Manufacturing process of a press-molded product

Abstract

To produce a press-formed product (1) comprising a plate-shaped portion (2) and a wall portion (3), a blank (10) having a plate shape is clamped by means of and between a first clamping structure (62) located on a first side in a thickness direction of the blank with respect to the blank and a second clamping structure (72) located on a second side opposite the first side in the thickness direction with respect to the blank (S10). The wall portion is formed on the blank by press-forming, which is performed by moving a first die (61) in a pressing direction parallel to the thickness direction and allowing the first die to come relatively closer to the blank (S20). The plate-shaped portion having a depressed part (21a, 21b) is formed on the blank by press-forming, which is performed by further moving the first die in the pressing direction (S30).

Description

STATE OF THE ART

[0001] The present disclosure relates to a manufacturing method of a press-molded product.

[0002] A method for forming an expansion flange on a plate-shaped blank by press forming is known. For example, the expansion flange is obtained by bending the blank, and a burr line corresponding to a part where the blank is bent has an arc shape that is recessed toward a non-bent part of the blank.

[0003] Japanese Unexamined Patent Application Publication No. 2017-042826 discloses a method of forming the expansion flange on the blank by press forming to prevent the occurrence of wrinkling on the blank by clamping and fixing the blank by means of and between a punch and a pad. SUMMARY

[0004] A case of forming a press-molded product including, in addition to the expansion flange, a recessed part recessed in a plate thickness direction in a plate-shaped portion that is a portion opposite to the expansion flange with respect to the ridge line will be discussed.

[0005] In the conventional method, such as that disclosed in Japanese Unexamined Patent Application Publication No. 2017-042826, in a case where the expansion flange and the recessed portion are simultaneously formed by press forming, the punch or pad must be provided with a protruding portion protruding in the plate thickness direction to form the recessed portion using the punch and pad clamping the blank therebetween. When the blank is thus clamped by and between the punch and the pad, the protruding portion causes a gap between the blank and the punch or between the blank and the pad, which is sized greater than or equal to the thickness of the blank.

[0006] When the expansion flange is formed by press forming with the gap created between the blank and the punch or between the blank and the pad, the blank is prone to wrinkling, especially when the blank is made of a material with lower ductility, such as a high-strength steel sheet.

[0007] Accordingly, if the press-formed product with the expansion flange and the recessed part is to be obtained, the forming of the recessed part must be performed in the step after the expansion flange forming to prevent the occurrence of wrinkling during the expansion flange forming process. Furthermore, another press mold for forming the recessed part must be prepared separately from a press mold for the expansion flange.

[0008] In one aspect of the present disclosure, it is desirable to reduce the number of compression molding steps.

[0009] One aspect of the present disclosure is a manufacturing method of a press-formed product comprising: a plate-shaped portion having a depressed part recessed in a first thickness direction of the plate-shaped portion; and a wall portion extending from an edge of the plate-shaped portion in a direction intersecting with the plate-shaped portion. The manufacturing method of the press-formed product includes: clamping a blank; forming the wall portion on the blank; and forming the plate-shaped portion having the depressed part on the blank.

[0010] Clamping the blank comprises clamping the blank by means of and between a first clamping structure and a second clamping structure. The first clamping structure is located on a first side in a second thickness direction, which is a thickness direction of the blank having a plate shape. The second clamping structure is located on a second side opposite the first side in the second thickness direction with respect to the blank.

[0011] Forming the wall portion on the blank comprises forming the wall portion on the blank by performing press forming on the blank clamped by and between the first clamping structure and the second clamping structure, and the press forming is performed by moving at least one of a first die and a clamping / clamped body in a pressing direction. The first die is located on the first side with respect to the blank. The clamping / clamped body is a collection comprising the first clamping structure, the second clamping structure, the blank, and a second die. The second die is located on the second side with respect to the blank. The pressing direction is a direction parallel to the second thickness direction and allows the first die to get relatively closer to the blank.

[0012] The forming of the plate-shaped portion having the depressed part on the blank includes forming the plate-shaped portion having the depressed part on the blank by performing press forming on the blank on which the wall portion is being formed, and the press forming is performed by further moving at least one of the first die and the clamping / clamped body in the pressing direction so that the first die and the second die are allowed to come closer to each other.

[0013] With such a configuration, it is possible to form the wall portion and the recessed part on the blank by moving the blank in the same pressing direction in a state where the first die and the second die are respectively arranged in advance on the first side and the second side with respect to the blank. This enables a reduction in the number of press-forming steps.

[0014] In one aspect of the present disclosure, forming the wall portion on the blank may include forming the wall portion by moving the first die in the pressing direction. Forming the plate-shaped portion with the recessed part on the blank may include forming the plate-shaped portion by further moving the first die in the pressing direction so that the recessed part is formed on the blank by bringing the first die and the second die closer to each other.

[0015] With such a configuration, it is possible to form the wall portion and the recessed portion on the blank through a single movement of the first die in the pressing direction. This enables a reduction in the number of press-forming steps.

[0016] In one aspect of the present disclosure, the plate-shaped portion may include a first depressed portion and a second depressed portion. The first depressed portion is shaped as the depressed portion. The second depressed portion is depressed more shallowly in the first thickness direction than the first depressed portion. Clamping the blank may include clamping the blank by and between the first clamping structure and the second clamping structure to thereby form the second depressed portion on the blank.

[0017] With such a configuration, it is possible to form the second recessed portion with a shallower recess than the first recessed portion when the blank is clamped by and between the first clamping structure and the second clamping structure. This enables a reduction in the number of press-forming steps.

[0018] In one aspect of the present disclosure, clamping the blank may comprise clamping the blank by means of and between the first clamping structure and the second clamping structure at at least two points spaced apart in a direction perpendicular to the second thickness direction. The at least two points may comprise a first point and a second point. Forming the plate-shaped portion may comprise forming the depressed part on the blank by moving at least one of the first die and the second die such that a part of at least one of the first die and the second die passes between the first point and the second point.

[0019] With such a configuration, it is possible to form the recessed part between the two points on the blank clamped between the first clamping structure and the second clamping structure.

