Press-molded product manufacturing method

Abstract

To reduce press molding man-hours.SOLUTION: In order to manufacture a press-molded product comprising a tabular part and a wall part, a tabular blank is pinched by a first pinching structure which is positioned on a first side in a plate thickness direction with respect to the blank and a second pinching structure which is positioned on a second side opposite to the first side in the plate thickness direction with respect to the blank. By press molding that is performed moving a first metal mold in a press direction which is parallel to the plate thickness direction and in which the first metal mold relatively approaches the blank, the wall part is formed on the blank. By press molding that is performed by further moving the first metal mold in the press direction, the tabular part having a recess is formed on the blank.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a press-formed product.

Background Art

[0002] There is known a technique of forming an elongation flange on a plate-shaped blank material by press forming. The elongation flange is a shape formed, for example, by bending the blank material, and refers to a shape in which a ridge line at the bent portion is an arcuate shape concave with respect to the blank material.

[0003] For example, Patent Document 1 discloses a technique for suppressing wrinkles in a blank material by sandwiching and fixing the blank material between a punch and a pad when forming an elongation flange on the blank material by press forming.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In addition to the elongation flange, consider forming a press-formed product having a recess recessed in the plate thickness direction in a plate-shaped portion that is a portion on the side opposite to the elongation flange with respect to the ridge line. In the prior art as disclosed in Patent Document 1, when simultaneously forming the formation of the elongation flange and the formation of the recess by press forming, in order to form the recess by the punch and the pad that sandwich the blank material, a convex portion protruding in the plate thickness direction needs to be formed on the punch or the pad. For this reason, when the blank material is sandwiched between the punch and the pad, pad floating occurs in which the gap between the blank material and the punch or the pad becomes equal to or greater than the plate thickness due to the convex portion.

[0006] When forming an elongation flange by press forming in a state where pad floating occurs in the blank material, wrinkles are likely to occur in the blank material, particularly when the blank material is a material with a small material elongation such as a high-tensile material.

[0007] Therefore, in order to obtain a press-formed product having an elongation flange and a recess, it was necessary to form the recess in a process after the formation of the elongation flange in order to suppress the occurrence of wrinkles during the formation of the elongation flange. Furthermore, it was necessary to prepare a mold different from the mold used for the elongation flange for forming the recess.

[0008] One aspect of the present disclosure is to reduce the man-hours of press forming.

Means for Solving the Problems

[0009] One aspect of the present disclosure is a method for manufacturing a press-formed product including a plate-shaped portion having a recess recessed in the plate thickness direction and a wall portion extending from an end of the plate-shaped portion in a direction intersecting the plate-shaped portion. The method for manufacturing a press-formed product includes sandwiching a blank material, forming a wall portion on the blank material, and forming a plate-shaped portion having a recess in the blank material.

[0010] Sandwiching the blank material includes sandwiching the blank material by a first sandwiching structure and a second sandwiching structure. The first sandwiching structure is located on a first side in the plate thickness direction with respect to the plate-shaped blank material. The second sandwiching structure is located on a second side in the plate thickness direction opposite to the first side with respect to the blank material.

[0011] Forming the wall portion on the blank material includes performing press forming on the blank material sandwiched by the first sandwiching structure and the second sandwiching structure by moving at least one of the first mold and the sandwiching portion in a direction parallel to the plate thickness direction and in a press direction in which the first mold approaches the blank material relatively, and forming the wall portion on the blank material by the press forming. The first mold is located on the first side of the blank material. The sandwiching portion is a set of the first sandwiching structure, the second sandwiching structure, and the blank material.

[0012] Forming a plate-shaped portion having a recess in the blank material includes performing press forming on the blank material having a wall portion by further moving at least one of the first mold and the second mold in the press direction so that the first mold and the second mold approach each other, and forming a plate-shaped portion having a recess in the blank material by the press forming. The second mold is located on the second side of the blank material.

[0013] According to such a configuration, with the first mold and the second mold arranged on the first side and the second side of the blank material in advance, by moving the object in the same press direction, a wall portion and a recess can be formed in the blank material. Therefore, the man-hours of press forming can be reduced.

[0014] According to one aspect of the present disclosure, forming a wall portion may include forming a wall portion in the blank material by moving the first mold in the press direction. Forming a plate-shaped portion may include forming a plate-shaped portion having a recess in the blank material by further moving the first mold in the press direction so that a recess is formed in the blank material due to the approach of the first mold and the second mold.

[0015] According to such a configuration, by moving the first mold in the press direction once, a wall portion and a recess can be formed in the blank material. Therefore, the man-hours of press forming can be reduced. In one aspect of the present disclosure, the plate-shaped portion may have a first recess and a second recess. The first recess is configured as a recess. The second recess is shallower than the first recess and recesses in the plate thickness direction. Clamping the blank material may include forming the second recess in the blank material by clamping the blank material with a first clamping structure and a second clamping structure.

[0016] According to such a configuration, a second recess that is shallower than the first recess can be formed when the blank material is clamped by the first clamping structure and the second clamping structure. Therefore, the man-hours of press forming can be reduced.

[0017] In one aspect of the present disclosure, sandwiching the blank material may include sandwiching the blank material at at least two points separated in a direction orthogonal to the plate thickness direction by a first sandwiching structure and a second sandwiching structure. The at least two points may include a first point and a second point. Forming the plate-shaped portion may include forming a recess in the blank material by moving at least one of the first mold and the second mold so as to pass between the first point and the second point.

