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Press Forming Mold And Method For Manufacturing Press Formed Product

Abstract: A press forming mold equipped with a punch mold a die and a buckling suppression mold wherein a first surface of the buckling suppression mold has pressure receiving parts that receive reaction force for elastically deforming the buckling suppression mold at the end of press forming and buckling suppression pressure increasing parts that protrude toward the pressure receiving parts from a plate part of the punch mold and that when pressed in the pressing direction generate the aforementioned reaction force in the direction opposite the pressing direction.

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Patent Information

Application #
Filing Date
20 January 2015
Publication Number
26/2015
Publication Type
INA
Invention Field
MECHANICAL ENGINEERING
Status
Email
remfry-sagar@remfry.com
Parent Application
Patent Number
Legal Status
Grant Date
2022-06-16
Renewal Date

Applicants

NIPPON STEEL & SUMITOMO METAL CORPORATION
6 1 Marunouchi 2 chome Chiyoda ku Tokyo 1008071

Inventors

1. YOSHIDA Tohru
c/o NIPPON STEEL & SUMITOMO METAL CORPORATION 6 1 Marunouchi 2 chome Chiyoda ku Tokyo 1008071

Specification

PRESS-FORMING TOOL AND METHOD FOR MANUFACTURING PRESS-FORMED PRODUCT [Technical Field of the Invention] [OOOI] The present invention relates to a press-forming tool for a metal plate, and a method for manufacturing a press-formed product which is press-formed using the press-forming tool. Particularly, the present invention relates to a press-forming tool and a method for manufacturing a press-formed product for securing improved shape freezing properties by decreasing springback which is generated after the press forming is performed. [Related Art] [OOO2] It is possible to form members having various shapes by performing press forming using a metal plate such as a steel sheet or aluminum alloy plate. Accordingly, many press-formed products are used in members for an automobile and the like. [OOO3] In the press-formed product, there is a problem relating to a dimension accuracy defect (a shape freezing defect) due to an angular change or bending of the press-formed product, which is called springback, generated after the metal plate is press-formed. [OOO4] The springback is generated since the press-formed product is deformed by elastic recovery after the press forming due to residual stress introduced into the metal plate during the press forming. When the residual stress introduced into the metal plate is non-uniformly distributed in a plate thickness direction or an in-plane direction of the metal plate, the springback is easily generated. In order to decrease the springback and improve the dimension accuracy of the press-formed product, in the end phase of the press forming, it is effective to increase a wrinkle suppression force with respect to a blank material during the press forming. However, in order to increase the wrinkle suppression force during the press forming, a press forming apparatus, which includes a variable die cushion device using a servo valve or the like, is generally required. [0007] With respect to this proble~b,patentD ocument 1 discloses a press-forming tool in which an elastic body such as a spring is disposed in the press-forming tool. In this press-forming tool, it is possible to increase the wrinkle suppression force in the end phase of the press forming without the variable die cushion device. [OOOS] Patent Document 2 discloses a press-forming tool in which the disc spring is disposed in the press-forming tool. In this press-forming tool, since the disc spring which can generate a high load evcn by a low stroke is used, it is possible to make the wrinkle suppression force which is increased in the end phase of the press forming be larger even without the variable die cushion device. [0009] Patent Document 3 discloses a press-forming tool in which a wrinkle suppression mold is divided into a corner portion and a straight side portion. In this press-forming tool, it is possible to increase the wrinkle suppression force at every position in which the press forming is performed. [Prior Art Documenl] [Patcnt Document] [OO lo] [Patent Document 11 Japanese Unexamined Patent Application, First Publication No. 2002-32101 3 [Patent Document 21 Japanese Unexamined Patent Application, First Publication No. 2004-344925 [Patent Document 31 Japanese Unexamined Patent Application, First Publication No. 2003-941 19 [Disclosure of the Invention] [Problems to be Solved by the Inveqtkn] [OOll] In the press-forming tool disclosed in Patent Document 1, even when the portion which is added an increased the wrinkle suppression force is a part 01 [he entire wrinltle suppression portion, it is necessary to increase the wrinltle suppression force in the entire wrinkle suppression portion. That is to say, in order to suppress the springback of the press-formed product, it is necessary to increase the size of the spring disposed in the press-forming tool or to increase the number of the springs. However, a site capable of disposing the spring in the press-forming tool is limited. Accordingly, when a metal plate having a larger springback such as high tensile strength steel or high tensile strength aluminum alloy is press-formed as the blank material, it is difficult to sufficiently increase the wrinkle suppression force. [0012] In the press-forming tool disclosed in Patent Document 2, as the spring for increasing the wrinkle suppression force, the disc spring capable of obtaining the reaction force of the high load by the low stroke is used. Accordingly, in the end phase of the press forming at which the increase of the wrinkle suppression force is needed, it is possiblc to effectively increase the wrinkle suppression force by a slight stroke. However, also in this press-forming tool, even when the portion which is added the increased wrinltle suppression force is a part of the entire wrinkle suppression portion, it is also necessary to increase the wrinlcle suppression force of the entire wrinlcle suppression portion. Therefore, in recent years, when a metal plate which is further high-strengthened is press-formed as the blank material, even if the disc spring is used, the increase ofthe wrinkle suppression force is not sufficient. [0013] In the press-forming tool dlscJosed in Patent Document 3, in order to suppress occurrence of wrinkles (springback) in the corner portion of the press-formed product which becomes a shrinkage flange deformation region, the wrinltle suppression force in the early phase of the press-forming is increased. In addition, in order to avoid occurrence of breakage in the comer portion, the wrinkle suppression force during the press-forming is decreased. Moreover, in order to remove a shape freezing defect in the comer portion, the wrinkle suppression force is increased again immediately before a bottom dead center (press-forming ending point) of the press-forming. However, in this press-forming tool, in order to change the wrinkle suppression force in a part of the entire wrinkle suppression portion, the wrinkle suppression mold is set as a split-type. Since the wrinkle suppression mold is the split-type, a large spring force is not required, and only the wrinkle suppression force in the required region is increased However, generally, compared to an integral-type mold, the split mold has many problems with respect to manulacturing, operation, maintenance, repair, replacement, life span, or the like of the mold. Accordingly, since the split mold is adopted, management of the manufacturing process of the press-formed product becomes complicated, and the manufacturing cost of the press-formed product may be increased. Therefore, in a mass production process of press-forming members for an automobile or the like, i t is more preferable to change the wrinkle suppression rorce in a part of the entire wrinkle suppression portion not using the split-type wrinkle suppression mold but using the integral-type wrinkle suppression mold. In addition, the integral wrinkle suppression mold refers to a wrinkle suppression mold constituted of the minimum number of components difficult to be further split, from the viewpoint of the manufacturing of the press mold and the shape of the press-formed product. [0014] Moreover, the press-forming tool disclosed in Patent Document 3 is a pressforming tool for a drawing of the metal plate and is not suitable to press-form a highstrength metal plate. Specifically, in the press-forming tool disclosed in Patent Document 3, a steel sheet is mainly drawn in a deep cylindrical shape. Accordingly, the shape of the press-formed product obtained by this pressforming tool is different from the shape of the prcss-formed product in which the highstrength metal plate is mainly press-formed. In the press mold in which the highstrength metal plate is used as the blank material drawing and bending processing is often performed to obtain a press-formed product in which both ends in the longitudinal direction are opened (hat-shaped cross-section). When such the high strength metal plate is performed drawing and bending processing, there are problems which are different from the problems generated when the metal plate is drawn in a deep cylindrical shape. [0015] In the drawing processing of making the metal plate into a deep cylindrical shape, the drawn corner portion of the press-formed product becomes a shrinkage flange deformation region. On the other hand, in the drawing and bending processing of making the high-strength metal plate into the shape (for example, a memhcr part) having both ends opened in the longitudinal direction, a portion (for example, a flange portion corresponding to an inner side of a bent portion) of the comer portion of the press-formed product becomes an extension flange deformation region. Here, the shrinkage flange deformation refers to deformation in which extcnsion and shrinkage are simultaneously gerrerated in two axes an in-plane, and the extension flange deformation refers'tqdeformation in which the extension is generated in both two axes of the in-plane. That is to say, in the press-formed product drawn by the press-forming tool disclosed