[0020] In one aspect of the present disclosure, the blank may be formed from a high strength steel sheet.

[0021] With such a configuration, it is possible to prevent the occurrence of cracks and wrinkles in the press-formed product when the press-formed product is manufactured from the blank formed from a high-strength steel sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Exemplary embodiments of the present disclosure will now be described with reference to the accompanying drawings, in which: Fig. Figure 1 is a perspective view of a press-molded product; Fig. Figure 2 is a schematic perspective view of an upper cushion, a blank, a lower cushion and a lower die; Fig. 3 is a sectional view of the blank and the structures therearound along a pressing direction in a clamping step; Fig. 4 is a sectional view of the blank and the structures therearound along the pressing direction in a wall section forming step; Fig. 5 is a sectional view of the blank and the structures therearound along the pressing direction in a head plate portion forming step; Fig. 6 is an additional sectional view of a section of the blank and the structures around it along the pressing direction in the clamping step; Fig. Fig. 7 is an additional sectional view of a section of the blank and the structures around it along the pressing direction in the clamping step; Fig. 8 is an additional sectional view of a section of the blank and the structures therearound along the pressing direction in the head plate portion forming step; Fig. 9 is a sectional view of the blank and the structures therearound along the pressing direction in a wall portion forming step in another embodiment; Fig. 10 is a sectional view of the blank and the structures therearound along the pressing direction in a wall portion forming step in yet another embodiment; Fig. 11 is a schematic perspective view of a press-molded product in which a depressed part is located along an edge of a plate-shaped portion in still another embodiment; Fig. 12 is a schematic perspective view of a press-molded product in which a depressed part extends from a first end to a second end of a plate-shaped portion in still another embodiment; Fig. 13 is a schematic perspective view of a press-molded product in which a recessed part has a gently raised shape in still another embodiment; Fig. 14 is a flowchart showing a manufacturing process of the press-molded products; Fig. 15A is a perspective view of another press-molded product; Fig. 15B is a plan view of the press-molded product in Fig. 15A; and Fig. 15C is a side view of the molded product in Fig. 15A is. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0023] Embodiments of the present disclosure are not limited to the embodiments to be described below and may take various forms as long as they fall within the technical scope of the present disclosure. [1. First embodiment]

[0024] One in Fig. 1 is an exemplary press-molded product for describing a manufacturing method of a press-molded product according to a first embodiment. The manufacturing method in the present embodiment can be used not only for manufacturing the Fig. 1, but also for manufacturing press-molded products of various shapes. The manufacturing method in the present embodiment can be used to manufacture a press-molded product of any shape, including, for example, a plate-shaped portion having a depressed part recessed in a thickness direction of the plate-shaped portion; and a wall portion extending from an edge of the plate-shaped portion in a direction intersecting with the plate-shaped portion. [1-1. Structure of the press-molded product]

[0025] The Fig. The press-formed product 1 shown in FIG. 1 is formed by press-forming a metallic material. The press-formed product 1 is formed from a high-strength steel sheet. For example, the press-formed product 1 can be formed from a high-strength steel sheet with a tensile strength of 980 MPa or more or from a high-strength steel sheet with a tensile strength of 1180 MPa or more. The press-formed product 1 has a top plate portion 2, a wall portion 3 and a bottom plate portion 4.

[0026] Most of the head plate portion 2, except for some parts, extends in the same plane. The head plate portion 2 has a plate shape. The head plate portion 2 may be curved in a thickness direction thereof, or it may not be curved in the thickness direction. Hereinafter, the thickness direction of the head plate portion 2 is referred to as an up-down direction. The thickness direction may be read as a right-left direction or a front-to-back direction, without being limited to the up-down direction. "Up" and "down" may be read interchangeably in the up-down direction.

[0027] The head plate portion 2 has a first upwardly recessed part 21a, a first downwardly recessed part 21b, a second upwardly recessed part 22a and a second downwardly recessed part 22b.

[0028] The first upwardly recessed part 21a is recessed upwardly in the head plate portion 2. The first downwardly recessed part 21b is recessed downwardly in the head plate portion 2. The depth of the first upwardly recessed part 21a and the depth of the first downwardly recessed part 21b are both greater than the thickness of the head plate portion 2. That is, in a region corresponding to the first upwardly recessed part 21a, an upper front surface of the head plate portion 2 is located above an upper front surface of the head plate portion 2 in a region around the first upwardly recessed part 21a. In a region corresponding to the first downwardly recessed part 21b, a lower front surface of the head plate portion 2 is located below a lower front surface of the head plate portion 2 in a region around the first downwardly recessed part 21b.

[0029] The second upwardly recessed part 22a is recessed upwardly in the head plate portion 2. The first downwardly recessed part 22b is recessed downwardly in the head plate portion 2. The depth of the second upwardly recessed part 22a and the depth of the second downwardly recessed part 22b are both smaller than the thickness of the head plate portion 2. That is, the depth of the second upwardly recessed part 22a and the depth of the second downwardly recessed part 22b are both smaller than the depth of the first upwardly recessed part 21a and the depth of the first downwardly recessed part 21b.

[0030] The positions where the first upwardly depressed part 21a, the first downwardly depressed part 21b, the second upwardly depressed part 22a and the second downwardly depressed part 22b are provided are not limited, particularly as long as they are located on the head plate portion 2.

[0031] The wall portion 3 extends from an edge of the head plate portion 2 in a direction intersecting the head plate portion 2. The wall portion 3 has a plate shape. In the present embodiment, the wall portion 3 extends from the edge of the head plate portion 2 in a downward direction.

[0032] A part where the top plate portion 2 and the wall portion 3 meet forms a ridge line 3a. The ridge line 3a has an arcuate shape depressed in a direction parallel to the upper front 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 expansion flange formed along the edge of the head plate portion 2.