[0018] According to such a configuration, a recess can be formed between two points where the blank material is sandwiched by the first sandwiching structure and the second sandwiching structure. In one aspect of the present disclosure, the blank material may be made of a high-tensile material. The high-tensile material may be read as high-tensile steel.

[0019] According to such a configuration, when forming a press-formed product from a blank material made of a high-tensile material, it is possible to suppress the occurrence of cracks or wrinkles in the press-formed product.

Brief Description of the Drawings

[0020]

Figure 1

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Figure 15

Embodiments for Carrying Out the Invention

[0021] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. First Embodiment] The press-formed product 1 shown in FIG. 1 is an exemplary press-formed product 1 for explaining a method for manufacturing a press-formed product according to the first embodiment. The manufacturing method of this embodiment is not limited to the press-formed product 1 shown in FIG. 1 and can be used for manufacturing press-formed products of various shapes. The manufacturing method of this embodiment can be used, for example, for manufacturing press-formed products of any shape having a plate-like portion with a recessed portion recessed in the plate thickness direction and a wall portion extending from an end of the plate-like portion in a direction intersecting the plate-like portion.

[0022] [1-1. Configuration of Press-Formed Product] The press-formed product 1 shown in FIG. 1 is formed by press-forming a metal material. The press-formed product 1 is composed of a high-tensile steel material with high tensile strength called a high-tensile steel. For example, the press-formed product 1 may be composed of a high-tensile steel material with a tensile strength of 980 MPa or more, or may be composed of a high-tensile steel material with a tensile strength of 1180 MPa or more.

[0023] The press-formed product 1 includes a top plate portion 2, a wall portion 3, and a bottom plate portion 4. The top plate portion 2 is a plate-like part where most parts spread in the same plane except for a part. The top plate portion 2 may be curved in the plate thickness direction or may not be curved in the plate thickness direction. Hereinafter, the plate thickness direction of the top plate portion 2 is referred to as the vertical direction. The plate thickness direction is not limited to the vertical direction and may be read as the left-right direction or the front-back direction. The "up" and "down" in the vertical direction may be read interchangeably with each other.

[0024] The top plate portion 2 has a first upper concave portion 21a, a first lower concave portion 21b, a second upper concave portion 22a, and a second lower concave portion 22b. The first upper concave portion 21a is a portion that is recessed upward in the top plate portion 2 when viewed from below the top plate portion 2. The first lower concave portion 21b is a portion that is recessed downward in the top plate portion 2 when viewed from above the top plate portion 2. The depths of both the first upper concave portion 21a and the first lower concave portion 21b are larger than the plate thickness of the top plate portion 2. That is, the upper surface of the top plate portion 2 in the region corresponding to the first upper concave portion 21a is located above the upper surface of the top plate portion 2 in its peripheral region. The lower surface of the top plate portion 2 in the region corresponding to the first lower concave portion 21b is located below the lower surface of the top plate portion 2 in its peripheral region.

[0025] The second upper concave portion 22a is a portion that is recessed upward in the top plate portion 2 when viewed from below the top plate portion 2. The second lower concave portion 22b is a portion that is recessed downward in the top plate portion 2 when viewed from above the top plate portion 2. The depths of both the second upper concave portion 22a and the second lower concave portion 22b are smaller than the thickness of the top plate portion 2. That is, the depths of both the second upper concave portion 22a and the second lower concave portion 22b are smaller than the depths of the first upper concave portion 21a and the first lower concave portion 21b.

[0026] The positions where the first upper concave portion 21a, the first lower concave portion 21b, the second upper concave portion 22a, and the second lower concave portion 22b are provided are not particularly limited as long as they are on the top plate portion 2. The wall portion 3 is a plate-like portion that extends in a direction intersecting the top plate portion 2 from the end of the top plate portion 2. In the present embodiment, the wall portion 3 extends substantially downward from the end of the top plate portion 2.

[0027] The portion where the top plate portion 2 and the wall portion 3 are connected forms a ridge line 3a. The ridge line 3a is a concave arc shape that is recessed in a direction parallel to the upper surface of the top plate portion 2. As shown in FIG. 1, the wall portion 3 is curved along the ridge line 3a. The wall portion 3 corresponds to an extension flange formed at the end of the top plate portion 2.

[0028] The bottom plate portion 4 is a plate-like portion that spreads in a direction intersecting the wall portion 3 from the end of the wall portion 3 on the side opposite to the ridge line 3a. The bottom plate portion 4 spreads in a direction opposite to the direction in which the top plate portion 2 spreads with respect to the wall portion 3. Although not limited, in the present embodiment, the bottom plate portion 4 is substantially parallel to the top plate portion 2.

[0029] [1-2. Configuration of Press Forming Apparatus] The press-formed product 1 is formed by performing press forming on the blank material 10 using a press forming apparatus 5 (see FIGS. 2 to 8). The blank material 10 is a plate-like member. In the present embodiment, as an example, the blank material 10 is a high-tensile material made of metal.

[0030] As shown in FIGS. 2 to 8, the press molding apparatus 5 includes an upper mold 61, an upper pad 62, a gas cushion 63, a lower mold 71, a lower pad 72, and a die cushion 73. The upper mold 61 is a mold for press molding. The upper mold 61 has a top surface 61a, an upper contact portion 61b, an upper side wall forming portion 61c, an upper bottom plate forming portion 61d, and an upper convex portion 61e.

[0031] The top surface 61a is a surface located on the lower side of the upper mold 61 and extends in a direction perpendicular to the vertical direction (hereinafter referred to as the horizontal direction). The upper contact portion 61b is a portion protruding downward from a part of the top surface 61a.