in Patent Document 3, the corner portion which becomes the extensions flange deformation region such as the member part does not exist. Moreover, in the drawn press-formed product, the plate thickness of the flange portion at which the shrinkage flange deformation is generated is not changed or is increased. On the other hand, in the press-formed product afler the drawing and bending processing, the plate thiclcness of the flange portion at which thc extension flange deformation is generated is significantly decreased. In the region in which the plate thickness is significantly decreased during the press forming, the wrinkle suppression force is not easily transmitted to the blank material, and as a result, dimension accuracy defects such as wall warpage of the press-formed product or waviness of a vertical wall are easily generated. Here, the drawing processing refers to press forming (processing) to obtain a vessel-shaped (cylindrical) press-formed product which does not have the region being generated the extension flange deformation and which does not have opening portions on both ends in a direction perpendicular to an advancement direction (pressing direction) of a punch. Moreover, the drawing and bending processing refers to press forming (processing) to obtain a member-shaped press-formed product which has the region being generated the extension flange deformation and has openings on both ends in the longitudinal direction (the extension direction of the flange portion to which the wrinkle suppression force is applied). In the manufacturing process in which the high-slrength metal plate is pressformed in a member part or the like, development of a press-forming tool capable of suppressing springback at a portion'which becomes the extension flange deformation region in addition to the shrinkage flange deformation region is significantly required. [0016] In consideration of the above-described circumferences, an object ol'the present invention is to provide a press-forming tool in which a wrinkle suppression mold is not a split-type but an integral-type and springback can be suppressed in a portion which becomes an extension flange deformation region even when a highstrength metal plate is press-formed as a blank material, and a method for manufacturing a press-formed product which is press-formed using the press-forming tool. That is to say, the present invention provides a press-forming tool and a method for manufacturing a press-formed product in which a general press forming apparatus is used without a press forming apparatus having a variable die cushion device, and a press-formed product having high dimension accuracy can be obtained by sufficiently increasing a wrinkle suppression force with respect to a blank material in the end phase of the press forming when a metal plate such as high tensile strength steel or high strength aluminum alloy in which springback easily occurs is pressformed as a blank material. Particularly, another object of the present invention is to provide a pressforming tool and a method for manufacturing a press-formed product in which a pressformed product having an extension flange deformation region in addition to a shrinkage flange deformation region can be press-formed with high dimension accuracy by a press-forming tool by which a metal plate is performed drawing and bending processing. [Means for Solving the Problem] [0017] ' i The inventors earnestly reviewed a mold structure in which a wrinkle suppression force is effectively increased at a portion which is added the increased wrinkle suppression force, in a press-formed product having an extension flarige deformation region such as a member part. As a result, the inventors found a providing of a pressure receiving portion on a portion of a wrinkle suppression mold of the press-forming tool and providing of a wrinkle suppression force increasing ponion on a portion of a punch of the press-forming tool. According to this configuration, in the end phase of the press forming, the pressure receiving portion and the wrinlcle suppression force increasing portion come into contact with each other, the wrinlcle suppression mold is elastically deformed and bent, and thus, the wrinlcle suppression force can be locally added to a portion of the blank material which is added the increased wrinkle suppression force. Springback of a press-formed product having the extension flange deformation region such as a I member part can be significantly decreased. Here, the part having the extension flange deformation region such as the member part refers to a press-formed product having a hat-shaped cross section shape in which both ends in the longitudinal direction are opened. [0018] The gist of the present invention is as follows. [0019] (1) According to an aspect of the present invcntion, there is provided a pressforming tool comprising: a punch which includes a punch portion and a plate portion which are configured to transfer a shape to a blank material; a die which is paired with the punch and opposes the punch portion; a wrinkle suppression mold which includes a first surface which opposes the plate ort ti on and comes into contact with the plate portion at a press-forming ending point, a second surface which opposes the die and holds the blank material along with the die, and a third surface which is continuous between the first surfacc and the second surface and opposes the punch portiou, and is disposed between the third surface and the punch portion via a gap; a pressure receiving portion which includes a groove portion and which is disposed on the first surface of the wrinkle suppression mold; and a wrinkle suppression force increasing ~ portion which is disposed on the plate portion so as to oppose the first surface, protrudes toward the pressure receiving portion, and generates a reaction force in a direction opposite to a pressing direction when bcing pressed in the pressing direction in an end phase of a press forming. [0020] (2) In the press-forming tool according to (I), when a region in which a plate thickness is maximum in a flange portion of a press-formed product is defined as a plate thickness maximum portion and a region in which the plate thickness is more than 0% and less than or equal to 97% with respect to the plate thickness maximum portion is defined as a plate thickness decreasing portion, based on a case where the pressure receiving portion and the wrinkle suppression force increasing portion are removed from the press-forming tool, the pressure receiving portion may overlap with a portion of a region corresponding to the plate thickness decreasing portion in the blank material when viewed along the pressing direction. [0021] (3) In the press-forming tool according to (1) or (2), the pressure receiving portion is consisted of the groove portion, wherein when a thickness of the wrinkle suppression mold in a position of the groove portion is defined as L in mm units and a minimum value of the thickness of k e wrinkle suppression mold in a position which excludes the groove portion and comes into contact with the blank material is defined as 13 in mm units, the wrinkle suppression mold may satisfy a following Expression 1 or 2, and when a protruding height of the wrinklc suppression force increasing portion is defined as G in mm units and a press stroke distance from a press-forming starting point to the press-forming ending point is defined as PS in mm units, and the protruding height G of the wrinkle suppression force increasing portion may satisfy a following Expression 3: 20 < L i 0.8 x H when 40 i H 5 50 (Expression 1) 20 < L i 40 when 50 < H i 80 (Expression 2) 0.02 x PS + H - L i G 5 0.3 x PS + H - L (Expression 3). [0022] (4) In the press-lorming tool according to (1) or (2), a portion of a boundary I which partitions the pressure receiving portion may be the groove portion [0023] (5) In the press-forming tool according to any one of (1) to (4), the wrinkle suppression force increasing portion may include an elastic body which applies the reaction force. [0024] (6) In the press-forming tool according to any one of (1) to (S), the elastic body may be at least one of a disc spring, a helical spring, and a rubber. [0025] (7) According to another aspect of the present invention, there is provided a method for manufacturing a press-formed product which is press-formed using the press-forming tool according to any one of (1) t'o (6), including a step of increasing a wrinkle suppression force with respect to a portion of a blank material in an end phase of a press forming, which is started from a position at which a press stroke is 2% to 30% and which is ended at a forming end position, when a forming start position of the press stroke is defined as 100% and the forming end position of the press strolte is defined as 0% during the press forming of the blank material. [Effects of the Invention] [0026] According to the above-described aspects of the present invention, a pressure receiving portion is provided on a portion of a wrinkle suppression mold, and a wrinkle suppression force increasing portion is provided on a portion of a punch. The pressure receiving portion and the wrinkle suppression force increasing portion come into contact with each other in the end phase of the press forming, and thus, the wrinkle suppression mold is elastically deformed. As a result, the wrinkle suppression force generated from the wrinkle suppression force increasing portion is sufficiently transmitted to the portion of a blank matcrial which is added the increased wrinkle suppression force in the end phase of press forming. That is to say, even when the press-formcd product includes an extension flange deformation region in addition to a shrinkage flange deformation region, springback of the press-formed product can be effectively decreased. [0027] In a press-formed product which is press-formed using a press-forming tool of the related art in which the pressure receiving portion and the wrinkle suppression force increasing portion are removed from thc press-forming tool, when a portion in which a plate thiclmess of a flange portion is thinned is defined as a plate thickness decreasing portion, according to the above-described aspects of the present