[0033] The bottom plate portion 4 extends from an edge of the wall portion 3 opposite the position where the ridge line 3a intersects the wall portion 3 in a direction. The bottom plate portion 4 has a plate shape. The bottom plate portion 4 extends in a direction opposite to that in which the top plate portion 2 extends with respect to the wall portion 3. In the present embodiment, the bottom plate portion 4 extends substantially parallel to the top plate portion 2, but is not limited thereto. [1-1. Design of the press molding device]

[0034] The press-formed product 1 is produced by performing press forming on a blank 10 with a press forming device 5 (see Fig. 2 to 8). The blank 10 is a plate-shaped material. In the present embodiment, the blank 10 is, as an example, a high-strength steel sheet made of metal.

[0035] As in the Fig. 2 to 8, the press molding device 5 comprises an upper press mold 61, an upper cushion 62, a gas cushion 63, a lower press mold 71, a lower cushion 72 and a press mold cushion 73.

[0036] The upper die 61 is a die for press molding. The upper die 61 includes a head front surface 61a, an upper contact portion 61b, an upper wall forming portion 61c, an upper bottom plate forming portion 61d, and an upper protruding portion 61e.

[0037] The head front surface 61a is located on the lower side of a part of the upper die 61. The head front surface 61a extends in a direction perpendicular to the up-down direction (hereinafter referred to as the horizontal direction).

[0038] The upper contact part 61b projects downward from a part of the head front surface 61a.

[0039] The upper wall forming part 61c is a front surface extending downward from a position lower than the upper contact part 61b and extending away from the upper contact part 61b in the horizontal direction. The upper wall forming part 61c is curved to be convex toward the side where the upper contact part 61b is located in the horizontal direction. An angle formed between an imaginary plane extended from the upper wall forming part 61c and the head front surface 61a is substantially the same as an angle formed between the head plate portion 2 and the wall portion 3 in the press-formed product 1.

[0040] The upper bottom plate forming part 61d is a front surface extending in the horizontal direction from a lower edge of the upper wall forming part 61c so as to be away from the upper wall forming part 61c. The upper bottom plate forming part 61d is substantially parallel to the horizontal direction.

[0041] As in the Fig. 6 to 8, the upper contact portion 61b protrudes downward from a portion of the head front surface 61a. A lower end portion of the upper protruding portion 61e has a downwardly projecting shape for forming the first downwardly recessed portion 21b of the press-molded product 1.

[0042] The upper cushion 62 is a cushion for press molding. In the present embodiment, a portion of the upper cushion 62 along the up-down direction has a substantially rectangular shape. As shown in Fig. 2, the upper cushion 62 has an upper first recess forming part 62a, an upper second recess forming part 62b, and an upper through hole 62c.

[0043] As in the Fig. 2 and Fig. 3, the upper first recess forming part 62a is formed in a lower front surface of the upper cushion 62. The upper first recess forming part 62a is recessed upward. The upper first recess forming part 62a has a shape for forming the first upwardly recessed part 21a of the press-molded product 1.

[0044] As in Fig. 2, the upper first recess forming part 62a is formed in the lower front surface of the upper cushion 62. The upper second recess forming part 62b is recessed upward or protrudes downward to form the second upward recessed part 22a or the second downward recessed part 22b of the press-molded product 1, respectively.

[0045] As in the Fig. 2 and Fig. 6, the upper through-hole 62c penetrates the upper pad 62 in the up-down direction.

[0046] The Fig. The gas cushion 63 shown in Figures 3 to 8 utilizes a reaction force of compressed gas. According to pressure changes, the gas cushion 63 contracts or expands in the up-down direction.

[0047] An upper front surface of the gas cushion 63 is in contact with the head front surface 61a. A lower front surface of the gas cushion 63 is in contact with an upper front surface of the upper cushion 62. The lower front surface of the gas cushion 63 is located below the upper contact part 61b.

[0048] The lower die 71 is a die for compression molding. As shown in the Fig. 2 and Fig. 3, the lower die 71 has a bottom front surface 71a, a lower contact part 71b, a lower wall forming part 71c, a lower bottom plate forming part 71d, and a lower projecting part 71e.

[0049] The bottom front surface 71a is located on the upper side of a part of the lower die 71. The bottom front surface 71a extends in the horizontal direction.

[0050] The lower contact part 71b projects upwards from a part of the bottom front surface 71a.

[0051] The lower wall forming part 71c is a front surface that extends downward from a position higher than the lower contact part 71b and is horizontally distant from the lower contact part 71b. The lower wall forming part 71c is curved to be convex toward the side where the lower contact part 71b is located horizontally. In the press forming device 5, the upper wall forming part 61c and the lower wall forming part 71c are substantially parallel to each other.

[0052] The lower bottom plate forming part 71d extends from a lower edge of the lower wall forming part 61c in a horizontal direction away from the lower wall forming part 71c. The lower bottom plate forming part 71d has a plate shape.

[0053] The lower protruding portion 71e protrudes upward from a portion of the bottom front surface 71a. An upper end portion of the lower protruding portion 71e has an upwardly protruding shape for forming the first upwardly depressed portion 21a of the press-molded product 1.

[0054] The lower cushion 72 is a cushion for press molding. In the present embodiment, a portion of the lower cushion 72 along the up-down direction has a substantially rectangular shape. As shown in Fig. 2, the lower cushion 72 has a lower first recess forming part 72a, a lower second recess forming part 72b, and a lower through hole 72c.

[0055] As in the Fig. 2 and Fig. As shown in Fig. 6, the lower first recess forming part 72a is formed in an upper front surface of the lower cushion 72. The lower first recess forming part 72a is recessed downward. The lower first recess forming part 72a has a shape for forming the first downward recessed part 21b of the press-molded product 1.

[0056] As in Fig. 2, the lower second recess forming part 72a is formed in the upper front surface of the lower cushion 72. The lower second recess forming part 72b projects upward or is recessed downward, so as to form the second upward recessed part 22a or the second downward recessed part 22b of the press-molded product 1, respectively.

[0057] As in the Fig. 2 and Fig. 3, the lower through-hole 72c penetrates the lower pad 72 in the up-down direction.

[0058] As in the Fig. As shown in Figures 3 to 8, the die cushion 73 is a cushion for press molding. According to pressure changes, the die cushion 73 contracts or expands in the up-down direction. A reaction force of the die cushion 73 is greater than that of the gas cushion 63.