[0032] The upper side wall forming portion 61c is a plate-like portion that extends downward from a position below the upper contact portion 61b and away from the upper contact portion 61b in the horizontal direction. The angle formed by the virtual plane extending the upper side wall forming portion 61c and the top surface 61a substantially coincides with the angle formed by the top plate portion 2 and the wall portion 3 in the press molded product 1.

[0033] The upper bottom plate forming portion 61d is a plate-like portion that extends horizontally from the lower end of the upper side wall forming portion 61c away from the upper side wall forming portion 61c. As shown in FIGS. 6 to 8, the upper convex portion 61e is a portion protruding downward from a part of the lower side of the top surface 61a. The lower end of the upper convex portion 61e has a shape protruding downward to form the first lower concave portion 21b in the press molded product 1.

[0034] The upper pad 62 is a pad for press molding. In the present embodiment, the cross section of the upper pad 62 in the vertical direction is substantially rectangular. The upper pad 62 has, for example, an upper first recess forming portion 62a, an upper second recess forming portion 62b, and an upper through hole 62c as shown in FIGS. 2 and 3.

[0035] The upper first recess forming portion 62a is formed on the lower surface of the upper pad 62 and is a portion recessed upward. The upper first recess forming portion 62a has a shape for forming the first upper recess 21a in the press-formed product 1.

[0036] The upper second recess forming portion 62b is formed on the lower surface of the upper pad 62 and is a portion recessed from above or protruding downward for forming the second upper recess 22a or the second lower recess 22b in the press-formed product 1.

[0037] The upper through-hole 62c is a through-hole penetrating the upper pad 62 in the vertical direction. As shown in FIGS. 3 to 8, the gas cushion 63 is a cushion that utilizes the reaction force of compressed gas. The gas cushion 63 expands and contracts in the vertical direction by pressure.

[0038] The upper surface of the gas cushion 63 abuts against the lower surface of the top surface 61a. The lower surface of the gas cushion 63 abuts against the upper surface of the upper pad 62. The lower surface of the gas cushion 63 is located below the upper contact portion 61b.

[0039] The lower die 71 is a die for press forming. The lower die 71 has, for example, as shown in FIGS. 2 and 3, a bottom surface 71a, a lower contact portion 71b, an upper side wall forming portion 71c, a lower bottom plate forming portion 71d, and a lower convex portion 71e.

[0040] The bottom surface 71a is a surface located above the lower die 71 and extends in the horizontal direction. The lower contact portion 71b is a portion protruding upward from a part of the bottom surface 71a. The upper side wall forming portion 71c is a plate-like portion extending downward from a position above the lower contact portion 71b and away from the lower contact portion 71b in the horizontal direction. In the press forming apparatus 5, the upper side wall forming portion 61c and the upper side wall forming portion 71c are substantially parallel.

[0041] The lower bottom plate forming portion 71d is a plate-like portion that extends horizontally away from the upper wall forming portion 71c from the lower end of the upper wall forming portion 71c. The lower convex portion 71e is a portion that protrudes upward from a part of the upper side of the bottom surface 71a. The upper end of the lower convex portion 71e has a shape that protrudes upward in order to form the first upper concave portion 21a in the press-formed product 1.

[0042] The lower pad 72 is a pad for press forming. In the present embodiment, the vertical cross-section of the lower pad 72 is substantially rectangular. The lower pad 72 has, for example, as shown in FIGS. 2 and 3, a lower first recess forming portion 72a, a lower second recess forming portion 72b, and a lower through hole 72c.

[0043] The lower first recess forming portion 72a is formed on the upper surface of the lower pad 72 and is a portion that is recessed downward. The lower first recess forming portion 72a has a shape for forming the first lower concave portion 21b in the press-formed product 1.

[0044] The lower second recess forming portion 72b is formed on the upper surface of the lower pad 72 and is a portion that protrudes upward or is recessed downward from the lower side for forming the second upper concave portion 22a or the second lower concave portion 22b in the press-formed product 1.

[0045] The lower through hole 72c is a through hole that penetrates the lower pad 72 in the vertical direction. The die cushion 73 is a cushion for press forming as shown in FIGS. 3 to 8. The die cushion 73 expands and contracts in the vertical direction by pressure. The reaction force of the die cushion 73 is larger than the reaction force of the gas cushion 63.

[0046] The upper surface of the die cushion 73 abuts against the lower surface of the lower pad 72. The lower surface of the die cushion 73 abuts against the upper surface of the bottom surface 71a. The upper surface of the die cushion 73 is located above the lower contact portion 71b.

[0047] As shown in FIG. 2, the lower pad 72 is disposed above the lower die 71. The blank material 10 is disposed above the lower pad 72. The upper pad 62 is disposed above the blank material 10. Press forming is performed by moving the upper die 61 downward from above the upper pad 62 with respect to the members arranged in this way.

[0048] Press forming is not limited to moving only the upper die 61, but at least one of the upper die 61 and the clamping part, which is a set of the upper pad 62, the lower pad 72, and the blank material 10, may be moved in a direction parallel to the vertical direction and in a direction in which the upper die 61 approaches the blank material 10 relatively (in other words, the pressing direction).

[0049] As shown in FIG. 14, the method for manufacturing the press-formed product 1 includes a clamping step S10, a wall portion forming step S20, and a top plate portion forming step S30. The method for manufacturing the press-formed product 1 is executed in the order of the clamping step S10, the wall portion forming step S20, and the top plate portion forming step S30.

