
[0087]
(Second Modification)
　With reference to FIGS. 7A ~ Figure 7E for press-molding method will be described according to a second modification of the present invention.
　FIGS 7A ~-7E are explanatory views showing a process of manufacturing a press molded article of a steel plate S by press forming apparatus 100 '' over time.
[0088]
　In the present embodiment, the relative press forming apparatus 100 described in the first embodiment, the press molding apparatus 100 constructed by adding the driving unit D to the die pad 140 is controlled independently of the die 120 driven '' used.
　Omitted punch, die, punch pad, and the die pad a press forming apparatus 100 basically detailed description are denoted by the same reference numerals are the same described in the first embodiment.
[0089]
　In the press molding method according to this second modification, as shown in FIG. 7D, the state where the die 120 and the punch 110 is closest, further, the drive unit D by lowering the die pad 140, shown in FIG. 7E pushing the top plate 1a of the steel sheet in the punch 110 side as.
　According to the press-molding method, the two edges 1b of the steel sheet S in the press-forming, 1b and two ridge 1b, two vertical walls 1c respectively continuous to 1b, and 1c, two vertical walls 1c, and 1c each successive flanges 1d, 1d it is possible to narrow pressure in a die 120 and punch 110 to implement the push by the die pad 140 while loading the predetermined pressure.
　Accordingly, it is possible to realize a push to the punches side while applying a tension to the portion to be molded to the end portion of the top plate 1a of the steel sheet S, it is possible to increase the dimensional accuracy of the top plate 1a.
[0090]
　Having described the embodiments of the present invention based on various embodiments and variations, the present invention is not limited to these examples. The present invention, various modifications of the specific examples illustrated above include those changed.
　For example, the die 120 in the press forming apparatus 100 described in the first embodiment, it may be replaced with a die 220 in the press forming apparatus 200 described in the second embodiment.
　Further, for example, a punch pad 130 in the press forming apparatus 100 described in the first embodiment, it may be replaced with a punch pad 330 in press forming apparatus 300 described in the third embodiment.
　Similarly, the die pad 240 in the press forming apparatus 200 described in the second embodiment may be replaced with a die pad 440 in the press forming apparatus 400 described in the fourth embodiment. In this case, a portion out of contact with respect to the die side of the steel plate (non-contact portion) is, the die bottom end Kataren portion 223 of the die 220 is formed so as to straddle the end portion in the width direction of the die pad 440.
[0091]
　Furthermore, it is also included in the present invention the following aspects.
　In the above description has been given as an example steel sheet as the work plate, aluminum plate, titanium plate, or the like of the metal plate, FRP, glass fiber reinforced resin plate such as FRTP, more thereof can be used a composite plate.
　In the above description is made to lower the die, but raising the punch, or the die and punch may be closer together.
　Punch plate pressing surface in the above description, the die plate pressing surfaces were both flat, curved or stepped may be formed.
　In the above description directed to a cross-sectional hat-shaped press-formed article, it may cross groove type of the molded article and an L-shaped cross section of the press-molded product, or a hat-shaped side cross-section of the press-molded article as a target.
　In the above description has been described intended for bending as press molding, but the application of the present invention is not necessarily limited to bending, it can be applied to draw forming.
　In the above description has been described embodiments of obtaining a press molded product by performing press forming to the steel sheet S to the pre-flange was pre processed but, without performing pre-processing, i.e. to obtain a press-molded article by the mold of a set it may be in the form.
　In the above description has been pressed at cold press molding apparatus may be a thermal-press molding apparatus.
Example
[0092]
　With reference to examples illustrating the present invention more specifically.
　In Example 1, using the press forming apparatus 100 according to the first embodiment described with reference to FIGS. 2A ~ 2E, in the second embodiment, the press molding according to the first modified example described with reference to FIG 6A ~ FIG 6E using the apparatus 100 ', in Comparative example 1 were each press-molded using a press-forming device 3000 used in the third conventional example described with reference to FIGS. 17A ~ FIG 17D.