[0059] An upper front surface of the mold pad 73 contacts a lower front surface of the lower cushion 72. A lower front surface of the mold pad 73 contacts the bottom front surface 71a. The upper front surface of the mold pad 73 is located above the lower contact part 71b.

[0060] As in the Fig. 2 and Fig. As shown in Figure 3, the lower cushion 72 is disposed above the lower die 71. The blank 10 is disposed above the lower cushion 72. The upper cushion 62 is disposed above the blank 10. The upper die 61 is moved downward toward such an arrangement from above the upper cushion 62 to perform compression molding.

[0061] Such press forming is not performed only by moving the upper die 61. Such press forming may be performed by moving at least the upper die 61 and / or a clamping / clamped body in a pressing direction parallel to the up-down direction, which allows the upper die 61 to relatively approach the blank 10. The clamping / clamped body refers to a collection including the upper pad 62, the lower pad 72, the lower die 71, and the blank 10.

[0062] As in Fig. 14, the manufacturing method of the press-molded product 1 includes a chucking step S10, a wall portion forming step S20, and a top plate portion forming step S30, which are performed in this order. [1-3. Manufacturing method of a press-molded product with a recessed upward part]

[0063] The manufacturing process of the press-molded product 1 comprising, as viewed in section, the first upwardly recessed part 21a and the wall portion 3 will be described with reference to Fig. 3 to 5. [1-3-1. Clamping step]

[0064] The clamping step S10 is a step for clamping the blank 10 by means of and between the upper cushion 62 located above the blank 10 and the lower cushion 72 located below the blank 10, as shown in Fig. 3 is shown.

[0065] The upper pad 62 is in contact with an upper front surface of the blank 10. The lower pad 72 is in contact with a lower front surface of the blank 10. The blank 10 is clamped by and between the upper pad 62 and the lower pad 72 from the top and bottom, respectively. The upper pad 62, the lower pad 72, and the lower die 71 are arranged such that the positions of the upper first recessed forming part 62a of the upper pad 62, the lower through hole 72c in the lower pad 72, and the lower protruding part 71e of the lower die 71 in the horizontal direction are substantially equal to each other.

[0066] In this state, the blank 10 receives pressure from the upper pad 62 and the lower pad 72, thereby being deformed along the upper second recess forming part 62b and the lower second recess forming part 72b, which are in Fig. 2. This results in the formation of the second upwardly depressed part 22a and the second downwardly depressed part 22b on the blank 10. However, the blank 10 is displaceable in the horizontal direction even after the second upwardly depressed part 22a and the second downwardly depressed part 22b are formed on the blank 10.

[0067] Hereinafter, an imaginary plane positioned substantially on the same plane as a part of the blank 10 in contact with the upper cushion 62 and the lower cushion 72 is referred to as a reference plane A (see Fig. 4 and Fig. 5). [1-3-2. Wall section forming step]

[0068] The wall portion forming step S20 is a step of performing press forming on the blank 10 clamped by and between the upper cushion 62 and the lower cushion 72 by moving the upper die 61 downward, thereby forming the wall portion 3 on the blank 10 as shown in Fig. 4 is shown.

[0069] The upper bottom plate forming part 61d of the upper die 61 performs press forming on the blank 10 clamped in the clamping step S10 by moving it toward a part of the upper front surface of the blank 10 not in contact with the upper cushion 62.

[0070] A portion of the blank 10 in contact with the upper bottom plate forming part 61d receives pressure from the upper bottom plate forming part 61d, thereby deforming it to lie below the reference plane A. At this time, the blank 10 is bent downward at an edge of the part clamped by and between the upper cushion 62 and the lower cushion 72. This results in the formation of the ridge line 3a on the blank 10. Subsequently, the blank 10 is deformed to come into close contact with the upper wall forming part 61c. This results in the formation of the wall portion 3 on the blank 10.

[0071] In the wall portion forming step S20, the upper die 61 is moved downward until the upper contact part 61b comes into contact with the upper front surface of the upper pad 62. At this time, an upper edge of the upper wall forming part 61c is moved so that it is not located below the reference plane A. The blank 10 and the upper first recess forming part 62a are spaced apart from each other. The lower protruding part 71e is located below the reference plane A.

[0072] The reaction force of the gas cushion 63 is smaller than that of the die cushion 73. Thus, in the wall portion forming step S20, the gas cushion 63 is compressed downward by the head surface 61a and the upper cushion 62 due to the movement of the upper die 61. Although the die cushion 73 receives downward pressure from the lower cushion 72, the die cushion 73 is substantially not deformed. [1-3-3. Head plate section forming step]

[0073] The head plate portion forming step S30 is a step of performing press forming on the blank 10 on which the wall portion 3 is being formed by further moving the upper die 61 downward, thereby forming the head plate portion 2 having the first upwardly depressed part 21a on the blank 10 as shown in Fig. 5 is shown.

[0074] In the head plate portion forming step S30, the upper die 61 is continuously moved downward after the wall portion forming step S20. At this time, the upper die 61 is moved downward while contacting the upper pad 62 at the upper contact part 61b and the gas cushion 63 at the head front surface 61a. Thus, the upper die 61, the upper pad 62, and the gas cushion 63 are integrally moved downward. The following description of the head plate portion forming step S30 focuses on the movement of the upper pad 62. The upper pad 62 moved downward means that the upper die 61 and the gas cushion 63 are moved downward by the same distance as the upper pad 62.

[0075] The upper end part of the lower projecting part 71e of the lower die 71 is located within the lower through hole 72c in the lower cushion 72. The positions of the lower projecting part 71e and the upper first recess forming part 62a of the upper cushion 62 are substantially equal to each other in the horizontal direction.

[0076] By pushing the part of the blank 10 in contact with the upper cushion 62 and the lower cushion 72 downwards by the upper cushion 62, it is moved downwards following the upper cushion 62 together with the lower cushion 72.

