WO2023229025A1 - Hot-pressing device, production method for hot-pressed molded article, and hot-pressed molded article - Google Patents

Hot-pressing device, production method for hot-pressed molded article, and hot-pressed molded article Download PDF

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Publication number
WO2023229025A1
WO2023229025A1 PCT/JP2023/019628 JP2023019628W WO2023229025A1 WO 2023229025 A1 WO2023229025 A1 WO 2023229025A1 JP 2023019628 W JP2023019628 W JP 2023019628W WO 2023229025 A1 WO2023229025 A1 WO 2023229025A1
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WIPO (PCT)
Prior art keywords
hot press
plate
recess
mold
press
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Application number
PCT/JP2023/019628
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French (fr)
Japanese (ja)
Inventor
雅寛 斎藤
泰弘 伊藤
裕之 田上
淳一郎 鈴木
奨 湯浅
博司 吉田
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日本製鉄株式会社
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Publication of WO2023229025A1 publication Critical patent/WO2023229025A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/20—Deep-drawing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/20—Deep-drawing
    • B21D22/26—Deep-drawing for making peculiarly, e.g. irregularly, shaped articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D24/00—Special deep-drawing arrangements in, or in connection with, presses

Definitions

  • the present disclosure relates to a hot press apparatus, a method for manufacturing a hot press molded product, and a hot press molded product.
  • Patent Document 1 discloses a reinforcing material for a bumper that is provided with a small recess and a large recess surrounding the small recess for the purpose of increasing the peak load and increasing the amount of energy absorption. ing.
  • Such skeleton members are required to be lightweight and have sufficient load capacity. Furthermore, in recent years, with stricter collision safety standards for vehicles such as automobiles and stricter fuel efficiency regulations, there has been a demand for high-strength and lightweight members. In order to meet such demands, development of lightweight frame members using so-called high-strength materials having high tensile strength is underway.
  • Patent Document 2 discloses a technique for press-molding a plate material into a hat-shaped molded product having an uneven top surface.
  • Patent Document 2 discloses a technique for press-molding a plate material into a hat-shaped molded product having an uneven top surface.
  • the unevenness on the top surface of the molded product and the shoulder portion adjacent to the top surface are molded at the same time, these moldings interfere with each other, making it difficult to mold.
  • the unevenness on the top surface of the molded product is formed in advance, the unevenness is restrained with a punch and a die pad, and then the shoulder portion of the molded product is formed with the punch and die.
  • the key point of Patent Document 2 is not to perform two moldings at the same time.
  • the present disclosure has been made in view of the above.
  • the present disclosure provides a hot press device capable of suppressing the reduction in thickness and necking of a recessed portion of a hot press molded product formed by a die pad, a method for manufacturing a hot press molded product using the device, and a method for manufacturing a hot press molded product using the device, and a method for manufacturing a hot press molded product using the device. It is an object of the present invention to provide a hot press-formed product in which reduction in plate thickness at concave portions and necking are suppressed.
  • a hot press device includes: Equipped with punch, die and die pad,
  • the top surface of the punch has a groove, In a cross section along the press direction, the angle between the wall surface of the groove and the press direction is 2 to 8 degrees, There is a refrigerant flow path inside the punch,
  • the die and the die pad are arranged to face the punch in the pressing direction, the die pad is disposed facing the top surface of the punch;
  • the die pad has a convex portion at a position facing the groove in the pressing direction, and the convex portion has a shape that is an inversion of the groove.
  • the die has a step portion in contact with the die pad in the pressing direction, The die pad may be in contact with the die in the pressing direction at the bottom dead center of molding.
  • the angle between the press direction and a straight line connecting the rounded end of the side ridgeline portion of the wall surface of the groove and the rounded end of the bottom side ridgeline portion may be 2 to 8 degrees.
  • a method for manufacturing a hot press-formed product according to one embodiment of the invention according to the present disclosure A method for producing a hot press-formed product using the hot press apparatus according to any one of (1) to (3) above, placing a blank between the die and the punch; sandwiching the blank between the punch and the die pad; It is characterized by including the step of bringing the punch and the die closer to the pressing direction to the bottom dead center of the molding.
  • the hot press-formed product of one embodiment of the invention according to the present disclosure is A press-molded product comprising a first plate portion in which a recess is formed and a second plate portion inclined with respect to the first plate portion, A direction perpendicular to the side part of the recess and the plate surface of the first plate part in a cross-sectional view in a plane where the cross-sectional line length of the recess is the shortest among the planes passing through the point where the depth of the recess is the deepest.
  • the angle between the two is 2 to 8 degrees
  • the thickness of the thinnest portion of the recessed portion is 60% or more of the thickness of the portion of the first plate portion excluding the recessed portion.
  • the angle between the straight line connecting the rounded end of the side ridgeline part of the side part of the recess and the rounded end of the bottom side ridgeline part and the direction perpendicular to the plate surface of the first plate part is 2. It may be ⁇ 8°.
  • a hot press device capable of suppressing reduction in plate thickness and necking of a concave portion of a hot press molded product formed by a die pad, a method for manufacturing a hot press molded product using the device, and press forming. It is possible to provide a hot press-formed product in which reduction in plate thickness at the concave portion of the product and necking are suppressed.
  • FIG. 1 is a schematic perspective view of a hot press-formed product according to an embodiment of the present disclosure.
  • FIG. 2 is a schematic cross-sectional end view of the hot press-formed product of FIG. 1 in a direction along the Z coordinate axis.
  • FIG. 3 is an enlarged schematic cut-away end view of the hot press-formed product of FIG. 2 in the vicinity of a recess.
  • FIG. 1 is a schematic perspective view of a hot press apparatus according to an embodiment of the present disclosure.
  • FIG. 5 is a schematic cross-sectional end view of the hot press apparatus shown in FIG. 4 taken along the cross-sectional line AA in a direction along the Z coordinate axis.
  • FIG. 2 is a schematic cut-part end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to an embodiment of the present disclosure, and is a diagram showing a state in which a workpiece is placed. .
  • FIG. 2 is a schematic cut-part end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to an embodiment of the present disclosure, and is a diagram showing a state in which a recess is formed in a workpiece. be.
  • It is a schematic cut-part end view for explaining the hot press apparatus used for the manufacturing method of the hot press molded product based on one Embodiment of this indication, and is a figure which shows the state where press forming is completed.
  • FIG. 1 is a schematic cut-part end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to an embodiment of the present disclosure, and is a diagram showing a state in which a recess is formed in
  • FIG. 7 is a schematic cut-away end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to another embodiment of the present disclosure.
  • FIG. 7 is a schematic cut-part end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to another embodiment of the present disclosure, and is a diagram showing a state in which press forming has been completed.
  • FIG. 7 is a schematic cut-away end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to another embodiment of the present disclosure.
  • FIG. 2 is a schematic cut-away end view for explaining a recessed portion of a hot press-formed product according to an embodiment of the present disclosure.
  • FIG. 1 is a schematic cut-away end view of a hot press apparatus according to an embodiment of the present disclosure.
  • FIG. 2 is a schematic cut-away end view of a hot press-formed product according to an embodiment of the present disclosure.
  • FIG. 7 is a diagram for explaining a modified example of the recess according to an embodiment of the present disclosure, and is a schematic cut-away end view showing the vicinity of the recess of a hot press-formed product.
  • FIG. 7 is a diagram for explaining a modified example of the recess according to an embodiment of the present disclosure, and is a schematic cut-away end view showing the vicinity of the recess of a hot press-formed product.
  • FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure.
  • FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure.
  • FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure.
  • FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure.
  • FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure.
  • FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure.
  • FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure.
  • FIG. 7 is a schematic plan view for explaining a modification of the
  • FIG. 1 is a perspective view of a hot press-formed product 100, including a cut plane perpendicular to the longitudinal direction of the long hot press-formed product 100 at a central position in the longitudinal direction. This cut surface is also a cross section along the press direction P.
  • the hot press-formed product 100 according to the present embodiment is a long hot press-formed product 100, and includes a first plate portion extending in the longitudinal direction of the hot press-formed product 100. 110, a second plate part 120 that extends in the longitudinal direction of the hot press-formed product 100 and is inclined with respect to the first plate part 110, and smoothly connects the first plate part 110 and the second plate part 120.
  • the hot press-formed product 100 is a long member, and has a longitudinal direction and a transversal direction perpendicular to the longitudinal direction.
  • the longitudinal direction is the direction in which the hot press-formed product 100, which is a long member, extends.
  • the longitudinal direction of the hot press-formed product 100 and the Z coordinate axis are parallel.
  • the X coordinate axis and the Y coordinate axis in FIG. 1 constitute a plane including the lateral direction of the hot press-formed product 100.
  • the X, Y, and Z coordinate axes in FIG. 1 are orthogonal to each other.
  • the portion of the first plate portion 110 excluding the recessed portion 140 has a substantially flat plate shape and extends in the longitudinal direction of the hot press-formed product 100.
  • the portion of the first plate portion 110 excluding the recess 140 has a first plate surface 110a and a first plate surface 110b opposite to the first plate surface 110a.
  • the first plate part 110 extends in the length direction of the first plate part 110.
  • the second plate portion 120 is a substantially flat portion and extends in the longitudinal direction of the hot press-formed product 100.
  • the second plate portion 120 has a second plate surface 120a and a second plate surface 120b opposite to the second plate surface 120a.
  • the second plate part 120 extends in the length direction of the second plate part 120.
  • the second plate part 120 is in the width direction of the second plate part 120. extends to In the example of FIG. 1, the hot press-formed product 100 has a pair of second plate portions 120.
  • the ridgeline portion 130 is a portion that smoothly connects the first plate portion 110 and the second plate portion 120, and extends in the longitudinal direction of the hot press-formed product 100. Since the second plate part 120 is inclined with respect to the first plate part 110, the ridgeline part 130 connecting them is curved in a cross-sectional view perpendicular to the longitudinal direction of the hot press-formed product 100. It has a shape. When the second plate part 120 is inclined with respect to the first plate part 110, it means that the plate surface of the first plate part 110 and the plate surface of the second plate part 120 are not parallel. Further, the direction parallel to the longitudinal direction of the hot press-formed product 100 is defined as the longitudinal direction of the ridgeline portion 130.
  • the curved outer surface of the ridgeline portion 130 is defined as a ridgeline outer surface 130a
  • the curved inner surface of the ridgeline portion 130 is defined as a ridgeline inner surface 130b.
  • the first plate surface 110a and the second plate surface 120a are connected to the ridge outer surface 130a
  • the first plate surface 110b and the second plate surface 120b are connected to the ridge inner surface 130b.
  • One edge (first plate edge 110A) of the first plate portion 110 extending in the longitudinal direction of the hot press-formed product 100 is a ridgeline portion 130 extending in the longitudinal direction of the hot press-formed product 100. (ridgeline edge 130A).
  • second plate edge 120A One edge (second plate edge 120A) of the second plate part 120 extending in the longitudinal direction of the hot press-formed product 100 is connected to the other edge (the ridge line) extending in the longitudinal direction of the ridgeline part 130. edge 130B).
  • the hot press-formed product 100 has a pair of ridgeline portions 130.
  • a recess 140 is provided in the first plate portion 110.
  • the recess 140 extends in the length direction of the recess 140.
  • the recessed portion 140 may extend through the longitudinal center of the hot press-formed product 100 and along the ridgeline portion 130.
  • the center position in the longitudinal direction of the hot press-formed product 100 is a range of 20% of the longitudinal length of the hot press-formed product 100 from the center position that equally divides the longitudinal length of the hot press-formed product 100 into two. means the position included in When the recessed portion 140 extends along the ridgeline portion 130, it means that the recessed portion 140 is arranged substantially parallel to a portion of the adjacent ridgeline portion 130.
  • a flange portion may be formed on the edge portion extending in the longitudinal direction that is not connected to the ridgeline portion 130.
  • the first plate portion 110, the second plate portion 120, or the flange portion may be provided with a hole, a notch, a welded portion, or the like. Further, the second plate portion 120 or the flange portion may be provided with a bead.
  • FIG. 2 shows a cross-sectional end view of the hot press-formed product 100 in the longitudinal direction of the hot press-formed product 100 shown in FIG.
  • the recessed portion 140 is recessed in a direction perpendicular to the plate surface of the first plate portion 110, as will be described later. In the example of FIG. 2, the recessed portion 140 is recessed toward the side where the second plate portion 120 is located with respect to the first plate portion 110 (the first plate surface 110b side).
  • the recess 140 has a bottom 141, a pair of side parts 142, a bottom side ridgeline part 143, and a side side ridgeline part 144.
  • the bottom portion 141 of the recess is connected to each side portion 142 at each end via a pair of bottom side ridgeline portions 143 .
  • Each side portion 142 is connected to the first plate portion 110 via a side edge portion 144 .
  • the bottom portion 141 , the side portions 142 , the bottom edge portion 143 , and the side edge portion 144 extend in the length direction of the recess 140 .
  • the bottom 141 of the recess 140 has a bottom inner surface 141a located inside the recess 140 (on the side 142 side) and a bottom outer surface 141b opposite to the bottom inner surface 141a. That is, the bottom inner surface 141a constitutes a part of the inner surface of the recess 140.
  • FIG. 3 shows an enlarged view of the vicinity of the recess 140 of the hot press-formed product 100 of FIG. 2.
  • one of the boundaries between the first plate part 110 and the recessed part 140 (the boundary between the first plate part 110 and the side edge part 144) is defined as a boundary gb1, and the other Let the boundary be a boundary gb2.
  • the boundary gb1 and the boundary gb2 on a plane orthogonal to the longitudinal direction of the hot press-formed product 100 are defined by the side ridgeline portion 144.
  • the recessed portion 140 is a portion of the first plate portion 110 that is recessed toward the side where the second plate portion 120 is located (the first plate surface 110b side).
  • the recessed portion 140 may be a portion of the first plate portion 110 that is recessed on the side opposite to the side where the second plate portion 120 is located (the first plate surface 110a side). That is, the recess provided in the first plate portion 110 may be recessed toward the ridgeline outer surface 130a side (outside the hot press-formed product 100) or the ridgeline inner surface 130b side (inside the hot press-formed product 100).
  • the width w of the recess 140 is defined as the distance between the recess boundary gb1 and the recess boundary gb2 in a plane perpendicular to the longitudinal direction of the hot press-formed product 100.
  • the width w of the recess 140 may not be constant in the longitudinal direction of the hot press-formed product 100.
  • the width w of the recess 140 should be 10 mm to 52 mm because it can improve the compressive axial force performance in the direction along the Z coordinate axis and the moment bending performance in the direction along the X coordinate axis as shown in FIG. 1 etc. is preferred.
  • the width w of the recess 140 is preferably smaller than the length of the recess 140 in the extending direction.
  • the direction connecting the boundaries gb1 at both ends of the hot press-formed product 100 is defined as the longitudinal direction.
  • FIG. 4 shows an example of a press device (hot press device) used in the method for manufacturing a hot press-formed product according to the present embodiment.
  • the press apparatus 1000 shown in FIG. 4 includes a first mold 1100, a second mold 1200, and a third mold 1300 as press molds.
  • the first mold 1100 and the second mold 1200 are movable relative to each other in the press direction P.
  • a workpiece (blank) is sandwiched between the first mold 1100 and the second mold 1200.
  • the third mold 1300 is arranged adjacent to the first mold 1100 in the direction along the X coordinate axis, and is movable relative to the first mold 1100 and the second mold 1200.
  • the third mold 1300 is movable relative to the first mold 1100 and the second mold 1200 in the press direction P. Furthermore, a coolant flow path (not shown) is provided inside the second mold 1200 of the press apparatus 1000.
  • the press direction P in the press apparatus 1000 is the negative direction of the Y coordinate axis.
  • the X, Y, and Z coordinate axes in FIG. 4 are orthogonal to each other.
  • FIG. 5 shows a schematic cross-sectional end view of the press device 1000 taken along the sectional line AA shown in FIG. 4 in the direction along the Z coordinate axis. Note that the end views in FIGS. 5 to 8 are cross-sectional views along the press direction P.
  • the first mold 1100 has a press surface 1110 and a convex portion 1120 provided on the press surface 1110.
  • the convex portion 1120 has a bottom portion 1121 and a pair of side portions 1122.
  • the bottom part 1121 is connected to each side part 1122 at each end via a pair of bottom part side ridgeline parts 1123.
  • the convex portion 1120 is convex toward the negative direction of the Y coordinate axis.
  • Each side surface portion 1122 is connected to a holding surface portion 1130 of the press surface 1110 excluding the convex portion 1120 via a side surface portion side ridgeline portion 1124.
  • the bottom part 1121, the side part 1122, the bottom part side ridge line part 1123, and the side part side ridge line part 1124 extend in the direction in which the convex part 1120 extends, that is, in the direction along the Z coordinate axis in FIG. 4.
  • the second mold 1200 has a press surface (top surface) 1210 and a groove portion (concave surface portion) 1220 provided on the press surface 1210. That is, the second mold 1200 has a groove 1220 on its top surface.
  • the groove portion 1220 has a bottom portion 1221, a pair of side portions 1222, a bottom side ridgeline portion 1223, and a sidewall side ridgeline portion 1224.
  • the bottom part 1221 is connected to each side part 1222 at each end via a pair of bottom part side ridgeline parts 1223.
  • the groove portion 1220 has a shape that is recessed toward the negative direction of the Y coordinate axis.
  • Each side surface portion 1222 is connected to a holding surface portion 1230 of the press surface 1210 excluding the groove portion 1220 via a side surface portion side ridgeline portion 1224.
  • the bottom surface portion 1221, the side surface portion 1222, the bottom surface portion side ridgeline portion 1223, and the side surface portion side ridgeline portion 1224 have a constant length, and have a fixed length in the direction in which the groove portion 1220 extends, that is, the direction along the Z coordinate axis in FIG. extends to
  • the second mold 1200 further includes a side wall portion 1250 connected to the holding surface portion 1230 via a shoulder surface portion 1240.
  • the shoulder surface portion 1240 is a portion that smoothly connects the holding surface portion 1230 and the side wall portion 1250, and the shoulder surface portion 1240 and the side wall portion 1250 are connected in the direction in which the press surface 1210 extends, that is, the direction along the Z coordinate axis in FIG. extends to
  • the convex part 1120 of the first mold 1100 and the groove part 1220 of the second mold 1200 have surface shapes corresponding to each other, and by sandwiching the workpiece between the first mold 1100 and the second mold 1200, A recess 140 is formed in the workpiece.
  • the convex portion 1120 has a shape that is an inversion of the groove portion 1220.
  • the holding surface portion 1130 of the first mold 1100 and the holding surface portion 1230 of the second mold 1200 are parallel to each other. In the example of this embodiment, the holding surface portion 1130 and the holding surface portion 1230 are perpendicular to the pressing direction P.
  • the first mold 1100 has a convex portion 1120 at a position facing the groove portion 1220 in the press direction P.
  • the wall surface of the groove 1220 has an angle of 2 to 8 degrees with respect to the press direction P. More specifically, in the cross section along the press direction P, the R end of the side ridgeline portion 1224 located on the side surface portion 1222 side and the R end of the bottom side ridgeline portion 1223 located on the side surface portion 1222 side. The angle between the straight line connecting the two and the press direction P is 2 to 8 degrees.
  • a cross section along the press direction P is a plane that passes through a point on the bottom surface part 1221 where the depth of the groove part 1220 of the second mold 1200 is the deepest in the entire groove part 1220, and the cross-sectional line length of the groove part 1220 is This is the shortest plane.
  • the depth of the groove 1220 is determined on a virtual plane that includes the shortest straight line connecting the boundary between the pair of side ridges 1224 and the holding surface 1230, and in which the cross-sectional line length of the groove 1220 is the shortest when viewed in cross section. , means the distance from the straight line to the bottom surface portion 1221 in the direction orthogonal to the straight line connecting these boundaries.
  • the cross-sectional line length of the groove portion 1220 can be measured by creating a 3D model of the second mold 1200 based on three-dimensional shape measurement and deriving a plane with the shortest cross-sectional line length.
  • the radius of curvature of the bottom side ridgeline portion 1223 is 3 mm to 30 mm.
  • the radius of curvature of the side ridgeline portion 1224 is 3 mm to 30 mm.
  • the radius of curvature of the side surface portion 1222 is greater than 30 mm, or the side surface portion 1222 is flat. Even if the side surface portion 1222 is curved within such a radius of curvature, the wall surface of the groove portion 1220 can be approximated to a straight line in the above cross section, and the press direction P forms a straight line connecting the R stops as described above.
  • the angle can be defined.
  • the third mold 1300 has a press surface 1310.
  • the press surface 1310 extends in a direction along the Z coordinate axis in FIG. 4 .
  • the first mold 1100 and the third mold 1300 are arranged to face the second mold 1200 in the press direction P.
  • the first mold 1100 is placed facing the top surface of the second mold 1200.
