Manufacturing method for press-molded products

Abstract

To provide a method for manufacturing press-molded products that can suppress wrinkles and cracks in the molded products. [Solution] A method for manufacturing a press-formed product W2, wherein the punch 10 has an upper die punch 11 and a lower die punch 20, and the blank holder 3 has an upper die blank holder 30 and a lower die blank holder 40, the upper die blank holder 30 is divided into an upper die body 31 and an upper die split 36, the upper die split 36 ​​is positioned outside the deep drawing section 21, and the lower die blank holder 40 has a lower die body 41 facing the upper die body 31 and a lower die holding section 46 facing the upper die split 36, and the method includes a bending step in which bending is performed by clamping the blank W1 with the upper die split 36 ​​and the lower die holding section 46, a first drawing step in which the blank W1 is clamped with the upper die body 31 and the lower die body 41 and pressed against the lower die punch 20, and a second drawing step in which drawing is performed after the execution of the first drawing step.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for manufacturing a press-formed product using a press apparatus. BACKGROUND ART

[0002] Conventionally, as a press apparatus for subjecting a blank material to drawing processing, one having a die, a punch, and a blank holder is known. In such a press apparatus, in a state where the blank is held between the die and the blank holder, these are lowered integrally, and the blank material is pressed against the punch, thereby forming a component of a predetermined shape (for example, Patent Document 1). In the conventional technique described in Patent Document 1, a step portion is provided between a forming surface (recessed portion) provided on the upper die and a clamping surface. Further, in the conventional technique described in the above-mentioned Patent Document 1, a press-forming die provided with a flat portion that the clamped blank first comes into contact with is used. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0003] PATENT DOCUMENT 1 Japanese Unexamined Patent Application Publication No. 2019-42780 SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0004] However, in the press-forming die described in Patent Document 1, the step portion formed on the blank is set as a portion to be removed in the final product (component). Therefore, in forming the step portion, it is necessary to allow a large amount of material (blank) to flow in, and the portion (excess stock) to be finally removed increases, which becomes a factor of lowering the yield.

[0005] Accordingly, an object of the present invention is to provide a method for manufacturing a press-formed product that can suppress local elongation of the formed product and suppress wrinkles and cracks in the formed product without increasing the size of the blank. MEANS FOR SOLVING THE PROBLEM

[0006] (1) The present invention, provided to solve the above-mentioned problems, is a method for manufacturing a press-formed product, comprising a press device for forming a blank, wherein the press device comprises a punch for press-forming the blank and a blank holder for holding the blank, the punch comprises an upper die punch and a lower die punch, the blank holder comprises an upper die blank holder and a lower die blank holder, the upper die blank holder is divided into an upper die body and at least one upper die segment, the upper die segment is positioned outward from the deep drawing section that draws the blank relatively deeper, and The lower die blank holder has a lower die body portion provided so as to face the upper die body portion, and a lower die holding portion facing the upper die section portion, and is characterized by having a bending step in which the blank is bent in the drawing direction by clamping the blank with the upper die section portion and the lower die holding portion, a first drawing step in which the blank is clamped with the upper die body portion and the lower die body portion and the blank is pressed against the lower die punch in conjunction with the bending step or after the bending step, and a second drawing step in which drawing is performed by the upper die punch and the lower die punch after the first drawing step is performed.

[0007] In the press-formed product manufacturing method of the present invention described above, the upper die punch upper die blank holder is formed by dividing it into an upper die body and an upper die segment. Therefore, prior to the second drawing step in which deep drawing is performed on the blank, bending can be performed on the deep-drawn portion of the blank (press-formed product). As a result, the press-formed product manufacturing method of the present invention can perform deep drawing on the region where localized deep drawing is performed (also referred to as the deep-drawn portion) while suppressing the excess inflow of the blank (material). This allows the press-formed product manufacturing method of the present invention to suppress localized elongation of the molded product and to suppress wrinkles and cracks in the molded product. Consequently, the press-formed product manufacturing method of the present invention can improve the yield and quality of the molded product and reduce costs. Furthermore, in the press-formed product manufacturing method of the present invention, the first drawing step as shallow drawing can be performed on the blank together with or after the bending step, so that the second drawing step can be performed with the blank positioned in a predetermined position. As a result, the press-formed product manufacturing method of the present invention can perform press working with high precision. Here, the upper die punch in the press device used in the present invention corresponds to the die. The lower die holder may be provided independently, similar to the upper die section, or it may be provided integrally with the lower die punch, for example.