[0077] A portion of the blank 10 located horizontally in the same position as the upper first recess forming portion 62a and the lower through-hole 72c is moved downward and comes into contact with the upper end portion of the lower protruding portion 71e. Further downward movement of the upper pad 62 causes the lower pad 72 to move downward relative to the lower protruding portion 71e, following the upper pad 62. Such downward movement of the lower pad 72 relative to the lower protruding portion 71e causes the upper end portion of the lower protruding portion 71e to pass through the lower through-hole 72c to come into contact with the blank 10. A part of the blank 10 in contact with the lower projecting part 71e receives an upward pressure from the lower projecting part 71e and is thus deformed to be recessed upward from the reference plane A.Further downward movement of the upper pad 62 causes an upper front surface of the part of the blank 10 in contact with the lower protruding part 71e to come into contact with the upper first recess forming part 62a of the upper pad 62 and then to be further deformed so that it comes into close contact with the upper first recess forming part 62a. This results in the formation of the first upwardly recessed part 21a on the blank 10. In other words, the head plate portion 2 having the first upwardly recessed part 21a is formed on the blank 10.

[0078] In the head plate portion forming step S30, the upper pad 62 is moved downward until the blank 10 comes into close contact with the upper first recess forming part 62a. At this time, in the head plate portion forming step S30, the upper pad 62 can be moved downward until the lower pad 72 comes into contact with an upper front surface of the lower contact part 71b. The upper pad 62 reaches its bottom dead center by its downward movement in the head plate portion forming step S30.

[0079] When the upper cushion 62 reaches the bottom dead center, the wall portion 3 formed on the blank 10 is in close contact with the upper wall forming part 61c and the lower wall forming part 71c. A part of the blank 10 extending from the edge of the wall portion 3 opposite the ridge line 3a comes into close contact with the upper bottom plate forming part 61d and the lower bottom plate forming part 71d. This results in the formation of the bottom plate portion 4 on the blank 10.

[0080] In the head plate portion forming step S30, the distance between the head front surface 61a in contact with the gas cushion 63 and the upper cushion 62 is constant; thus, the gas cushion 63 is substantially not deformed. The die cushion 73 is compressed by the lower cushion 72 and the bottom front surface 71a due to the downward movement of the lower cushion 72.

[0081] In this way, a part comprising the first upwardly recessed part 21a and the wall portion 3 is formed on the press-formed product 1. A sectional view of the blank 10 in Fig. Figure 5 corresponds to a view of a section of the press-molded product 1 along the line VV in Fig. 1. [1-4. Manufacturing method of a press-molded product with a downward recessed part]

[0082] So far, the description of the manufacturing process of the press-molded product 1 has been made with reference to the Fig. 3 to 5, referring to the section of the press-molded product 1 along the line VV in Fig. 1. In the following, a description will be given of the manufacturing process of the press-molded product 1 with reference to the Fig. 6 to 8, wherein reference is made to a section of the press-molded product 1 along the line VIII-VIII in Fig. 1. In other words, a description will be given of the manufacturing method of the press-molded product 1 viewed in section, including the first downwardly recessed part 21b and the wall portion 3 in the press-molded product 1. [1-4-1. Clamping step]

[0083] In which as in Fig. In the clamping step S10 shown in Fig. 6, the upper die 61 and the upper cushion 62 are arranged above the blank 10, and the lower cushion 72 and the lower die 71 are arranged below the blank 10. In Fig. 6, an arrangement of the upper protruding part 61e of the upper die 61, the upper through-hole 62c in the upper pad 62, and the lower first recess forming part 72a of the lower pad 72 for forming the first downwardly recessed part 21b is noted. The upper die 61, the upper pad 62, and the lower pad 72 are arranged such that the positions of the upper protruding part 61e, the upper through-hole 62c, and the lower first recess forming part 72a in the horizontal direction are substantially the same. [1-4-2. Wall section forming step]

[0084] In which as in Fig. 7, until the upper contact part 61b comes into contact with the upper front surface of the upper cushion 62, the upper die 61 is moved downward so that the upper projecting part 61e comes into contact with the upper front surface of the blank 10.

[0085] When the upper protruding portion 61e comes into contact with the upper front surface of the blank 10, the upper contact portion 61b is spaced apart from the upper pad 62. A portion of the upper wall forming portion 61c near its upper edge has not yet been moved below the reference plane A. A lower end portion of the upper protruding portion 61e is located within the upper through hole 62c in the upper pad 62. The blank 10 and the lower first recess forming portion 72a are spaced apart from each other. A portion of the lower pad 72 is in contact with the upper front surface of the lower contact portion 71b.

[0086] A part of the blank 10 that contacts the lower edge of the upper wall forming part 61c (i.e., a part where the upper wall forming part 61c and the upper bottom plate forming part 61d meet) is deformed to be lower than the reference plane A by receiving pressure from the upper wall forming part 61c. In other words, the blank 10 is bent downward at an edge of the part clamped by and between the upper pad 62 and the lower pad 72. At this time, the wall portion 3 is being formed on the blank 10. [1-4-3. Head plate section forming step]

[0087] In which as in Fig. In the top plate portion forming step S30 shown in Figure 8, the press forming proceeds on the blank 10 on which the wall 3 is being formed by further moving the upper die 61 downward. As a result, the top plate portion 2 having the first downwardly depressed part 21b is formed on the blank 10.

[0088] In this step, the upper die 61 is further continuously moved downward after the wall portion forming step S20.

[0089] A part of the upper projecting part 61e is located within the upper through hole 62c in the upper cushion 62.

[0090] In this step, the lower cushion 72 is in contact with the upper front surface of the lower contact part 71b. Thus, the downward movement of the lower cushion 72 is restricted. A part of the blank 10 in contact with the upper protruding part 61e receives downward pressure from the upper protruding part 61e and is thus deformed to be recessed downward from the reference plane A. Further downward movement of the upper die 61 causes a lower front surface of the part of the blank 10 in contact with the upper protruding part 61e to come into contact with the lower first recess forming part 72a of the lower cushion 72 and to be further deformed to come into close contact with the lower first recess forming part 72a. This results in the formation of the first downward recessed part 21b on the blank 10.In other words, the head plate portion 2 is formed with the first downwardly recessed part 21b on the blank 10.