  • the third mold 1300 is connected to a slide plate 1400.
  • the first mold 1100 is connected to the slide plate 1400 via a support portion 1410 (spring or piston).
  • the third mold 1300 moves.
  • the first mold 1100 moves via the support section 1410.
  • the press device 1000 may be provided with a drive unit (not shown) that can drive each of the first mold 1100, the second mold 1200, and the third mold 1300 independently. Further, any one of the first mold 1100, the second mold 1200, and the third mold 1300 may be fixed to the press device 1000.
  • the first mold 1100 is a die pad
  • the second mold 1200 is a punch
  • the third mold 1300 is a die.
  • a method for manufacturing a hot press-formed product according to the present embodiment includes hot pressing a workpiece to form a press-formed product including a first plate portion in which a recess is formed. It is.
  • a workpiece (blank) 1 is placed between a first mold 1100 and a second mold 1200.
  • the first mold 1100 is located above the second mold 1200 in the vertical direction, and the workpiece 1 is placed on the holding surface portion 1230 of the second mold 1200.
  • the temperature of the workpiece 1 at the start of press-forming may be 600 to 800°C.
  • the above-described hot press apparatus has the effect of being able to mold a component while it is hot and has low deformation resistance.
  • the first mold 1100 and the second mold 1200 are moved relative to each other in the press direction P (lower side in the vertical direction) and brought close to each other.
  • the third mold 1300 may move together with the first mold 1100, or the third mold 1300 may not move.
  • a portion of the hot press-formed product 100 of the workpiece 1 corresponding to the first plate portion 110 is sandwiched between the first mold 1100 and the second mold 1200.
  • the first mold 1100 is further moved in the pressing direction P from the state where the convex portion 1120 of the first mold 1100 is in contact with the workpiece 1.
  • the workpiece 1 is sandwiched between the first mold 1100 and the second mold 1200, and the workpiece 1 is sandwiched between the convex part 1120 of the first mold 1100 and the groove part 1220 of the second mold 1200.
  • a recess 140 is formed in.
  • the pressing force when forming the recess 140 by the first mold 1100 and the second mold 1200 may be 0.4 to 22.0 MPa. More preferably, this pressing force may be 0.4 to 4.4 MPa. Thereby, it is possible to mold the workpiece while the deformation resistance is low, and furthermore, the molding load of the first mold 1100 can be set to the minimum load force, and the mold cost can be reduced.
  • the third mold 1300 is further moved to the bottom dead center, and as shown in FIG. 8, the workpiece 1 is sandwiched between the second mold 1200 and the third mold 1300, and A second plate portion 120 is formed between the mold 1300 and press molding is completed.
  • the first plate part 110, the second plate part 120, the ridgeline part 130, and the recessed part 140 are formed in the hot press-formed product 100.
  • a flange portion may be formed between the second mold 1200 and the third mold 1300.
  • the first mold 1100 may reach the bottom dead center before the third mold 1300 reaches the bottom dead center, and the third mold 1300 may reach the bottom dead center. At the same time as reaching the point, the first mold 1100 may reach the bottom dead center.
  • FIG. 9 illustrates a hot press apparatus used in a method for manufacturing a hot press molded product according to another embodiment of the present disclosure. Similar to FIG. 5, FIG. 9 is a schematic cross-sectional end view of the press device taken along the cross-sectional line AA shown in FIG. 4 in the direction along the Z coordinate axis. Note that the end views of the cut portion in FIGS. 9 to 11 are views taken in a cross section along the press direction P.
  • the press device 1000 shown in FIG. 9 has the same configuration as the press device 1000 shown in FIG. 5 etc., except that it includes a stepped portion 1320, so the description thereof will be omitted here. That is, the configuration of the press apparatus 1000 shown in FIGS. 4 to 8 described above can be applied to the press apparatus 1000 shown in FIG.
  • the step portion 1320 may extend in the direction along the Z coordinate axis. Note that in the example of FIG. 9, two third molds 1300 are shown in the X coordinate axis direction. These two third molds 1300 may be connected to each other in the X coordinate axis direction.
  • FIG. 10 shows a state in which a workpiece is sandwiched between the molds and the third mold 1300 is moved to the bottom dead center.
  • a workpiece is sandwiched between a second die 1200 and a third die 1300, a second plate part 120 is formed between the second die 1200 and the third die 1300, and the press Complete the molding.
  • the first plate part 110, the second plate part 120, the ridgeline part 130, and the recessed part 140 are formed in the hot press-formed product 100.
  • the third mold 1300 includes the stepped portion 1320, the first mold 1100 contacts the third mold 1300 in the press direction P at the bottom dead center of molding. This makes it possible to suppress necking even when the first mold 1100 is pressed against the third mold 1300 and the pressing force of the first mold 1100 is insufficient.
  • the support portion 1410 is deformed so as to contract in the pressing direction P.
  • FIG. 11 Another form of the press device 1000 is shown in FIG. 11.
  • the press device 1000 in FIG. 11 is also a schematic cross-sectional end view of the press device in the direction along the Z coordinate axis, taken along the cross-sectional line AA as shown in FIG. 4, similar to FIG. 5 and the like.
  • the third mold 1300 is provided only on one side. Further, the third mold 1300 includes a stepped portion 1320.
  • the first mold 1100 has a press surface 1140 on the opposite side from the third mold 1300 in the X-axis direction.
  • the press surface 1140 is provided so as to be connected to the press surface 1110 of the first mold 1100.
  • the press surface 1140 extends in a direction along the Z coordinate axis.
  • the press apparatus 1000 shown in FIG. 11 has the same configuration as the press apparatus 1000 shown in FIG. 9 except that the third mold 1300 is provided only on one side, so the description thereof will be omitted here. That is, the configuration of the press apparatus 1000 according to FIG. 9 can be applied to the press apparatus 1000 shown in FIG. 11. In the press apparatus 1000 of FIG. 11, the area where the pressurizing mechanism of the third mold 1300 on the upper side of the press apparatus 1000 can be arranged can be increased, so there is an advantage that the press load design can have a likelihood. be.
  • the ratio of the area of the recess 140 to the area of the first plate part 110 when viewed in plan in a direction perpendicular to the plate surface of the first plate part 110 is 30. % or more.
  • the direction perpendicular to the plate surface of the first plate part 110 is defined as a direction on a virtual plane that includes the shortest straight line connecting the boundary gb1 and the boundary gb2, and in which the cross-sectional line length of the recessed part 140 is the shortest when viewed in cross-section. , means the direction perpendicular to the straight line connecting the boundary gb1 and the boundary gb2.
  • the cross-sectional line length of the recess 140 can be measured by creating a 3D model of the hot press-formed product 100 based on three-dimensional shape measurement and deriving a plane with the shortest cross-sectional line length.
  • the three-dimensional shape measurement described in this embodiment can be performed using a 3D scanner such as Atos (manufactured by GOM).
  • the definitions of the area of the first plate portion 110 and the area of the recessed portion 140 are as described later.
  • press forming may be performed such that the maximum depth dmax of the depth d of the recess 140 in the press direction P is 15 mm or more.
  • the depth d of the recess 140 means the depth in the pressing direction P.
  • the pressing direction P is a direction perpendicular to the plate surface of the first plate portion 110.
  • the maximum depth dmax means the maximum value of the depth d of the recess 140 in the entire recess 140.
  • the depth of the recess 140 means the distance from the straight line in the direction perpendicular to the plate surface of the first plate part 110 described above to the bottom inner surface 141a. More preferably, the maximum depth dmax is 20 mm or more to further improve axial force and bending moment performance. More preferably, the upper limit of the maximum depth dmax is preferably 50 mm from the viewpoint of suppressing deterioration in productivity due to an increase in press stroke due to an increase in pad stroke.
  • the cross-sectional line length of the recess 140 is the shortest among the planes passing through the point pd where the depth d of the recess 140 is the deepest. Pressing is performed so that the angle ⁇ between the side portion 142 of the recess 140 and the pressing direction P is 2 to 8 degrees when viewed in cross section on a plane (a cross section taken in the pressing direction). More specifically, the side ridgeline portion 144 located on the side portion 142 side in the plane where the cross-sectional line length of the recess 140 is the shortest among the planes passing through the point pd where the depth d of the recess 140 is the deepest.
  • Pressing is performed so that the angle formed by the pressing direction P and the straight line connecting the rounded end of the bottom edge line portion 143 located on the side portion 142 side is 2 to 8°.
  • a plane that passes through the point pd where the depth d of the recess 140 is the deepest and where the cross-sectional line length of the recess 140 is the shortest is parallel to the pressing direction P.
  • the point pd at which the depth d of the recess 140 is the deepest is the point at which the depth d of the recess 140 becomes the maximum depth dmax in the entire recess 140.
  • the radius of curvature of the bottom side ridgeline portion 143 is 3 mm to 30 mm.
  • the radius of curvature of the side edge portion 144 is 3 mm to 30 mm.
  • the radius of curvature of side 142 is greater than 30 mm, or side 142 is flat. Even if the side portion 142 is curved within such a range of curvature radius, the side portion 142 can be approximated to a straight line in the above cross section, and the angle between the straight line connecting the R stops as described above and the press direction P. can be specified.
  • FIG. 12 shows an end view of a cut portion in a cross-sectional view on a plane where the cross-sectional line length of the recess 140 is the shortest among the planes passing through the point pd where the depth d of the recess 140 is the deepest.
  • FIG. 12 shows the hot press-formed product 100 placed on the press device 1000 after completion of press forming, and is an enlarged view of the vicinity of the recess 140 of the hot press-formed product 100.
  • the cross-sectional line length of the recess 140 means the line length along the inner surface of the recess 140 from the boundary gb1 to the boundary gb2 in a plane including the shortest straight line connecting the boundary gb1 and the boundary gb2.
  • the cross section defining the curve C corresponding to the shape of the recess 140 is the plane in which the cross-sectional line length of the recess 140 is the shortest among the planes passing through the point pd.
  • the curve C corresponds to the shape of the inner surface of the recess 140 in this cross section.
  • the curve C has a point iP1 and a point iP2, which are one end point of the side portion 142, between the boundary gb1 or the boundary gb2 and the point pd.
  • Point iP1 and point iP2 are also the rounded ends of the side ridgeline portion 144.
  • the processing of the recess 140 formed by the first mold 1100 can be made easier.
  • the angle ⁇ is 2° or more, there is an effect that the mold can be easily released after press molding. Furthermore, by setting the angle ⁇ to 8° or less, it is possible to reduce the portion of the workpiece 1 that is not in contact with the first mold 1100 or the second mold 1200 during molding with the first mold 1100. This reduces the number of areas where cooling does not proceed. If there are only a few areas where cooling does not progress, the thickness of the workpiece 1 will not locally decrease and lead to necking during forming, resulting in the ability to form parts without excessive thickness reduction or necking. be.
  • the slope of the side portion 142 matches the slope of the tangent ti1 or the slope of ti2.
  • the slope of the tangent ti1 or the slope of ti2 is the slope of the straight line connecting the round end of the side ridge line portion 144 located on the side portion 142 side and the round end of the bottom side ridge line portion 143 located on the side portion 142 side. matches.
  • the side parts 142 are drawn to have the same inclination with respect to the press direction P, but as long as the two side parts 142 satisfy the angle requirements with respect to the press direction P, The angles with respect to the direction P may be different from each other.
  • the ratio of the area of the recess 140 to the area of the first plate part 110 when viewed in plan in a direction perpendicular to the plate surface of the first plate part 110 is It may be 30% or more.
  • the area of the first plate part 110 is the area including the recess 140 and excluding the second plate part 120 and the ridgeline part 130 between the second plate part 120.
  • the area of the recessed portion 140 is the area from the boundary gb1 to the boundary gb2 when viewed in plan in a direction perpendicular to the plate surface of the first plate portion 110.
  • the area of the recessed portion 140 is 30% or more of the area of the first plate portion 110 when viewed from above in a direction perpendicular to the plate surface of the first plate portion 110, so that the area along the Z coordinate axis shown in FIG.
  • the effect is that the compressive axial force performance in the direction along the X coordinate axis and the moment bending performance in the direction along the X coordinate axis can be improved.
  • the area of the recessed portion 140 with respect to the area of the first plate portion 110 is 50% or more, since the axial force and bending moment performance can be further improved.
  • the area of the first plate part 110 is determined by the boundary between the ridgeline part 130 and the first plate part 110 and the longitudinal end of the first plate part 110 in a plan view in a direction perpendicular to the plate surface of the first plate part 110. Let it be the area of the range surrounded by.
  • the boundary between the first plate part 110 and the ridge line part 130 is determined by creating a 3D model of the hot press-formed product 100 based on three-dimensional shape measurement, and from this 3D model, the boundary between the first plate part 110 and the ridge line part 130. It can be identified by detecting.
  • the area of the recess 140 is the area of the range on the recess 140 side surrounded by the boundary between the side ridgeline part 144 and the first plate part 110.
  • the boundary between the first plate part 110 and the side ridge line part 144 is also determined by creating a 3D model of the hot press-formed product 100 based on three-dimensional shape measurement, and from this 3D model, the first plate part 110 and the side edge part 144 are It can be identified by detecting the boundary with the side ridgeline portion 144.
  • the maximum depth dmax of the recess 140 in the direction perpendicular to the plate surface of the first plate portion 110 may be 15 mm or more.
  • a maximum depth dmax of 15 mm or more it is possible to improve the compression axial force performance in the direction along the Z coordinate axis as shown in Fig. 1, and the moment bending performance in the direction along the X coordinate axis. It will be done.
  • the maximum depth dmax is 20 mm or more because it can further improve axial force and bending moment performance.
  • the depth d of the recess 140 is determined by the depth d between the boundary gb1 and the boundary gb2 on a virtual plane that includes the shortest straight line connecting the boundary gb1 and the boundary gb2 and where the cross-sectional line length of the recess 140 is the shortest when viewed in cross section. It means the distance from the straight line to the bottom inner surface 141a in the direction orthogonal to the straight line connecting.
  • the recess 140 in a cross-sectional view in a plane that passes through the point PD where the depth d of the recess 140 is the deepest and where the cross-sectional line length of the recess 140 is the shortest, the recess 140 is The angle between the side part 142 of the first plate part 110 and the direction perpendicular to the plate surface of the first plate part 110 is 2 to 8 degrees. Further, the thickness of the portion of the recess 140 where the thickness is the smallest is 60% or more of the thickness of the portion of the first plate portion 110 excluding the recess 140 .
  • the thickness of the portion of the first plate portion 110 excluding the recess 140 is defined as the average value of the thickness of any three points in the portion of the first plate portion 110 excluding the recess 140. Board thickness. Note that a plane that passes through the point pd where the depth d of the recess 140 is the deepest and where the cross-sectional line length of the recess 140 is the shortest is orthogonal to the plate surface of the first plate portion 110. According to the above-described manufacturing method, it is possible to suppress a reduction in the thickness of the recessed portion, so that in the hot press-formed product 100, the thickness of the portion of the recessed portion 140 where the thickness is the smallest is the same as that of the recessed portion 140 of the first plate portion 110. The thickness can be 60% or more of the plate thickness excluding the parts.
  • the hot press-formed product 100 deformation occurs when a load of a certain level or more is applied in a direction perpendicular to the longitudinal direction of the hot-press-formed product 100 or in the longitudinal direction of the hot press-formed product 100. arise. At this time, a tensile force or a compressive force is applied in a direction perpendicular to the direction in which the recess 140 extends.
  • the plate thickness at the part where the plate thickness is the smallest in the recess 140 is 60% or more of the plate thickness of the part of the first plate part 110 excluding the recess 140. 140 can improve the axial force and bending moment performance of the member.
  • the plate thickness of the first plate part 110 and the recessed part 140 is measured by creating a 3D model based on three-dimensional shape measurement of the hot press-formed product 100 as described above, and detecting the plate thickness from this 3D model. .
  • the average plate thickness t1 of the first plate portion 110 may be 0.8 to 2.6 mm.
  • the plate thickness of the workpiece 1 is measured at three or more locations from the 3D model, and the arithmetic mean value of the measured values of the plate thickness at these locations is set as the average plate thickness t1 of the workpiece 1.
  • the average plate thickness t1 of the first plate portion 110 is determined by the following method. In a plane orthogonal to the longitudinal direction of the hot press-formed product 100 at the central position in the longitudinal direction of the hot press-formed product 100, the plate thickness at any position of the first plate portion 110 excluding the recess 140 is calculated from the 3D model. Measure at more than one location. The arithmetic mean value of the measured values of the plate thickness at these locations is defined as the average plate thickness t1.
  • the average plate thickness t of the workpiece 1 may be 0.8 to 2.6 mm.
  • the plate thickness of the workpiece 1 is measured at three or more locations from the 3D model, and the arithmetic mean value of the measured values of the plate thickness at these locations is set as the average plate thickness t of the workpiece 1.
  • the convex portion 1120 of the first mold 1100 used in the method for manufacturing a hot press-formed product according to the present embodiment has a maximum distance in the pressing direction from the press surface 1110 to the convex portion 1120 of 15 mm or more. Good too.
  • the pressing direction intersects with the pressing surface 1110.
  • the maximum distance from the pressing surface 1110 to the convex portion 1120 in the pressing direction means the maximum distance from the holding surface portion 1130 to the convex portion 1120 in the pressing direction.
  • the surface shape of the convex portion 1120 is shown in cross-sectional view in a plane that passes through the point where the distance from the press surface 1110 of the first mold 1100 to the convex portion 1120 is the longest and where the cross-sectional line length of the convex portion 1120 is the shortest.
  • the side surface portion 1222 of the groove portion 1220 of the second mold 1200 has an angle of 2 to 8 degrees with respect to the pressing direction.
  • the press mold or press device used in the method for manufacturing a hot press-formed product according to the present disclosure is not limited to the configuration described above, and may be modified in various ways as long as it has a configuration that can perform the press forming described above. can be applied.
  • the press device 2000 may further include a fourth mold 2400. Similar to FIG. 5, FIG. 13 is a schematic cross-sectional end view of the press device 2000 taken along the longitudinal direction of the first mold 2100.
  • the configurations of the first mold 2100, the second mold 2200, and the third mold 2300 are as described above, and the fourth mold 2400 is connected to the second plate part 120 and the second plate part 120 during press molding.
  • the flange portion to be formed is processed while being held together with the third mold 2300.
  • the fourth mold 2400 it is possible to suppress the occurrence of wrinkles in the flange portion.
  • the third mold 2300 is connected to the slide plate 1400.
  • the first mold 2100 is connected to the slide plate 1400 via a support portion 1410 (spring or piston).
  • a recess 250 may further be provided. This has the effect of improving compression axial force performance in the direction along the Z coordinate axis and moment bending performance in the direction along the X coordinate axis as shown in FIG. 1 and the like.
  • the hot press-formed product 100 including the two second plate portions 120 was described as an example, but the hot press-formed product according to the present disclosure includes the first plate portion 110.
  • the second plate portion 120 may be provided only on one side.
  • the hot press-formed product 100 including the second plate portion 120 connected to the first plate portion 110 via the ridgeline portion 130 has been described, but the hot press-formed product according to the present disclosure is The second plate portion and the ridgeline portion may not be provided. That is, even in the case of the hot press-formed product 100 including the first plate portion 110 provided with the recessed portion 140, the effect of the present disclosure of suppressing the reduction in the thickness of the recessed portion 140 and necking can be obtained.
  • the hot press-formed product 100 is preferably a long member. That is, when viewed from above in a direction perpendicular to the plate surface of the first plate part 110, it is preferable that the size of the first plate part 110 in the longitudinal direction is larger than the size in the transverse direction. Further, the lengthwise size and the widthwise size of the first plate portion 110 may be the same.
  • the recessed portion 140 may be provided along the longitudinal direction of the first plate portion 110, or a portion of the recessed portion 140 may be provided along the transverse direction of the first plate portion 110. Alternatively, a part of the recess 140 may extend in a direction intersecting the longitudinal direction or the lateral direction of the first plate part 110.
  • the hot press-formed product 100 has a tensile strength of 1470 MPa or more.
  • the tensile strength of the hot press-formed product 100 is more preferably 2000 MPa or more because it has a higher yield stress.
  • the tensile strength of the hot press-formed product 100 is determined as follows. Specifically, from the first plate part 110 or the second plate part 120 of the hot press-formed product 100, a sample of a size conforming to either the JIS No. 5 tensile test, the JIS No. 13B tensile test, or the JIS No.
  • the 14B tensile test is obtained. Then, the tensile strength of this sample was measured using a universal testing machine or a hydraulic servo type strength testing machine according to a method according to JIS Z 2241, and this tensile strength was taken as the tensile strength of the hot press-formed product 100. . Note that if a test piece specified by JIS cannot be collected, a micro tensile test piece may be used as the sample. In the micro tensile test, the width and plate thickness of the parallel part are preferably 0.2 to 2.0 mm, and the test piece shape is preferably such that a uniform load is applied within the parallel part of the tensile test. Wire cut electric discharge machining is preferred for test piece machining.