[0008] (2) The method for manufacturing a press-molded product of the present invention described above is preferably characterized in that the upper mold portion is divided into a plurality of parts.

[0009] The method for manufacturing press-formed products of the present invention, as described above, allows for the formation of separate drawing allowances in the blank by configuring it as described in (2) above, thus enabling appropriate press processing according to the molding of complex shapes. As a result, the method for manufacturing press-formed products of the present invention can further suppress localized elongation of the molded product, as well as further suppress wrinkles and cracks in the molded product.

[0010] (3) In the method for manufacturing a press-formed product of the present invention as described above, the lower die holding portion is provided in the lower die punch so as to extend outward from the deep drawing portion and face the upper die section, and the bending step is characterized in that the blank is held between the lower die holding portion and the upper die section, thereby bending the blank to the extent of the drawing allowance in the deep drawing portion.

[0011] As described above, the method for manufacturing a press-formed product of the present invention is configured as shown in (3) above. By clamping the blank with the lower die holding part and the upper die split part, the bending process for the drawing allowance in the deep-drawing section can be performed prior to deep drawing. Therefore, in the method for manufacturing a press-formed product of the present invention, the drawing process by the upper die punch is not performed all at once, so the excess flow of the blank into the processing area can be effectively suppressed. As a result, the method for manufacturing a press-formed product of the present invention can further suppress localized elongation of the molded product, as well as further suppress wrinkles and cracks in the molded product.

[0012] (4) In the method for manufacturing a press-formed product of the present invention as described above, the upper die portion is preferably positioned at a location that is at least the amount of processing allowance by the upper die punch in the direction outward of the deep drawing portion.

[0013] The method for manufacturing press-formed products of the present invention, as described above, is configured as in (4) above, so that the drawing process by the upper die punch is not performed all at once, and thus the excess flow of blank into the processed area can be effectively suppressed. As a result, the method for manufacturing press-formed products of the present invention can further suppress localized elongation of the molded product, and can further suppress wrinkles and cracks in the molded product.

[0014] (5) In the method for manufacturing a press-formed product of the present invention as described above, the bending step is characterized in that the blank is bent in the deep drawing section so as to be inclined downward toward the lower die holding section.

[0015] The method for manufacturing press-formed products of the present invention, as described above, is configured as in (5) above, so that in the bending process, a minimum drawing allowance is secured in the blank, and a second drawing process as deep drawing can be performed, thereby reducing the clamping allowance of the blank. Therefore, the method for manufacturing press-formed products of the present invention can further suppress localized elongation of the molded product, and can further suppress wrinkles and cracks in the molded product. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a method for manufacturing press-molded products that suppresses localized elongation of the molded product and suppresses wrinkles and cracks in the molded product without increasing the size of the blank. [Brief explanation of the drawing]

[0017] [Figure 1] This is a perspective view showing a press apparatus used in the method for manufacturing press-formed products of the present invention. [Figure 2] Figure 1 is a perspective view showing the press apparatus with the upper punch, lower punch, upper blank holder, and lower blank holder partially assembled. [Figure 3] (a) to (c) are explanatory diagrams illustrating the process in the manufacturing method of press-formed products. [Figure 4] (a) and (b) are explanatory diagrams illustrating the process following Figure 3. [Figure 5] (a) and (b) are enlarged diagrams illustrating the main steps in the manufacturing method of press-formed products. [Figure 6] (a) to (c) are enlarged explanatory diagrams of key parts illustrating the process that follows Figure 5. [Modes for carrying out the invention]

[0018] Hereinafter, a method for manufacturing a press-formed product W2 according to an embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that each drawing is schematically represented for ease of understanding, and may differ from the actual shape, size, and arrangement of component parts. In addition, reference numerals for similar members and the like in each drawing may be omitted.

[0019] The method for manufacturing the press-formed product W2 (see Fig. 4(b)) is a method of forming a blank W1 using a press apparatus 1 to produce the press-formed product W2. First, for the sake of explanation, an example of the press-formed product W2 and each configuration of the press apparatus 1 will be described, and then the method for manufacturing the press-formed product W2 will be explained.

[0020] As shown in Fig. 1 and Fig. 2, the press apparatus 1 is configured to form a plate-shaped metal material (hereinafter simply referred to as "blank W1" for description). The blank W1 is composed of a metal plate, for example a steel plate, particularly a high-tensile steel material. In the following description, the formed product obtained by press-forming the blank W1 (press-formed product W2) may be simply referred to as "press-formed product W2" for explanation.