[0091] In this step, the upper die 61 is moved downward until the blank 10 comes into close contact with the lower first recess forming part 72a. At this time, the upper die 61 can be moved downward until the upper contact part 61b comes into contact with the upper pad 62. The upper die 61 can be moved downward until the upper edge of the upper wall forming part 61c comes into contact with the blank 10. The upper die 61 reaches its bottom dead center by its downward movement in this step.

[0092] When the upper die 61 reaches the bottom dead center, a portion of the blank 10 located between the upper wall forming part 61c and the lower wall forming part 71c is in close contact with the upper wall forming part 61c and the lower wall forming part 71c. This results in the formation of the wall portion 3 on the blank 10. The portion of the blank 10 extending from the lower edge of the wall portion 3 comes into close contact with the upper bottom plate forming part 61d and the lower bottom plate forming part 71d. This results in the formation of the bottom plate portion 4 on the blank 10.

[0093] In this step, the gas cushion 63 is compressed downward by the head front surface 61a and the upper cushion 62 due to the movement of the upper die 61. Since the distance between the bottom front surface 71a in contact with the die cushion 73 and the lower cushion 72 is constant, the die cushion 73 is substantially not deformed.

[0094] In this way, a part comprising the first downwardly recessed part 21b and the wall portion 3 is formed in the press-formed product 1. A sectional view of the blank 10 in Fig. Figure 8 corresponds to a view of a section of the press-molded product 1 along the line VIII-VIII in Fig. 1. [1-5. Actions and Effects]

[0095] The above detailed embodiment provides the actions and effects described below.

[0096] (1a) In the Fig. 4 and Fig. In the wall portion forming step S20 shown in Fig. 7, the press forming device 5 performs press forming by moving the upper die 61 downward, thereby forming the wall portion 3 on the blank 10. Subsequently, the press forming device 5 performs the Fig. 5 and Fig. 8, press forming is performed by moving the upper die 61 further downward, thereby forming the first upwardly depressed part 21a and the first downwardly depressed part 21b on the blank 10, respectively. In the head plate portion forming step S30, the upper die 61 is continuously moved downward after the wall portion forming step S20.

[0097] With such a configuration, the upper die 61 is moved downward only once during the wall portion forming step S20 and the top plate portion forming step S30. Thus, it is possible to form the wall portion 3, the first upwardly depressed part 21a, and the first downwardly depressed part 21b on the blank 10 through such a single press forming. This enables a reduction in the number of press forming steps.

[0098] (1b) The depths of the second upwardly recessed part 22a and the second downwardly recessed part 22b are smaller than those of the first upwardly recessed part 21a and the first downwardly recessed part 21b. The second upwardly recessed part 22a and the second downwardly recessed part 22b are formed in the blank 10 by receiving pressure from the upper pad 62 and the lower pad 72 in the chucking step S10.

[0099] With such a configuration, it is possible to form the second upwardly depressed part 22a and the second downwardly depressed part 22b, which are relatively flat, when the blank 10 is clamped by and between the upper pad 62 and the lower pad 72. This enables a reduction in the number of press-forming steps.

[0100] In addition, the depths of the second upwardly recessed part 22a and the second downwardly recessed part 22b are smaller than the thickness of the head plate section 2. Therefore, when the second upwardly recessed part 22a and the second downwardly recessed part 22b are clamped by and between the upper cushion 62 and the lower cushion 72, it is possible to prevent the generation of a gap sized greater than or equal to the thickness of the blank 10 between the blank 10 and the upper cushion 62 and between the blank 10 and the lower cushion 72.

[0101] (1c) The first upwardly recessed part 21a and the first downwardly recessed part 21b are not clamped by and between the upper cushion 62 and the lower cushion 72.

[0102] With such a configuration, the first upwardly recessed part 21a and the first downwardly recessed part 21b, which are relatively deep, are less sensitive to pressure from the upper cushion 62 and the lower cushion 72. This makes it possible to prevent the occurrence of wrinkling and cracking in the first upwardly recessed part 21a and the first downwardly recessed part 21b.

[0103] (1d) In the wall portion forming step S20, a part of the blank 10 is clamped by and between the upper cushion 62 and the lower cushion 72.

[0104] With such a configuration, when the blank 10 is bent downward in the wall portion forming step S20, the occurrence of wrinkling on the blank 10 can be prevented.

[0105] (1e) Even after the second upwardly depressed part 22a and the second downwardly depressed part 22b are formed on the blank 10 in the clamping step S10, the blank 10 is displaceable in the horizontal direction. In the wall portion forming step S20, neither the first upwardly depressed part 21a nor the first downwardly depressed part 21b are formed on the blank 10.

[0106] With such a configuration, the displacement of the blank 10 when the blank 10 is bent downward in the wall portion forming step S20 causes an inflow of the material into the part where the blank 10 is bent. This makes it possible to prevent the occurrence of cracks in the blank 10 in the wall portion forming step S20. [1-6. Correspondence relationships between concepts]

[0107] In the embodiment described above, the top plate portion 2 corresponds to an example of the plate-shaped portion, the top side corresponds to an example of the first side in the thickness direction, and the bottom side corresponds to an example of the second side in the thickness direction.

[0108] The upper cushion 62 corresponds to an example of the first clamping structure, the lower cushion 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.

[0109] The first upwardly depressed part 21a and the first downwardly depressed part 21b each correspond to an example of the first depressed part, and the second upwardly depressed part 22a and the second downwardly depressed part 22b each correspond to an example of the second depressed part.

[0110] In a part of the upper pad 62 adjacent to the upper through-hole 62c, two points that are mutually adjacent in a radial direction across the upper through-hole 62c correspond to an example of the first point and an example of the second point, respectively.

[0111] In a part of the lower cushion 72 adjacent to the lower through-hole 72c, two points that are mutually adjacent in a radial direction across the lower through-hole 72c correspond to an example of the first point and an example of the second point, respectively.