  • micro-tensile test piece is, for example, the Journal of the Welding Society of Japan, Vol. 75 (2006), No. 6, pp. 461-465 (https://www.jstage.jst.go.jp/article/jjws/75/6/75_6_461/ _pdf/-char/ja) test piece can be adopted.
  • the hot press-formed product 100 according to the above embodiment preferably has a length in the longitudinal direction of 700 to 1700 mm, and the length in the width direction of the first plate portion 110 (from the first plate edge 110A to The length (to the other edge) is more preferably 30 to 200 mm. Further, in the hot press-formed product 100 according to the above embodiment, it is more preferable that the length of the second plate portion 120 in the width direction is 30 to 200 mm.
  • the recess has a V-shaped cross-sectional shape partially including a curve as shown in FIG. 15, or a cross-sectional shape consisting of a curve as shown in FIG. You can leave it there.
  • the recess 340 of the hot press-formed product 300 may have a bottom portion 341 and a pair of side portions 342 having a curved cross section.
  • the bottom portion 341 is connected to side portions 342, and each side portion 342 is connected to the first plate portion 310 via a side edge portion 344.
  • the first plate part 310 has a first plate part plate surface 310a and a first plate part plate surface 310b opposite to the first plate part plate surface 310a.
  • the bottom 341 has a bottom inner surface 341a located inside the recess 340 and a bottom outer surface 341b opposite to the bottom inner surface.
  • one of the boundaries between the first plate part 310 and the recessed part 340 (the boundary between the first plate part 310 and the side edge part 344) is defined as a boundary gb1, and the other Let the boundary be a boundary gb2.
  • the boundary gb1 and the boundary gb2 on the plane orthogonal to the longitudinal direction of the hot press-formed product 300 are points on the plate surface on the outside of the bending of the side ridgeline portion 344.
  • the width of the recess 340 is defined as the distance between the boundary gb1 and the boundary gb2 in a plane perpendicular to the longitudinal direction of the hot press-formed product 300. Note that also in the case of the shape shown in FIG. 15, the definition of the curve corresponding to the shape of the recess is the same as in the above embodiment.
  • the recess 440 does not have flat sides as illustrated in FIG. 3, but has a curved line corresponding to the shape of the inner surface of the recess 440.
  • the curve consists of a curved portion 441 and a curved portion 442, and the intersection of the curved portion 441 and the curved portion 442 is a point ip.
  • the shape of the first plate portion of the recessed portion of the press-formed product according to the present disclosure in plan view is not particularly limited. 17 to 23 illustrate modified examples of the recess provided in the first plate portion. In FIGS. 17 to 23, only the shape of the recess provided in the first plate portion is schematically shown.
  • the press-formed product according to the above embodiment is preferably used as a hot press-formed product for vehicles such as a front bumper reinforcement, a rear bumper reinforcement, a side sill outer, a side sill inner, a door impact beam, a front side member, a rear side member, etc. .
  • Example 1 In Example 1, a three-point bending test was conducted on a hot press-formed product having three recesses as shown in FIG. 14 in a simulation.
  • the plate thickness of the workpiece was 1.2 mm, and the tensile strength of the workpiece was 2000 MPa class.
  • the simulation conditions for the three-point bending test were three-point bending in which the center of the member was statically pressed down, and the thickness of the central concave portion of the member was determined from the forming simulation.
  • the span of the receiving jig for three-point bending was set to 1000 mm.
  • the area ratio of the recess was 40%, the maximum depth was 15 mm, and the width was 35 mm, and the angle between the side of the recess and the pressing direction during press molding was changed as shown in Table 1.
  • ta-tmin based on the arithmetic average ta of the plate thickness at any three points in the first plate part excluding the recessed part and the plate thickness tmin of the thinnest part in the recessed part.
  • the plate thickness reduction rate in the recessed portion can be calculated by dividing the reduced plate thickness at the portion where the plate thickness is reduced the most in the recessed portion by the plate thickness of the first plate portion in a simulation.
  • the yield strength of the member for evaluating the member performance was calculated from the simulation results of the three-point bending test.
  • the yield strength is the value obtained by dividing the load received from the test specimen by the impactor pressed down in the three-point bending test by the weight, and this is evaluated as the component performance.
  • the load in Table 1 is the load that the impactor receives from the test specimen, and the weight is the weight of the hot press-formed product.
  • FIG. 24 shows the results of this simulation. According to FIG. 24, it was confirmed that the plate thickness reduction rate could be suppressed by setting the angle of the side part of the recess to 8° or less with respect to the pressing direction. It was also found that high component performance of 7.96 kN/kg or more can be achieved by setting the side angle of the recess in the range of 2 to 8 degrees with respect to the pressing direction. It was also found that when the angle of the side part of the recess was 2° or more with respect to the pressing direction, the press-molded product could be easily released from the mold. From these results, those with good overall component performance evaluation were rated B (Good), and the others were rated C (Bad).
  • the angle between the side of the recess and the direction perpendicular to the plate surface of the first plate is the same as the angle between the side of the recess and the pressing direction. It was a value.
  • the angle of the side portion of the recess with respect to the pressing direction is defined as in the embodiment described above.
  • Example 2 In Example 2, a three-point bending test was conducted on a hot press-formed product having a shape having one recess as shown in FIG. 1 etc. in a simulation.
  • the plate thickness of the workpiece was 2.01 mm, and the tensile strength of the workpiece was 2000 MPa class.
  • the simulation conditions for the three-point bending test were three-point bending in which the center of the member was statically pressed down, and the thickness of the central concave portion of the member was determined from the forming simulation.
  • the span of the receiving jig for three-point bending was set to 1000 mm.
  • the area ratio of the recess is 35%, the maximum depth is 20 mm, and the width is 35 mm, and the angle between the side of the recess and the pressing direction during press forming is changed as shown in Table 2, and the plate thickness in the recess is reduced.
  • the ratio and component performance were investigated. The results are shown in Table 2.
  • the definition and calculation method of the plate thickness reduction rate in the recessed portion and the component performance are the same as in Example 1.
  • the definitions of loads and the like in Table 2 are the same as in Table 1.
  • FIG. 25 shows the results of this simulation. According to FIG. 25, it was confirmed that the plate thickness reduction rate could be suppressed by setting the angle of the side part of the recess to 8° or less with respect to the pressing direction. It was also found that when the angle of the side part of the recess is in the range of 2 to 8 degrees with respect to the pressing direction, high component performance of 7.50 kN/kg or higher, which is the target component performance, can be achieved. It was also found that when the angle of the side part of the recess was 2° or more with respect to the pressing direction, the press-molded product could be easily released from the mold. From these results, those with good overall component performance evaluation were rated B (Good), and the others were rated C (Bad).
  • Example 3 As shown in Table 3, the thickness of the workpiece, the number of recesses, the tensile strength of the workpiece, and the pad pressure during molding (the pressing force of the first mold) were varied, and the test specimen was subjected to a three-point bending test. This was done through simulation, and a comprehensive evaluation was made based on the member's strength performance and mold cost.
  • the cross-sectional dimensions were such that the height of the second plate part was 65 mm, the width of the first plate part was 100 mm, and the width of the recess was 40 mm and the depth was 23 mm.
  • the angle of the sides of the recess was 5° with respect to the pressing direction.
  • the first plate part When the number of recesses in the first plate part was one, it was arranged at the center in the width direction, and when there were two recesses, a shallow groove with a depth of 8 mm was provided between the recess at the center in the width direction and the second plate part.
  • Table 3 In this example, the span of the receiving jig for three-point bending was set to 1300 mm.
  • a hot press device capable of suppressing reduction in plate thickness and necking of a concave portion of a hot press molded product formed by a die pad, a method for manufacturing a hot press molded product using the device, and press forming. It is extremely useful industrially because it can provide a hot press-formed product in which reduction in plate thickness in the recessed part of the product and necking are suppressed.
  • Hot press-formed product 110 First plate part 120 Second plate part 130 Ridge line part 140 Recessed part 141 Bottom part 142 Side part 143 Bottom side ridge line part 144 Side side ridge line part 1000 Press device 1100 First mold (die pad) 1200 Second mold (punch) 1300 Third mold (die)

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Abstract

Provided is a hot-pressing device (1000) that comprises a punch (1200), a die (1300), and a die pad (1100) and is characterized in that there is a groove (1220) in a top surface (1210) of the punch (1200), the angle formed between a wall surface of the groove (1220) and the pressing direction (P) in a cross-section taken along the pressing direction (P) being 2°–8°, there is a refrigerant channel inside the punch (1200), the die (1300) and the die pad (1100) are arranged so as to face the punch (1200) in the pressing direction (P), the die pad (1100) facing the top surface (1210) of the punch (1200), and there is a protrusion (1120) on the die pad (1100) at a position that is opposite the groove (1220) in the pressing direction (P), the protrusion (1120) having the inverse shape of the groove (1220).

Description

熱間プレス装置、熱間プレス成形品の製造方法及び熱間プレス成形品Hot press equipment, method for producing hot press-formed products, and hot press-formed products
　本開示は、熱間プレス装置、熱間プレス成形品の製造方法及び熱間プレス成形品に関する。
　本願は、２０２２年５月２６日に日本に出願された特願２０２２－０８５７７８号に基づき優先権を主張し、その内容をここに援用する。 The present disclosure relates to a hot press apparatus, a method for manufacturing a hot press molded product, and a hot press molded product.
This application claims priority based on Japanese Patent Application No. 2022-085778 filed in Japan on May 26, 2022, the contents of which are incorporated herein.
　従来、自動車の骨格部材として、金属製の板状部材を所定の断面形状に加工した部材が使用されている。骨格部材を有する製品に対して、衝突による衝撃が加えられた場合には、骨格部材が所望の変形モードを実現して衝撃を効率的に吸収することが求められる。例えば、特許文献１には、ピーク荷重を高くしたり、エネルギー吸収量を大きくしたりすることを目的として、小凹部とこの小凹部を囲む大凹部とが設けられたバンパーの補強材が開示されている。 Conventionally, members made of metal plate-shaped members processed into a predetermined cross-sectional shape have been used as frame members of automobiles. When a product having a skeletal member is subjected to impact due to a collision, the skeletal member is required to realize a desired deformation mode and efficiently absorb the impact. For example, Patent Document 1 discloses a reinforcing material for a bumper that is provided with a small recess and a large recess surrounding the small recess for the purpose of increasing the peak load and increasing the amount of energy absorption. ing.
　このような骨格部材には、軽量化を実現するとともに、十分な耐荷重を有することが求められる。また近年では、自動車等の車両の衝突安全基準の厳格化、並びに燃費規制の厳格化に伴い、高強度かつ軽量な部材が求められている。このような要求に応じるため、高い引張強度を有する、いわゆる高強度材を採用した軽量な骨格部材の開発が進められている。 Such skeleton members are required to be lightweight and have sufficient load capacity. Furthermore, in recent years, with stricter collision safety standards for vehicles such as automobiles and stricter fuel efficiency regulations, there has been a demand for high-strength and lightweight members. In order to meet such demands, development of lightweight frame members using so-called high-strength materials having high tensile strength is underway.
　特許文献２には、板材を、頂面に凹凸のあるハット形状の成形品にプレス成形する技術が開示されている。しかし、成形品の頂面の凹凸の成形と頂面に隣接する肩部の成形を同時に成形すると、これらの成形が互いに干渉して成形しにくくなる。特許文献２では成形品の頂面の凹凸の成形を予め行い、パンチとダイパッドで凹凸を拘束した後、パンチとダイで成形品の肩部を成形している。このように、２つの成形を同時に行わないのが特許文献２の要点である。 Patent Document 2 discloses a technique for press-molding a plate material into a hat-shaped molded product having an uneven top surface. However, if the unevenness on the top surface of the molded product and the shoulder portion adjacent to the top surface are molded at the same time, these moldings interfere with each other, making it difficult to mold. In Patent Document 2, the unevenness on the top surface of the molded product is formed in advance, the unevenness is restrained with a punch and a die pad, and then the shoulder portion of the molded product is formed with the punch and die. Thus, the key point of Patent Document 2 is not to perform two moldings at the same time.
日本国特許第５３２９１８８号公報Japanese Patent No. 5329188 日本国特開２０２０－０７５２７５号公報Japanese Patent Application Publication No. 2020-075275
　熱間プレスで頂面に溝部のあるハット形状の成形品あるいは溝形部材を成形する場合、特許文献２の方法を熱間プレスに適用すると、２回熱間プレスを実施することになる。１回の熱間プレスで成形する場合、加熱された板材にダイパッドとパンチで溝部を成形し、次にパンチとダイで肩部を成形することが考えられる。しかし、そうした場合、２つの課題がある。第１に、特許文献２のようにバネを介して溝部を成形した場合、バネの力が弱いため、ダイパットが成形下死点まで到達できずに溝部が所望の形状（パンチの頂部の溝部に沿った形状）に成形できない。第２に、ダイがダイパッドを押して成形下死点まで到達させたとしても、成形品の溝部の中で局所的な板厚減少が生じてしまう。ダイが成形下死点に到達するまでの間、パンチの頂部の溝部とダイパッドの間の被加工材が均一に金型に接していないため被加工材に温度むらが生じる。板厚減少が生じるのは、ダイとダイパッドが成形下死点に到達したときに被加工材の温度むらに起因する局所的な軟化部が優先して引き伸ばされるからである。 When forming a hat-shaped molded product or a groove-shaped member with a groove on the top surface by hot pressing, if the method of Patent Document 2 is applied to hot pressing, hot pressing will be performed twice. In the case of forming by one hot press, it is conceivable to form the groove part on the heated plate material using a die pad and a punch, and then to form the shoulder part using the punch and die. However, in such a case, there are two problems. First, when forming the groove using a spring as in Patent Document 2, the force of the spring is weak, so the die pad cannot reach the bottom dead center of the forming, and the groove does not form the desired shape (the groove at the top of the punch). It cannot be formed into a shape that follows the shape. Second, even if the die pushes the die pad to reach the bottom dead center of the molding, a local thickness reduction occurs within the groove of the molded product. Until the die reaches the bottom dead center of molding, the workpiece between the groove at the top of the punch and the die pad is not in uniform contact with the mold, resulting in temperature unevenness in the workpiece. The reason why the plate thickness decreases is that when the die and die pad reach the bottom dead center of molding, localized softened portions caused by temperature unevenness of the workpiece are stretched preferentially.
　本開示は、上記に鑑みてなされたものである。本開示は、ダイパッドによって成形される熱間プレス成形品の凹部の板厚減少やネッキングを抑制可能な熱間プレス装置、当該装置を使用した熱間プレス成形品の製造方法、並びにプレス成形品の凹部の板厚減少やネッキングが抑制された熱間プレス成形品を提供することを課題とする。 The present disclosure has been made in view of the above. The present disclosure provides a hot press device capable of suppressing the reduction in thickness and necking of a recessed portion of a hot press molded product formed by a die pad, a method for manufacturing a hot press molded product using the device, and a method for manufacturing a hot press molded product using the device, and a method for manufacturing a hot press molded product using the device. It is an object of the present invention to provide a hot press-formed product in which reduction in plate thickness at concave portions and necking are suppressed.
（１）本開示に係る発明の一態様の熱間プレス装置は、
　パンチとダイとダイパッドを備え、
　前記パンチの頂面には溝部があり、
　プレス方向に沿った横断面において、前記溝部の壁面と前記プレス方向とがなす角度が２～８°であり、
　前記パンチの内部には冷媒流路があり、
　前記ダイ及び前記ダイパッドは、前記プレス方向において前記パンチに向かい合うように配置され、
　前記ダイパッドは前記パンチの頂面に向かい合って配置され、
　前記ダイパッドには、前記プレス方向において前記溝部に対向する位置に凸部があり、前記凸部は前記溝部が反転した形状であることを特徴とする。
（２）上記（１）の熱間プレス装置では、
　前記ダイは、前記プレス方向において前記ダイパッドと接する段差部を有し、
　成形下死点において前記ダイパッドは前記ダイと前記プレス方向で接していてもよい。
（３）上記（１）又は（２）の熱間プレス装置では、
　前記横断面において、前記溝部の壁面の側面部側稜線部のＲ止まりと底面部側稜線部のＲ止まりとを結ぶ直線と前記プレス方向とがなす角度が２～８°であってもよい。
（４）本開示に係る発明の一態様の熱間プレス成形品の製造方法は、
　上記（１）から（３）のいずれか１項の熱間プレス装置を使用した熱間プレス成形品の製造方法であって、
　前記ダイと前記パンチの間にブランクを配置すること、
　前記パンチと前記ダイパッドで前記ブランクを挟むこと、
　前記パンチと前記ダイを成形下死点まで前記プレス方向に近づけること、を含むことを特徴とする。
（５）本開示に係る発明の一態様の熱間プレス成形品は、
　凹部が形成された第一板部と、前記第一板部に対して傾斜する第二板部とを備えるプレス成形品であって、
　前記凹部の深さが最も深くなる点を通る平面のうち、前記凹部の断面線長が最も短くなる平面における断面視で、前記凹部の側部と前記第一板部の板面に垂直な方向とがなす角度が２～８°であり、
　前記凹部で最も板厚が小さい箇所における板厚が、前記第一板部のうち、前記凹部を除く部位における板厚の６０％以上であることを特徴とする。
（６）上記（５）の熱間プレス成形品では、
　前記断面視で、前記凹部の側部の側部側稜線部のＲ止まりと底部側稜線部のＲ止まりとを結ぶ直線と前記第一板部の板面に垂直な方向とがなす角度が２～８°であってもよい。 (1) A hot press device according to one embodiment of the invention according to the present disclosure includes:
Equipped with punch, die and die pad,
The top surface of the punch has a groove,
In a cross section along the press direction, the angle between the wall surface of the groove and the press direction is 2 to 8 degrees,
There is a refrigerant flow path inside the punch,
The die and the die pad are arranged to face the punch in the pressing direction,
the die pad is disposed facing the top surface of the punch;
The die pad has a convex portion at a position facing the groove in the pressing direction, and the convex portion has a shape that is an inversion of the groove.
(2) In the hot press device of (1) above,
The die has a step portion in contact with the die pad in the pressing direction,
The die pad may be in contact with the die in the pressing direction at the bottom dead center of molding.
(3) In the hot press device of (1) or (2) above,
In the cross section, the angle between the press direction and a straight line connecting the rounded end of the side ridgeline portion of the wall surface of the groove and the rounded end of the bottom side ridgeline portion may be 2 to 8 degrees.
(4) A method for manufacturing a hot press-formed product according to one embodiment of the invention according to the present disclosure,
A method for producing a hot press-formed product using the hot press apparatus according to any one of (1) to (3) above,
placing a blank between the die and the punch;
sandwiching the blank between the punch and the die pad;
It is characterized by including the step of bringing the punch and the die closer to the pressing direction to the bottom dead center of the molding.
(5) The hot press-formed product of one embodiment of the invention according to the present disclosure is
A press-molded product comprising a first plate portion in which a recess is formed and a second plate portion inclined with respect to the first plate portion,
A direction perpendicular to the side part of the recess and the plate surface of the first plate part in a cross-sectional view in a plane where the cross-sectional line length of the recess is the shortest among the planes passing through the point where the depth of the recess is the deepest. The angle between the two is 2 to 8 degrees,
The thickness of the thinnest portion of the recessed portion is 60% or more of the thickness of the portion of the first plate portion excluding the recessed portion.
(6) In the hot press-formed product of (5) above,
In the cross-sectional view, the angle between the straight line connecting the rounded end of the side ridgeline part of the side part of the recess and the rounded end of the bottom side ridgeline part and the direction perpendicular to the plate surface of the first plate part is 2. It may be ~8°.
　本開示によれば、ダイパッドによって成形される熱間プレス成形品の凹部の板厚減少やネッキングを抑制可能な熱間プレス装置、当該装置を使用した熱間プレス成形品の製造方法、並びにプレス成形品の凹部の板厚減少やネッキングが抑制された熱間プレス成形品を提供できる。 According to the present disclosure, there is provided a hot press device capable of suppressing reduction in plate thickness and necking of a concave portion of a hot press molded product formed by a die pad, a method for manufacturing a hot press molded product using the device, and press forming. It is possible to provide a hot press-formed product in which reduction in plate thickness at the concave portion of the product and necking are suppressed.