[0050] [1-3. Method for manufacturing a press-formed product having a recess recessed upward] The method for manufacturing the press-formed product 1 in a cross section including the first upper recess 21a and the wall portion 3 will be described with reference to FIGS. 3 to 5.

[0051] [1-3-1. Clamping step] As shown in FIG. 3, the clamping step S10 is a step of clamping the blank material 10 by the upper pad 62 located above the blank material 10 and the lower pad 72 located below the blank material 10.

[0052] The upper pad 62 abuts on the upper surface of the blank material 10. The lower pad 72 abuts on the lower surface of the blank material 10. The blank material 10 is clamped from above and below by the upper pad 62 and the lower pad 72. The upper pad 62, the lower pad 72, and the lower die 71 are arranged such that the horizontal positions of the upper first recess forming portion 62a of the upper pad 62, the lower through hole 72c of the lower pad 72, and the lower convex portion 71e of the lower die 71 are all substantially the same.

[0053] At this time, the blank material 10 is deformed along the upper second recess forming portion 62b and the lower second recess forming portion 72b by receiving pressure from the upper pad 62 and the lower pad 72. As a result, a second upper recess 22a and a second lower recess 22b are formed in the blank material 10. However, even after the second upper recess 22a and the second lower recess 22b are formed in the blank material 10, the blank material 10 is slidable in the horizontal direction.

[0054] Hereinafter, a virtual plane located substantially on the same plane as the portion of the blank material 10 in contact with the upper pad 62 and the lower pad 72 is referred to as a reference plane A (see FIGS. 4 and 5). [1-3-2. Wall portion forming step] As shown in FIG. 4, in the wall portion forming step S20, press forming is performed by moving the upper die 61 downward with respect to the blank material 10 sandwiched between the upper pad 62 and the lower pad 72, and the wall portion 3 is formed in the blank material 10.

[0055] The upper bottom plate forming portion 61d of the upper die 61 performs press forming by moving toward the surface of the blank material 10 where the upper pad 62 does not contact with respect to the blank material 10 sandwiched in the sandwiching step S10.

[0056] The portion of the blank material 10 in contact with the upper bottom plate forming portion 61d is deformed to be located below the reference plane A by receiving pressure from the upper bottom plate forming portion 61d. At this time, the blank material 10 bends downward from the end of the portion sandwiched between the upper pad 62 and the lower pad 72. As a result, a ridge line 3a is formed in the blank material 10. Thereafter, the blank material 10 is deformed to contact along the upper wall forming portion 61c. As a result, the wall portion 3 is formed in the blank material 10.

[0057] In the wall forming step S20, the upper die 61 moves downward until the upper contact portion 61b contacts the upper surface of the upper pad 62. At this time, the upper end of the upper wall forming portion 61c does not move below the reference plane A. The blank material 10 and the upper first recess forming portion 62a are separated. The lower convex portion 71e is located below the reference plane A.

[0058] The reaction force of the gas cushion 63 is smaller than the reaction force of the die cushion 73. Therefore, in the wall forming step S20, the gas cushion 63 is compressed downward by the upper die 61 moving between the top surface 61a and the upper pad 62. The die cushion 73 receives downward pressure from the lower pad 72 but does not substantially deform.

[0059] [1-3-3. Top plate forming step] As shown in FIG. 5, the top plate forming step S30 is a step of performing press forming on the blank material 10 having the wall portion 3 formed thereon by further moving the upper die 61 downward, and forming the top plate portion 2 having the first upper recess 21a in the blank material 10.

[0060] In the top plate forming step S30, the upper die 61 further moves downward continuously from the wall forming step S20. At this time, the upper die 61 moves downward in a state of contacting the upper pad 62 at the upper contact portion 61b and contacting the gas cushion 63 at the top surface 61a. Therefore, the upper die 61, the upper pad 62, and the gas cushion 63 move downward integrally. Regarding the following description of the top plate forming step S30, the movement of the upper pad 62 will be described with attention. The downward movement of the upper pad 62 means that the upper die 61 and the gas cushion 63 move downward by the same amount as the upper pad 62.

[0061] The lower convex portion 71e in the lower die 71 is located inside the lower through hole 72c in the lower pad 72. The horizontal positions of the lower convex portion 71e and the upper first recess forming portion 62a in the upper pad 62 are substantially the same.

[0062] The portion of the blank material 10 in contact with the upper pad 62 and the lower pad 72 is pushed downward from the upper pad 62 and moves downward following the upper pad 62 together with the lower pad 72.

[0063] In the blank material 10, the portion at the same position as both the upper first recess forming portion 62a and the lower through hole 72c in the horizontal direction moves downward following the upper pad 62 and abuts against the upper end portion of the lower convex portion 71e. When the upper pad 62 further moves downward, the lower pad 72 moves following the upper pad 62, and the lower pad 72 moves downward relative to the lower convex portion 71e. When the lower pad 72 moves downward relative to the lower convex portion 71e, the lower convex portion 71e penetrates through the lower through hole 72c and abuts against the blank material 10. The portion of the blank material 10 in contact with the lower convex portion 71e receives an upward pressure from the lower convex portion 71e and deforms so as to be recessed above the reference plane A. When the upper pad 62 further moves downward, the portion of the blank material 10 in contact with the lower convex portion 71e abuts against the upper first recess forming portion 62a in the upper pad 62 and then further deforms so as to abut along the outer surface of the upper first recess forming portion 62a. Thereby, the first upper recess 21a is formed in the blank material 10. That is, the top plate portion 2 having the first upper recess 21a is formed in the blank material 10.