[0093]
　Example 1, Example 2, Comparative Example 1, thickness 1.4 mm, using 1180MPa grade cold rolled steel sheet (steel sheet S) as the work plate, the cross-sectional shape of the hat-type dimensions shown in FIG. 8 the press-molded product 30 having been produced. Press-molded product 30 has the top plate 30a, the ridge line 30b, the vertical wall 30c.
[0094]
　Then, on the mouth opening amount ΔY after release (after spring back), the initial deflection amount of the portion to be molded in the top plate 30a of the steel sheet S at the time of press molding (punch shoulder portion during press forming initiator and press forming of the influence of the pressing direction distance) between the part to be molded in the top plate 30a of the steel sheet S, and numerical analysis.
[0095]
　Figure 9 is an explanatory diagram for showing the dimensions of the mold each portion of the press forming apparatus 100 of the analysis in Example 1.
[0096]
　Various dimensions of the press forming apparatus 100 shown in FIG. 9, a punch shoulder R of Rp = 5 mm, a width W1 = 80 mm between the punch Kataren portion, the width W2 = 56 mm die plate pressing surface of the punch plate pressing surface width W3 = was 56mm.
[0097]
　The results are summarized in the graph of FIG. 10. In the graph of FIG. 10,
□: Example using the press forming apparatus 100 1,
○: performed using the press forming apparatus 100 'Example 2,
△: comparative example using a press forming apparatus 3000 1,
indicating each.
[0098]
　As shown in the graph of FIG. 10, in order to keep the mouth opening amount ΔY target of ± 0.5 mm, the setting of the initial deflection amount of the portion to be molded to the end portion of the top plate 30a of the steel sheet S at the time of press forming tolerance, whereas only be ensured 0.5mm in the conventional example, in example 1 using the press forming apparatus 100 1.3 mm, of 1.9mm in example 2 using a press molding apparatus 100 'set tolerance range have been obtained, and press-forming device 100, 100 according to examples 1 and 2 'may be superior in mass productivity stability than press forming apparatus 3000 of Comparative example 1, and, in example 2 than in example 1 more widely set permissible range of the initial deflection amount, it can be seen that more excellent mass stability.
[0099]
　In Example 2, the top plate 30a of the press-molded product 30 obtained in Comparative Example 1, the ridge line 30b, in the vertical wall 30c, and numerical analysis mouth closing direction moment after molding. It shows the analysis results are summarized in Figure 11.
[0100]
　As shown in FIG. 11, the press-molded article 30 obtained by Comparative Example 1, the initial deflection amount of 3 mm, changes 5 mm, with respect to the mouth closing direction moments that greatly changes at both sites A, B, in the press-molded product 30 obtained in example 2, the initial deflection amount is 5 mm, changes 7 mm, mouth closing direction moment, but varies greatly at site a, it is understood that changes in site B is small. That is, in Embodiment 2, even if the initial deflection amount is changed, it can be seen that the variation of the moment of the portion B that affect the mouth opening amount ΔY is smaller than Comparative Example 1.
[0101]
　Further, Example 1, obtained in Example 2 and Comparative Example 1 was numerically analyzed the shape of the press-molded product 30 after the release (after spring back). It shows the analysis results are summarized in Figure 12. The initial deflection amount at the time of molding, the optimum value in the graph of FIG. 10, i.e., in Comparative Example 1 3.5 mm, Example 1, was 6mm in Example 2.
[0102]
　As shown in FIG. 12, in Comparative Example 1, but slightly dimensional inaccuracy caused by bending habit although there are (error due to deflection residual) is 1.0mm generated, in the first embodiment, the bending habit dimensional accuracy due to defective ( residual deflection due to error) 0.3 mm, is reduced to 1/3 or less of the conventional example, also in the second embodiment, the dimensional accuracy failure due to bending habit (error due to deflection residual) is 0.2 mm, in Comparative example 1 about 1/5 are reduced to, it can be seen that the curl is substantially eliminated.