[0021] The press apparatus 1 is capable of forming various components such as automobile fenders, hoods, roofs, front doors, and rear doors. The press-formed product W2 shown as an example in Fig. 2 is used as a roof after excess portions are removed.

[0022] As shown in Fig. 4(b), the press-formed product W2 includes a draw-formed portion W2a that forms the arcuate curved portion of the roof main body. The press-formed product W2 further includes a front-end-side draw-formed portion W2b formed along the width direction (the depth direction in the drawing) on the front end side (the left side in the drawing) of the draw-formed portion W2a. The press-formed product W2 further includes a rear-end-side draw-formed portion W2c (also referred to as a deep draw-formed portion W2c) formed along the width direction on the rear end side of the draw-formed portion W2a. The deep draw-formed portion W2c is a portion that is drawn relatively deeply with respect to the blank W1.

[0023] Furthermore, the manufacturing method for the press-molded product W2 of the present invention is not limited to the molding of roofs, but can be used to manufacture various parts. In particular, it can be suitably used when molding parts in which deeply drawn bent portions (bending ridges) are extended.

[0024] Next, we will describe in detail the press apparatus 1 used in the manufacturing method of the press-molded product W2 of the present invention. Figure 1 is an exploded perspective view showing the molding surfaces of each component of the press apparatus 1. Figure 2 is an exploded perspective view showing some of the components of the press apparatus 1 combined.

[0025] As shown in Figures 1 and 2, the press device 1 includes a punch 10 having an upper punch 11 and a lower punch 20, an upper blank holder 30 and a lower blank holder 40 as blank holders 3, and so on.

[0026] The upper die punch 11 and the lower die punch 20 move relative to each other in the vertical direction to move closer together or further apart, thereby pressing the blank W1 and performing press processing. The upper die body 31 also moves relative to each other in the vertical direction to move closer together or further apart, thereby clamping (holding) the blank W1 between itself and the lower die body 41. The upper die segment 36 also moves relative to each other in the vertical direction to move closer together or further apart, thereby clamping (holding) the blank W1 between itself and the lower die holding segment 46.

[0027] In this embodiment, the upper punch 11 and the lower punch 20 are formed to extend in a predetermined axial direction (left-right direction in the figure). The upper punch 11 and the lower punch 20 each have a molding surface with irregularities corresponding to the press-formed product W2. In this embodiment, a pair of upper die presser portions 12, 12 are provided at the rear end of the upper punch 11, extending to the rearward side, spaced apart in the width direction. The upper die presser portions 12, 12 can hold the blank W1 between themselves and a pair of grooves 47, 47 of the lower die holding portion 46, which will be described later. In this embodiment, a deep drawing portion 21 that is drawn relatively deeply is formed at the rear end (right side in the figure) of the lower punch 20.

[0028] In the press device 1 of this embodiment, the upper punch 11 is able to move up and down relative to the lower punch 20 by an appropriate drive source. More specifically, in the press device 1 of this embodiment, the upper punch 11, the upper die body 31, and the upper die section 36 are attached to the upper die body (not shown) so that they can move up and down in the vertical direction. The lower punch 20 and the lower die body 41 are attached to the lower die body (not shown). In this embodiment, the lower die holder 46 is connected to the rear end portion of the lower punch 20 and is integrated with the lower punch 20. Therefore, in the press device 1 of this embodiment, the upper punch 11 (corresponding to the die) is movable, and the lower punch 20 is fixed.

[0029] In the following explanation, the vertical direction (up and down direction) of the upper punch 11, upper die body 31, and upper die segment 36 may be simply referred to as "up and down direction H" or "up and down direction H".

[0030] The upper mold blank holder 30 comprises an upper mold main body 31 and an upper mold segment 36, etc. In other words, in this embodiment, the upper mold blank holder 30 is divided into an upper mold main body 31 and an upper mold segment 36.

[0031] As shown in Figure 1, the upper die body 31 is formed in a roughly U-shape so as to be located on the front end side of the blank W1 and on both sides of the blank W1 in the width direction. The upper die body 31 is also positioned above the blank W1. The upper die body 31 can support (hold) the blank W1 by sandwiching it between itself and the lower die body 41, which will be described later. In other words, the upper die body 31 and the lower die body 41 perform a part of the bending process (for example, shallow drawing) in the pre-molding stage and also function as members for holding the blank W1. The upper die body 31 is attached to the upper die body via a cylinder or the like (not shown), and is movable relative to the lower die body 41 in the vertical direction H.