[0064] In the top plate portion forming step S30, the upper pad 62 moves downward until the blank material 10 abuts along the outer surface of the upper first recess forming portion 62a. At this time, the upper pad 62 may move downward until the lower pad 72 abuts against the upper surface of the lower contact portion 71b in the top plate portion forming step S30. The upper pad 62 reaches the bottom dead center by the downward movement in the top plate portion forming step S30.

[0065] When the upper pad 62 reaches the bottom dead center, the wall portion 3 formed on the blank material 10 abuts along the upper side wall forming portion 61c and the upper side wall forming portion 71c. In the blank material 10, the portion extending from the end portion on the opposite side of the ridge line 3a in the wall portion 3 abuts along the upper bottom plate forming portion 61d and the lower bottom plate forming portion 71d. Thereby, the bottom plate portion 4 is formed on the blank material 10.

[0066] In the top plate portion forming step S30, since the distance between the top surface 61a contacting the gas cushion 63 and the upper pad 62 is constant, the gas cushion 63 is not substantially deformed. The die cushion 73 is compressed downward by the lower pad 72 and the bottom surface 71a due to the movement of the lower pad 72.

[0067] In the above manner, the portion including the first upper concave portion 21a and the wall portion 3 in the press-formed product 1 is formed. The cross-sectional view of the blank material 10 in FIG. 5 corresponds to the V-V cross-sectional view of the press-formed product 1 in FIG. 1.

[0068] [1-4. Manufacturing method of a press-formed product having a recess recessed downward] Above, with reference to FIGS. 3 to 5, focusing on the V-V cross-section of the press-formed product 1 in FIG. 1, the manufacturing method of the press-formed product 1 has been described. Below, with reference to FIGS. 6 to 8, focusing on the VIII-VIII cross-section of the press-formed product 1 in FIG. 1, the manufacturing method of the press-formed product 1 will be described. That is, the manufacturing method of the press-formed product 1 in the cross-section including the first lower concave portion 21b and the wall portion 3 in the press-formed product 1 will be described.

[0069] [1-4-1. Clamping step] In the clamping step S10, as shown in FIG. 6, above the blank material 10, the upper die 61 and the upper pad 62 are arranged, and below the blank material 10, the lower pad 72 and the lower die 71 are arranged. What should be noted in FIG. 6 is the arrangement of the upper convex portion 61e of the upper die 61, the upper through hole 62c of the upper pad 62, and the lower first recess forming portion 72a of the lower pad 72 for forming the first lower recess 21b. The upper die 61, the upper pad 62, and the lower pad 72 are arranged such that the horizontal positions of the upper convex portion 61e, the upper through hole 62c, and the lower first recess forming portion 72a are all substantially the same.

[0070] [1-4-2. Wall forming step] In the wall forming step S20, as shown in FIG. 7, the upper die 61 moves downward so that the upper convex portion 61e contacts the upper surface of the blank material 10 in the process until the upper contact portion 61b contacts the upper surface of the upper pad 62.

[0071] When the upper convex portion 61e contacts the upper surface of the blank material 10, the upper contact portion 61b is separated from the upper pad 62. The upper end of the upper wall forming portion 61c has not yet moved below the reference plane A. The upper convex portion 61e is located inside the upper through hole 62c in the upper pad 62. The blank material 10 and the lower first recess forming portion 72a are separated. The lower pad 72 is in contact with the upper surface of the lower contact portion 71b.

[0072] The blank material 10 does not deform until it contacts along the upper wall forming portion 61c and is separated from the upper wall forming portion 61c. However, the blank material 10 is in contact with the lower end of the upper wall forming portion 61c (in other words, the portion where the upper wall forming portion 61c and the upper bottom plate forming portion 61d are connected). That is, the blank material 10 is in a state where the wall portion 3 is being formed on the blank material 10.

[0073] [1-4-3. Top plate forming step] As shown in FIG. 8, in the top plate portion forming step S30, the upper die 61 further moves downward with respect to the blank material 10 in a state where the wall portion 3 is being formed, and the press forming proceeds, and the top plate portion 2 having the first downward concave portion 21b is formed in the blank material 10.

[0074] In this step, the upper die 61 further moves downward continuously from the wall portion forming step S20. The upper convex portion 61e is located inside the upper through hole 62c in the upper pad 62.

[0075] In this step, since the lower pad 72 is in contact with the upper surface of the lower contact portion 71b, the downward movement is restricted. The portion of the blank material 10 in contact with the upper convex portion 61e receives a downward pressure from the upper convex portion 61e and deforms so as to be recessed below the reference plane A. When the upper die 61 further moves downward, the portion of the blank material 10 in contact with the upper convex portion 61e comes into contact with the lower first recess forming portion 72a in the lower pad 72 and further deforms so as to be in contact along the lower first recess forming portion 72a. As a result, the first downward concave portion 21b is formed in the blank material 10. That is, the top plate portion 2 having the first downward concave portion 21b is formed in the blank material 10.

[0076] The upper die 61 moves downward in this step until the blank material 10 comes into contact along the lower first recess forming portion 72a. At this time, the upper die 61 may move downward until the upper contact portion 61b comes into contact with the upper pad 62. The upper die 61 may move downward until the upper end portion of the upper wall forming portion 61c comes into contact with the blank material 10. The upper die 61 reaches the bottom dead center by the downward movement in this step.

[0077] When the upper die 61 reaches the bottom dead center, the portion of the blank material 10 located between the upper side wall forming portion 61c and the upper side wall forming portion 71c abuts along the upper side wall forming portion 61c and the upper side wall forming portion 71c. Thereby, the wall portion 3 is formed on the blank material 10. In the blank material 10, the portion spreading from the end portion on the side opposite to the ridge line 3a of the wall portion 3 abuts along the upper bottom plate forming portion 61d and the lower bottom plate forming portion 71d. Thereby, the bottom plate portion 4 is formed on the blank material 10.