[0103]
　In Example 1, the top plate 30a of the press-molded product 30 obtained in Example 2, ridge 30b, and numerical analysis mouth closing direction moment in the vertical wall 30c. The analysis result 13, are summarized in Figure 14.
[0104]
　13, the initial deflection amount Example 1 in the analysis of Figure 14, Example 2 both 5 mm, and 7 mm, in Example 1, 1 mm higher than the molding bottom dead center for Example 2, and molding bottom dead center, respectively showing the shape and mouth closing direction moment of the press-molded product 30.
[0105]
　As shown in FIG. 13, in the first embodiment, since the die bottom end Kataren portion at 1mm higher than the molding bottom dead center does not contact the steel sheet S, residual deflection exemplary site B at a molding bottom dead center it is found greater than the example 2. In Example 2, together with the die bottom end Kataren portion is bent back once in contact with the press-molded product 30 to the molding bottom dead center, because the tension is generated in the steel sheet S when the die pad presses, molding under residual portion B at the dead point bending seen that less than invention example 1.
[0106]
　Furthermore, by comparing FIGS. 13 and 14, the initial deflection amount is large conditions, residual deflection with greater than the B portion of Example 1, Example 2, regardless of the initial deflection amount of large and small, B residual parts deflection is small, and it is found to be comparable.
Industrial Applicability
[0107]
　According to the present invention, Patent Document 1, as in the invention disclosed in Patent Document 2, while generating a deflection of a predetermined amount of the top plate from the molding initial press molded, crush the deflection molding late press molding in the method, while expanding the initial deflection amount of the allowable setting range for dimensional accuracy securing the mouth opening of the vertical wall, the dimensional accuracy of the top plate surface due to deflection to be generated by the end of the top plate in the press forming to improve, it is possible to provide a technique for realizing a simple method.
DESCRIPTION OF SYMBOLS
[0108]
100, 200, 300, 400 press-forming device
110, 210, 310, and 410 punches
111, 211, 311 and 411 punch shoulder
113,213,313,413 punch Kataren portions
115,215,315,415 punch pad housing parts
120, 220, 320, 420 die
121,221,321,421 die bottom end shoulder
123,223,323,423 die bottom end Kataren portions
125,225,325,425 die pad accommodating portion
130, 230, 330 , 430 punch pad
135,235,335,435 punch plate pressing surfaces
140, 240, 340, 440 die pads
145,245,345,435 die plate pressing surface

The scope of the claims
[Claim 1]
　A punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed;
　disposed opposite to the punch, and a die bottom end shoulder portion corresponding to the punch shoulder part, the die bottom end and Kataren portion, a die and a die pad accommodating part provided is formed on the die bottom end Kataren portion;
　disposed in the punch pad accommodating portion, and a punch pad punch plate pressing surface is formed;
　the disposed on the die pad accommodating portion, and the die pad die plate pressing surface is formed;
a with a press molding apparatus comprising a from target plate a press forming process for producing the press molded product,
　by said said die punch in the case where nipped the target plate, wherein the die bottom end shoulder portion and the die-side surface is the die and the die pad and the non-contact section between locations in contact with the die pad of the work plate Yes And said end surface adjacent to the punch shoulder part of the punch plate pressing surface is in the punch inside side of the punch shoulder part flush or the punch shoulder
press forming method characterized by.
[Claim 2]
　When nipped the target plate by said and said die punch, the end surface adjacent to the punch shoulder part of the punch plate pressing surface is the punch shoulder flush
claims, characterized in that press molding method according to 1.
[Claim 3]
　From a state in which nipped the target plate by said and said die punch, further pushed the die pad on the punch side
press forming method according to claim 2, characterized in that.
[Claim 4]
　When nipped the target plate by said and said die punch, the end surface adjacent to the punch shoulder part of the punch plate pressing surface is in the punch inside side of the punch shoulder part
, characterized in that press forming method according to claim 1.