[0032] The lower mold blank holder 40 is divided into a lower mold body portion 41 and a lower mold holding portion 46. The lower mold body portion 41 is positioned opposite the upper mold body portion 31. The lower mold body portion 41 is formed in substantially the same shape (U-shape) as the upper mold body portion 31, and can hold and support (hold) the blank W1 between itself and the upper mold body portion 31.

[0033] The upper die section 36 (corresponding to the upper blank holder 30 of the present invention) is positioned on the rear end side of the blank W1, above the blank W1. That is, the upper die section 36 is positioned outward from the deep drawing section 21 that draws the blank W1 relatively deeply. To put it another way, the upper die section 36 is positioned outward from the deep drawing section 21 by at least the amount of processing allowance by the upper die punch 11. In this embodiment, the upper die section 36 is provided in divisions relative to the upper die punch 11. The upper die section 36 is divided into three parts along the width direction (depth direction in the illustration). Each of the three divided upper die section 36 is formed in a rectangular shape. Hereinafter, the divided upper die section 36 will also be referred to as upper die section 36a, 36b, and 36c, and will be collectively referred to as the upper die section 36 unless there is a need to explain them separately.

[0034] The upper mold section 36 can support (hold) the blank W1 by sandwiching it between itself and the lower mold holding section 46 (corresponding to the lower mold blank holder 40 of the present invention), which will be described later. In other words, the upper mold section 36 and the lower mold holding section 46 perform bending of the blank W1 in the pre-molding stage and also function as members for holding the blank W1. The three-part upper mold section 36 is attached to the upper mold body via cylinders or the like (not shown), and is movable relative to the lower mold holding section 46 in the vertical direction H. The upper mold sections 36a, 36b, and 36c may move up and down independently relative to the lower mold holding section 46, or they may move up and down integrally relative to the lower mold holding section 46.

[0035] In this embodiment, the lower die holder 46 is connected to the rear end of the lower die punch 20. That is, the lower die holder 46 is integrally formed with the lower die punch 20. In other words, the lower die holder 46 is provided at the rear end of the lower die punch 20, extending toward the rear. The lower die holder 46 also has three holding surfaces 46a, 46b, and 46c that face each of the upper die sections 36a, 36b, and 36c, respectively. In this embodiment, the holding surfaces 46a, 46b, and 46c of the lower die holder 46 are connected via a pair of grooves 47, 47 formed along the front-rear direction. That is, the lower die holder 46 has each of its holding surfaces 46a, 46b, and 46c that are integrally formed and separated by grooves 47, 47. Note that, similar to the upper die section 36, the holding surfaces 46a, 46b, and 46c of the lower die holder 46 may be independently separated. Furthermore, the lower die holding section 46 may be separated independently from the lower die punch 20.

[0036] The above describes the configuration of the press apparatus 1 used in the method for manufacturing the press-molded product W2 of the present invention. Next, the method for manufacturing the press-molded product W2 of the present invention will be described.

[0037] ≪Each step in the manufacturing method of press-molded products≫ The manufacturing method for the press-formed product W2 of this embodiment includes a bending process, a first drawing process, and a second drawing process. Details of each process will be described below. Figures 3 to 6 are explanatory cross-sectional views taken in the direction of arrow AA in Figure 2, and Figures 5 and 6 are enlarged explanatory views of the main parts, showing the area around the deep-drawn section 21 in Figures 3 and 4.

[0038] ≪Bending Process≫ As shown in Figures 3(a) and 5(a), prior to the bending process, the blank W1 is placed on the lower die body 41 of the lower die blank holder 40 and on the molding surface of the lower die punch 20. Once the blank W1 is placed on the lower die body 41 and the lower die punch 20, the upper die section 36 of the upper die blank holder 30 descends, pushing the rear end of the blank W1 downwards toward the lower die holding section 46 (also referred to as the bending preparation process).

[0039] As shown in Figures 3(b) and 5(b), the upper die section 36 descends further, and the upper die body 31 of the upper die blank holder 30 also descends. Subsequently, as shown in Figure 3(c), the front end of the blank W1 is clamped between the upper die body 31 and the lower die body 41, and as shown in Figures 3(c) and 6(b), the rear end of the blank W1 is clamped between the upper die section 36 and the lower die holding section 46 (also referred to as the bending process). In the bending process, the blank W1 is clamped between the upper die section 36 and the lower die holding section 46, and the blank W1 is bent in the drawing direction. In addition, in the bending process, the blank W1 is clamped between the lower die holding section 46 and the upper die section 36, and the blank W1 is bent by the amount of the drawing allowance in the deep drawing section 21. Furthermore, the bending process involves bending the blank W1 in the deep drawing section 21 so that it slopes downward toward the lower die holding section 46.