本開示の一実施形態に係る熱間プレス成形品の概略的な斜視図である。FIG. 1 is a schematic perspective view of a hot press-formed product according to an embodiment of the present disclosure. 図１の熱間プレス成形品をＺ座標軸に沿った方向に断面視した概略的な切断部端面図である。FIG. 2 is a schematic cross-sectional end view of the hot press-formed product of FIG. 1 in a direction along the Z coordinate axis. 図２の熱間プレス成形品の凹部近傍を拡大した概略的な切断部端面図である。FIG. 3 is an enlarged schematic cut-away end view of the hot press-formed product of FIG. 2 in the vicinity of a recess. 本開示の一実施形態に係る熱間プレス装置の概略的な斜視図である。FIG. 1 is a schematic perspective view of a hot press apparatus according to an embodiment of the present disclosure. 図４に示す熱間プレス装置を断面線Ａ－ＡにおいてＺ座標軸に沿った方向に断面視した概略的な切断部端面図である。FIG. 5 is a schematic cross-sectional end view of the hot press apparatus shown in FIG. 4 taken along the cross-sectional line AA in a direction along the Z coordinate axis. 本開示の一実施形態に係る熱間プレス成形品の製造方法に用いる熱間プレス装置を説明するための概略的な切断部端面図であり、被加工材を載置した状態を示す図である。FIG. 2 is a schematic cut-part end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to an embodiment of the present disclosure, and is a diagram showing a state in which a workpiece is placed. . 本開示の一実施形態に係る熱間プレス成形品の製造方法に用いる熱間プレス装置を説明するための概略的な切断部端面図であり、被加工材に凹部を形成した状態を示す図である。FIG. 2 is a schematic cut-part end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to an embodiment of the present disclosure, and is a diagram showing a state in which a recess is formed in a workpiece. be. 本開示の一実施形態に係る熱間プレス成形品の製造方法に用いる熱間プレス装置を説明するための概略的な切断部端面図であり、プレス成形が完了した状態を示す図である。It is a schematic cut-part end view for explaining the hot press apparatus used for the manufacturing method of the hot press molded product based on one Embodiment of this indication, and is a figure which shows the state where press forming is completed. 本開示の他の実施形態に係る熱間プレス成形品の製造方法に用いる熱間プレス装置を説明するための概略的な切断部端面図である。FIG. 7 is a schematic cut-away end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to another embodiment of the present disclosure. 本開示の他の実施形態に係る熱間プレス成形品の製造方法に用いる熱間プレス装置を説明するための概略的な切断部端面図であり、プレス成形が完了した状態を示す図である。FIG. 7 is a schematic cut-part end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to another embodiment of the present disclosure, and is a diagram showing a state in which press forming has been completed. 本開示の他の実施形態に係る熱間プレス成形品の製造方法に用いる熱間プレス装置を説明するための概略的な切断部端面図である。FIG. 7 is a schematic cut-away end view for explaining a hot press apparatus used in a method for manufacturing a hot press-formed product according to another embodiment of the present disclosure. 本開示の一実施形態に係る熱間プレス成形品の凹部を説明するための概略的な切断部端面図である。FIG. 2 is a schematic cut-away end view for explaining a recessed portion of a hot press-formed product according to an embodiment of the present disclosure. 本開示の一実施形態に係る熱間プレス装置の概略的な切断部端面図である。FIG. 1 is a schematic cut-away end view of a hot press apparatus according to an embodiment of the present disclosure. 本開示の一実施形態に係る熱間プレス成形品の概略的な切断部端面図である。FIG. 2 is a schematic cut-away end view of a hot press-formed product according to an embodiment of the present disclosure. 本開示の一実施形態に係る凹部の変形例を説明するための図であって、熱間プレス成形品の凹部近傍を示す概略的な切断部端面図である。FIG. 7 is a diagram for explaining a modified example of the recess according to an embodiment of the present disclosure, and is a schematic cut-away end view showing the vicinity of the recess of a hot press-formed product. 本開示の一実施形態に係る凹部の変形例を説明するための図であって、熱間プレス成形品の凹部近傍を示す概略的な切断部端面図である。FIG. 7 is a diagram for explaining a modified example of the recess according to an embodiment of the present disclosure, and is a schematic cut-away end view showing the vicinity of the recess of a hot press-formed product. 本開示に係る熱間プレス成形品の凹部の変形例を説明するための概略的な平面図である。FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure. 本開示に係る熱間プレス成形品の凹部の変形例を説明するための概略的な平面図である。FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure. 本開示に係る熱間プレス成形品の凹部の変形例を説明するための概略的な平面図である。FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure. 本開示に係る熱間プレス成形品の凹部の変形例を説明するための概略的な平面図である。FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure. 本開示に係る熱間プレス成形品の凹部の変形例を説明するための概略的な平面図である。FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure. 本開示に係る熱間プレス成形品の凹部の変形例を説明するための概略的な平面図である。FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure. 本開示に係る熱間プレス成形品の凹部の変形例を説明するための概略的な平面図である。FIG. 7 is a schematic plan view for explaining a modification of the recessed portion of the hot press-formed product according to the present disclosure. 実施例１の実験結果を示すグラフである。3 is a graph showing experimental results of Example 1. 実施例２の実験結果を示すグラフである。7 is a graph showing experimental results of Example 2.
　以下、本開示の実施形態について例を挙げて説明するが、本開示は以下で説明する例に限定されないことは自明である。以下の説明では、具体的な数値や材料を例示する場合があるが、本開示の効果が得られる限り、他の数値や材料を適用してもよい。また、以下の実施形態の各構成要素は、互いに組み合わせることができる。 Hereinafter, embodiments of the present disclosure will be described using examples, but it is obvious that the present disclosure is not limited to the examples described below. In the following description, specific numerical values and materials may be illustrated, but other numerical values and materials may be applied as long as the effects of the present disclosure can be obtained. Moreover, each component of the following embodiments can be combined with each other.
　先ず、図１を用いて、本実施形態に係る熱間プレス装置及び熱間プレス成形品の製造方法によって得られる熱間プレス成形品１００を説明する。 First, a hot press-formed product 100 obtained by a hot press apparatus and a method for manufacturing a hot press-formed product according to the present embodiment will be described with reference to FIG.
［熱間プレス成形品］
　図１は、熱間プレス成形品１００の斜視図であり、長尺の熱間プレス成形品１００の長手方向の中央位置において長手方向と直交する切断面を含む図である。この切断面は、プレス方向Ｐに沿った横断面でもある。本実施形態に係る熱間プレス成形品１００は、図１に示すように、長尺の熱間プレス成形品１００であって、熱間プレス成形品１００の長手方向に延在する第一板部１１０と、熱間プレス成形品１００の長手方向に延在しかつ第一板部１１０に対して傾斜する第二板部１２０と、第一板部１１０と第二板部１２０とを滑らかに接続しかつ熱間プレス成形品１００の長手方向に延在する稜線部１３０とを備える。熱間プレス成形品１００は長尺部材であり、長手方向と、長手方向と直交する短手方向とを有する。長手方向は、長尺部材である熱間プレス成形品１００が延在する方向である。なお、図１において、熱間プレス成形品１００の長手方向とＺ座標軸とは平行である。図１のＸ座標軸及びＹ座標軸は、熱間プレス成形品１００の短手方向を含む面を構成する。図１のＸ座標軸、Ｙ座標軸、Ｚ座標軸はそれぞれが互いに直交する。 [Hot press molded product]
FIG. 1 is a perspective view of a hot press-formed product 100, including a cut plane perpendicular to the longitudinal direction of the long hot press-formed product 100 at a central position in the longitudinal direction. This cut surface is also a cross section along the press direction P. As shown in FIG. 1, the hot press-formed product 100 according to the present embodiment is a long hot press-formed product 100, and includes a first plate portion extending in the longitudinal direction of the hot press-formed product 100. 110, a second plate part 120 that extends in the longitudinal direction of the hot press-formed product 100 and is inclined with respect to the first plate part 110, and smoothly connects the first plate part 110 and the second plate part 120. It also includes a ridgeline portion 130 extending in the longitudinal direction of the hot press-formed product 100. The hot press-formed product 100 is a long member, and has a longitudinal direction and a transversal direction perpendicular to the longitudinal direction. The longitudinal direction is the direction in which the hot press-formed product 100, which is a long member, extends. In addition, in FIG. 1, the longitudinal direction of the hot press-formed product 100 and the Z coordinate axis are parallel. The X coordinate axis and the Y coordinate axis in FIG. 1 constitute a plane including the lateral direction of the hot press-formed product 100. The X, Y, and Z coordinate axes in FIG. 1 are orthogonal to each other.
　図１の例では、第一板部１１０の凹部１４０を除く部位は略平板状であり、熱間プレス成形品１００の長手方向に延在する。第一板部１１０の凹部１４０を除く部位は、第一板部板面１１０ａ及び第一板部板面１１０ａと反対側の第一板部板面１１０ｂを有する。熱間プレス成形品１００の長手方向に平行な方向を第一板部１１０の長さ方向としたとき、第一板部１１０は第一板部１１０の長さ方向に延在する。 In the example shown in FIG. 1, the portion of the first plate portion 110 excluding the recessed portion 140 has a substantially flat plate shape and extends in the longitudinal direction of the hot press-formed product 100. The portion of the first plate portion 110 excluding the recess 140 has a first plate surface 110a and a first plate surface 110b opposite to the first plate surface 110a. When the direction parallel to the longitudinal direction of the hot press-formed product 100 is defined as the length direction of the first plate part 110, the first plate part 110 extends in the length direction of the first plate part 110.
　第二板部１２０は略平板状の部位であり、熱間プレス成形品１００の長手方向に延在する。第二板部１２０は、第二板部板面１２０ａ及び第二板部板面１２０ａと反対側の第二板部板面１２０ｂを有する。熱間プレス成形品１００の長手方向に平行な方向を第二板部１２０の長さ方向としたとき、第二板部１２０は第二板部１２０の長さ方向に延在する。第二板部１２０の長さ方向および第二板部１２０の板厚方向と直交する方向を第二板部１２０の幅方向としたとき、第二板部１２０は第二板部１２０の幅方向に延在する。図１の例では、熱間プレス成形品１００は一対の第二板部１２０を有する。 The second plate portion 120 is a substantially flat portion and extends in the longitudinal direction of the hot press-formed product 100. The second plate portion 120 has a second plate surface 120a and a second plate surface 120b opposite to the second plate surface 120a. When the direction parallel to the longitudinal direction of the hot press-formed product 100 is the length direction of the second plate part 120, the second plate part 120 extends in the length direction of the second plate part 120. When the direction perpendicular to the length direction and the thickness direction of the second plate part 120 is the width direction of the second plate part 120, the second plate part 120 is in the width direction of the second plate part 120. extends to In the example of FIG. 1, the hot press-formed product 100 has a pair of second plate portions 120.
　稜線部１３０は第一板部１１０と第二板部１２０とを滑らかに接続する部位であり、熱間プレス成形品１００の長手方向に延在する。第二板部１２０は第一板部１１０に対して傾斜しているため、これらを接続する稜線部１３０は、熱間プレス成形品１００の長手方向と直交する断面視において曲線を描くように湾曲した形状を有している。第二板部１２０が第一板部１１０に対して傾斜するとは、第一板部１１０の板面と第二板部１２０の板面が平行ではない状態を意味する。また、熱間プレス成形品１００の長手方向に平行な方向を稜線部１３０の長さ方向とする。稜線部１３０の曲げ外側の面を稜線外面１３０ａとし、稜線部１３０の曲げ内側の面を稜線内面１３０ｂとする。第一板部板面１１０ａ及び第二板部板面１２０ａは稜線外面１３０ａと接続され、第一板部板面１１０ｂ及び第二板部板面１２０ｂは稜線内面１３０ｂと接続される。熱間プレス成形品１００の長手方向に延在する第一板部１１０の一方の縁部（第一板部縁部１１０Ａ）が、熱間プレス成形品１００の長手方向に延在する稜線部１３０の一方の縁部（稜線縁部１３０Ａ）に接続される。熱間プレス成形品１００の長手方向に延在する第二板部１２０の一方の縁部（第二板部縁部１２０Ａ）が、稜線部１３０の長手方向に延在する他方の縁部（稜線縁部１３０Ｂ）に接続される。図１の例では、熱間プレス成形品１００は一対の稜線部１３０を有する。 The ridgeline portion 130 is a portion that smoothly connects the first plate portion 110 and the second plate portion 120, and extends in the longitudinal direction of the hot press-formed product 100. Since the second plate part 120 is inclined with respect to the first plate part 110, the ridgeline part 130 connecting them is curved in a cross-sectional view perpendicular to the longitudinal direction of the hot press-formed product 100. It has a shape. When the second plate part 120 is inclined with respect to the first plate part 110, it means that the plate surface of the first plate part 110 and the plate surface of the second plate part 120 are not parallel. Further, the direction parallel to the longitudinal direction of the hot press-formed product 100 is defined as the longitudinal direction of the ridgeline portion 130. The curved outer surface of the ridgeline portion 130 is defined as a ridgeline outer surface 130a, and the curved inner surface of the ridgeline portion 130 is defined as a ridgeline inner surface 130b. The first plate surface 110a and the second plate surface 120a are connected to the ridge outer surface 130a, and the first plate surface 110b and the second plate surface 120b are connected to the ridge inner surface 130b. One edge (first plate edge 110A) of the first plate portion 110 extending in the longitudinal direction of the hot press-formed product 100 is a ridgeline portion 130 extending in the longitudinal direction of the hot press-formed product 100. (ridgeline edge 130A). One edge (second plate edge 120A) of the second plate part 120 extending in the longitudinal direction of the hot press-formed product 100 is connected to the other edge (the ridge line) extending in the longitudinal direction of the ridgeline part 130. edge 130B). In the example of FIG. 1, the hot press-formed product 100 has a pair of ridgeline portions 130.
　第一板部１１０には、凹部１４０が設けられている。熱間プレス成形品１００の長手方向に平行な方向を凹部１４０の長さ方向としたとき、凹部１４０は凹部１４０の長さ方向に延在する。 A recess 140 is provided in the first plate portion 110. When the direction parallel to the longitudinal direction of the hot press-formed product 100 is defined as the length direction of the recess 140, the recess 140 extends in the length direction of the recess 140.
　凹部１４０は、熱間プレス成形品１００の長手方向の中央位置を通りかつ、稜線部１３０に沿って延在してもよい。熱間プレス成形品１００の長手方向の中央位置とは、熱間プレス成形品１００の長手方向長さを２等分する中心位置から熱間プレス成形品１００の長手方向長さの２０％の範囲に含まれる位置を意味する。凹部１４０が稜線部１３０に沿って延在するとは、凹部１４０が、隣り合う稜線部１３０の一部に略平行となるように配置されることを意味する。 The recessed portion 140 may extend through the longitudinal center of the hot press-formed product 100 and along the ridgeline portion 130. The center position in the longitudinal direction of the hot press-formed product 100 is a range of 20% of the longitudinal length of the hot press-formed product 100 from the center position that equally divides the longitudinal length of the hot press-formed product 100 into two. means the position included in When the recessed portion 140 extends along the ridgeline portion 130, it means that the recessed portion 140 is arranged substantially parallel to a portion of the adjacent ridgeline portion 130.
　第二板部１２０では、長手方向に延在する縁部のうちで稜線部１３０に接続されない側の縁部にフランジ部が形成されていてもよい。なお、第一板部１１０、第二板部１２０又はフランジ部には、穴部、切り欠き、溶接部等が設けられていてもよい。また、第二板部１２０又はフランジ部には、ビードが設けられていてもよい。 In the second plate portion 120, a flange portion may be formed on the edge portion extending in the longitudinal direction that is not connected to the ridgeline portion 130. Note that the first plate portion 110, the second plate portion 120, or the flange portion may be provided with a hole, a notch, a welded portion, or the like. Further, the second plate portion 120 or the flange portion may be provided with a bead.
　図２に、図１に示す熱間プレス成形品１００の長手方向において、熱間プレス成形品１００の長手方向と直交する平面で熱間プレス成形品１００を断面視した切断部端面図を示す。凹部１４０は、後述するような、第一板部１１０の板面に垂直な方向へ凹んでいる。図２の例では、凹部１４０は第一板部１１０に対して第二板部１２０が位置する側（第一板部板面１１０ｂ側）へ凹んでいる。 FIG. 2 shows a cross-sectional end view of the hot press-formed product 100 in the longitudinal direction of the hot press-formed product 100 shown in FIG. The recessed portion 140 is recessed in a direction perpendicular to the plate surface of the first plate portion 110, as will be described later. In the example of FIG. 2, the recessed portion 140 is recessed toward the side where the second plate portion 120 is located with respect to the first plate portion 110 (the first plate surface 110b side).
　図２の例では、凹部１４０は、底部１４１、一対の側部１４２、底部側稜線部１４３及び側部側稜線部１４４を有する。凹部の底部１４１は、各端部において、一対の底部側稜線部１４３を介してそれぞれの側部１４２と接続されている。それぞれの側部１４２は、側部側稜線部１４４を介して第一板部１１０に接続されている。底部１４１、側部１４２、底部側稜線部１４３、並びに側部側稜線部１４４は、凹部１４０の長さ方向に延在する。 In the example of FIG. 2, the recess 140 has a bottom 141, a pair of side parts 142, a bottom side ridgeline part 143, and a side side ridgeline part 144. The bottom portion 141 of the recess is connected to each side portion 142 at each end via a pair of bottom side ridgeline portions 143 . Each side portion 142 is connected to the first plate portion 110 via a side edge portion 144 . The bottom portion 141 , the side portions 142 , the bottom edge portion 143 , and the side edge portion 144 extend in the length direction of the recess 140 .
　凹部１４０の底部１４１は、凹部１４０の内側（側部１４２の側）に位置する底部内面１４１ａと底部内面１４１ａと反対側の底部外面１４１ｂとを有している。すなわち、底部内面１４１ａは、凹部１４０の内面の一部を構成する。 The bottom 141 of the recess 140 has a bottom inner surface 141a located inside the recess 140 (on the side 142 side) and a bottom outer surface 141b opposite to the bottom inner surface 141a. That is, the bottom inner surface 141a constitutes a part of the inner surface of the recess 140.
　図３に、図２の熱間プレス成形品１００の凹部１４０近傍の拡大図を示す。熱間プレス成形品１００の長手方向と直交する平面において、第一板部１１０と凹部１４０との境界（第一板部１１０と側部側稜線部１４４との境界）の一方を境界ｇｂ１、他方の境界を境界ｇｂ２とする。ここで、図３に示すように、熱間プレス成形品１００の長手方向における熱間プレス成形品１００の長手方向と直交する平面上での、境界ｇｂ１及び境界ｇｂ２は、側部側稜線部１４４の曲げ外側の板面上の点とする。換言すれば、これら境界とは、側部側稜線部１４４の曲げ外側の板面におけるＲ止まりでもある。 FIG. 3 shows an enlarged view of the vicinity of the recess 140 of the hot press-formed product 100 of FIG. 2. In a plane perpendicular to the longitudinal direction of the hot press-formed product 100, one of the boundaries between the first plate part 110 and the recessed part 140 (the boundary between the first plate part 110 and the side edge part 144) is defined as a boundary gb1, and the other Let the boundary be a boundary gb2. Here, as shown in FIG. 3, the boundary gb1 and the boundary gb2 on a plane orthogonal to the longitudinal direction of the hot press-formed product 100 are defined by the side ridgeline portion 144. The point on the plate surface on the outside of the bend. In other words, these boundaries are also the curved ends of the plate surface on the outside of the bending of the side ridgeline portion 144.
　本実施形態の例では、凹部１４０は第一板部１１０において、第二板部１２０が位置する側（第一板部板面１１０ｂ側）に凹んでいる部分である。凹部１４０は、第一板部１１０において、第二板部１２０が位置する側とは反対側（第一板部板面１１０ａ側）に凹んでいる部分であってもよい。すなわち、第一板部１１０に設けられる凹部は、稜線外面１３０ａ側（熱間プレス成形品１００の外側）、又は稜線内面１３０ｂ側（熱間プレス成形品１００の内側）に凹んでいてもよい。 In the example of this embodiment, the recessed portion 140 is a portion of the first plate portion 110 that is recessed toward the side where the second plate portion 120 is located (the first plate surface 110b side). The recessed portion 140 may be a portion of the first plate portion 110 that is recessed on the side opposite to the side where the second plate portion 120 is located (the first plate surface 110a side). That is, the recess provided in the first plate portion 110 may be recessed toward the ridgeline outer surface 130a side (outside the hot press-formed product 100) or the ridgeline inner surface 130b side (inside the hot press-formed product 100).