invention, a portion (a portion which is added arf increased the wrinkle suppression force) of a region corresponding to the plate thickness decreasing portion of the blank material and the pressure receiving portion overlap with each other when viewed along the pressing direction. Accordingly, the wrinkle suppression force at the portion which is addcd the increased wrinkle suppression force is preferably increased in the end phase of the press forming. As a result, even when the press-formed product includes the extension flange deformation region in addition to the shrinkage flange deformation region, springhack of the press-formed product can be further decreased. [0028] In addition, according to the above-described aspects of the present invention, even when a metal plate, in which the springback easily occurs, such as high tensile strength steel or high strength aluminum alloy, is used as the blank material, an integral-type wrinkle suppression mold, which is a general press forming apparatus which does not include a variable die cushion device and which is not a split-type is used, and even when the press-formed product includes the extension flange deformation region in addition to the shrinkage flange deformation region, it is possible to obtain a press-formed product having high dimension accuracy. [Brief Description of the Drawings] [0029] FIG. 1A is a view showing a schematic configuration of a press-forming tool according to a first embodiment of the present invention, and is a perspective view showing the entirety thereof. FIG. 1B is a plan view of a punch of the press-forming tool according to the first embodiment. FIG. 2 is a view showing a'wwnkle suppression mold of the press-forming tool according to the first embodiment and is a perspective view when viewed from a first surface side. FIG. 3A is an explanatory view schematically showing movements or the punch, a die, and the wrinkle suppression mold when a blank material is press-formed, and is a perspective view when the press forming starts. FIG. 3B is an explanatory view schematically showing the movements of the punch, the die, and the wrinkle suppression mold when the blank material is pressformed, and is a perspective view during the press forming. FIG. 4A is a view showing a wrinkle suppression force increasing portion of the press-forming tool according to the first embodiment, and a vertical cross-sectional view showing a state where a wrinkle suppression force is not increased when a plurality of disc springs are piled. FIG. 4B is a view showing the wrinkle suppression force increasing portion of thc press-forming tool according to the first embodiment, and a vertical cross-sectional view showing a state where the wrinkle suppression force is increased when the plurality of disc springs are piled. FIG. 5 is a vertical cross-sectional view when viewed from an arrow I direction shown in FIG. 2. FIG. 6A is a perspective view showing a press-formed product which is formed by the press-forming tool according to the first embodiment. FIG. 6B is a vertical cross-sectional view when viewed from an arrow A direction in FIG. 6A. FIG. 7A is a view showing a schematic configuration of a press-forming tool according to a second embodiment of the present invention, and is a perspective view showing the entirety thereof. FIG. 7B is a plan view of a punch of the press-forming tool according to the second embodiment. FIG. 8 is a view showing a wrinkle suppression mold of the press-forming tool according to the second embodiment and is a perspective view when viewed from a first surface side. FIG. 9A is a view showing a schematic configuration of a press-forming tool according to a third embodiment of the present invention, and is a perspective view showing the entirety thereof. FIG. 9B is a plan view of a punch of the press-forming tool according to the third embodiment. FIG. IOA is a view showing a schematic configuration of a press-forming tool according to a fourth embodiment of the present invention, and is a perspective view showing the entirety thereof. FIG. 10B is a plan view of a punch of the press-forming tool according to the fourth embodiment. FIG. 11 is a view showing a wrinkle suppression mold of the press-forming tool according to the fourth embodiment and is a perspective view when viewed from a first surface side. FIG. 12 is a vertical cross-sectional view when viewed in an arrow C direction shown in FIG. 11 FIG. 13A is a view showing a schematic configuration of a press-forming tool of the related art which does not include a pressure receiving portion and a wrinkle suppression force increasing portion and is a perspective view showing the entirety thereof. FIG. 13B is a plan view shbying a punch of the press-forming tool of the related art which does not include the pressure receiving portion and the wrinkle suppression force increasing portion. FIG. 14 is an explanatory view showing a plate thickness distribution of a flange portion in a press-formed product which is formed by the press-forming tool of the related art shown in FIG. 13A. FIG. 15 is an explanatory view exemplifying positions at which the pressure receiving portion and the wrinkle suppression force increasing portion are disposed in the view showing the plate thickness distribution of the flange portion in the pressformed product which is formed by the press-forming tool of the related art shown in FIG. 13A. FIG. 16A is a perspective view showing the press-formed product after the finishing processing (restriking processing). FIG. 16B is a vertical cross-sectional view when viewed from an arrow B i direction in FIG. 16A FIG. 17 is a view showing a schematic configuration of a restriking processing mold performing the finishing processing (restriking processing) and is a perspective view showing the entirety thereof. FIG. 18 is a vertical cross-sectional view perpendicular to a longitudinal direction of the press-lbrmed product which is performed drawing and bending processing, and an explanatory view showing a generation state of wall warpage (springback). FIG. 19 is a vertical cross-sectional view peipendicular to the longitudinal direction of the press-formed product after the finishing processing (restriking processing), and an explanatory view showing the generation state of the wall warpage (springback). FIG. 20 is a perspective view showing the press-formed product after the finishing processing (restriking processing) and an explanatory view showing a generation state of wavrness. FIG. 21A is a perspective view showing the press-formed product after the finishing processing (restriking processing) and an explanatory view showing a measurement position of the waviness. FIG. 21B is a graph showing an example of the measured result of the waviness in the press-formed product after the finishing processing (restriking processing). FIG. 22 is a view showing a contact pressure distribution on a second surface of the wrinkle suppression mold when a thickness ratio L/H of the wrinkle suppression mold is 100%. FIG. 23 is a view showing a contact pressure distribution on the second surface of the wrinkle suppression mold when the thickness ratio L/H of the wrinkle suppression mold is 90%. FIG. 24 is a view showing a contact pressure distribution on the second surface of the wrinkle suppression mold when the thickness ratio L/H of the wrinkle suppression mold is 80%. FIG. 25 is a vicw showing a contact pressure distribution on the second surface of the wrinkle suppression mold when the thickness ratio LIH of the wrinkle suppression mold is 70%. FIG. 26 is a view showing disposed positions of the pressure receiving portion and the wrinkle suppression force increasing portion of the press-forming tool. FIG. 27 is a view showing an example of a press-forming tool in which the thickness of the wrinkle suppressioh mold is not constant, and is a perspective view showing the entirety thereof. [Embodiments of the Invention] [0030] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. I-rowever, the present invention is not limited to only the configurations of the following embodiments, and various modifications may be applied to the present invention within a scope which does not depart from the gist of the present invention. Moreover, in the drawings used for the following description, in order to make the description easier to be understood, for convenience, a portion becoming a main portion may be shown to be enlarged, and it is not limited that a dimension ratio of each component or the like is the same as the actual condition. [003 11 FIGS. 1A and 1B are views showing a schematic configuration ola pressforming tool according to a first embodiment of the present invention. FIG. 1A is a perspective view showing the entirety thereof and FIG. 1B is a plan view of a punch configuring the press-forming tool. In FIG. 1 A, a reference numeral 1 indicates the press-forming tool according to the present embodiment. The press-forming tool 1 according to the present embodiment includes a punch 10, a die 20, and wrinkle suppression molds 25a and 25b. The punch 10 includes a punch portion 12 and a plate portion 14 configured to transfer a shape to a blank material. The punch portion 12 and the plate portion 14 are fixed to each other by a fastening member (not shown) and become the punch 10. Alternatively, the punch portion 12 and the plate portion 14 may integrally form the punch 10. As shown in FIG. lB, wridklg suppression force increasing portions 16a and 16b are disposed on a surface of the plate portion 14 opposing the wrinkle suppression molds 25a and 25b. The wrinkle suppression force increasing portions 16a and 16b protrude toward the wrirdde suppression molds 25a and 25b and generate a reaction force in a direction opposite to a pressing direction when the wrinkle suppression force increasing portions are pressed in the pressing direction in the end phase of press forming. [0033] The die 20 is paired with the punch 10 and is disposed so as to oppose the punch portion 12. The wrinkle suppression molds 25a and 25b are disposed between the punch 10 and the die 20. The wrinkle suppression molds 25a and 25b according to the present embodiment are constituted of the minimum number of components, which is difficult