[0078] In this step, the gas cushion 63 is compressed downward by the upper surface 61a and the upper pad 62 due to the movement of the upper die 61. Since the distance between the bottom surface 71a in contact with the die cushion 73 and the lower pad 72 is constant, the die cushion 73 does not substantially deform.

[0079] In the above manner, the portion including the first lower concave portion 21b and the wall portion 3 in the press-formed product 1 is formed. The cross-sectional view of the blank material 10 in FIG. 8 corresponds to the VIII-VIII cross-sectional view of the press-formed product 1 in FIG. 1.

[0080] [1-5. Action, Effect] According to the embodiment described in detail above, the following actions and effects can be obtained. (1a) In the wall portion forming step S20 shown in FIGS. 4 and 7, the press forming apparatus 5 performs press forming by moving the upper die 61 downward to form the wall portion 3 on the blank material 10. Thereafter, in the top plate portion forming step S30 shown in FIGS. 5 and 8, the press forming apparatus 5 performs press forming by further moving the upper die 61 downward to form the first upper concave portion 21a and the first lower concave portion 21b on the blank material 10. In the top plate portion forming step S30, the upper die 61 further moves downward continuously from the wall portion forming step S20.

[0081] According to such a configuration, the upper die 61 moves downward only once in total through the wall portion forming step S20 and the top plate portion forming step S30. Therefore, by one press forming, the wall portion 3, the first upper concave portion 21a, and the first lower concave portion 21b can be formed in the blank material 10. Accordingly, the man-hours of the press forming can be reduced.

[0082] (1b) The depths of both the second upper concave portion 22a and the second lower concave portion 22b are smaller than any of the depths of the first upper concave portion 21a and the first lower concave portion 21b. The second upper concave portion 22a and the second lower concave portion 22b are formed in the blank material 10 by receiving pressure from the upper pad 62 and the lower pad 72 in the clamping step S10.

[0083] According to such a configuration, the relatively shallow second upper concave portion 22a and the second lower concave portion 22b can be formed when the blank material 10 is clamped by the upper pad 62 and the lower pad 72. Therefore, the man-hours of the press forming can be reduced.

[0084] In addition, since the depths of both the second upper concave portion 22a and the second lower concave portion 22b are smaller than the plate thickness of the top plate portion 2, it is possible to suppress the occurrence of pad lifting when the second upper concave portion 22a and the second lower concave portion 22b are clamped by the upper pad 62 and the lower pad 72.

[0085] (1c) The first upper concave portion 21a and the first lower concave portion 21b are not clamped by the upper pad 62 and the lower pad 72. According to such a configuration, the relatively deep first upper concave portion 21a and the first lower concave portion 21b are less likely to be pressurized by the upper pad 62 and the lower pad 72. Therefore, it is possible to suppress the occurrence of wrinkles and cracks in the first upper concave portion 21a and the first lower concave portion 21b.

[0086] (1d) In the wall portion forming step S20, the blank material 10 is clamped by the upper pad 62 and the lower pad 72. According to such a configuration, in the wall forming step S20, when the blank material 10 is bent downward, it is possible to suppress the occurrence of wrinkles in the blank material 10.

[0087] (1e) Even after the second upper concave portion 22a and the second lower concave portion 22b are formed in the blank material 10 in the clamping step S10, the blank material 10 is slidable in the horizontal direction. In the wall forming step S20, neither the first upper concave portion 21a nor the first lower concave portion 21b is formed in the blank material 10.

[0088] According to such a configuration, in the wall forming step S20, when the blank material 10 is bent downward, as the blank material 10 slides, material flows into the bent portion of the blank material 10. Therefore, in the wall forming step S20, it is possible to suppress the occurrence of cracks in the blank material 10.

[0089] [1-6. Corresponding relationships between terms] In the above embodiment, the top plate portion 2 corresponds to an example of the plate-like portion, the upper side corresponds to an example of the first side in the plate thickness direction, and the lower side corresponds to an example of the second side in the plate thickness direction.

[0090] The upper pad 62 corresponds to an example of the first clamping structure, the lower pad 72 corresponds to an example of the second clamping structure, the upper die 61 corresponds to an example of the first die, and the lower die 71 corresponds to an example of the second die. The first upper concave portion 21a and the first lower concave portion 21b correspond to an example of the concave portion and the first concave portion, and the second upper concave portion 22a and the second lower concave portion 22b correspond to an example of the second concave portion.

[0091] In a portion adjacent to the upper through hole 62c in the upper pad 62, two points located on the opposite side of the upper through hole 62c in the radial direction of the upper through hole 62c correspond to an example of the first point and the second point.

[0092] In a portion of the lower pad 72 adjacent to the lower through hole 72c, two points located on the opposite side of the lower through hole 72c in the radial direction of the lower through hole 72c correspond to an example of a first point and a second point.

[0093] The clamping step S10 corresponds to an example of clamping the blank material, the wall portion forming step S20 corresponds to an example of forming a wall portion on the blank material, and the top plate portion forming step S30 corresponds to an example of forming a plate-like portion having a recess in the blank material.

[0094] [2. Other Embodiments] As described above, the embodiments of the present disclosure have been described. Needless to say, the present disclosure is not limited to the above embodiments and can take various forms.