[0112] The clamping step S10 corresponds to an example of clamping the blank, the wall portion forming step S20 corresponds to an example of forming the wall portion on the blank, and the head plate portion forming step S30 corresponds to an example of forming the plate-shaped portion having the depressed part on the blank. [2. Other embodiments]

[0113] Although the embodiment of the present disclosure has been described so far, the present disclosure may take various forms without being limited to the embodiment described above.

[0114] (2a) In the above-described embodiment, the first upwardly depressed portion 21a is formed by press-molding the blank 10 into close contact with the upper first depression forming portion 62a of the upper cushion 62. However, the structure for forming the first upwardly depressed portion 21a is not limited to the upper first depression forming portion 62a. For example, a Fig. 9, which comprises an upper die 161 having an upper recessed portion 161f in place of the upper die 61 and an upper cushion 162 having an upper through-hole 162c in place of the upper cushion 62.

[0115] The upper recessed portion 161f protrudes downward from a part of the head front surface 61a. A lower end portion of the upper protruding portion 161f has an upwardly recessed shape for forming the first upwardly recessed portion 21a of the press-molded product 1. The upper through hole 162c penetrates the upper pad 162 in the up-down direction.

[0116] Here, in the head plate portion forming step S30, a lower part of the upper recessed part 161f is located within the upper through hole 162c. The lower end part of the upper recessed part 161f is substituted for the upper first recess forming part 62a. When the upper die 161 is moved downward, a part of the blank 10 in contact with the lower protruding part 71e receives upward pressure from the lower protruding part 71e, thereby deforming it to be recessed upward from the reference plane A, then coming into contact with the lower end part of the upper recessed part 161f, and then further deforming it to come into close contact with the lower end part of the upper recessed part 161f. This results in the formation of the first upwardly recessed part 21a on the blank 10.

[0117] (2b) In the above-described embodiment, the first downwardly depressed portion 21b is formed by press-molding the blank 10 into close contact with the lower first depression forming portion 72a of the lower cushion 72. However, the structure for forming the first downwardly depressed portion 21b is not limited to the lower first depression forming portion 72a. For example, a Fig. 10, which includes a lower die 271 having a lower head front surface 271a and a lower recessed part 271f, instead of the lower die 71 and the lower cushion 72.

[0118] The lower head front surface 271a is located on the upper surface of a part of the lower die 271. The lower head front surface 271a extends in the horizontal direction. During the clamping step S10, the wall portion forming step S20, and the head plate portion forming step S30, the lower head front surface 271a contacts the lower front surface of the blank 10 to clamp the blank 10.

[0119] The lower recessed portion 271f is formed in the lower head front surface 271a. The lower recessed portion 271f is recessed downward. The lower recessed portion 271f has a mold for forming the first downward recessed portion 21b of the press-molded product 1.

[0120] Here, in the head plate portion forming step S30, a lower front surface of the blank 10, including the part in contact with the upper protruding part 61e, is in contact with the lower recessed part 271f, which is a substitute for the lower first recessed part 72a, and such a part of the blank 10 is deformed to come into close contact with the lower recessed part 271f. This results in the formation of the first downward recessed part 21b on the blank 10.

[0121] In the above-described embodiment, the lower die 271 corresponds to an example of the second clamping structure.

[0122] (2c) In the above-described embodiment, the first upwardly recessed part 21a is formed at a position other than where the edge of the head plate portion 2 is present. However, the position at which the first upwardly recessed part 21a is formed is not limited thereto. For example, as in a Fig. 11, a first upwardly recessed part 121a may be formed in a part of a head plate portion 102 continuous with the wall portion 3. Alternatively, as in a Fig. 12, a first upwardly depressed part 221a may be formed so as to extend from an edge of a head plate portion 202 continuous with the wall portion 3 to an edge of the head plate portion 202 opposite the wall portion 3.

[0123] (2d) In the above-described embodiment, the first upwardly depressed part 21a and the first downwardly depressed part 21b each have a square shape. However, the shapes of the first upwardly depressed part 21a and the first downwardly depressed part 21b do not have to be square. For example, as in a Fig. 13, a first upwardly depressed part 321a may be formed on a head plate portion 302 to have a gently raised shape. The shape of the first upwardly depressed part 321a may be a preliminary shape before being squared.

[0124] (2e) The manufacturing method in the above-described embodiment is used to manufacture the exemplary press-molded product 1. However, the manufacturing method of press-molded products is not limited to being used to manufacture the press-molded product 1. For example, as shown in FIGS. Fig. 15A, Fig. 15B and Fig. 15C, the manufacturing method can be used to manufacture a press-molded product 401 having a configuration equivalent to that of the press-molded product 1.

[0125] The press-molded 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 of the press-molded product 1. A part where the top plate portion 402 and the wall portion 403 meet forms a ridge line 403a as a part corresponding to the ridge line 3a.

[0126] The head plate portion 402 is curved in the thickness direction. In a case of forming the press-formed product 401 in which the head plate portion 402 is curved in the thickness direction using the press forming device 5, front surfaces of the upper pad 62 and the lower pad 72 in contact with the blank 10 are curved along the curvature of the head plate portion 402, respectively.

[0127] The head plate portion 402 has a first upwardly depressed part 421a, a first downwardly depressed part 421b, a second upwardly depressed part 422a, and a second downwardly depressed part 422b as parts corresponding to the first upwardly depressed part 21a, the first downwardly depressed part 21b, the second upwardly depressed part 22a, and the second downwardly depressed part 22b.

[0128] The positions where the first upwardly depressed part 421a, the first downwardly depressed part 421b, the second upwardly depressed part 422a, and the second downwardly depressed part 422b are arranged are not limited, particularly as long as they are located on the head plate portion 402.

[0129] For example, the press-formed product 401 is used as a component forming a body of a vehicle. The press-formed product 401 may be used as a component forming a portion of a vehicle other than the body. The press-formed product 401 may be used as a component not mounted in the vehicle.