to divide it further, from the viewpoint of a structure of a press mold and a shape of a press-lormed product. That is to say, the wrinkle suppression molds 25a and 25b are not split-type wrinkle suppression molds but integral-type wrinkle suppression molds. The wrinkle suppression molds 25a and 25b include first surfaccs 3 la and 31 b which oppose the plate portion 14 of the punch 10 and which come into contact with the plate portion 14 at a press-forming ending point. In addition, the wrinlcle suppression molds 25a and 25b include second surfaces 32a and 32b which oppose the die 20 and which hold the blank material along with the die 20. [0034] A side surface (third surface) 33a which is continuous between the first surface 31a and the second surface 32a oppose the punch portion 12 via a predetermined gap (clearance). Similarly, a side surface (third surface) 33b which is continuous between the first surface"3Sb and the second surface 32b oppose the punch portion 12 via a predetermined gap (clearance). By setting the gap appropriately, occurrence of wrinkles of the press-formed product or cracks of the press-formed product can be preferably prevented. The setting of the gap may be determ~ned according to a routine procedure. FIG. 2 is a perspective view when the wrinkle suppression molds 25a and 25b are viewed from the first surfaces 3 la and 3 lb sides. As shown in FIG. 2, the wrinkle suppression molds 25a and 25b include pressure receiving portions (groove portions) 30a and 30b, which receive the reaction force to elastically deform the wrinkle suppression molds 25a and 25b in the end phase of the press forming, on the first surfaces 3 la and 3 1b. In the press-forming tool 1 according to the present embodiment, each of the pressure receiving portions 30a and 30b is formed of a groove portion. In the end phase of the press forming, the wrinkle suppression force increasing portions 16a and 16b come into contact with the pressure receiving portions 30a and 30b and are pressed in the pressing direction. If the reaction force is generated in a direction opposite to the pressing direction, the wrinkle suppression molds 25a and 25b receive the reaction force and are elastically deformed. [0036] FIGS. 3A and 3B are explanatory views schematically showing the movements of the punch 10, the die 20, and the wrinkle suppression molds 25a and 25b when the blank material 5 is press-formed. FIG. 3A is a perspective view when the press forming starts, and FIG. 3B is a perspective view during the press forming. A blank material 5 is disposed on the second surfaces 32a and 32b of the wrinkle suppression molds 25a and25b in a state where the second surfaces 32a and 32b of the wrinkle suppression molds 25a and 25b and a tip surface 13 of the punch portion 12 are flush with each other. [0038] As shown in FIG. 3A, the die 20 is lowered in the pressing direction, and a flange portion of the blank material 5 is held by a constant load by the die 20 and the wrinkle suppression molds 25a and 2%. [0039] Moreover, as shown in FIG. 3B, in the state where the blank material 5 is held by the die 20 and the wrinkle suppression molds 25a and 25b, the die 20 moves in the pressing direction, that is to say, a direction of the plate portion 14 of the punch 10 (downward in FIG. 3B), and thus, the prcss forming of the blank material 5 is performed by the punch portion 12. [0040] At a predetermined position in the end phase of the press forming, the pressure receiving portions 30a and 30b provided on the first surfaces 3 1 a and 3 1 b of the wrinkle suppression molds 25a and 25h come into contact with the wrinkle suppression force increasing portions 16a and 16b. Moreover, the pressure receiving portions 30a and 30b press the wrinkle suppression force increasing portions 16a and 16b in the pressing direction in conjunction with the press forming from the predetermined position of the end phase of the press forming to the press-forming ending point. As a result, the reaction force in the direction opposite to the pressing direction is generated from the wrinkle suppression force increasing portions 16a and 16h. The pressure receiving portions 30a and 30b receive the reaction force, and the wrinkle suppression force with respect to the blank material 5 in the end phase of the press forming is increased. [0041] FIGS. 4A and 4B are vertical cross-sectional views showing when a plurality of disc springs overlap with each other as the wrinkle suppression force increasing portions. FIG. 4A shows a state where the wrinkle suppression force is not increased, and FIG. 40 shows a state where the wrinkle suppression force is increased. [0042] As shown in FIG. 4A, the wrinkle suppression force increasing portion 16a includes a pin 40a and a disc spring 42a. In this way, the wrinkle suppression force increasing portion 16a includes an elastic body which applies the reaction force. In the present embodiment, 12 disc springs 42a pile in parallel and in series. However, the number and arrangement of the disc springs 42a are not limited to this. For example, 4 disc springs 42a may pile in series. Although it is not shown, the wrinkle suppression force increasing portion 16b is similar to the above-described configuration. [0043] Instead of the disc spring 42a, an elastic body such as a helical spring or a rubber may be used. It is preferable that the disc spring 42a is used since it is possible to obtain a high load even by a low stroke. [0044] As shown in FIG. 4B, the pressure receiving portion 30a provided on the first surface 3 la of the wrinkle suppression mold 25a presses the pin 40a in the pressing direction, and thus, the disc spring 42a is compressed. The wrinkle suppression mold 25a receives the reaction force in the direction opposite to the pressing direction from the disc spring 42a. i As a result, the reaction force is transmitted to the blank material 5 which is held between the second surface 32a of the wrinkle suppression mold 25a and the die 20, and thus, the wrinkle suppression force with respcct to the blanlc material 5 can be increased in the end phase of the press forming. [0045] The wrinkle suppression mold 25a which receives the reaction force from the disc spring 42a includes the pressure receiving portion 30a which is constituted of a groove portion, and thus, the wrinkle suppression mold 25a is convexly and elastically deformed to the blank material 5 side and is bent. That is to say, when viewed along the pressing direction, a portion which is convexly and elastically deformed on the second surface 32a corresponding to the pressure receiving portion 30a effectively transmits the reaction force to the blank material 5. Here, the pressure receiving portion 30a is formed on the first surface 3 la of the wrinkle suppression mold 25a. I If the wrinkle suppression mold 25a does not include the pressure receiving portion 30a, the reaction force from the disc spring 42a is distributed to the entire wrinlcle suppression mold 25a. Accordingly, since the reaction force cannot be I locally applied to the blank material 5, the transmission efficiency of the reaction force is decreased. [0046] FIG. 5 is a view explaining a thickness of the wrinlcle suppression mold 25a, and is a vertical cross-sectional view when the wrinkle suppression mold 25a is viewed from an arrow I direction shown in FIG. 2. As shown in FIG. 5, the thickness of the wrinkle suppression mold 25a on the pressure receiving portion 30a which is constituted of a groove portion is defined as L in mm units. Moreover, the thickness of the wrinkle suppression mold 252 qn the region which excludes the pressure receiving portion 30a and which comes into contact with the blank material 5 is defined as H in mm units. In the press-forming tool 1 according to the present embodiment, thc thickness H is constant. However, when the thickness is not constant, the minimum value of the thickness on the region which excludes the pressure receiving portion 30a and comes into contact with the blank material 5 may be set to H. For example, as the case where the thickness 13 is not constant, there is a case where a press-formed product in which the height of the flange surface is not constant is formed, as shown in FIG. 27. The lower limit ofthe thickness L is preferably set to 20 mm. If the thickness I, is less than 20 mm, the wrinkle suppression mold 25a may be plastically deformed or damaged during drawing and bending processing (during press forming). On the other hand, in the case of 40 5 H 5 50, the upper limit of the thickness L is preferably set to 0.8 x 14. If the thickness L exceeds 0.8 x H, even when the pressure receiving portion 30a receives the reaction force from the wrinkle suppression force increasing portion 16a, the wrinlcle suppression mold 25a is not elastically deformed, and thus, the reaction force may not be effectively transmitted to the blanlc material 5. In the case of 40 5 H 5 50, the preferable upper limit of the thickness L is 0.6 x N. If the upper limit of the thickness L is 0.6 x H, even when capability of the wrinkle suppression force increasing portion 16a is small, the reaction force generated by the wrinkle suppression force increasing portion 16a can be effectively transmitted to the blank material 5. [0048] In the case of 50 < H 5 80, the upper limit of the thickness L is preferably set to 40 mm regardless of the thickness H. The maximum value of the reaction force: which is received from the wrinkle suppression force increasing portion 16a to the pressure receiving portion 30a, is 6.5 MPa. Accordingly, if the thickness L exceeds 40 mm, stiffness of the pressure receiving portion 30a is increased, and the wrinkle suppression mold 25 may not be elastically deformed even by the maximum value of the reaction force. [0049] If the thiclcness H is less than 40 mm, the stiffness of the entire wrinkle suppression mold 25a is not suflicient. On the other hand, if the thickness H exceeds 80 mm, the stiflness of the wrinkle suppression mold 25a is increased more than necessary, and a material cost of the wrinkle suppression mold 25a is also increased. [0050] In summary about the thicknesses of the wrinkle suppression mold 25a, a relationship between the thickness L and the thickness H preferably satisfies the relationship of the following Expression 1 or 2. Moreover, although it is not shown, the wrinkle suppression mold 25b is also similar to the above. 