[0095] (2a) In the above embodiment, the first upper recess 21a is formed by abutting along the upper first recess forming portion 62a of the upper pad 62 by press forming. However, the structure in which the first upper recess 21a is formed is not limited to the upper first recess forming portion 62a. For example, as shown in FIG. 9, the press forming apparatus 105 may include an upper die 161 having an upper recess 161f and an upper pad 162 having an upper through hole 162c instead of the upper die 61 and the upper pad 62.

[0096] The upper recess 161f is a portion that protrudes downward from a part below the top surface 61a. The lower end portion of the upper recess 161f has a concave shape upward for forming the first upper recess 21a in the press formed product 1.

[0097] The upper through hole 162c is a through hole that penetrates the upper pad 162 in the vertical direction. In this case, in the top plate portion forming step S30, the upper recess 161f is located inside the upper through hole 162c. Instead of the upper first recess forming portion 62a, the upper recess 161f is disposed. When the upper die 161 moves downward, the portion of the blank material 10 that contacts the lower convex portion 71e receives an upward pressure from the lower convex portion 71e, deforms so as to be recessed above the reference plane A, contacts the upper recess 161f, and further deforms so as to contact along the upper recess 161f. Thereby, a first upper recess 21a is formed in the blank material 10.

[0098] (2b) In the above embodiment, the first lower recess 21b is formed by contacting along the lower first recess forming portion 72a of the lower pad 72 by press forming. However, the structure in which the first lower recess 21b is formed is not limited to the lower first recess forming portion 72a. For example, as shown in FIG. 10, the press forming apparatus 205 may include a lower die 271 having a lower top surface 271a and a lower recess 271f instead of the lower die 71 and the lower pad 72.

[0099] The lower top surface 271a is a surface located on the upper side of the lower die 271 and extends in the horizontal direction. The lower top surface 271a contacts and clamps the lower surface of the blank material 10 in the clamping step S10, the wall portion forming step S20, and the top plate portion forming step S30.

[0100] The lower recess 271f is formed in the lower top surface 271a and is a portion recessed downward. The lower recess 271f has a shape for forming the first lower recess 21b in the press formed product 1.

[0101] In this case, in the top plate portion forming step S30, the portion of the blank material 10 that contacts the upper convex portion 61e contacts the lower recess 271f instead of the lower first recess forming portion 72a, and further deforms so as to contact along the lower recess 271f. Thereby, a first lower recess 21b is formed in the blank material 10.

[0102] In the above embodiment, the lower top surface 271a corresponds to an example of the second clamping structure. (2c) In the above-described embodiment, the first upper concave portion 21a is formed in a portion other than the end portion of the top plate portion 2. However, the position where the first upper concave portion 21a is formed is not limited to this. For example, as shown in FIG. 11, in the press-formed product 101, the first upper concave portion 121a may be formed in a portion of the top plate portion 102 that connects to the wall portion 3. Alternatively, as shown in FIG. 12, in the press-formed product 201, the first upper concave portion 221a may be formed so as to extend from the end portion of the top plate portion 202 that connects to the wall portion 3 to the end portion on the side opposite to the wall portion 3.

[0103] (2d) In the above-described embodiment, the first upper concave portion 21a and the first lower concave portion 21b have an angular shape. However, the shapes of the first upper concave portion 21a and the first lower concave portion 21b do not have to be angular. For example, as shown in FIG. 13, in the press-formed product 301, the first upper concave portion 321a may be formed in the top plate portion 302 so as to gently bulge. The first upper concave portion 321a may be a preliminary shape before forming an angular shape.

[0104] (2e) The manufacturing method of the above-described embodiment is used for manufacturing the exemplary press-formed product 1. However, the manufacturing method of the press-formed product is not limited to being used for manufacturing the press-formed product 1. For example, as shown in FIG. 15, it may be used for manufacturing a press-formed product 401 having the same configuration as the press-formed product 1.

[0105] The press-formed product 401 includes a top plate portion 402, a wall portion 403, and a bottom plate portion 404 as portions corresponding to the top plate portion 2, the wall portion 3, and the bottom plate portion 4 in the press-formed product 1. A ridge line 403a is formed at a portion where the top plate portion 402 and the wall portion 403 are connected as a portion corresponding to the ridge line 3a.

[0106] The top plate portion 402 is curved in the plate thickness direction. When forming the press-formed product 401 in which the top plate portion 402 is curved in the plate thickness direction by the press-forming apparatus 5, the surfaces of both the upper pad 62 and the lower pad 72 that contact the blank material 10 are curved along the direction in which the top plate portion 402 is curved.

[0107] The top plate portion 402 has a first upper concave portion 421a, a first lower concave portion 421b, a second upper concave portion 422a, and a second lower concave portion 422b as portions corresponding to the first upper concave portion 21a, the first lower concave portion 21b, the second upper concave portion 22a, and the second lower concave portion 22b.

[0108] The positions where the first upper concave portion 421a, the first lower concave portion 421b, the second upper concave portion 422a, and the second lower concave portion 422b are provided are not particularly limited as long as they are on the top plate portion 402. The press-formed product 401 is used, for example, as a member constituting a vehicle body. The press-formed product 401 may be used as a member constituting parts other than the body in a vehicle, or may be used as a member not mounted on a vehicle.

[0109] (2f) In the above embodiment, the wall portion 3 has a shape corresponding to an extension flange. However, the shape of the wall portion 3 is not limited to an extension flange, and may be, for example, a bent flange or a shrink flange.