[Claim 5]
　A bending
press forming method according to any one of claims 1 to 4, characterized in that.
[Claim 6]
　A punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed;
　disposed opposite to the punch, and a die bottom end shoulder portion corresponding to the punch shoulder part, the die bottom end and Kataren portion, a die and a die pad accommodating part provided is formed on the die bottom end Kataren portion;
　disposed in the punch pad accommodating portion, and a punch pad punch plate pressing surface is formed;
　the disposed on the die pad accommodating portion, and the die pad die plate pressing surface is formed;
equipped with,
　in the punch in a section from the punch shoulder to the edge of the punch pad receiving portion, the punch than the punch shoulder recess is formed on the inner side of the
press-molding apparatus characterized by.
[Claim 7]
　A punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed;
　disposed opposite to the punch, and a die bottom end shoulder portion corresponding to the punch shoulder part, the die bottom end and Kataren portion, a die and a die pad accommodating part provided is formed on the die bottom end Kataren portion;
　disposed in the punch pad accommodating portion, and a punch pad punch plate pressing surface is formed;
　the disposed on the die pad accommodating portion, and the die pad die plate pressing surface is formed;
equipped with,
　the said die bottom end Kataren portion of said die, from the die bottom end shoulder portion to an edge of the die pad accommodating portion in the section, the recess in the interior side of the die is formed than the die bottom end shoulder
press forming apparatus, characterized in that.
[8.]
　A punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed;
　disposed opposite to the punch, and a die bottom end shoulder portion corresponding to the punch shoulder part, the die bottom end and Kataren portion, a die and a die pad accommodating part provided is formed on the die bottom end Kataren portion;
　disposed in the punch pad accommodating portion, and a punch pad punch plate pressing surface is formed;
　the disposed on the die pad accommodating portion, and the die pad die plate pressing surface is formed;
equipped with,
　in the punch said punch pad accommodating portion is provided as an edge of the punch shoulder part,
　the width of the punch plate pressing surface, narrower than the width of the punch pad accommodating portion, the end portion of the punch plate pressing surface is on a plane perpendicular to the press direction, the same position as an end portion of the die plate pressing surface
press-forming device, characterized in that .
[Claim 9]
　A punch shoulder, and a punch Kataren portion, the punch and the punch pad accommodating portion is formed;
　disposed opposite to the punch, and a die bottom end shoulder portion corresponding to the punch shoulder part, the die bottom end and Kataren portion, a die and a die pad accommodating part provided is formed on the die bottom end Kataren portion;
　disposed in the punch pad accommodating portion, and a punch pad punch plate pressing surface is formed;
　the disposed on the die pad accommodating portion, and the die pad die plate pressing surface is formed;
equipped with,
　wherein the die is provided as the edge of the end of the die pad receiving portion the die bottom end shoulder portion,
　of the die plate pressing surface width is narrower than the width of the die pad receiving portion, an end portion of the die plate pressing surface is on a plane perpendicular to the press direction, the same position as an end portion of the punch plate pressing surface
, characterized in that the press molding apparatus.
[Claim 10]
　In a state in which said said punch die is closest, the punch from the shoulder portion of the work plate corresponding to the area to the end of the die plate pressing surface of the die pad residual deflection relative to the die and the die pad is a non-contact
press forming apparatus according to any one of claims 6-9, characterized in that.
[Claim 11]
　From a state in which said said die punch is closest, further comprising a driving unit for pushing toward the die pad to the punch
press forming apparatus according to any one of claims 6 to 10, characterized in that.
[Claim 12]
　Width of the die plate pressing surface is approximately equal to the width of the punch plate pressing surface
press-forming apparatus according to any one of claims 6-11, characterized in that.
[Claim 13]
　A cold press forming apparatus
press-forming apparatus according to any one of claims 6 to 12, characterized in that.