2 0 i L i 0 . 8 x H w h e n 4 0 i H i 5 0 (Expression 1) 20 5 L i 40 whcn 50 < H 5 80 (Expression 2) [0051] The reaction force from the wrinkle suppression force increasing portion 16a is generated from contacting the pressure receiving portion 30a provided on the wrinkle suppression mold 25a with the pin 40a, until the pressure receiving portion 30a reaches the press-forming ending point. The position of contacting the pressure receiving portion 30a provided on the,.wri&le suppression mold 25a with the pin 40a may be a predetermined position in the end phase of the press forming. The position of contacting the pressure receiving portion 30a with the pin 40a may be controlled by changing the protruding length (height) of the tip of the pin 40a from the suiiace of the plate 14. [0052] As shown in FIG. 4A, a protruding height G of the tip of the pin 40a from the surface of the plate 14 may be a height which adds a groove depth (a value which is obtained by subtracting L from H) of the pressure receiving portion 30a which is constituted of a groove portion and a distance from the surface of the plate portion 14 to the above-described predetermined position which is added the increased wrinlcle suppression force in the end phase of the press forming. [0053] The protruding height or the tip of the pin 40a of the wrinkle suppression forcc increasing portion 16a from the surface of the plate 14 is defined as G in mm units. A press strolte distance from a press-forming starting point, which is a press stroke position at which the plastic deformation of the blank material 5 starts, to the press-forming ending point is defined as PS in mm units. At this time, the protruding height G of the wrinkle suppression force increasing portion 16a may preferably satisfy the following Expression 3. Moreover, although it is not shown, the wrinkle suppression force increasing portion 16b is also similar to the above. 0.02 x PS + H - L 5 G 5 0.3 x PS + H - L (Expression 3) [0054] The protruding height G of the pin 40a is preferably equal to or more than a value which adds the groove depth (H-L) of the pressure receiving portion 30a to 2% of the press strolte distance PS (0.02 x,PS). That is to say, the interval of the press stroke which increase the wrinkle suppression force in the end phase of the press forming is preferably equal to or more than 2% of the press strolte distance PS. If the protruding height G is less than the value (0.02 x PS + 13 - L), Lhe increase ofthe wrinkle suppression force is not sufficient, and the effects which is exerted by decreasing the springback may be unstable. In order to further decrease the springback, the value of the protruding height G is preferably equal to or more than (0.05 x PS + H - L). [0055] On the othcr hand, it is preferable that the protruding height G of the pin 40a be less than or equal to a value which adds the groove depth (H-L) of the pressure receiving portion 30a to 30% ofthe press stroke distance PS (0.3 x PS). That is to say, the interval of the press stroke which increases the wrinkle suppression force in the end I phase of the press forming is preferably less than or equal to 30% of the press strolce 1 I distance PS. I If the protruding height G exceeds the value (0.3 x PS + H - L), since the interval of increasing the wrinlcle suppression force becomes too long, a difference in the wrinkle suppression force becomes smaller between the press-forming starling I point and the press-forming ending point. Accordingly, the effect which is exerted by increasing the wrinkle suppression force is decreased only in the end phase of the press forming is decreased, and thus, the springback may occur to the contrary. In order to further decrease the springback, the value of the protruding height G is preferably less than or equal to (0.15 x PS + H L ) . [0056] So far, it is mainly described regardingthe wrinkle suppression mold 25a and the wrinkle suppression force increasipg portion 16a. I-Iowever, the wrinkle suppression mold 25b and the wrinkle suppression force increasing portion 16a are similar to the above. [0057] FIGS. 6A and 6B show the press-formed product which is formed by the press-forming tool 1 according to the present embodiment. FIG. 6A is a perspective view, and FIG. 6B is a vertical cross-sectional view when viewed from an arrow A direction in FIG. 6A. In FIGS. 6A and 6B. a reference numeral 50 indicates the press-formed product. [005S] The press-formed product 50 includes flange portions 54a and 54b, vertical wall portions 55a and 55b, and a top portion 5%. Moreover, straight side portions 5 la and 5 1 b and a bent portion 52 interposed between the straight side portions 5 1 a and 5 1b arc provided on both ends of the press-formed product 50. When viewed from the cross section perpendicular to the longitudinal direction, the press-formed product 50 has a so-called hat-shaped cross section, and both ends in the longitudinal direction of the press-lormed product 50 are opened. Here, when viewed from an arrow A direction in FIG. 6A, the hat-shaped cross section is a shape which includes the top portion 55c provided on the center portion in the width direction, the vertical wall portions 55a and 55b provided to be inclined 14om both ends of the top portion 55c toward one surface side of the top portion 55c, and the flange portions 54a and 54b provided to be parallel with the top portion 55c fiom the tips of the vertical wall portions 55a and 55b. [0059] When the press forming is performed, according to the shape of the pressformed product 50, it is generated thata portion in which a plastic flow of the blank material 5 is easily occurred and a portion in which the plastic flow is not easily occurred. According to a difference in ease of the generation of the plastic flow, nonuniformity of residual stress in a plate thickness direction or an in-plane direction of the press-formed product 50 occurs, Moreover, due to the non-uniformity of the residual stress, for example, springback such as warpage, twist, or waviness of the vertical wall portlons 5521 and 55b occurs on the press-formed product 50. Particularly, when the shape of thc pressformed product 50 has a curved portion, shrinkage flange deformation or extension flange deformation is applied in the longitudinal direction of the press-lormed product 50. Accordingly, the non-uniformity of the residual stress in the plate thickness direction or the in-plane direction is increased. In general, after the drawing and bending processing is performed, finishing processing (restriking processing) is performed to the press-formed product 50. According to the restriking processing, when the press-formed product 50 is processed :: to the shape of a press-formed product 57 shown in FIGS. 16A and 16B described I below, remarlcable waviness occurs on the vertical wall portion 55a or the like of the bent portion 52. In order to decrease dimension accuracy defects of the press-formed product 57, in general, an advanced estimation of a deformation amount generated by the springback into mold dimensions at the time of design is often performed. However, I when the springback is waviness, it is difficult to estimate the deformation amount in advance. In addition, since correction of the mo1.d in order to solve the waviness ofthe press-formed product 57 includes trialand error, a lot of time and costs are required for the correction of the mold. [0061] The waviness is generated since the vertical wall portion 55a of the bent portion 52 becomes the extension flange deformation region by the drawing and bending processing (press forming). Accordingly, tensile stress in the longitudinal direction of the press-formed product 50 is increased, and the non-uniformity of the residual stress in the plate thickness direction or the in-plane direction of the pressformed product 50 is promoted. Due to the non-uniformity of the residual stress of the press-formed product after drawing and bending processing 50, waviness occurs on the press-formed product after restriking processing 57. Accordingly, in order to remove the waviness of the bent portion 52, the wrinltle suppression force applied to the bent portion 52 is preferably increased in the end phase of the press forming of the draw-bending processing. [0062] In order to increase the wrinltle suppression force applied to the bent portion 52 in the end phase of the press forming compared to the straight side portions 51a and 51 b, as shown in FIGS. 1A to 2, the pressure receiving portion 30a is provided on the wrinkle suppression mold 25a and the pressure receiving portion 30b is provided on the wrinkle suppression mold 25b. In order to elastically deform the wrinkle suppression molds 25a and 25b in the end phase of the press forming, the wrinltle suppression force increasing portions 16a and 16b are disposed on the plate portion 14. [0063] As described above, the wrinkle suppression force is increased in the end phase of the press forming, and thuS, tension of the vertical wall portion 55a of the bent portion 52, which is the region in which the extension flange deformation occurs, is increased. As a result, the non-uniformity of the residual stress in the plate thickness direction or the in-planc direction, which occurs the springback, of the press-formed product 50 is decreased The region in which the shrinkage flange deformation occurs is also similar to the above. That is to say, as described above, the wrinltle suppression force is increased in the end phase of the press forming, and thus, tension of the vertical wall portion 55b of the bent portion 52 which is the region in which the shrinkage flange deformation occurs is also increased. As a result, the springback at the region in which the shrinkage flange deformation occurs is also decreased. LO0641 When the pressure receiving portions 30a and 30b are not provided on the wrinltle suppression molds 25a and 25b, the wrinltle suppression molds 25a and 25b are not elastically deformed. The reaction force from the wrinkle suppression force increasing portions 16a and 16b is distributed on the entire wrinkle suppression