[0110] (2g) A plurality of functions of one component in the above embodiment may be realized by a plurality of components, or one function of one component may be realized by a plurality of components. Also, a plurality of functions of a plurality of components may be realized by one component, or one function realized by a plurality of components may be realized by one component. Also, a part of the configuration of the above embodiment may be omitted. Also, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of another above embodiment.

[0111] [Technical idea disclosed in this specification] [Item 1] A method for manufacturing a press-formed product including a plate-shaped portion having a concave portion recessed in the plate thickness direction and a wall portion extending from an end of the plate-shaped portion in a direction intersecting the plate-shaped portion, A first clamping structure located on the first side in the plate thickness direction with respect to the plate-shaped blank material, and a second clamping structure located on the second side in the plate thickness direction opposite to the first side with respect to the blank material, clamp the blank material. Performing press forming on the blank material clamped by the first clamping structure and the second clamping structure, with a first mold located on the first side of the blank material and at least one of the clamping part, which is a set of the first clamping structure, the second clamping structure, and the blank material, moved in a direction parallel to the plate thickness direction and in the press direction in which the first mold approaches the blank material, and forming the wall portion on the blank material by the press forming. Performing press forming on the blank material with the wall portion formed, by further moving at least one of the first mold and a second mold located on the second side of the blank material closer to the first mold in the press direction, and forming the plate-shaped portion having the recess on the blank material by the press forming. Including A method for manufacturing a press-formed product.

[0112] [Item 2] The method for manufacturing a press-formed product according to Item 1, Forming the wall portion includes forming the wall portion on the blank material by moving the first mold in the press direction. Forming the plate-shaped portion includes forming the plate-shaped portion having the recess on the blank material by further moving the first mold in the press direction so that the recess is formed in the blank material due to the approach of the first mold and the second mold. A method for manufacturing a press-formed product.

[0113] [Item 3] The method for manufacturing a press-formed product according to Item 1 or Item 2, The plate-shaped portion has a first recess as the recess and a second recess that is shallower than the first recess and recessed in the plate thickness direction. Clamping the blank material includes forming the second recess in the blank material by clamping the blank material with the first clamping structure and the second clamping structure. Method for manufacturing a press-formed product.

[0114] [Item 4] A method for manufacturing a press-formed product according to any one of Items 1 to 3, wherein clamping the blank material includes clamping the blank material at at least two points separated in a direction orthogonal to the plate thickness direction by the first clamping structure and the second clamping structure. The at least two points include a first point and a second point. Forming the plate-like portion includes forming the recess in the blank material by moving at least one of the first mold and the second mold so as to pass between the first point and the second point. Method for manufacturing a press-formed product.

[0115] [Item 5] A method for manufacturing a press-formed product according to any one of Items 1 to 4, wherein the blank material is made of a high-tensile material. Method for manufacturing a press-formed product.

Explanation of Reference Numerals

[0116] 1,101,201,301,401... press-formed products, 2,102,202,302,402... top plate portions, 3,403... wall portions, 5,105,205... press-forming apparatuses, 10... blank materials, 21a,121a,221a,321a,421a... first upper recesses, 21b,421b... first lower recesses, 61,161... upper molds, 62,162... upper pads, 71,271... lower molds, 72... lower pads, S10... clamping step, S20... wall portion forming step, S30... top plate portion forming step.

Claims

1. A method for manufacturing a press-formed product, comprising a plate-shaped portion having a recess recessed in the plate thickness direction, and a wall portion extending from an end of the plate-shaped portion in a direction intersecting the plate-shaped portion, clamping the blank material with a first clamping structure located on a first side in the plate thickness direction with respect to the plate-shaped blank material and a second clamping structure located on a second side in the plate thickness direction opposite to the first side with respect to the blank material, performing press forming on the blank material clamped by the first clamping structure and the second clamping structure, by moving at least one of a first mold located on the first side of the blank material and a clamping portion, which is a set of the first clamping structure, the second clamping structure, and the blank material, in a direction parallel to the plate thickness direction and in a pressing direction in which the first mold approaches the blank material relatively, and forming the wall portion on the blank material by the press forming, performing press forming on the blank material having the wall portion formed thereon, by further moving at least one of the first mold and a second mold located on the second side of the blank material in the pressing direction so that the first mold and the second mold approach each other, and forming the plate-shaped portion having the recess on the blank material by the press forming, including a method for manufacturing a press-formed product.

2. The method for manufacturing a press-formed product according to claim 1, wherein forming the wall portion includes forming the wall portion on the blank material by moving the first mold in the pressing direction, and forming the plate-shaped portion includes forming the plate-shaped portion having the recess on the blank material by further moving the first mold in the pressing direction so that the recess is formed in the blank material by the approach of the first mold and the second mold. a method for manufacturing a press-formed product.

3. The method for manufacturing a press-formed product according to claim 1, wherein the plate-shaped portion has a first recess as the recess and a second recess that is shallower than the first recess and recessed in the plate thickness direction, and clamping the blank material includes forming the second recess in the blank material by clamping the blank material with the first clamping structure and the second clamping structure. a method for manufacturing a press-formed product.

4. The method for manufacturing a press-formed product according to claim 1, Clamping the blank material includes clamping the blank material at at least two points separated in a direction orthogonal to the plate thickness direction by the first clamping structure and the second clamping structure. The at least two points include a first point and a second point. Forming the plate-like portion includes forming the concave portion in the blank material by moving at least one of the first mold and the second mold so as to pass between the first point and the second point. A method for manufacturing a press-formed product.

5. A method for manufacturing a press-formed product according to claim 1, wherein the blank material is made of a high-tensile material. A method for manufacturing a press-formed product.

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