　熱間プレス成形品１００の長手方向と直交する平面における、凹部の境界ｇｂ１と凹部の境界ｇｂ２との距離を凹部１４０の幅ｗとする。凹部１４０の幅ｗは熱間プレス成形品１００の長手方向において一定でなくともよい。凹部１４０の幅ｗは、図１等で示されるＺ座標軸に沿った方向の圧縮軸力性能や、Ｘ座標軸に沿った方向回りのモーメント曲げ性能を高められるという理由から、１０ｍｍ～５２ｍｍであることが好ましい。凹部１４０の幅ｗは、凹部１４０の延在方向の長さよりも小さいことが好ましい。
　なお、長尺部材である熱間プレス成形品１００が延在する方向において、熱間プレス成形品１００の両端部の境界ｇｂ１を結ぶ方向を長手方向とする。 The width w of the recess 140 is defined as the distance between the recess boundary gb1 and the recess boundary gb2 in a plane perpendicular to the longitudinal direction of the hot press-formed product 100. The width w of the recess 140 may not be constant in the longitudinal direction of the hot press-formed product 100. The width w of the recess 140 should be 10 mm to 52 mm because it can improve the compressive axial force performance in the direction along the Z coordinate axis and the moment bending performance in the direction along the X coordinate axis as shown in FIG. 1 etc. is preferred. The width w of the recess 140 is preferably smaller than the length of the recess 140 in the extending direction.
In addition, in the direction in which the hot press-formed product 100, which is a long member, extends, the direction connecting the boundaries gb1 at both ends of the hot press-formed product 100 is defined as the longitudinal direction.
［プレス装置］
　次に、本実施形態に係る熱間プレス成形品の製造方法に用いるプレス装置（熱間プレス装置）について説明する。 [Press equipment]
Next, a press apparatus (hot press apparatus) used in the method for manufacturing a hot press-formed product according to the present embodiment will be described.
　図４に、本実施形態に係る熱間プレス成形品の製造方法に用いるプレス装置（熱間プレス装置）の一例を示す。図４に示すプレス装置１０００は、プレス用金型として、第一金型１１００と、第二金型１２００と、第三金型１３００とを備える。第一金型１１００と第二金型１２００はプレス方向Ｐにおいて互いに相対移動可能である。第一金型１１００と第二金型１２００との間で被加工材（ブランク）を挟み込む。第三金型１３００は、Ｘ座標軸に沿った方向において第一金型１１００に隣り合うように配され、第一金型１１００及び第二金型１２００に対して相対移動可能である。本実施形態の例では、第三金型１３００は、プレス方向Ｐにおいて、第一金型１１００及び第二金型１２００に対して相対移動可能である。また、プレス装置１０００の第二金型１２００の内部には、冷媒流路（図示せず）が設けられている。ここで、プレス装置１０００におけるプレス方向Ｐは、Ｙ座標軸の負の方向である。図４のＸ座標軸、Ｙ座標軸、Ｚ座標軸はそれぞれが互いに直交する。 FIG. 4 shows an example of a press device (hot press device) used in the method for manufacturing a hot press-formed product according to the present embodiment. The press apparatus 1000 shown in FIG. 4 includes a first mold 1100, a second mold 1200, and a third mold 1300 as press molds. The first mold 1100 and the second mold 1200 are movable relative to each other in the press direction P. A workpiece (blank) is sandwiched between the first mold 1100 and the second mold 1200. The third mold 1300 is arranged adjacent to the first mold 1100 in the direction along the X coordinate axis, and is movable relative to the first mold 1100 and the second mold 1200. In the example of this embodiment, the third mold 1300 is movable relative to the first mold 1100 and the second mold 1200 in the press direction P. Furthermore, a coolant flow path (not shown) is provided inside the second mold 1200 of the press apparatus 1000. Here, the press direction P in the press apparatus 1000 is the negative direction of the Y coordinate axis. The X, Y, and Z coordinate axes in FIG. 4 are orthogonal to each other.
　第一金型１１００、第二金型１２００及び第三金型１３００は、Ｚ座標軸に沿った方向に長手方向を有する。図５に、図４に示す断面線Ａ－Ａにおいてプレス装置１０００をＺ座標軸に沿った方向に断面視した概略的な切断部端面図を示す。なお、図５～図８の端面図は、プレス方向Ｐに沿った横断面における図である。 The first mold 1100, the second mold 1200, and the third mold 1300 have their longitudinal directions along the Z coordinate axis. FIG. 5 shows a schematic cross-sectional end view of the press device 1000 taken along the sectional line AA shown in FIG. 4 in the direction along the Z coordinate axis. Note that the end views in FIGS. 5 to 8 are cross-sectional views along the press direction P.
　第一金型１１００は、プレス面１１１０とプレス面１１１０に設けられた凸部１１２０とを有する。図５の例では、凸部１１２０は、底面部１１２１及び一対の側面部１１２２を有する。底面部１１２１は、各端部において、一対の底面部側稜線部１１２３を介してそれぞれの側面部１１２２と接続されている。図５の例では、凸部１１２０は、Ｙ座標軸の負の方向に向けて凸となっている。それぞれの側面部１１２２は、側面部側稜線部１１２４を介して凸部１１２０を除くプレス面１１１０の保持面部１１３０に接続されている。底面部１１２１、側面部１１２２、底面部側稜線部１１２３、並びに側面部側稜線部１１２４は、凸部１１２０が延在する方向、すなわち図４のＺ座標軸に沿った方向に延在する。 The first mold 1100 has a press surface 1110 and a convex portion 1120 provided on the press surface 1110. In the example of FIG. 5, the convex portion 1120 has a bottom portion 1121 and a pair of side portions 1122. The bottom part 1121 is connected to each side part 1122 at each end via a pair of bottom part side ridgeline parts 1123. In the example of FIG. 5, the convex portion 1120 is convex toward the negative direction of the Y coordinate axis. Each side surface portion 1122 is connected to a holding surface portion 1130 of the press surface 1110 excluding the convex portion 1120 via a side surface portion side ridgeline portion 1124. The bottom part 1121, the side part 1122, the bottom part side ridge line part 1123, and the side part side ridge line part 1124 extend in the direction in which the convex part 1120 extends, that is, in the direction along the Z coordinate axis in FIG. 4.
　第二金型１２００は、プレス面（頂面）１２１０とプレス面１２１０に設けられた溝部（凹面部）１２２０とを有する。すなわち、第二金型１２００の頂面には溝部１２２０がある。図５の例では、溝部１２２０は、底面部１２２１、一対の側面部１２２２、底面部側稜線部１２２３及び側面部側稜線部１２２４を有する。底面部１２２１は、各端部において、一対の底面部側稜線部１２２３を介してそれぞれの側面部１２２２と接続されている。図５の例では、溝部１２２０は、Ｙ座標軸の負の方向に向けて凹む形状を有している。それぞれの側面部１２２２は、側面部側稜線部１２２４を介して溝部１２２０を除くプレス面１２１０の保持面部１２３０に接続されている。底面部１２２１、側面部１２２２、底面部側稜線部１２２３、並びに側面部側稜線部１２２４は、一定の長さを有し、溝部１２２０が延在する方向、すなわち図４のＺ座標軸に沿った方向に延在する。第二金型１２００は、肩面部１２４０を介して保持面部１２３０と接続される側壁部１２５０を更に備えている。肩面部１２４０は、保持面部１２３０と側壁部１２５０とを滑らかに接続する部位であり、肩面部１２４０と側壁部１２５０は、プレス面１２１０が延在する方向、すなわち図４のＺ座標軸に沿った方向に延在する。 The second mold 1200 has a press surface (top surface) 1210 and a groove portion (concave surface portion) 1220 provided on the press surface 1210. That is, the second mold 1200 has a groove 1220 on its top surface. In the example of FIG. 5, the groove portion 1220 has a bottom portion 1221, a pair of side portions 1222, a bottom side ridgeline portion 1223, and a sidewall side ridgeline portion 1224. The bottom part 1221 is connected to each side part 1222 at each end via a pair of bottom part side ridgeline parts 1223. In the example of FIG. 5, the groove portion 1220 has a shape that is recessed toward the negative direction of the Y coordinate axis. Each side surface portion 1222 is connected to a holding surface portion 1230 of the press surface 1210 excluding the groove portion 1220 via a side surface portion side ridgeline portion 1224. The bottom surface portion 1221, the side surface portion 1222, the bottom surface portion side ridgeline portion 1223, and the side surface portion side ridgeline portion 1224 have a constant length, and have a fixed length in the direction in which the groove portion 1220 extends, that is, the direction along the Z coordinate axis in FIG. extends to The second mold 1200 further includes a side wall portion 1250 connected to the holding surface portion 1230 via a shoulder surface portion 1240. The shoulder surface portion 1240 is a portion that smoothly connects the holding surface portion 1230 and the side wall portion 1250, and the shoulder surface portion 1240 and the side wall portion 1250 are connected in the direction in which the press surface 1210 extends, that is, the direction along the Z coordinate axis in FIG. extends to
　第一金型１１００の凸部１１２０と第二金型１２００の溝部１２２０とは、互いに対応する表面形状を有し、第一金型１１００と第二金型１２００によって被加工材を挟み込むことで、被加工材に凹部１４０が形成される。換言すれば、凸部１１２０は溝部１２２０が反転した形状を有する。また、第一金型１１００の保持面部１１３０と第二金型１２００の保持面部１２３０とは互いに平行である。本実施形態の例では、保持面部１１３０と保持面部１２３０は、プレス方向Ｐに対して垂直である。第一金型１１００には、プレス方向Ｐにおいて溝部１２２０に対向する位置に凸部１１２０がある。
　プレス方向Ｐに沿った横断面において、溝部１２２０の壁面はプレス方向Ｐに対して２～８°の角度を有する。より具体的には、プレス方向Ｐに沿った横断面における、側面部１２２２側に位置する側面部側稜線部１２２４のＲ止まりと側面部１２２２側に位置する底面部側稜線部１２２３のＲ止まりとを結ぶ直線と、プレス方向Ｐとがなす角度が２～８°である。プレス方向Ｐに沿った横断面とは、溝部１２２０の全体において第二金型１２００の溝部１２２０の深さが最も深くなる底面部１２２１上の点を通る平面のうち、溝部１２２０の断面線長が最も短くなる平面である。溝部１２２０の深さは、一対の側面部側稜線部１２２４と保持面部１２３０との境界を結ぶ最も短い直線を含み、かつ、断面視した際に溝部１２２０の断面線長が最も短くなる仮想平面上において、これらの境界同士を結ぶ直線に直交する方向における当該直線から底面部１２２１までの距離を意味する。溝部１２２０の断面線長は、第二金型１２００について３次元の形状測定に基づく３Ｄモデルを作成し、断面線長が最も短い平面を導出することで測定できる。
　底面部側稜線部１２２３の曲率半径は３ｍｍ～３０ｍｍである。側面部側稜線部１２２４の曲率半径は３ｍｍ～３０ｍｍである。側面部１２２２の曲率半径は３０ｍｍ超、又は側面部１２２２は平面である。側面部１２２２がこのような曲率半径の範囲で湾曲していたとしても、上記の横断面において溝部１２２０の壁面は直線に近似でき、上記のようなＲ止まりを結ぶ直線とプレス方向Ｐとがなす角度を規定することができる。 The convex part 1120 of the first mold 1100 and the groove part 1220 of the second mold 1200 have surface shapes corresponding to each other, and by sandwiching the workpiece between the first mold 1100 and the second mold 1200, A recess 140 is formed in the workpiece. In other words, the convex portion 1120 has a shape that is an inversion of the groove portion 1220. Further, the holding surface portion 1130 of the first mold 1100 and the holding surface portion 1230 of the second mold 1200 are parallel to each other. In the example of this embodiment, the holding surface portion 1130 and the holding surface portion 1230 are perpendicular to the pressing direction P. The first mold 1100 has a convex portion 1120 at a position facing the groove portion 1220 in the press direction P.
In the cross section along the press direction P, the wall surface of the groove 1220 has an angle of 2 to 8 degrees with respect to the press direction P. More specifically, in the cross section along the press direction P, the R end of the side ridgeline portion 1224 located on the side surface portion 1222 side and the R end of the bottom side ridgeline portion 1223 located on the side surface portion 1222 side. The angle between the straight line connecting the two and the press direction P is 2 to 8 degrees. A cross section along the press direction P is a plane that passes through a point on the bottom surface part 1221 where the depth of the groove part 1220 of the second mold 1200 is the deepest in the entire groove part 1220, and the cross-sectional line length of the groove part 1220 is This is the shortest plane. The depth of the groove 1220 is determined on a virtual plane that includes the shortest straight line connecting the boundary between the pair of side ridges 1224 and the holding surface 1230, and in which the cross-sectional line length of the groove 1220 is the shortest when viewed in cross section. , means the distance from the straight line to the bottom surface portion 1221 in the direction orthogonal to the straight line connecting these boundaries. The cross-sectional line length of the groove portion 1220 can be measured by creating a 3D model of the second mold 1200 based on three-dimensional shape measurement and deriving a plane with the shortest cross-sectional line length.
The radius of curvature of the bottom side ridgeline portion 1223 is 3 mm to 30 mm. The radius of curvature of the side ridgeline portion 1224 is 3 mm to 30 mm. The radius of curvature of the side surface portion 1222 is greater than 30 mm, or the side surface portion 1222 is flat. Even if the side surface portion 1222 is curved within such a radius of curvature, the wall surface of the groove portion 1220 can be approximated to a straight line in the above cross section, and the press direction P forms a straight line connecting the R stops as described above. The angle can be defined.
　第三金型１３００は、プレス面１３１０を有する。プレス面１３１０は、図４のＺ座標軸に沿った方向に延在する。第一金型１１００及び第三金型１３００は、プレス方向Ｐにおいて第二金型１２００に向かい合うように配置されている。第一金型１１００は第二金型１２００の頂面に向かい合って配置されている。 The third mold 1300 has a press surface 1310. The press surface 1310 extends in a direction along the Z coordinate axis in FIG. 4 . The first mold 1100 and the third mold 1300 are arranged to face the second mold 1200 in the press direction P. The first mold 1100 is placed facing the top surface of the second mold 1200.
　また、第三金型１３００はスライドプレート１４００に接続されている。また、第一金型１１００は、支持部１４１０（ばねやピストン）を介してスライドプレート１４００に接続されている。スライドプレート１４００の移動に伴い、第三金型１３００が移動する。スライドプレート１４００の移動に伴い、第一金型１１００は支持部１４１０を介して移動する。プレス装置１０００には、第一金型１１００、第二金型１２００及び第三金型１３００を、それぞれが独立して駆動可能な駆動部（図示せず）が設けられていてもよい。また、第一金型１１００、第二金型１２００及び第三金型１３００のいずれかが、プレス装置１０００に固定されていてもよい。 Further, the third mold 1300 is connected to a slide plate 1400. Further, the first mold 1100 is connected to the slide plate 1400 via a support portion 1410 (spring or piston). As the slide plate 1400 moves, the third mold 1300 moves. As the slide plate 1400 moves, the first mold 1100 moves via the support section 1410. The press device 1000 may be provided with a drive unit (not shown) that can drive each of the first mold 1100, the second mold 1200, and the third mold 1300 independently. Further, any one of the first mold 1100, the second mold 1200, and the third mold 1300 may be fixed to the press device 1000.
　ここで、本願の実施形態では、第一金型１１００をダイパッド、第二金型１２００をパンチ、第三金型１３００をダイとする。 Here, in the embodiment of the present application, the first mold 1100 is a die pad, the second mold 1200 is a punch, and the third mold 1300 is a die.
［熱間プレス成形品の製造方法］
　本実施形態に係る熱間プレス成形品の製造方法は、被加工材を熱間プレスして、凹部が形成された第一板部を含むプレス成形品を形成する熱間プレス成形品の製造方法である。本実施形態に係る熱間プレス成形品の製造方法においては、まず、図６に示すように、被加工材（ブランク）１を第一金型１１００と第二金型１２００の間に載置する。図６の例では、第一金型１１００が第二金型１２００の鉛直方向上側に位置し、被加工材１は第二金型１２００の保持面部１２３０上に載置されている。 [Manufacturing method of hot press molded product]
A method for manufacturing a hot press-formed product according to the present embodiment includes hot pressing a workpiece to form a press-formed product including a first plate portion in which a recess is formed. It is. In the method for manufacturing a hot press-formed product according to the present embodiment, first, as shown in FIG. 6, a workpiece (blank) 1 is placed between a first mold 1100 and a second mold 1200. . In the example of FIG. 6, the first mold 1100 is located above the second mold 1200 in the vertical direction, and the workpiece 1 is placed on the holding surface portion 1230 of the second mold 1200.
　本実施形態に係る熱間プレス成形品の製造方法では、プレス成形開始時の被加工材１の温度が６００～８００℃であってもよい。これにより、上述の熱間プレス装置により、熱間で変形抵抗が低い間に部品を成形できるという効果が得られる。 In the method for manufacturing a hot press-formed product according to the present embodiment, the temperature of the workpiece 1 at the start of press-forming may be 600 to 800°C. As a result, the above-described hot press apparatus has the effect of being able to mold a component while it is hot and has low deformation resistance.
　次いで、第一金型１１００と第二金型１２００とをプレス方向Ｐ（鉛直方向下側）において相対移動させ、互いに近接させる。このとき、第三金型１３００は、第一金型１１００と共に移動してもよく、第三金型１３００は移動しなくてもよい。これにより、被加工材１の熱間プレス成形品１００における第一板部１１０に相当する箇所を第一金型１１００と第二金型１２００によって挟み込む。 Next, the first mold 1100 and the second mold 1200 are moved relative to each other in the press direction P (lower side in the vertical direction) and brought close to each other. At this time, the third mold 1300 may move together with the first mold 1100, or the third mold 1300 may not move. As a result, a portion of the hot press-formed product 100 of the workpiece 1 corresponding to the first plate portion 110 is sandwiched between the first mold 1100 and the second mold 1200.
　次いで、第一金型１１００の凸部１１２０が被加工材１と接触した状態から、さらに第一金型１１００をプレス方向Ｐへ移動させる。これにより、図７に示すように、被加工材１を第一金型１１００と第二金型１２００で挟み込み、第一金型１１００の凸部１１２０と第二金型１２００の溝部１２２０との間に凹部１４０を形成する。 Next, the first mold 1100 is further moved in the pressing direction P from the state where the convex portion 1120 of the first mold 1100 is in contact with the workpiece 1. As a result, as shown in FIG. 7, the workpiece 1 is sandwiched between the first mold 1100 and the second mold 1200, and the workpiece 1 is sandwiched between the convex part 1120 of the first mold 1100 and the groove part 1220 of the second mold 1200. A recess 140 is formed in.
　本実施形態に係る熱間プレス成形品の製造方法では、第一金型１１００と第二金型１２００によって凹部１４０を形成する際の押圧力が０．４～２２．０ＭＰａであってもよい。より好ましくは、この押圧力は０．４～４．４ＭＰａであってもよい。これにより、被加工材の変形抵抗が低い間に成形でき、さらに第一金型１１００の成形荷重を最低限の負荷力に設定でき、金型費用を低減できるという効果が得られる。 In the method for manufacturing a hot press-formed product according to the present embodiment, the pressing force when forming the recess 140 by the first mold 1100 and the second mold 1200 may be 0.4 to 22.0 MPa. More preferably, this pressing force may be 0.4 to 4.4 MPa. Thereby, it is possible to mold the workpiece while the deformation resistance is low, and furthermore, the molding load of the first mold 1100 can be set to the minimum load force, and the mold cost can be reduced.
　その後、さらに第三金型１３００を下死点まで移動させ、図８に示すように、被加工材１を第二金型１２００と第三金型１３００で挟み込み、第二金型１２００と第三金型１３００との間に第二板部１２０を形成し、プレス成形を完了させる。この時点で、熱間プレス成形品１００には、第一板部１１０、第二板部１２０、稜線部１３０及び凹部１４０が形成されている。また、第二金型１２００と第三金型１３００との間にフランジ部が形成されてもよい。 Thereafter, the third mold 1300 is further moved to the bottom dead center, and as shown in FIG. 8, the workpiece 1 is sandwiched between the second mold 1200 and the third mold 1300, and A second plate portion 120 is formed between the mold 1300 and press molding is completed. At this point, the first plate part 110, the second plate part 120, the ridgeline part 130, and the recessed part 140 are formed in the hot press-formed product 100. Further, a flange portion may be formed between the second mold 1200 and the third mold 1300.
　なお、成形性の観点からは、第一金型１１００は、第三金型１３００が下死点に到達するよりも前に下死点に到達してもよく、第三金型１３００が下死点に到達するのと同時に、第一金型１１００が下死点に到達してもよい。 Note that from the viewpoint of formability, the first mold 1100 may reach the bottom dead center before the third mold 1300 reaches the bottom dead center, and the third mold 1300 may reach the bottom dead center. At the same time as reaching the point, the first mold 1100 may reach the bottom dead center.