molds 25a and 25b. Accordingly, the wrinkle suppression force cannot be locally increased on the bent portion 52 in the end phase of the press forming, and thus, the wrinkle suppression force needed in the bent portion 52 cannot be applied. As a result, tension which is necessary to suppress the springback cannot be applied on the vertical wall portions 55a and 55b of the bent portion 52. Accordingly, effects which is exerted by decreasing the springback of the press-formed product 50 are significantly decreased. In order to decrease the distribution ofthe reaction force from the abovedescribed wrinkle suppression force! ipcreasing portions 16a and 16b by increasing capability of the wrinkle suppression force increasing portions 16a and 16b, for example, it is necessary to increase the diameter of the disc spring 42a or increase the number of the disc springs 42. In this case, the sizes of the wrinkle suppression force increasing portions 16a and 16b are increased. On the other hand, in order to press-form a metal plate having a large plastic flow resistance and large springback such as high tensile strength steel or high strength aluminum alloy, since the shape of the press-formed product 50 is curved, it is particularly necessary to increase the wrinkle suppression force in the end phase ofthe press forming on the region in which the extension flange deformation or the shrinkage flange deformation occurs, or the like Accordingly, when the high tensile strength steel, the high strength aluminum alloy, or the like is press-formed, and in the case of decreasing the distribution of the reaction force by increasing the capability of the wrinkle suppression force increasing portions 16a and 16b, it is necessary to significantly increase the sizes of the wrinkle suppression force increasing portions 16a and 16b. Accordingly, it is difficult to dispose the wrinkle suppression force increasing portions 16a and 16b on the pressforming tool 1. 100671 Next, a press-forming tool according to a second embodiment of the present invention will be described. FIGS. 7A and 7B are views showing a schematic configuration of the press-forming tool according to the second embodiment of the present invention. FIG. 7A is a perspective view showing the entirety thereof and FIG. 7B is a plan view of a punch configuring the press-forming tool. FIG. 8 is a perspective view of a wrinkle suppression mold of the pressforming tool according to the present embodiment when viewed from a first surface side. [0068] A press-forming tool 2 of the present embodiment is the same as the pressforming tool 1 of the first embodiment except that only the wrinkle suppression force increasing portion 16b is provided on the plate 14, the pressure receiving portion 30b formed of a groove portion is disposed only on the wrinkle suppression mold 25b, and a wrinkle suppression mold 25e does not include the pressure receiving portion. [0069] In the press-forming tool 2 according to the present embodiment, the wrinkle suppression force with respect to the blank material 5 can be increased only on the region (only the portion which is particularly added the increased wrinlcle suppression force) in which thc extension flange deformation occurs. That is to say, when the tensile strength of the blank material 5 is not so high, each of the pressure receiving portion 30b and the wrinkle suppression force increasing portion 16b may be disposed according to curvature or the like of the bent portion 52 of the press-formed product 50. [0070] Next, a press-forming tool according to a third embodiment of the present invention will be described. FIGS. 9A and 9B are views showing a schematic configuration oT the press-forming tool according to the third embodiment of the present invention. FIG. 9A is a perspective view showing the entirety thereof and FIG. 9B is a plan view of a punch configuring the press-forming tool. [0071] A press-forming tool 3 according to the present embodiment is the same as the press-forming tool 1 according to the Qrst embodiment except that wrinkle suppression force increasing portions 16a, 16b, 16c, 16d, 16e, and 16f are disposed on the plate portion 14. Moreover, the wrinkle suppression molds 25a and 25b of the press-hrming tool 3 according to the present embodiment shown in FIG. 9A are the same as the wrinkle suppression molds 25a and 25b of the press-forming tool 1 according to the first embodiment shown in FIG. 2. [0072] As shown in FIGS. 9A and 9B, the press-forming tool 3 according to the present embodiment includes the wrinkle suppression force increasing portions 16c to 16f in addition to the wrinkle suppression force increasing portions 16a and 16b which come into contact with the pressure receiving portions 30a and 30b in the end phase of the press forming. Accordingly, it is possible to precisely control the wrinkle supprcssion force with respect to the blank material 5 in the end phase of the press forming. However, compared to the wrinkle suppression force increasing portions 16a and 16b which come into contact with the pressure receiving portions 30a and 30b, in the wrinkle suppression force increasing portions 16c to 16f which come into contact with the first surfaces 3 la and 31b not the pressure receiving portions 30a and 30b, the effect which is exerted by increasing the wrinkle suppression lorce with respect to the blank material 5 is smaller. That is to say, whether or not disposing the wrinkle suppression force increasing portions 16c to 16f which come into contact with the first surface 3 la and 3 lb, which is not the pressure receiving portions 30a and 30h, may be determined according to the shape of the press-formed product or the structure of the press mold. [0073] i Next, a press-forming tool according to a fourth embodiment of the present invention will be described. FIGS. 10A and 10B arc views showing a schematic configuration of the press-forming tool according to the fourth embodiment of the present invention. FIG. 1OA is a perspective view showing the entirety thereof and FIG. 10B is a plan view of a punch configuring the press-forming tool. FIG. 11 is a perspective view when a wrinkle suppression mold of the pressforming tool according to the fourth embodiment is viewed from a first surlace side. FIG. 12 is a view explaining the wrinkle suppression mold according to the present embodiment and is a vertical cross-sectional view of the wrinkle suppression mold when viewed 12om an arrow C direction shown in FIG. 11. [0074] A press-forming tool 4 according to the present embodiment is the same as the press-forming tool 1 according to the first embodiment except that the pressure I I receiving portions 30c and 30d of the wrinkle suppression molds 25c and 25d include 1 groove portions 35c and 35d and the groove portions 35c and 35d, become a portion of the boundary portion and partition the pressure receiving portions 30c and 30d. ~ In addition, the punch 10 according to the present embodiment shown in FIG. ;I IOB is the same as the punch 10 according to the first embodiment. [0075] The wrinkle suppression molds 25c and 25d according to the present embodiment are constituted of the minimum number of components which is difficult to divide it further, from the viewpoint of the structure of the press mold and the shape of the press-formed product. That is to say, the wrinkle suppression molds 25c and 25d are not split-type wrinkle suppression molds but integral-type wrinkle suppression molds. The wrinkle suppression molds 25c and 25d include first surfaces 3 1c and 31d which oppose the plate portion 14 of the punch 10 and come into contact with the plate portion 14 at the press-forming ending point. In addition, the wrinkle suppression molds 25c and 25d includes second surfaces 32c and 32d which oppose the die 20 and hold the blank material 5 along with the die 20 100761 In the wrinkle suppression molds 25c and 25d, the pressure receiving portions 30c and 30d which receive the reaction force for elastically deforming the wrinkle suppression molds 25c and 25d in the end phase of the press forn~inga re provided on the first surfaces 3 1c and 3 Id. The pressure receiving portions 30c and 30d include the groove portions 35c and 35d. The groove portions 35c and 35d become a poition of the boundary portion, and the pressure receiving portions 30c and 30d are partitioned on the first surfaces 3 1 c and 3 id. Specifically, as shown in FIG. 11, the pressure receiving portions 30c and 30d are partitioned by the groove portions 35c and 35d and partial edges of the first surfaces 3 1 c and 3 1d on the first surfaces 3 1 c and 3 1 d. [0077] In the end phase of the press forming, the pressure receiving portions 30c and 30d and the wrinkle suppression force increasing portions 16a and 16b come into contact with each other, and thus, the wrinkle suppression molds 25c and 25d are elastically deformed. As a result, it is possible to locally add the wrinkle suppression force to the portion of the blank material 5 which is added the increased wrinkle suppression force. Accordingly, the wrinkle suppression force in the shrinkage flange deformation region or the extensiod W g e deformation region can be locally increased in the end phase of the press forming, and thus, it is possible to effectively suppress the springback. [007S] In the end phase of the press forming, the wrinltle suppression molds 25c and 25d receive the reaction force from the wrinkle suppression force increasing portions 16a and 16b by the pressure receiving portions 30c and 30d, the wrinkle suppression molds 25c and 25d include the groove portions 35c and 35d. Accordingly, the reaction force is not distributed to the entire wrinkle suppression molds 25c and 25d. If the wrinkle suppression molds 25c and 25d receive the reaction force from the wrinkle suppression force increasing portions 16a and 16b, the wrinkle suppression molds 25c and 25d are convexly and elastically deformed to the die 20 (blank material 5) side with the groove portions 35c and 35d as the boundary portion. As aresult, it is possible to locally and intensively increase the wrinkle suppression force with respect to the blank material 5. [0079] The depths, widths, or the like of the groove portions 35c and 35d of the present emhodiment are