[0130] (2f) In the above-described embodiment, the wall portion 3 has a shape corresponding to an expansion flange. However, the shape of the wall portion 3 is not limited to that of the expansion flange. For example, the shape of the wall portion 3 may be such that it corresponds to a bent flange or a shrink flange.

[0131] (2g) In the above-described embodiments, functions of a single element can be performed by a plurality of elements, and a single function of a single element can be performed by a plurality of elements. Functions of a plurality of elements can be performed by a single element, and a single function performed by a plurality of elements can be performed by a single element. Part of the configuration of the above-described embodiments may be omitted. At least part of the configuration in the above-described embodiments may be added to a configuration in other embodiments or replace a configuration in other embodiments. [Technical ideas disclosed herein][Item 1]

[0132] A manufacturing method of a press-molded product comprising: a plate-shaped portion having a depressed part depressed in a first thickness direction of the plate-shaped portion; and a wall portion extending from an edge of the plate-shaped portion in a direction intersecting with the plate-shaped portion, the manufacturing method comprising: Clamping a blank having a plate shape by means of and between a first clamping structure and a second clamping structure, wherein the first clamping structure is located on a first side in a second thickness direction, which is a thickness direction of the blank, wherein the second clamping structure is located on a second side opposite the first side in the second thickness direction with respect to the blank; Forming the wall portion on the blank by performing press forming on the blank clamped by means of and between the first clamping structure and the second clamping structure, wherein the press forming is carried out by moving at least one first press die located on the first side with respect to the blank and / or a clamping / clamped body, which is a collection comprising the first clamping structure, the second clamping structure, the blank and a second press die, in a pressing direction that is parallel to the second thickness direction and that allows the first press die to come relatively closer to the blank, wherein the second press die is located on the second side with respect to the blank; and Forming the plate-shaped portion having the recessed part on the blank by performing press forming on the blank on which the wall portion is being formed, wherein the press forming is performed by further moving at least one of the first die and the clamping / clamped body in the pressing direction to allow the first die and the second die to come closer to each other. [Point 2]

[0133] A manufacturing method of a press-formed product according to item 1, wherein forming the wall portion on the blank comprises forming the wall portion by moving the first die in the pressing direction, and wherein forming the plate-shaped portion with the depressed part on the blank comprises forming the plate-shaped portion by further moving the first die in the pressing direction so that the depressed part is formed on the blank by bringing the first die and the second die closer to each other. [Point 3]

[0134] A manufacturing method of a press-formed product according to item 1 or 2, wherein the plate-shaped portion includes a first depressed part as the depressed part and a second depressed part which is shallower in the first thickness direction than the first depressed part, and wherein clamping the blank comprises clamping the blank by means of and between the first clamping structure and the second clamping structure to thereby form the second recessed portion on the blank. [Point 4]

[0135] Manufacturing process of a press-molded product according to any one of items 1 to 3, wherein clamping the blank comprises clamping the blank by means of and between the first clamping structure and the second clamping structure at at least two points spaced apart in a direction perpendicular to the second thickness direction, wherein the at least two points comprise a first point and a second point and wherein forming the plate-shaped portion comprises forming the recessed part on the blank by moving at least one of the first die and the second die such that a part of at least one of the first die and the second die passes between the first point and the second point. [Point 5]

[0136] Manufacturing process of a press-molded product according to any one of items 1 to 4, wherein the press-formed product is formed from a high-strength steel sheet. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2017-042826

[0003]

Claims

[1] A manufacturing method of a press-molded product (1) comprising: a plate-shaped portion (2) having a recessed part (21a, 21b) recessed in a first thickness direction of the plate-shaped portion; and a wall portion (3) extending from an edge of the plate-shaped portion in a direction intersecting with the plate-shaped portion, the manufacturing method comprising: Clamping a blank (10) having a plate shape by means of and between a first clamping structure (62) and a second clamping structure (72), wherein the first clamping structure is located on a first side in a second thickness direction, which is a thickness direction of the blank, wherein the second clamping structure is located on a second side opposite the first side in the second thickness direction with respect to the blank (S10); Forming the wall portion on the blank by performing press forming on the blank clamped by means of and between the first clamping structure and the second clamping structure, wherein the press forming is carried out by moving at least one first press die (61) located on the first side with respect to the blank and / or a clamping / clamped body (62, 72, 10, 71), which is a collection comprising the first clamping structure, the second clamping structure, the blank, and a second press die (71), in a pressing direction that is parallel to the second thickness direction and that allows the first press die to come relatively closer to the blank, wherein the second press die is located on the second side with respect to the blank (S20); and Forming the plate-shaped portion having the recessed part on the blank by performing press forming on the blank on which the wall portion is being formed, wherein the press forming is performed by further moving at least one of the first die and the clamping / clamped body in the pressing direction to allow the first die and the second die to come closer to each other (S30). [2] A method of manufacturing a press-molded product according to claim 1, wherein forming the wall portion on the blank comprises forming the wall portion by moving the first die in the pressing direction and wherein forming the plate-shaped portion with the depressed part on the blank comprises forming the plate-shaped portion by further moving the first die in the pressing direction so that the depressed part is formed on the blank by bringing the first die and the second die closer to each other. [3] A method of manufacturing a press-molded product according to claim 1 or 2, wherein the plate-shaped portion comprises a first recessed part (21a, 21b) as the recessed part and a second recessed part (22a, 22b) which is recessed shallower in the first thickness direction than the first recessed part, and wherein clamping the blank comprises clamping the blank by means of and between the first clamping structure and the second clamping structure to thereby form the second recessed portion on the blank. [4] A method of manufacturing a press-molded product according to claim 1 or 2, wherein clamping the blank comprises clamping the blank by means of and between the first clamping structure and the second clamping structure at at least two points spaced apart in a direction perpendicular to the second thickness direction, wherein the at least two points comprise a first point and a second point and wherein forming the plate-shaped portion comprises forming the recessed part on the blank by moving at least one of the first die and the second die such that a part of at least one of the first die and the second die passes between the first point and the second point. [5] A manufacturing method of a press-formed product according to claim 1 or 2, wherein the press-formed product is formed from a high-strength steel sheet.

Images