　図９に、本開示の他の実施形態に係る熱間プレス成形品の製造方法に用いる熱間プレス装置を例示する。図９は、図５と同様に、図４に示すような断面線Ａ－Ａにおいてプレス装置をＺ座標軸に沿った方向に断面視した概略的な切断部端面図である。なお、図９～図１１の切断部端面図は、プレス方向Ｐに沿った横断面における図である。図９に示すプレス装置１０００は、段差部１３２０を備えている以外は、図５などに示すプレス装置１０００と同様の構成であるため、ここでは説明を省略する。すなわち、図９に示すプレス装置１０００には、上述した図４～図８に係るプレス装置１０００の構成を適用することができる。段差部１３２０は、Ｚ座標軸に沿った方向に延在していてもよい。
　なお、図９の例では、Ｘ座標軸方向において２つの第三金型１３００が示されている。これら２つの第三金型１３００は、Ｘ座標軸方向において互いに接続されていてもよい。 FIG. 9 illustrates a hot press apparatus used in a method for manufacturing a hot press molded product according to another embodiment of the present disclosure. Similar to FIG. 5, FIG. 9 is a schematic cross-sectional end view of the press device taken along the cross-sectional line AA shown in FIG. 4 in the direction along the Z coordinate axis. Note that the end views of the cut portion in FIGS. 9 to 11 are views taken in a cross section along the press direction P. The press device 1000 shown in FIG. 9 has the same configuration as the press device 1000 shown in FIG. 5 etc., except that it includes a stepped portion 1320, so the description thereof will be omitted here. That is, the configuration of the press apparatus 1000 shown in FIGS. 4 to 8 described above can be applied to the press apparatus 1000 shown in FIG. 9. The step portion 1320 may extend in the direction along the Z coordinate axis.
Note that in the example of FIG. 9, two third molds 1300 are shown in the X coordinate axis direction. These two third molds 1300 may be connected to each other in the X coordinate axis direction.
　図１０は、金型に被加工材を挟み込み、第三金型１３００を下死点まで移動させた状態を示している。図１０に示すように、被加工材を第二金型１２００と第三金型１３００で挟み込み、第二金型１２００と第三金型１３００との間に第二板部１２０を形成し、プレス成形を完了させる。この時点で、熱間プレス成形品１００には、第一板部１１０、第二板部１２０、稜線部１３０及び凹部１４０が形成されている。
　第三金型１３００が段差部１３２０を備えていることにより、成形下死点において第一金型１１００は第三金型１３００とプレス方向Ｐで接する。これにより、第一金型１１００が第三金型１３００に押し付けられ、第一金型１１００の押圧力が不足している場合にも、ネッキングを抑制することが可能となる。この際、支持部１４１０は、プレス方向Ｐにおいて縮むように変形している。 FIG. 10 shows a state in which a workpiece is sandwiched between the molds and the third mold 1300 is moved to the bottom dead center. As shown in FIG. 10, a workpiece is sandwiched between a second die 1200 and a third die 1300, a second plate part 120 is formed between the second die 1200 and the third die 1300, and the press Complete the molding. At this point, the first plate part 110, the second plate part 120, the ridgeline part 130, and the recessed part 140 are formed in the hot press-formed product 100.
Since the third mold 1300 includes the stepped portion 1320, the first mold 1100 contacts the third mold 1300 in the press direction P at the bottom dead center of molding. This makes it possible to suppress necking even when the first mold 1100 is pressed against the third mold 1300 and the pressing force of the first mold 1100 is insufficient. At this time, the support portion 1410 is deformed so as to contract in the pressing direction P.
　また、プレス装置１０００の他の形態を図１１に示す。図１１のプレス装置１０００も、図５等と同様に、図４に示すような断面線Ａ－Ａにおいてプレス装置をＺ座標軸に沿った方向に断面視した概略的な切断部端面図である。図１１に示すプレス装置１０００は、第三金型１３００が片側にのみ設けられている。また、第三金型１３００が段差部１３２０を備えている。また、第一金型１１００が、Ｘ軸方向において第三金型１３００とは反対側に、プレス面１１４０を有している。プレス面１１４０は、第一金型１１００のプレス面１１１０に接続するように設けられている。プレス面１１４０はＺ座標軸に沿った方向に延在する。 Further, another form of the press device 1000 is shown in FIG. 11. The press device 1000 in FIG. 11 is also a schematic cross-sectional end view of the press device in the direction along the Z coordinate axis, taken along the cross-sectional line AA as shown in FIG. 4, similar to FIG. 5 and the like. In the press apparatus 1000 shown in FIG. 11, the third mold 1300 is provided only on one side. Further, the third mold 1300 includes a stepped portion 1320. Further, the first mold 1100 has a press surface 1140 on the opposite side from the third mold 1300 in the X-axis direction. The press surface 1140 is provided so as to be connected to the press surface 1110 of the first mold 1100. The press surface 1140 extends in a direction along the Z coordinate axis.
　図１１に示すプレス装置１０００は、第三金型１３００が片側にのみ設けられていること以外は、図９に示すプレス装置１０００と同様の構成であるため、ここでは説明を省略する。すなわち、図１１に示すプレス装置１０００には、図９に係るプレス装置１０００の構成を適用することができる。図１１のプレス装置１０００では、プレス装置１０００の上側の第三金型１３００の加圧機構を配置する領域を多くすることができるため、プレス荷重設計に尤度を持たせることができるという利点がある。 The press apparatus 1000 shown in FIG. 11 has the same configuration as the press apparatus 1000 shown in FIG. 9 except that the third mold 1300 is provided only on one side, so the description thereof will be omitted here. That is, the configuration of the press apparatus 1000 according to FIG. 9 can be applied to the press apparatus 1000 shown in FIG. 11. In the press apparatus 1000 of FIG. 11, the area where the pressurizing mechanism of the third mold 1300 on the upper side of the press apparatus 1000 can be arranged can be increased, so there is an advantage that the press load design can have a likelihood. be.
　本実施形態に係る熱間プレス成形品の製造方法では、第一板部１１０の板面に垂直な方向で平面視した際の、第一板部１１０の面積に対する凹部１４０の面積の割合が３０％以上となるようにプレス成形を行ってもよい。第一板部１１０の板面に垂直な方向とは、境界ｇｂ１と境界ｇｂ２とを結ぶ最も短い直線を含み、かつ、断面視した際に凹部１４０の断面線長が最も短くなる仮想平面上において、境界ｇｂ１と境界ｇｂ２とを結ぶ直線に直交する方向を意味する。なお、凹部１４０の断面線長は、熱間プレス成形品１００について３次元の形状測定に基づく３Ｄモデルを作成し、断面線長が最も短い平面を導出することで測定できる。なお、本実施形態で説明する３次元の形状測定は、Ａｔｏｓ（ＧＯＭ社製）等の３Ｄスキャナを用いて計測することができる。
　第一板部１１０の面積及び凹部１４０の面積の定義などについては後述の通りである。 In the method for manufacturing a hot press-formed product according to the present embodiment, the ratio of the area of the recess 140 to the area of the first plate part 110 when viewed in plan in a direction perpendicular to the plate surface of the first plate part 110 is 30. % or more. The direction perpendicular to the plate surface of the first plate part 110 is defined as a direction on a virtual plane that includes the shortest straight line connecting the boundary gb1 and the boundary gb2, and in which the cross-sectional line length of the recessed part 140 is the shortest when viewed in cross-section. , means the direction perpendicular to the straight line connecting the boundary gb1 and the boundary gb2. Note that the cross-sectional line length of the recess 140 can be measured by creating a 3D model of the hot press-formed product 100 based on three-dimensional shape measurement and deriving a plane with the shortest cross-sectional line length. Note that the three-dimensional shape measurement described in this embodiment can be performed using a 3D scanner such as Atos (manufactured by GOM).
The definitions of the area of the first plate portion 110 and the area of the recessed portion 140 are as described later.
　本実施形態に係る熱間プレス成形品の製造方法では、プレス方向Ｐにおける、凹部１４０の深さｄの最大の深さｄｍａｘが１５ｍｍ以上となるようにプレス成形を行ってもよい。凹部１４０の深さｄはプレス方向Ｐにおける深さを意味する。プレス方向Ｐは第一板部１１０の板面に垂直な方向である。最大の深さｄｍａｘとは、凹部１４０の全体における、凹部１４０の深さｄの最大値を意味する。最大の深さｄｍａｘが１５ｍｍ以上であることで、図１等で示されるＺ座標軸に沿った方向の圧縮軸力性能や、Ｘ座標軸に沿った方向回りのモーメント曲げ性能を高められるという効果が得られる。凹部１４０の深さは、上述した第一板部１１０の板面に垂直な方向における当該直線から底部内面１４１ａまでの距離を意味する。
　より好ましくは、最大の深さｄｍａｘは、更に軸力や曲げモーメント性能を向上させるという理由から、２０ｍｍ以上である。より好ましくは、パッドのストローク増加によりプレスストロークが増えることによる生産性の悪化を抑制するという観点から、最大の深さｄｍａｘの上限は５０ｍｍが好ましい。 In the method for manufacturing a hot press-formed product according to the present embodiment, press forming may be performed such that the maximum depth dmax of the depth d of the recess 140 in the press direction P is 15 mm or more. The depth d of the recess 140 means the depth in the pressing direction P. The pressing direction P is a direction perpendicular to the plate surface of the first plate portion 110. The maximum depth dmax means the maximum value of the depth d of the recess 140 in the entire recess 140. By having a maximum depth dmax of 15 mm or more, it is possible to improve the compression axial force performance in the direction along the Z coordinate axis as shown in Fig. 1, and the moment bending performance in the direction along the X coordinate axis. It will be done. The depth of the recess 140 means the distance from the straight line in the direction perpendicular to the plate surface of the first plate part 110 described above to the bottom inner surface 141a.
More preferably, the maximum depth dmax is 20 mm or more to further improve axial force and bending moment performance. More preferably, the upper limit of the maximum depth dmax is preferably 50 mm from the viewpoint of suppressing deterioration in productivity due to an increase in press stroke due to an increase in pad stroke.
　本実施形態に係る熱間プレス成形品の製造方法では、凹部１４０を形成する際に、凹部１４０の深さｄが最も深くなる点ｐｄを通る平面のうち、凹部１４０の断面線長が最も短くなる平面（プレス方向で切断した横断面）における断面視で、凹部１４０の側部１４２とプレス方向Ｐとがなす角度αが２～８°となるようにプレスする。より具体的には、凹部１４０の深さｄが最も深くなる点ｐｄを通る平面のうち、凹部１４０の断面線長が最も短くなる平面における、側部１４２側に位置する側部側稜線部１４４のＲ止まりと側部１４２側に位置する底部側稜線部１４３のＲ止まりとを結ぶ直線と、プレス方向Ｐとがなす角度が２～８°となるようにプレスする。なお、凹部１４０の深さｄが最も深くなる点ｐｄを通りかつ、凹部１４０の断面線長が最も短くなる平面は、プレス方向Ｐに対して平行となる。凹部１４０の深さｄが最も深くなる点ｐｄとは、凹部１４０の全体における、凹部１４０の深さｄが最大の深さｄｍａｘとなる点である。
　底部側稜線部１４３の曲率半径は３ｍｍ～３０ｍｍである。側部側稜線部１４４の曲率半径は３ｍｍ～３０ｍｍである。側部１４２の曲率半径は３０ｍｍ超、又は側部１４２は平面である。側部１４２がこのような曲率半径の範囲で湾曲していたとしても、上記の横断面において側部１４２は直線に近似でき、上記のようなＲ止まりを結ぶ直線とプレス方向Ｐとがなす角度を規定することができる。 In the method for manufacturing a hot press-formed product according to the present embodiment, when forming the recess 140, the cross-sectional line length of the recess 140 is the shortest among the planes passing through the point pd where the depth d of the recess 140 is the deepest. Pressing is performed so that the angle α between the side portion 142 of the recess 140 and the pressing direction P is 2 to 8 degrees when viewed in cross section on a plane (a cross section taken in the pressing direction). More specifically, the side ridgeline portion 144 located on the side portion 142 side in the plane where the cross-sectional line length of the recess 140 is the shortest among the planes passing through the point pd where the depth d of the recess 140 is the deepest. Pressing is performed so that the angle formed by the pressing direction P and the straight line connecting the rounded end of the bottom edge line portion 143 located on the side portion 142 side is 2 to 8°. Note that a plane that passes through the point pd where the depth d of the recess 140 is the deepest and where the cross-sectional line length of the recess 140 is the shortest is parallel to the pressing direction P. The point pd at which the depth d of the recess 140 is the deepest is the point at which the depth d of the recess 140 becomes the maximum depth dmax in the entire recess 140.
The radius of curvature of the bottom side ridgeline portion 143 is 3 mm to 30 mm. The radius of curvature of the side edge portion 144 is 3 mm to 30 mm. The radius of curvature of side 142 is greater than 30 mm, or side 142 is flat. Even if the side portion 142 is curved within such a range of curvature radius, the side portion 142 can be approximated to a straight line in the above cross section, and the angle between the straight line connecting the R stops as described above and the press direction P. can be specified.
　図１２に、凹部１４０の深さｄが最も深くなる点ｐｄを通る平面のうち、凹部１４０の断面線長が最も短くなる平面における断面視図での切断部端面図を示す。図１２は、プレス装置１０００に載置されたプレス成形完了後の熱間プレス成形品１００を示し、熱間プレス成形品１００の凹部１４０近傍の拡大図である。図１２に示すように、凹部１４０の断面線長とは、境界ｇｂ１と境界ｇｂ２を結ぶ最も短い直線を含む平面において、境界ｇｂ１から境界ｇｂ２までの凹部１４０の内面に沿った線長を意味する。凹部１４０の形状に対応する曲線Ｃを定める断面は、点ｐｄを通る平面のうち、凹部１４０の断面線長が最も短くなる平面である。 FIG. 12 shows an end view of a cut portion in a cross-sectional view on a plane where the cross-sectional line length of the recess 140 is the shortest among the planes passing through the point pd where the depth d of the recess 140 is the deepest. FIG. 12 shows the hot press-formed product 100 placed on the press device 1000 after completion of press forming, and is an enlarged view of the vicinity of the recess 140 of the hot press-formed product 100. As shown in FIG. 12, the cross-sectional line length of the recess 140 means the line length along the inner surface of the recess 140 from the boundary gb1 to the boundary gb2 in a plane including the shortest straight line connecting the boundary gb1 and the boundary gb2. . The cross section defining the curve C corresponding to the shape of the recess 140 is the plane in which the cross-sectional line length of the recess 140 is the shortest among the planes passing through the point pd.
　曲線Ｃは、この断面における、凹部１４０の内面の形状に対応している。曲線Ｃは、境界ｇｂ１又は境界ｇｂ２から点ｐｄまでの間に、側部１４２の一方の端点である点ｉＰ１及び点ｉＰ２を有する。点ｉＰ１及び点ｉＰ２は側部側稜線部１４４のＲ止まりでもある。この断面において、凹部１４０の側部１４２と、プレス方向Ｐとがなす角度αが２～８°となるようにプレスすることで、第一金型１１００で成形される凹部１４０の加工をより下死点に近い成形高さまで成形することができ、凹部の板厚減少やネッキングを抑制することができる。角度αが２°以上であることで、プレス成形後に離型しやすいという効果がある。また角度αが８°以下であることで、第一金型１１００での成形時に、第一金型１１００と、又は第二金型１２００と接触していない被加工材１の部位を減らすことができ、冷却が進まない部位を減らすことができる。冷却の進まない部位が少ない場合、被加工材１の成形時の板厚減少が局所的に生じてネッキングに至ることがないため、過度な板厚減少やネッキングのない部品を成形できるという効果がある。 The curve C corresponds to the shape of the inner surface of the recess 140 in this cross section. The curve C has a point iP1 and a point iP2, which are one end point of the side portion 142, between the boundary gb1 or the boundary gb2 and the point pd. Point iP1 and point iP2 are also the rounded ends of the side ridgeline portion 144. In this cross section, by pressing so that the angle α between the side part 142 of the recess 140 and the pressing direction P is 2 to 8 degrees, the processing of the recess 140 formed by the first mold 1100 can be made easier. It is possible to mold to a molding height close to the dead center, and it is possible to suppress the reduction in plate thickness at the recessed portion and necking. When the angle α is 2° or more, there is an effect that the mold can be easily released after press molding. Furthermore, by setting the angle α to 8° or less, it is possible to reduce the portion of the workpiece 1 that is not in contact with the first mold 1100 or the second mold 1200 during molding with the first mold 1100. This reduces the number of areas where cooling does not proceed. If there are only a few areas where cooling does not progress, the thickness of the workpiece 1 will not locally decrease and lead to necking during forming, resulting in the ability to form parts without excessive thickness reduction or necking. be.
　なお、図１２に例示するように、凹部１４０の側部１４２が平坦である場合には、側部１４２の傾きと、接線ｔｉ１の傾き又はｔｉ２の傾きとが一致する。また、接線ｔｉ１の傾き又はｔｉ２の傾きは、側部１４２側に位置する側部側稜線部１４４のＲ止まりと側部１４２側に位置する底部側稜線部１４３のＲ止まりとを結ぶ直線の傾きと一致する。なお、図１２等の例では、側部１４２はプレス方向Ｐに対して同じ傾きを有するように描かれているが、２つの側部１４２は、プレス方向Ｐに対する角度の要件を満たす限り、プレス方向Ｐに対する角度が互いに異なってもよい。 Note that, as illustrated in FIG. 12, when the side portion 142 of the recess 140 is flat, the slope of the side portion 142 matches the slope of the tangent ti1 or the slope of ti2. The slope of the tangent ti1 or the slope of ti2 is the slope of the straight line connecting the round end of the side ridge line portion 144 located on the side portion 142 side and the round end of the bottom side ridge line portion 143 located on the side portion 142 side. matches. In addition, in the example of FIG. 12 etc., the side parts 142 are drawn to have the same inclination with respect to the press direction P, but as long as the two side parts 142 satisfy the angle requirements with respect to the press direction P, The angles with respect to the direction P may be different from each other.
　上述した製造方法によって得られた熱間プレス成形品１００では、第一板部１１０の板面に垂直な方向で平面視した際の、第一板部１１０の面積に対する凹部１４０の面積の割合が３０％以上であってもよい。第一板部１１０の面積は、凹部１４０を含みかつ、第二板部１２０及び第二板部１２０との間の稜線部１３０を除く部位の面積とする。 In the hot press-formed product 100 obtained by the manufacturing method described above, the ratio of the area of the recess 140 to the area of the first plate part 110 when viewed in plan in a direction perpendicular to the plate surface of the first plate part 110 is It may be 30% or more. The area of the first plate part 110 is the area including the recess 140 and excluding the second plate part 120 and the ridgeline part 130 between the second plate part 120.
　凹部１４０の面積は、第一板部１１０の板面に垂直な方向で平面視した際の、境界ｇｂ１から境界ｇｂ２までの面積である。第一板部１１０の板面に垂直な方向で平面視した際の、第一板部１１０の面積に対する凹部１４０の面積が３０％以上であることで、図１等で示されるＺ座標軸に沿った方向の圧縮軸力性能や、Ｘ座標軸に沿った方向回りのモーメント曲げ性能を高められるという効果が得られる。より好ましくは、第一板部１１０の面積に対する凹部１４０の面積は、さらに軸力や曲げモーメント性能を向上させられるという理由から、５０％以上である。
　第一板部１１０の面積は、第一板部１１０の板面に垂直な方向の平面視において、稜線部１３０と第一板部１１０との境界と第一板部１１０の長手方向端部とにより囲まれた範囲の面積とする。第一板部１１０と稜線部１３０との境界は、熱間プレス成形品１００について３次元の形状測定に基づく３Ｄモデルを作成し、この３Ｄモデルから第一板部１１０と稜線部１３０との境界を検出することで特定できる。凹部１４０の面積は、同様に、側部側稜線部１４４と第一板部１１０との境界により囲まれた凹部１４０側の範囲の面積とする。第一板部１１０と側部側稜線部１４４との境界もまた、熱間プレス成形品１００について３次元の形状測定に基づく３Ｄモデルを作成し、この３Ｄモデルから第一板部１１０と側部側稜線部１４４との境界を検出することで特定できる。 The area of the recessed portion 140 is the area from the boundary gb1 to the boundary gb2 when viewed in plan in a direction perpendicular to the plate surface of the first plate portion 110. The area of the recessed portion 140 is 30% or more of the area of the first plate portion 110 when viewed from above in a direction perpendicular to the plate surface of the first plate portion 110, so that the area along the Z coordinate axis shown in FIG. The effect is that the compressive axial force performance in the direction along the X coordinate axis and the moment bending performance in the direction along the X coordinate axis can be improved. More preferably, the area of the recessed portion 140 with respect to the area of the first plate portion 110 is 50% or more, since the axial force and bending moment performance can be further improved.
The area of the first plate part 110 is determined by the boundary between the ridgeline part 130 and the first plate part 110 and the longitudinal end of the first plate part 110 in a plan view in a direction perpendicular to the plate surface of the first plate part 110. Let it be the area of the range surrounded by. The boundary between the first plate part 110 and the ridge line part 130 is determined by creating a 3D model of the hot press-formed product 100 based on three-dimensional shape measurement, and from this 3D model, the boundary between the first plate part 110 and the ridge line part 130. It can be identified by detecting. Similarly, the area of the recess 140 is the area of the range on the recess 140 side surrounded by the boundary between the side ridgeline part 144 and the first plate part 110. The boundary between the first plate part 110 and the side ridge line part 144 is also determined by creating a 3D model of the hot press-formed product 100 based on three-dimensional shape measurement, and from this 3D model, the first plate part 110 and the side edge part 144 are It can be identified by detecting the boundary with the side ridgeline portion 144.