not particularly limited. The groove portions 35c and 35d may have appropriate dimensions according to the shape of the press-formed product 50 and the structure oT the press mold 4. The thickness L of each of the wrinltle suppression mold 25c and 25d in the pressure receiving portions 30c and 30d excluding the groove portions 35c and 35d, and the thickness H of each of the wrinkle suppression mold 25c and 25d in the region which excludes the pressure receiving portions 30c and 30d and comes into contact with the blank material 5 are not particularly limited. In the present embodiment: 4though it is shown that the aspect in which the thickness Land the thickness H are the same as each other, it is suflicient that the thickness L is 20 5 L i H. Moreover, if the thickness L satisfies 20 5 L 5 H, similar to the first embodiment, it is sufficient that the protruding height G of each of the wrinkle suppression forcc increasing portions 16a and 16b is 0.02 x PS + H - L i G 5 0.3 xPS+H-L. [0080] The press-forming tools 1 to 4 according to the first to fourth embodiments of the present invention are described above. Next, effective positions to dispose the wrinkle suppression force increasing portions 16a to 16f and the pressure receiving portions 30a to 30d will be described. [OOSl] FIGS. 13A and 13B are views showing a schematic configuration of a pressforming tool of the related art which does not include the pressure receiving portion and the wrinkle suppression force increasing portion. FIG. 13A is a perspective view showing the entirety thereof, and FIG. 13B is a plan view showing a punch configuring the press-forming tool of the related art. In FIG. 13A, a reference numeral 91 indicates the press-forming tool of the related art. [0082] FIG. 14 is an explanatory view showing a plate thickness distribution of a flange portion in a press-formed product when the blank material 5 having the plate thickness of 1.0 mm is performed drawing and bending processing (press-forming) using the press-forming tool of the related art shown in FIG. 13A. That is to say, FIG. 14 is a view showing the state of the press-formed product 50 after the blank material 5 is performed drawing and bending processing (pressforming) using the press-forming tobl,9l shown in FIG. 13A, and is plan view when viewed along the pressing direction in a state where the die 20 is omitted. In FIG. 14, the measurement results of the plate thickness of the flange portions 54a and 54b arc shown. As shown in FIG. 14, the flange portions 34a and 54b include a curved outside portion 6a, a curved inside portion 6b, and straight line portions 6c, 6d, 6e, and 6f. [0083] As shown in FIG. 14, the plate thickness of the curved outside portion 6a is thick. The curved outside portion 6a becomes a plate thickness maximum portion in which the plate thiclcness is the maximum in the flange portions 54a and 54b of the press-formed product 50. On the other hand, the plate thickness of the curved inside portion 6b is thin. In this way, in the press-formed product 50 which is press-formed using the press-forming tool 91 of the related art, the plate thiclcnesses in respective portions in the flange portions 54a and 54b are not the same as one another. The second surfaces 32e and 32f of wrinkle suppression molds 25e and 25f and the die 20 which hold the blank material 5 are flat. Accordingly, in the wrinltle suppression mold 91 in which the pressure receiving portions 30a to 30d are not provided like the wrinkle suppression molds 25e and 25f, when the plate thickness of each position in the flange portions 54a and 54b is changed during the press forming, a portion to which the wrinkle suppression force is strongly applied and a portion to which the wrinkle suppression force is weakly applied exist. If the magnitude of the wrinkle suppression force is changed according to the portion during the press forming, a balance in the plastic flow of the blank material 5 during the plastic deformation is 10% As a result, dimension accuracy of the pressformed product 50 after the press forming is decreased. [0084] In order to suppress the decrease in the dimension accuracy of the plessformed product 50 due to the above-described coexistence of the portion to which the wrinkle suppression force is strongly applied and the portion to which the wrinkle suppression force is weakly applied, it is preferable to increase the wrinkle suppression force at the portion at which the plate thickness in the flange portions 54a and 54b is decreased during the press forming, in the end phase of the press forming. Specifically, the press-forming tool 91 of the related art in which the pressure receiving portions 30a to 30d and the wrinkle suppression force increasing portions 16a to 16f are removed from the press-forming tools 1 to 4 is set as a reference. A region in which the plate thickness becomes the maximum in the flange portions 54a I and 54b of the press-formed product 50 is defined as a plate thickness maximum portion, and a region in which the plate thickness is more than 0% and less than or equal to 97% with respect to the plate thickness maximum portion is defined as a plate thickness decreasing portion. In this case, when viewed along the pressing direction, the pressure receiving portions 30a to 30d of the wrinkle suppression molds 25a to 25d are preferably disposed to overlap with a portion of the plate thickness decreasing portion on the blank material 5. As a result, the wrinkle suppression force at the portion at which the plate thickness in the flange portions 54a and 54b is decreased during the press forming can be preferably increased in the end phase of the press forming. The wrinkle suppression force on the plate thickness decreasing portion, in which the plate thickness is more than 0% and less than or equal to 97% with respect to the plate thickness maximum portion, is preferqbly increased in the end phase of the press forming, and thus, the springback orthe press-formed product 50 can be effectively decreased. [0085] FIG. 15 is an explanatory view exemplifying preferable positions at which the pressure receiving portion and the wrinkle suppression force increasing portion are disposed in the view showing the plate thickness distribution of the flange portion in the press-formed product which is formed by the press-forming tool of the related art shown in FIG. 13A. That is to say, as an example, FIG. 15 is an explanatory view in which the disposition positions of the pressure receiving portions 30b and 30d and the wrinkle suppression force increasing portion 16b are overlapped in FIG. 14. [0086] As shown in FIG. 15, the pressure receiving portions 30b and 30d are preferably disposed so that a portion of the curved inside portion 6b (the portion which becomes the plate thiclcness decreasing portion having the plate thickness of more than 0% and less than or more than 97% with respect to the plate thicltness maximum portion) overlaps with the curved outside portion 6a (the portion which becomes the plate thickness maximum portion in the flange portions 54a and 54b of the pressformed product 50 press-formed by the press-forming tool 91 of the related art). The wrinkle suppression force increasing portion lbb is preferably disposed such that the wrinkle suppression force increasing portion 16b protrudes toward the pressure receiving portions 30b and 30d, and generate the reaction force opposite to the pressing direction when the wrinkle suppression force increasing portion is pressed in the pressing direction, and elastically deform the wrinlcle suppression molds 25b and 25d. As a result, it is possible to' preferably increase the wrinkle suppression force of the curved inside portion 6b in which the plate thicliness is decreased in the flange portions 54a and 54b during the press forming, in the end phase of the press forming. [0087] In this way, by disposing the pressure receiving portions 30b and 30d and the wrinkle suppression force increasing portions 16b, the wrinkle suppression molds 25b and 25d are convexly and elastically deformed to the blank material 5 side by the pressure receiving portions 30b and 30d in the end phase of the press forming, and thus, it is possible to locally and intensively increase the wrinkle suppression force on the curved inside portion 6b, [OOSS] The press-forming tools according to each aspect of the present invention - 41 - described above are summarized as follows. (1) The press-forming tools 1 to 4 according to each aspect of the present invention include the punch 10 which includes the punch portion 12 and the plate portion 14 configured to transfer a shape to the blank material 5, the die 20 which is paired with the punch 10 and opposes the punch portion 12, and wrinkle suppression molds 25a to 25d. The wrinkle suppression molds 25a to 25d include the first surfaces 3 la to 3 Id, the second surfaces 32a to 32d, and the side surfaces (third surfaces) 37a and 33b which are continuous between the first surface 3 la to 3 1d and the second surface 32a to 32d and which oppose the punch portion 12. The wrinkle suppression molds 25a to 25d are disposed between the side surfaces (third surfaces) 33a and 33b and the punch portion 12 via a gap. The first surfaces 3 1 a to 3 1 d oppose ttie plate portion 14 and come into contact with the plate portion 14 at i hp~res s-forming ending point. The second surfaces 32a to 32d oppose the die 20 and hold the blank material 5 along with the die The press-forniing tools 1 to 4 according to each aspect of the presenl invention include: pressure receiving portions 30a to 30d which include the groove portion, which receives the reaction force to elastically deform the wrinkle suppression molds 25a to 25d in the end phase of the press forming, on the first surfaces 31a to 3 1d of the wrinkle suppression molds 25a to 25d; and wrinkle suppression force increasing portions 16a and 16b which are disposed on surfaces opposing the first surfaces 3 la to 3 id of the plate portion 14, protrude toward the pressure receiving portions 30a to 30d, and generate the reaction force in a direction opposite to the pressing direction when the wrinkle suppression force increasing portions are pressed in the pressing direction in the cnd phase of press forming. [0089] (2) Based