　本実施形態に係る熱間プレス成形品１００は、第一板部１１０の板面に垂直な方向において、凹部１４０の最大の深さｄｍａｘが１５ｍｍ以上であってもよい。最大の深さｄｍａｘが１５ｍｍ以上であることで、図１等で示されるＺ座標軸に沿った方向の圧縮軸力性能や、Ｘ座標軸に沿った方向回りのモーメント曲げ性能を高められるという効果が得られる。より好ましくは、最大の深さｄｍａｘは、さらに軸力や曲げモーメント性能を向上させられるという理由から、２０ｍｍ以上である。 In the hot press-formed product 100 according to the present embodiment, the maximum depth dmax of the recess 140 in the direction perpendicular to the plate surface of the first plate portion 110 may be 15 mm or more. By having a maximum depth dmax of 15 mm or more, it is possible to improve the compression axial force performance in the direction along the Z coordinate axis as shown in Fig. 1, and the moment bending performance in the direction along the X coordinate axis. It will be done. More preferably, the maximum depth dmax is 20 mm or more because it can further improve axial force and bending moment performance.
　凹部１４０の深さｄは、境界ｇｂ１と境界ｇｂ２とを結ぶ最も短い直線を含み、かつ、断面視した際に凹部１４０の断面線長が最も短くなる仮想平面上において、境界ｇｂ１と境界ｇｂ２とを結ぶ直線に直交する方向における当該直線から底部内面１４１ａまでの距離を意味する。 The depth d of the recess 140 is determined by the depth d between the boundary gb1 and the boundary gb2 on a virtual plane that includes the shortest straight line connecting the boundary gb1 and the boundary gb2 and where the cross-sectional line length of the recess 140 is the shortest when viewed in cross section. It means the distance from the straight line to the bottom inner surface 141a in the direction orthogonal to the straight line connecting.
　上述した製造方法によって得られた熱間プレス成形品１００では、凹部１４０の深さｄが最も深くなる点ｐｄを通りかつ、凹部１４０の断面線長が最も短くなる平面における断面視で、凹部１４０の側部１４２と第一板部１１０の板面に垂直な方向とがなす角度が２～８°である。
　また、凹部１４０で最も板厚が小さい箇所における板厚が、第一板部１１０のうち、凹部１４０を除く部位における板厚の６０％以上である。ここで凹部１４０を除く部分の板厚とは、第一板部１１０のうち、凹部１４０を除く部位において任意の３点の板厚の平均値を第一板部１１０の凹部１４０を除く部分の板厚とする。なお、凹部１４０の深さｄが最も深くなる点ｐｄを通りかつ、凹部１４０の断面線長が最も短くなる平面は、第一板部１１０の板面と直交する。上述した製造方法によれば、凹部の板厚減少を抑制することができるため、熱間プレス成形品１００において、凹部１４０で最も板厚が小さい箇所における板厚を第一板部１１０の凹部１４０を除く部分の板厚の６０％以上とすることができる。 In the hot press-formed product 100 obtained by the manufacturing method described above, in a cross-sectional view in a plane that passes through the point PD where the depth d of the recess 140 is the deepest and where the cross-sectional line length of the recess 140 is the shortest, the recess 140 is The angle between the side part 142 of the first plate part 110 and the direction perpendicular to the plate surface of the first plate part 110 is 2 to 8 degrees.
Further, the thickness of the portion of the recess 140 where the thickness is the smallest is 60% or more of the thickness of the portion of the first plate portion 110 excluding the recess 140 . Here, the thickness of the portion of the first plate portion 110 excluding the recess 140 is defined as the average value of the thickness of any three points in the portion of the first plate portion 110 excluding the recess 140. Board thickness. Note that a plane that passes through the point pd where the depth d of the recess 140 is the deepest and where the cross-sectional line length of the recess 140 is the shortest is orthogonal to the plate surface of the first plate portion 110. According to the above-described manufacturing method, it is possible to suppress a reduction in the thickness of the recessed portion, so that in the hot press-formed product 100, the thickness of the portion of the recessed portion 140 where the thickness is the smallest is the same as that of the recessed portion 140 of the first plate portion 110. The thickness can be 60% or more of the plate thickness excluding the parts.
　本実施形態に係る熱間プレス成形品１００では、熱間プレス成形品１００の長手方向と直交する方向、あるいは熱間プレス成形品１００の長手方向に一定以上の荷重が加えられたときに変形が生じる。このとき、凹部１４０の延在方向と直交する方向において引張力又は圧縮力が付加される。本実施形態に係る熱間プレス成形品１００では、凹部１４０で最も板厚が小さい箇所における板厚が第一板部１１０の凹部１４０を除く部分の板厚の６０％以上であることで、凹部１４０によって生じる部材の軸力や曲げモーメント性能を高められる。 In the hot press-formed product 100 according to the present embodiment, deformation occurs when a load of a certain level or more is applied in a direction perpendicular to the longitudinal direction of the hot-press-formed product 100 or in the longitudinal direction of the hot press-formed product 100. arise. At this time, a tensile force or a compressive force is applied in a direction perpendicular to the direction in which the recess 140 extends. In the hot press-formed product 100 according to the present embodiment, the plate thickness at the part where the plate thickness is the smallest in the recess 140 is 60% or more of the plate thickness of the part of the first plate part 110 excluding the recess 140. 140 can improve the axial force and bending moment performance of the member.
　第一板部１１０及び凹部１４０の板厚は、上述したような、熱間プレス成形品１００について３次元の形状測定に基づく３Ｄモデルを作成し、この３Ｄモデルから板厚を検出して測定する。 The plate thickness of the first plate part 110 and the recessed part 140 is measured by creating a 3D model based on three-dimensional shape measurement of the hot press-formed product 100 as described above, and detecting the plate thickness from this 3D model. .
　本実施形態に係る熱間プレス成形品は、第一板部１１０の平均板厚ｔ１が０．８～２．６ｍｍであってもよい。３Ｄモデルから被加工材１の板厚を３箇所以上測定し、これらの箇所の板厚の測定値の算術平均値を被加工材１の平均板厚ｔ１とする。第一板部１１０の平均板厚ｔ１は次の方法によって定める。熱間プレス成形品１００の長手方向の中央位置において熱間プレス成形品１００の長手方向と直交する平面において、凹部１４０を除く第一板部１１０の任意の位置における板厚を、３Ｄモデルから３箇所以上測定する。これらの箇所の板厚の測定値の算術平均値を平均板厚ｔ１とする。 In the hot press-formed product according to the present embodiment, the average plate thickness t1 of the first plate portion 110 may be 0.8 to 2.6 mm. The plate thickness of the workpiece 1 is measured at three or more locations from the 3D model, and the arithmetic mean value of the measured values of the plate thickness at these locations is set as the average plate thickness t1 of the workpiece 1. The average plate thickness t1 of the first plate portion 110 is determined by the following method. In a plane orthogonal to the longitudinal direction of the hot press-formed product 100 at the central position in the longitudinal direction of the hot press-formed product 100, the plate thickness at any position of the first plate portion 110 excluding the recess 140 is calculated from the 3D model. Measure at more than one location. The arithmetic mean value of the measured values of the plate thickness at these locations is defined as the average plate thickness t1.
　なお、本実施形態に係る熱間プレス成形品の製造方法では、被加工材１の平均板厚ｔが０．８～２．６ｍｍであってもよい。３Ｄモデルから被加工材１の板厚を３箇所以上測定し、これらの箇所の板厚の測定値の算術平均値を被加工材１の平均板厚ｔとする。 Note that in the method for manufacturing a hot press-formed product according to the present embodiment, the average plate thickness t of the workpiece 1 may be 0.8 to 2.6 mm. The plate thickness of the workpiece 1 is measured at three or more locations from the 3D model, and the arithmetic mean value of the measured values of the plate thickness at these locations is set as the average plate thickness t of the workpiece 1.
　本実施形態に係る熱間プレス成形品の製造方法に用いられる、第一金型１１００の凸部１１２０は、プレス面１１１０から凸部１１２０までの、プレス方向における最大の距離が１５ｍｍ以上であってもよい。本実施形態に係る熱間プレス成形品の製造方法に用いられる、第一金型１１００では、プレス方向はプレス面１１１０と交差する。ここで、プレス面１１１０から凸部１１２０までの、プレス方向における最大の距離とは、保持面部１１３０から凸部１１２０までの、プレス方向における最大の距離を意味する。 The convex portion 1120 of the first mold 1100 used in the method for manufacturing a hot press-formed product according to the present embodiment has a maximum distance in the pressing direction from the press surface 1110 to the convex portion 1120 of 15 mm or more. Good too. In the first mold 1100 used in the method for manufacturing a hot press-formed product according to this embodiment, the pressing direction intersects with the pressing surface 1110. Here, the maximum distance from the pressing surface 1110 to the convex portion 1120 in the pressing direction means the maximum distance from the holding surface portion 1130 to the convex portion 1120 in the pressing direction.
　また、第一金型１１００のプレス面１１１０から凸部１１２０までの距離が最も長くなる点を通りかつ、凸部１１２０の断面線長が最も短くなる平面における断面視で、凸部１１２０の表面形状に対応する曲線において、第二金型１２００の溝部１２２０の側面部１２２２がプレス方向に対して２～８°の角度を有する。 In addition, the surface shape of the convex portion 1120 is shown in cross-sectional view in a plane that passes through the point where the distance from the press surface 1110 of the first mold 1100 to the convex portion 1120 is the longest and where the cross-sectional line length of the convex portion 1120 is the shortest. In the curve corresponding to , the side surface portion 1222 of the groove portion 1220 of the second mold 1200 has an angle of 2 to 8 degrees with respect to the pressing direction.
　本開示に係る熱間プレス成形品の製造方法に用いられるプレス用金型又はプレス装置は上述のような構成に限定されず、上述のプレス成形を実施できる構成のものであれば、種々の変形を適用できる。例えば、一実施形態として、図１３に示すように、プレス装置２０００は、第四金型２４００をさらに備えていてもよい。図１３は、図５と同様に、プレス装置２０００を第一金型２１００の長手方向に沿った方向に断面視した概略的な切断部端面図である。第一金型２１００、第二金型２２００及び第三金型２３００の構成は上述の通りであり、第四金型２４００は、プレス成形時に、第二板部１２０及び第二板部１２０に接続されるフランジ部を第三金型２３００と共に挟持しながら加工する。第四金型２４００をさらに備えることで、フランジ部に生じるしわの発生を抑制できるという効果がある。また、第三金型２３００はスライドプレート１４００に接続されている。また、第一金型２１００は、支持部１４１０（ばねやピストン）を介してスライドプレート１４００に接続されている。 The press mold or press device used in the method for manufacturing a hot press-formed product according to the present disclosure is not limited to the configuration described above, and may be modified in various ways as long as it has a configuration that can perform the press forming described above. can be applied. For example, as one embodiment, as shown in FIG. 13, the press device 2000 may further include a fourth mold 2400. Similar to FIG. 5, FIG. 13 is a schematic cross-sectional end view of the press device 2000 taken along the longitudinal direction of the first mold 2100. The configurations of the first mold 2100, the second mold 2200, and the third mold 2300 are as described above, and the fourth mold 2400 is connected to the second plate part 120 and the second plate part 120 during press molding. The flange portion to be formed is processed while being held together with the third mold 2300. By further providing the fourth mold 2400, it is possible to suppress the occurrence of wrinkles in the flange portion. Further, the third mold 2300 is connected to the slide plate 1400. Further, the first mold 2100 is connected to the slide plate 1400 via a support portion 1410 (spring or piston).
　本開示に係る熱間プレス成形品１００では、一実施形態として、図１４に例示するように、熱間プレス成形品２００の長手方向の断面視で、第一板部２１０に凹部２４０よりも浅い凹部２５０がさらに設けられていてもよい。これにより、図１等で示されるＺ座標軸に沿った方向の圧縮軸力性能や、Ｘ座標軸に沿った方向回りのモーメント曲げ性能を高められるという効果がある。 In the hot press-formed product 100 according to the present disclosure, as an embodiment, as illustrated in FIG. A recess 250 may further be provided. This has the effect of improving compression axial force performance in the direction along the Z coordinate axis and moment bending performance in the direction along the X coordinate axis as shown in FIG. 1 and the like.
　なお、上記の実施形態では、２つの第二板部１２０を備える熱間プレス成形品１００を例に挙げて説明を行ったが、本開示に係る熱間プレス成形品は第一板部１１０の片側にのみ第二板部１２０を備えていてもよい。 In the above embodiment, the hot press-formed product 100 including the two second plate portions 120 was described as an example, but the hot press-formed product according to the present disclosure includes the first plate portion 110. The second plate portion 120 may be provided only on one side.
　また、上記の実施形態では、稜線部１３０を介して第一板部１１０と接続する第二板部１２０を備える熱間プレス成形品１００について説明したが、本開示に係る熱間プレス成形品は第二板部や稜線部を備えていなくともよい。すなわち、凹部１４０が設けられた第一板部１１０から構成される熱間プレス成形品１００であっても、凹部１４０の板厚減少やネッキングが抑制されるという本開示の効果が得られる。 Further, in the above embodiment, the hot press-formed product 100 including the second plate portion 120 connected to the first plate portion 110 via the ridgeline portion 130 has been described, but the hot press-formed product according to the present disclosure is The second plate portion and the ridgeline portion may not be provided. That is, even in the case of the hot press-formed product 100 including the first plate portion 110 provided with the recessed portion 140, the effect of the present disclosure of suppressing the reduction in the thickness of the recessed portion 140 and necking can be obtained.
　なお、上記の実施形態に係る熱間プレス成形品１００は、長尺の部材であることが好ましい。すなわち、第一板部１１０の板面に垂直な方向で平面視した際に、第一板部１１０の長手方向の大きさが短手方向の大きさよりも大きいことが好ましい。また、第一板部１１０の長手方向の大きさと短手方向の大きさが同じであってもよい。凹部１４０は第一板部１１０の長手方向に沿って設けられてもよく、凹部１４０の一部が第一板部１１０の短手方向に沿って設けられてもよい。あるいは、凹部１４０の一部が、第一板部１１０の長手方向または短手方向と交差する方向に延在していてもよい。 Note that the hot press-formed product 100 according to the above embodiment is preferably a long member. That is, when viewed from above in a direction perpendicular to the plate surface of the first plate part 110, it is preferable that the size of the first plate part 110 in the longitudinal direction is larger than the size in the transverse direction. Further, the lengthwise size and the widthwise size of the first plate portion 110 may be the same. The recessed portion 140 may be provided along the longitudinal direction of the first plate portion 110, or a portion of the recessed portion 140 may be provided along the transverse direction of the first plate portion 110. Alternatively, a part of the recess 140 may extend in a direction intersecting the longitudinal direction or the lateral direction of the first plate part 110.
　上記の実施形態に係る熱間プレス成形品１００は、１４７０ＭＰａ以上の引張強度を有する。熱間プレス成形品１００の引張強度を１４７０ＭＰａ以上とすることで、一定の降伏応力を確保することができ、ひずみを抑制することができる。熱間プレス成形品１００の引張強度は、より高い降伏応力を有するという理由から、２０００ＭＰａ以上であることがさらに好ましい。熱間プレス成形品１００の引張強度は次のようにして求める。具体的には、熱間プレス成形品１００の第一板部１１０又は第二板部１２０から、ＪＩＳ５号引張試験、ＪＩＳ１３Ｂ号引張試験又はＪＩＳ１４Ｂ号引張試験のいずれかに準じたサイズのサンプルを取得して、このサンプルについてＪＩＳ　Ｚ　２２４１に準じた手法によって、万能試験機や油圧サーボ式の強度試験機を用いて引張強度を測定し、この引張強度を熱間プレス成形品１００の引張強度とする。なお、ＪＩＳで規定される試験片が採取できない場合には、微小引張試験片をサンプルとしてもよい。微小引張試験は、平行部の幅や板厚は０．２～２．０ｍｍが好ましく、引張試験の平行部内において均一な荷重が加わる試験片形状が好ましい。試験片加工は、ワイヤカット放電加工が好ましい。微小引張試験片は、例えば、溶接学会誌　第７５巻（２００６）第６号，４６１－４６５頁（ｈｔｔｐｓ：／／ｗｗｗ．ｊｓｔａｇｅ．ｊｓｔ．ｇｏ．ｊｐ／ａｒｔｉｃｌｅ／ｊｊｗｓ／７５／６／７５＿６＿４６１／＿ｐｄｆ／－ｃｈａｒ／ｊａ）の試験片を採用できる。 The hot press-formed product 100 according to the above embodiment has a tensile strength of 1470 MPa or more. By setting the tensile strength of the hot press-formed product 100 to 1470 MPa or more, a constant yield stress can be ensured and distortion can be suppressed. The tensile strength of the hot press-formed product 100 is more preferably 2000 MPa or more because it has a higher yield stress. The tensile strength of the hot press-formed product 100 is determined as follows. Specifically, from the first plate part 110 or the second plate part 120 of the hot press-formed product 100, a sample of a size conforming to either the JIS No. 5 tensile test, the JIS No. 13B tensile test, or the JIS No. 14B tensile test is obtained. Then, the tensile strength of this sample was measured using a universal testing machine or a hydraulic servo type strength testing machine according to a method according to JIS Z 2241, and this tensile strength was taken as the tensile strength of the hot press-formed product 100. . Note that if a test piece specified by JIS cannot be collected, a micro tensile test piece may be used as the sample. In the micro tensile test, the width and plate thickness of the parallel part are preferably 0.2 to 2.0 mm, and the test piece shape is preferably such that a uniform load is applied within the parallel part of the tensile test. Wire cut electric discharge machining is preferred for test piece machining. The micro-tensile test piece is, for example, the Journal of the Welding Society of Japan, Vol. 75 (2006), No. 6, pp. 461-465 (https://www.jstage.jst.go.jp/article/jjws/75/6/75_6_461/ _pdf/-char/ja) test piece can be adopted.
　上記の実施形態に係る熱間プレス成形品１００は、長手方向の長さが７００～１７００ｍｍであることがより好ましく、第一板部１１０の幅方向の長さ（第一板部縁部１１０Ａから他方の縁部までの長さ）が３０～２００ｍｍであることがより好ましい。また、上記の実施形態に係る熱間プレス成形品１００は、第二板部１２０の幅方向の長さが３０～２００ｍｍであることがより好ましい。 The hot press-formed product 100 according to the above embodiment preferably has a length in the longitudinal direction of 700 to 1700 mm, and the length in the width direction of the first plate portion 110 (from the first plate edge 110A to The length (to the other edge) is more preferably 30 to 200 mm. Further, in the hot press-formed product 100 according to the above embodiment, it is more preferable that the length of the second plate portion 120 in the width direction is 30 to 200 mm.
　上記の実施形態に係る熱間プレス成形品では、凹部は、図１５に示すような一部に曲線を含むＶ字状の断面形状、あるいは図１６に示すような曲線からなる断面形状を有していてもよい。 In the hot press-formed product according to the above-described embodiment, the recess has a V-shaped cross-sectional shape partially including a curve as shown in FIG. 15, or a cross-sectional shape consisting of a curve as shown in FIG. You can leave it there.
　また、図１５に例示するように、熱間プレス成形品３００の凹部３４０は、断面が曲線からなる底部３４１及び一対の側部３４２を有してもよい。底部３４１は側部３４２と接続され、それぞれの側部３４２は、側部側稜線部３４４を介して第一板部３１０に接続されている。第一板部３１０は、第一板部板面３１０ａ及び第一板部板面３１０ａと反対側の第一板部板面３１０ｂを有する。底部３４１は、凹部３４０の内側に位置する底部内面３４１ａと底部内面と反対側の底部外面３４１ｂとを有している。熱間プレス成形品３００の長手方向と直交する平面において、第一板部３１０と凹部３４０との境界（第一板部３１０と側部側稜線部３４４との境界）の一方を境界ｇｂ１、他方の境界を境界ｇｂ２とする。熱間プレス成形品３００の長手方向と直交する平面上での、境界ｇｂ１及び境界ｇｂ２は、側部側稜線部３４４の曲げ外側の板面上の点とする。熱間プレス成形品３００の長手方向と直交する平面における、境界ｇｂ１と境界ｇｂ２との距離を凹部３４０の幅とする。なお、図１５に示す形状の場合にも、凹部の形状に対応する曲線の定義は上記実施形態と同様である。 Further, as illustrated in FIG. 15, the recess 340 of the hot press-formed product 300 may have a bottom portion 341 and a pair of side portions 342 having a curved cross section. The bottom portion 341 is connected to side portions 342, and each side portion 342 is connected to the first plate portion 310 via a side edge portion 344. The first plate part 310 has a first plate part plate surface 310a and a first plate part plate surface 310b opposite to the first plate part plate surface 310a. The bottom 341 has a bottom inner surface 341a located inside the recess 340 and a bottom outer surface 341b opposite to the bottom inner surface. In a plane perpendicular to the longitudinal direction of the hot press-formed product 300, one of the boundaries between the first plate part 310 and the recessed part 340 (the boundary between the first plate part 310 and the side edge part 344) is defined as a boundary gb1, and the other Let the boundary be a boundary gb2. The boundary gb1 and the boundary gb2 on the plane orthogonal to the longitudinal direction of the hot press-formed product 300 are points on the plate surface on the outside of the bending of the side ridgeline portion 344. The width of the recess 340 is defined as the distance between the boundary gb1 and the boundary gb2 in a plane perpendicular to the longitudinal direction of the hot press-formed product 300. Note that also in the case of the shape shown in FIG. 15, the definition of the curve corresponding to the shape of the recess is the same as in the above embodiment.
　図１６の例では、凹部４４０は図３に例示するような平坦な側部を有さず、凹部４４０の内面の形状に対応する曲線からなる。曲線は、曲線部４４１と曲線部４４２とからなり、曲線部４４１と曲線部４４２との交点が点ｉｐとなる。 In the example of FIG. 16, the recess 440 does not have flat sides as illustrated in FIG. 3, but has a curved line corresponding to the shape of the inner surface of the recess 440. The curve consists of a curved portion 441 and a curved portion 442, and the intersection of the curved portion 441 and the curved portion 442 is a point ip.
　本開示に係るプレス成形品の凹部の第一板部の平面視での形状は特に限定されない。図１７～図２３に、第一板部に設けられた凹部の変形例を例示する。図１７～図２３では、第一板部に設けられた凹部の形状のみ概略的に示す。 The shape of the first plate portion of the recessed portion of the press-formed product according to the present disclosure in plan view is not particularly limited. 17 to 23 illustrate modified examples of the recess provided in the first plate portion. In FIGS. 17 to 23, only the shape of the recess provided in the first plate portion is schematically shown.
　上記の実施形態に係るプレス成形品は、フロントバンパーレインフォース、リアバンパーレインフォース、サイドシルアウタ、サイドシルインナ、ドアインパクトビーム、フロントサイドメンバー、リアサイドメンバー等の車両用の熱間プレス成形品として好ましく用いられる。 The press-formed product according to the above embodiment is preferably used as a hot press-formed product for vehicles such as a front bumper reinforcement, a rear bumper reinforcement, a side sill outer, a side sill inner, a door impact beam, a front side member, a rear side member, etc. .
（実施例１）
　実施例１では、シミュレーション上で、図１４に示すような３つの凹部を有する形状の熱間プレス成形品について、３点曲げ試験を行った。被加工材の板厚は１．２ｍｍとし、被加工材の引張強度は２０００ＭＰａ級とした。３点曲げ試験のシミュレーションの条件は、部材中央を静的に押下する３点曲げとし、部材の中央凹部の板厚を、成形シミュレーションより求めた板厚とした。なお、本実施例では、３点曲げの受けジグのスパンを１０００ｍｍに設定した。 (Example 1)
In Example 1, a three-point bending test was conducted on a hot press-formed product having three recesses as shown in FIG. 14 in a simulation. The plate thickness of the workpiece was 1.2 mm, and the tensile strength of the workpiece was 2000 MPa class. The simulation conditions for the three-point bending test were three-point bending in which the center of the member was statically pressed down, and the thickness of the central concave portion of the member was determined from the forming simulation. In this example, the span of the receiving jig for three-point bending was set to 1000 mm.
　凹部の面積率は４０％、最大の深さは１５ｍｍ、幅は３５ｍｍとし、プレス成形時における凹部の側部とプレス方向とがなす角度を表１に示すように変化させた。また、凹部における板厚減少率と部品性能（耐力）について調べた。その結果を表１に示す。ここで、第一板部のうち、凹部を除く部位において任意の３点の板厚の算術平均ｔａと、凹部における最も板厚の薄い部分の板厚ｔｍｉｎに基づき、（ｔａ－ｔｍｉｎ）／ｔａを凹部における板厚減少率とする。凹部における板厚減少率は、シミュレーション上で、凹部において最も板厚が減少した部位における減少した分の板厚を第一板部の板厚で除することで算出できる。部材性能を評価するための部材の耐力は、３点曲げ試験のシミュレーション結果から算出した。ここで、耐力とは、三点曲げ試験にて押下するインパクターが、試験体から受ける荷重を重量で除した数値であり、これを部品性能として評価する。また、表１の荷重はインパクターが試験体から受ける荷重であり、重量は熱間プレス成形品の重量である。 The area ratio of the recess was 40%, the maximum depth was 15 mm, and the width was 35 mm, and the angle between the side of the recess and the pressing direction during press molding was changed as shown in Table 1. We also investigated the plate thickness reduction rate and component performance (yield strength) in the recess. The results are shown in Table 1. Here, based on the arithmetic average ta of the plate thickness at any three points in the first plate part excluding the recessed part and the plate thickness tmin of the thinnest part in the recessed part, (ta-tmin)/ta Let be the plate thickness reduction rate at the recess. The plate thickness reduction rate in the recessed portion can be calculated by dividing the reduced plate thickness at the portion where the plate thickness is reduced the most in the recessed portion by the plate thickness of the first plate portion in a simulation. The yield strength of the member for evaluating the member performance was calculated from the simulation results of the three-point bending test. Here, the yield strength is the value obtained by dividing the load received from the test specimen by the impactor pressed down in the three-point bending test by the weight, and this is evaluated as the component performance. Further, the load in Table 1 is the load that the impactor receives from the test specimen, and the weight is the weight of the hot press-formed product.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　また、図２４に、このシミュレーションの結果を示す。図２４によれば、凹部の側部の角度がプレス方向に対して８°以下であることで板厚減少率を抑制できることが確認できた。また、凹部の側部の角度がプレス方向に対して２～８°の領域にあることで目標とする部品性能７．９６ｋＮ／ｋｇ以上という高い部品性能を発揮できることがわかった。また、凹部の側部の角度がプレス方向に対して２°以上であることで、プレス成形品を金型から離型させやすいこともわかった。これらの結果より、総合的な部品性能判定が良いものをＢ（Ｇｏｏｄ）とし、これ以外をＣ（Ｂａｄ）とした。実施例１から実施例３に係るプレス成形品において、凹部の側部と第一板部の板面に垂直な方向とがなす角度は、それぞれ凹部の側部とプレス方向とがなす角度と同じ値であった。なお、実施例１から実施例３において、凹部の側部のプレス方向に対する角度の定義は上述の実施形態の通りとする。 Additionally, FIG. 24 shows the results of this simulation. According to FIG. 24, it was confirmed that the plate thickness reduction rate could be suppressed by setting the angle of the side part of the recess to 8° or less with respect to the pressing direction. It was also found that high component performance of 7.96 kN/kg or more can be achieved by setting the side angle of the recess in the range of 2 to 8 degrees with respect to the pressing direction. It was also found that when the angle of the side part of the recess was 2° or more with respect to the pressing direction, the press-molded product could be easily released from the mold. From these results, those with good overall component performance evaluation were rated B (Good), and the others were rated C (Bad). In the press-formed products according to Examples 1 to 3, the angle between the side of the recess and the direction perpendicular to the plate surface of the first plate is the same as the angle between the side of the recess and the pressing direction. It was a value. In Examples 1 to 3, the angle of the side portion of the recess with respect to the pressing direction is defined as in the embodiment described above.
（実施例２）
　実施例２では、シミュレーション上で、図１等に示すような１つの凹部を有する形状の熱間プレス成形品について、３点曲げ試験を行った。被加工材の板厚は２．０１ｍｍとし、被加工材の引張強度は２０００ＭＰａ級とした。３点曲げ試験のシミュレーションの条件は、部材中央を静的に押下する３点曲げとし、部材の中央凹部の板厚を、成形シミュレーションより求めた板厚とした。なお、本実施例では、３点曲げの受けジグのスパンを１０００ｍｍに設定した。 (Example 2)
In Example 2, a three-point bending test was conducted on a hot press-formed product having a shape having one recess as shown in FIG. 1 etc. in a simulation. The plate thickness of the workpiece was 2.01 mm, and the tensile strength of the workpiece was 2000 MPa class. The simulation conditions for the three-point bending test were three-point bending in which the center of the member was statically pressed down, and the thickness of the central concave portion of the member was determined from the forming simulation. In this example, the span of the receiving jig for three-point bending was set to 1000 mm.
　凹部の面積率は３５％、最大の深さは２０ｍｍ、幅は３５ｍｍとし、プレス成形時における凹部の側部とプレス方向とがなす角度を表２に示すように変化させ、凹部における板厚減少率と部品性能（耐力）について調べた。その結果を表２に示す。ここで、凹部における板厚減少率、部品性能の定義や算出方法は実施例１と同様である。また、表２の荷重等の定義は表１と同様である。 The area ratio of the recess is 35%, the maximum depth is 20 mm, and the width is 35 mm, and the angle between the side of the recess and the pressing direction during press forming is changed as shown in Table 2, and the plate thickness in the recess is reduced. The ratio and component performance (yield strength) were investigated. The results are shown in Table 2. Here, the definition and calculation method of the plate thickness reduction rate in the recessed portion and the component performance are the same as in Example 1. Furthermore, the definitions of loads and the like in Table 2 are the same as in Table 1.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　また、図２５に、このシミュレーションの結果を示す。図２５によれば、凹部の側部の角度がプレス方向に対して８°以下であることで板厚減少率を抑制できることが確認できた。また、凹部の側部の角度がプレス方向に対して２～８°の領域にあることで目標とする部品性能７．５０ｋＮ／ｋｇ以上という高い部品性能を発揮できることがわかった。また、凹部の側部の角度がプレス方向に対して２°以上であることで、プレス成形品を金型から離型させやすいこともわかった。これらの結果より、総合的な部品性能判定が良いものをＢ（Ｇｏｏｄ）とし、これ以外をＣ（Ｂａｄ）とした。 Additionally, FIG. 25 shows the results of this simulation. According to FIG. 25, it was confirmed that the plate thickness reduction rate could be suppressed by setting the angle of the side part of the recess to 8° or less with respect to the pressing direction. It was also found that when the angle of the side part of the recess is in the range of 2 to 8 degrees with respect to the pressing direction, high component performance of 7.50 kN/kg or higher, which is the target component performance, can be achieved. It was also found that when the angle of the side part of the recess was 2° or more with respect to the pressing direction, the press-molded product could be easily released from the mold. From these results, those with good overall component performance evaluation were rated B (Good), and the others were rated C (Bad).
（実施例３）
　表３に示すように、被加工材の板厚、凹部の数、被加工材の引張強度、成形時のパッド圧力（第一金型の押圧力）を変化させ、試験体の３点曲げ試験をシミュレーション上で行い、部材耐力性能と金型費用から総合的な評価を行った。断面寸法は、第二板部の高さ６５ｍｍ、第一板部の幅１００ｍｍとし、凹部の幅は４０ｍｍ、深さは２３ｍｍとした。凹部の側部の角度はプレス方向に対して５°とした。第一板部の凹部の数が１本の場合は幅方向中央に配置し、２本の場合は幅方向中央の凹部と第二板部との間に深さ８ｍｍの浅い溝を設けた。その結果を表３に示す。なお、本実施例では、３点曲げの受けジグのスパンを１３００ｍｍに設定した。 (Example 3)
As shown in Table 3, the thickness of the workpiece, the number of recesses, the tensile strength of the workpiece, and the pad pressure during molding (the pressing force of the first mold) were varied, and the test specimen was subjected to a three-point bending test. This was done through simulation, and a comprehensive evaluation was made based on the member's strength performance and mold cost. The cross-sectional dimensions were such that the height of the second plate part was 65 mm, the width of the first plate part was 100 mm, and the width of the recess was 40 mm and the depth was 23 mm. The angle of the sides of the recess was 5° with respect to the pressing direction. When the number of recesses in the first plate part was one, it was arranged at the center in the width direction, and when there were two recesses, a shallow groove with a depth of 8 mm was provided between the recess at the center in the width direction and the second plate part. The results are shown in Table 3. In this example, the span of the receiving jig for three-point bending was set to 1300 mm.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表３では、金型費用の評価基準において、パッド圧力１０．０ＭＰａ以下の条件をＡ（Ｖｅｒｙ　Ｇｏｏｄ）とし、パッド圧力１０．０ＭＰａ超５０．０ＭＰａ以下をＢ（Ｇｏｏｄ）とした。また、総合評価では、部材耐力性能評価結果が６．６ｋＮ／ｋｇ以上であり、金型費用がＢの条件に該当するもの、あるいは部材耐力性能評価結果が６．６ｋＮ／ｋｇ未満であっても、金型費用がＡの条件に該当するものをＡ（Ｖｅｒｙ　Ｇｏｏｄ）とし、部材耐力性能評価結果が６．６ｋＮ／ｋｇ未満であり、金型費用がＢの条件に該当するものをＢ（Ｇｏｏｄ）とした。 In Table 3, in the mold cost evaluation criteria, the condition of pad pressure of 10.0 MPa or less was designated as A (Very Good), and the condition of pad pressure of more than 10.0 MPa and 50.0 MPa or less was designated as B (Good). In addition, in the comprehensive evaluation, even if the member strength performance evaluation result is 6.6 kN/kg or more and the mold cost falls under condition B, or the member strength performance evaluation result is less than 6.6 kN/kg. If the mold cost falls under the condition A, it is marked A (Very Good), and if the member strength performance evaluation result is less than 6.6 kN/kg and the mold cost falls under the condition B, it is marked B (Good). ).
　本開示によれば、ダイパッドによって成形される熱間プレス成形品の凹部の板厚減少やネッキングを抑制可能な熱間プレス装置、当該装置を使用した熱間プレス成形品の製造方法、並びにプレス成形品の凹部の板厚減少やネッキングが抑制された熱間プレス成形品を提供できるため、産業上極めて有用である。 According to the present disclosure, there is provided a hot press device capable of suppressing reduction in plate thickness and necking of a concave portion of a hot press molded product formed by a die pad, a method for manufacturing a hot press molded product using the device, and press forming. It is extremely useful industrially because it can provide a hot press-formed product in which reduction in plate thickness in the recessed part of the product and necking are suppressed.
１００　熱間プレス成形品
１１０　第一板部
１２０　第二板部
１３０　稜線部
１４０　凹部
１４１　底部
１４２　側部
１４３　底部側稜線部
１４４　側部側稜線部
１０００　プレス装置
１１００　第一金型（ダイパッド）
１２００　第二金型（パンチ）
１３００　第三金型（ダイ） 100 Hot press-formed product 110 First plate part 120 Second plate part 130 Ridge line part 140 Recessed part 141 Bottom part 142 Side part 143 Bottom side ridge line part 144 Side side ridge line part 1000 Press device 1100 First mold (die pad)
1200 Second mold (punch)
1300 Third mold (die)

Claims (6)

  1. 　パンチとダイとダイパッドを備え、
    　前記パンチの頂面には溝部があり、
    　プレス方向に沿った横断面において、前記溝部の壁面と前記プレス方向とがなす角度が２～８°であり、
    　前記パンチの内部には冷媒流路があり、
    　前記ダイ及び前記ダイパッドは、前記プレス方向において前記パンチに向かい合うように配置され、
    　前記ダイパッドは前記パンチの頂面に向かい合って配置され、
    　前記ダイパッドには、前記プレス方向において前記溝部に対向する位置に凸部があり、前記凸部は前記溝部が反転した形状である
    ことを特徴とする熱間プレス装置。     Equipped with punch, die and die pad,
    The top surface of the punch has a groove,
    In a cross section along the press direction, the angle between the wall surface of the groove and the press direction is 2 to 8 degrees,
    There is a refrigerant flow path inside the punch,
    The die and the die pad are arranged to face the punch in the pressing direction,
    the die pad is disposed facing the top surface of the punch;
    The hot press apparatus is characterized in that the die pad has a convex portion at a position facing the groove in the pressing direction, and the convex portion has a shape that is an inversion of the groove.
  2. 　前記ダイは、前記プレス方向において前記ダイパッドと接する段差部を有し、
    　成形下死点において前記ダイパッドは前記ダイと前記プレス方向で接している
    ことを特徴とする請求項１に記載の熱間プレス装置。     The die has a step portion in contact with the die pad in the pressing direction,
    The hot press apparatus according to claim 1, wherein the die pad is in contact with the die in the pressing direction at the bottom dead center of forming.
  3. 　前記横断面において、前記溝部の壁面の側面部側稜線部のＲ止まりと底面部側稜線部のＲ止まりとを結ぶ直線と前記プレス方向とがなす角度が２～８°である
    ことを特徴とする請求項１に記載の熱間プレス装置。     In the cross section, the angle between the pressing direction and a straight line connecting the rounded end of the side ridgeline portion of the wall surface of the groove and the rounded end of the bottom side ridgeline portion is 2 to 8 degrees. The hot press apparatus according to claim 1.
  4. 　請求項１から３のいずれか１項に記載の熱間プレス装置を使用した熱間プレス成形品の製造方法であって、
    　前記ダイと前記パンチの間にブランクを配置すること、
    　前記パンチと前記ダイパッドで前記ブランクを挟むこと、
    　前記パンチと前記ダイを成形下死点まで前記プレス方向に近づけること、を含む
    ことを特徴とする熱間プレス成形品の製造方法。     A method for producing a hot press-formed product using the hot press apparatus according to any one of claims 1 to 3, comprising:
    placing a blank between the die and the punch;
    sandwiching the blank between the punch and the die pad;
    A method for manufacturing a hot press-formed product, comprising: bringing the punch and the die close to the bottom dead center of the press in the pressing direction.
  5. 　凹部が形成された第一板部と、前記第一板部に対して傾斜する第二板部とを備えるプレス成形品であって、
    　前記凹部の深さが最も深くなる点を通る平面のうち、前記凹部の断面線長が最も短くなる平面における断面視で、前記凹部の側部と前記第一板部の板面に垂直な方向とがなす角度が２～８°であり、
    　前記凹部で最も板厚が小さい箇所における板厚が、前記第一板部のうち、前記凹部を除く部位における板厚の６０％以上である
    ことを特徴とする熱間プレス成形品。     A press-molded product comprising a first plate portion in which a recess is formed and a second plate portion inclined with respect to the first plate portion,
    A direction perpendicular to the side part of the recess and the plate surface of the first plate part in a cross-sectional view in a plane where the cross-sectional line length of the recess is the shortest among the planes passing through the point where the depth of the recess is the deepest. The angle between the two is 2 to 8 degrees,
    A hot press-formed product characterized in that a thickness at a point where the thickness is smallest in the recess is 60% or more of a thickness at a portion of the first plate portion excluding the recess.
  6. 　前記断面視で、前記凹部の側部の側部側稜線部のＲ止まりと底部側稜線部のＲ止まりとを結ぶ直線と前記第一板部の板面に垂直な方向とがなす角度が２～８°である
    ことを特徴とする請求項５に記載の熱間プレス成形品。     In the cross-sectional view, the angle between the straight line connecting the rounded end of the side ridgeline part of the side part of the recess and the rounded end of the bottom side ridgeline part and the direction perpendicular to the plate surface of the first plate part is 2. The hot press-formed product according to claim 5, characterized in that the angle is 8°.
PCT/JP2023/019628 2022-05-26 2023-05-26 Hot-pressing device, production method for hot-pressed molded article, and hot-pressed molded article WO2023229025A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5956927A (en) * 1982-09-24 1984-04-02 Nissan Motor Co Ltd Press die
WO2020111061A1 (en) * 2018-11-28 2020-06-04 日本製鉄株式会社 Press formed article manufacturing method, metal plate set, press device, and press line
WO2021215391A1 (en) * 2020-04-20 2021-10-28 豊田鉄工株式会社 Press-molding method for elongated component, and vehicle pillar member molded using said molding method
JP6985989B2 (en) * 2018-06-26 2021-12-22 株式会社神戸製鋼所 Manufacturing method of press-molded products

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5956927A (en) * 1982-09-24 1984-04-02 Nissan Motor Co Ltd Press die
JP6985989B2 (en) * 2018-06-26 2021-12-22 株式会社神戸製鋼所 Manufacturing method of press-molded products
WO2020111061A1 (en) * 2018-11-28 2020-06-04 日本製鉄株式会社 Press formed article manufacturing method, metal plate set, press device, and press line
WO2021215391A1 (en) * 2020-04-20 2021-10-28 豊田鉄工株式会社 Press-molding method for elongated component, and vehicle pillar member molded using said molding method

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