on a case where the pressure receiving portions 30a to 30d and the wrinkle suppression force increasing portions 16a and 16b are removed from the pressforming tools 1 to 4, the region in which the plate thickness is maximum in the flaigc portions 54a and 54b of the press-formed product 50 is defined as the plate thickness maximum portion. The region in which the plate thickness is more than 0% and less than and equal to 97% with respect to the plate thickness ma~imump ortion is defined as the plate thicltness decreasing portion. In this case, the pressure receiving portion 30a to 30d may overlap with a portion of the region corresponding to the plate I thickness decreasing portion in the blank material 5 when viewed along the pressing direction. [0090] (3) The pressure receiving bortions 30a and 30b is constituted of a groove portion, the thickness of each of the wrinkle suppression molds 25a and 25b in the positions of the pressure receiving portions (groove portions) 30a and 30b is defined as L in mm units. The minimum value of the thickness of each of the wrinltle suppression molds 25a and 25b in the position which excludes the pressure receiving portions (groove portions) 30a and 30b and comes into contact with the blank material 5 is defined as H in mm units. In this case, each of the wrinkle suppression molds 25a and 25b may satisfy the following Expressions 1 and 2, and when the protruding height of each of the wrinkle suppression force increasing portions 16a and 16b from the surface of the plate portion 14 is defined as G in mm units and the press stroke distance from the press-forming starting point to the press-forming ending point is defined as PS in mm units, the protruding height G of each of the wrinkle suppression force increasing portions 16a and 16b may satisfy the following Expression 3. 20 5 L 5 0.8 x H when 40 5 H 5 50 (Expression 1) 20 5 L 5 40 when 50 < H 5 80 (Expression 2) 0.02xPS+H-LiG50.3 xPS+H-L(Expression3) [0091] (4) Aportion of the boundary which partitions the pressure receiving portions 30c and 30d may be the groove portions 35c and 35d. Specifically, the pressure receiving portions 30c and 30d may include the groove portions 35c and 35d, the groove portions 35c and 35d become a portion ofthe boundary portion, and thus, the pressure receiving portions 30c and 30d may be partitioned on the first surfaces 31c and 3 1 d. [0092] (5) The wrinkle suppression force increasing portions 1 6a and 16b may include an elastic body which appli&s\the reaction force. (6) The elastic body may be at least one of the disc spring 42a, a helical spring, and rubber. [0093] Next, a method for manufacturing the press-formed product 50 which is pressformed using the press-forming tools 1 to 4 according to the embodiments of the present invention will be described. [0094] A method for manufacturing the press-formed product 50 according to an aspect of the present invention, including: a step of increasing the wrinkle suppression force with respect to a portion of the blank material 5 during the press forming in the end phase of the press forming from the position at which the press stroke is 2% to 30% to the forming end position using the press-forming tools 1 to 4 according the above-described aspects, and when the forming start position of the press stroke when the blank material 5 is press-formed is defined as 100% and the forming end position of the press stroke is defined as 0%. [0095] According to the method of manufacturing the press-formed product 50, the springback is suppressed, and thus, the press-formed product 50 having high dimension accuracy can be obtained. In the method for manufacturing, if thc position of the press stroke which is a starting position of increasing the wrinkle suppression force is less than 2%, the increase in the wrinkle suppression force is not sufficient, and thus, the effect which is exerted by decreasing the springback may be unstable. On the other hand, if the position of the press stroke which is a starting position of increasing the wrinkle suppression force is more than 30%, the interval of increasing the wrinkle suppression for,ce becomes too long. Accordingly, the difference in the wrinkle suppression force is decreased between the forming starting position of the press stroke and the forming ending position of the press stork. Therefore, the effect which is exerted by increasing the wrinkle suppression force only in the end phase of the press forming is decreased, and thus, the springback may occur to the contrary. Moreover, in order to further decrease the springback, the position of the press stroke which is a starting position of increasing the wrinkle suppression force is preferably 5% to 15%. [Example 11 [0096] Effects of the aspects of the present invention will be further described according to Examples. However, conditions of Examples are conditions adopted to coniirm feasibility and effects of the present invention, and the present invention is not limited to the conditions. The present invention adopts various conditions if achieving the object of the present invention without departing from the gist of the prescnt invention. [0097] (Example 1) The blank material 5 was obtained by laser-cutting the high tensile strength steel sheet in a predetermined shape. The blank material 5 was performed drawing and bending processing (press-forming) so that the shape became a hat-shaped cross section. Moreover, after the drawing and bending processing, the blank material was performed finishing processing (restriking processing). Conditions or the like for each process are described below. [0098] The high tensile strength sted sheet having 1.0 mm in the plate thickness and 590 MPa in the tensile strength was used as the material, the high tensile strength steel sheet was laser-cut so that the shape after the finishing processing (restriking processing) became a cross-section width of 60 mm and a height of 80 mm as shown in FIGS. 16Aand 16B, and thus, the blank material 5 was obtained. The blank material 5 was performed drawing and bending processing (pressforming) to have the shape (hat-shaped cross section) shown in FIGS. 6A and 6B using the press-forming tool 1 FIGS, lA to 2 (the press-forming tool 1 according to the first embodiment), the press-forming tool 2 shown in FIGS. 7A to 8 (the press-forming tool 2 according to the second embodiment), and the press-forming tool 3 shown in FIGS 9A and 9B (the press-forming tool 3 according to the third embodiment). [OlOO] As the wrinkle suppression force increasing portions 16a to 16f, the disc spring unit which is a combination of disc springs 42a shown in FIG. 4A was used. The load (reaction force) to which the wrinkle suppression force increasing portions 16a to 16f were applied to the wrinkle suppression molds 25a and 25b in the end phase of the press forming and were changed according to the number and the combination method (parallel, series, and parallel series) of the disc springs 42a. In the press-forming tool 3 (the press-forming tool 3 according to the third embodiment) shown in FIGS. 9A and 9B, in addition to the pressure receiving portions 30a and 30b, the wrinkle suppression force increasing portions 16c to 16f were disposed. [OlOl] The thicknesses H of the wrinkle suppression molds 25a and 25b on the region which exclude the pressure

Documents

Application Documents

# Name Date
1 477-DELNP-2015-IntimationOfGrant16-06-2022.pdf 2022-06-16
1 477-DELNP-2015.pdf 2015-01-28
2 477-delnp-2015-Form-1-(02-02-2015).pdf 2015-02-02
2 477-DELNP-2015-PatentCertificate16-06-2022.pdf 2022-06-16
3 477-DELNP-2015-Correspondence-020719.pdf 2019-07-08
3 477-delnp-2015-Correspondence Others-(02-02-2015).pdf 2015-02-02
4 POWER OF AUTHORITY.pdf 2015-03-12
4 477-DELNP-2015-OTHERS-020719.pdf 2019-07-08
5 FORM 5.pdf 2015-03-12
5 477-DELNP-2015-Power of Attorney-020719.pdf 2019-07-08
6 FORM 3.pdf 2015-03-12
6 477-DELNP-2015-AMENDED DOCUMENTS [01-07-2019(online)].pdf 2019-07-01
7 FORM 2 + SPECIFICATION.pdf 2015-03-12
7 477-DELNP-2015-FORM 13 [01-07-2019(online)].pdf 2019-07-01
8 Drawing.pdf 2015-03-12
8 477-DELNP-2015-RELEVANT DOCUMENTS [01-07-2019(online)].pdf 2019-07-01
9 477-DELNP-2015-Correspondence-140619.pdf 2019-06-27
9 477-delnp-2015-Form-3-(10-06-2015).pdf 2015-06-10
10 477-delnp-2015-Correspondence Others-(10-06-2015).pdf 2015-06-10
10 477-DELNP-2015-Power of Attorney-140619.pdf 2019-06-27
11 477-DELNP-2015-ABSTRACT [10-06-2019(online)].pdf 2019-06-10
11 477-DELNP-2015-FER.pdf 2019-03-08
12 477-DELNP-2015-CLAIMS [10-06-2019(online)].pdf 2019-06-10
12 477-DELNP-2015-OTHERS [10-06-2019(online)].pdf 2019-06-10
13 477-DELNP-2015-COMPLETE SPECIFICATION [10-06-2019(online)].pdf 2019-06-10
13 477-DELNP-2015-FER_SER_REPLY [10-06-2019(online)].pdf 2019-06-10
14 477-DELNP-2015-DRAWING [10-06-2019(online)].pdf 2019-06-10
15 477-DELNP-2015-COMPLETE SPECIFICATION [10-06-2019(online)].pdf 2019-06-10
15 477-DELNP-2015-FER_SER_REPLY [10-06-2019(online)].pdf 2019-06-10
16 477-DELNP-2015-CLAIMS [10-06-2019(online)].pdf 2019-06-10
16 477-DELNP-2015-OTHERS [10-06-2019(online)].pdf 2019-06-10
17 477-DELNP-2015-FER.pdf 2019-03-08
17 477-DELNP-2015-ABSTRACT [10-06-2019(online)].pdf 2019-06-10
18 477-DELNP-2015-Power of Attorney-140619.pdf 2019-06-27
18 477-delnp-2015-Correspondence Others-(10-06-2015).pdf 2015-06-10
19 477-DELNP-2015-Correspondence-140619.pdf 2019-06-27
19 477-delnp-2015-Form-3-(10-06-2015).pdf 2015-06-10
20 477-DELNP-2015-RELEVANT DOCUMENTS [01-07-2019(online)].pdf 2019-07-01
20 Drawing.pdf 2015-03-12
21 477-DELNP-2015-FORM 13 [01-07-2019(online)].pdf 2019-07-01
21 FORM 2 + SPECIFICATION.pdf 2015-03-12
22 477-DELNP-2015-AMENDED DOCUMENTS [01-07-2019(online)].pdf 2019-07-01
22 FORM 3.pdf 2015-03-12
23 477-DELNP-2015-Power of Attorney-020719.pdf 2019-07-08
23 FORM 5.pdf 2015-03-12
24 477-DELNP-2015-OTHERS-020719.pdf 2019-07-08
24 POWER OF AUTHORITY.pdf 2015-03-12
25 477-DELNP-2015-Correspondence-020719.pdf 2019-07-08
25 477-delnp-2015-Correspondence Others-(02-02-2015).pdf 2015-02-02
26 477-DELNP-2015-PatentCertificate16-06-2022.pdf 2022-06-16
26 477-delnp-2015-Form-1-(02-02-2015).pdf 2015-02-02
27 477-DELNP-2015.pdf 2015-01-28
27 477-DELNP-2015-IntimationOfGrant16-06-2022.pdf 2022-06-16

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