[0040] ≪First pressing process≫ In this embodiment, after the bending process, a first drawing process is performed as shown in Figure 3(c). In the first drawing process, the blank W1 is held between the upper die body 31 and the lower die body 41, and the blank W1 is pressed against the lower die punch 20, thereby performing shallow drawing on the molding surface of the blank W1 in areas other than the deep drawing section 21. The first drawing process may be performed together with the bending process. The first drawing process only needs to be shallow enough to allow the blank W1 to follow the lower die punch 20. By performing the first drawing process, the blank W1 can be accurately positioned relative to the upper die punch 11 and the lower die punch 20. The first drawing process can also be omitted.

[0041] ≪Second pressing process≫ When the bending process and the first drawing process are performed, the upper die punch 11 descends, as shown in Figures 4(a) and 6(b), initiating the second drawing process (also referred to as the deep drawing process). In the second drawing process, as shown in Figures 4(b) and 6(c), the blank W1 is clamped between the upper die punch 11 and the lower die punch 20, thereby performing deep drawing. In the second drawing process, the upper die punch 11 is pressed against the lower die punch 20, causing deep drawing of the blank W1 in the deep drawing section 21. The execution of the second drawing process forms a press-formed product W2. In addition, the second drawing process causes deep drawing of the blank W1, forming a deep-drawn section W2c in the press-formed product W2. Thus, in the method for manufacturing a press-formed product W2 of the present invention, since the bending process is performed prior to the second drawing process, the excess material of the blank W1 flowing into the deep drawing section 21 can be minimized, and the elongation of the blank W1 in the deep drawing section 21 can be suppressed. Furthermore, since the gripping allowance of the blank W1 by the upper mold section 36 and the lower mold holding section 46 can be reduced, the amount of excess material removed from the press-molded product W2 can be reduced. This makes it possible to reduce material costs.

[0042] The above is one embodiment of the method for manufacturing the press-molded product W2 of the present invention. Next, the effects and advantages realized by the method for manufacturing the press-molded product W2 of the present invention will be described in detail below.

[0043] The method for manufacturing the press-molded product W2 of the present invention described above has the following characteristic configurations: (a) and (b) to (e). Therefore, the method for manufacturing the press-molded product W2 of the present invention can achieve unique effects that cannot be achieved by the prior art, as described below.

[0044] (a) The method for manufacturing the press-formed product W2 of this embodiment described above is a method for manufacturing the press-formed product W2 in which a blank W1 is formed using a press device 1, wherein the press device 1 has a punch 10 for press-forming the blank W1 and a blank holder 3 for holding the blank W1, the punch 10 has an upper die punch 11 and a lower die punch 20, the blank holder 3 has an upper die blank holder 30 and a lower die blank holder 40, the upper die blank holder 30 is divided into an upper die body 31 and at least one upper die sub-part 36, the upper die sub-part 36 is positioned outward from the deep drawing section 21 that draws the blank W1 relatively deeply, The lower die blank holder 40 has a lower die body 41 provided so as to face the upper die body 31, and a lower die holding part 46 facing the upper die split 36, and is characterized by having a bending step in which the blank W1 is bent in the drawing direction by clamping the blank W1 with the upper die split 36 ​​and the lower die holding part 46, a first drawing step in which the blank W1 is clamped with the upper die body 31 and the lower die body 41 and shallow drawing is performed by pressing the blank W1 against the lower die punch 20 together with the bending step or after the bending step, and a second drawing step in which drawing is performed by the upper die punch 11 and the lower die punch 20 after the first drawing step.

[0045] In the manufacturing method of the press-formed product W2 of this embodiment described above, the upper die blank holder 30 is divided into an upper die body portion 31 and an upper die sub-part portion 36. Therefore, prior to the second drawing step in which deep drawing is performed on the blank W1, bending can be performed on the deep-drawn portion W2c of the blank W1 (press-formed product W2). As a result, the manufacturing method of the press-formed product W2 of this embodiment can perform deep drawing on the region where deep drawing is performed locally (also referred to as the deep-drawn portion 21) while suppressing the excess inflow of the blank W1 (material). This makes it possible to suppress localized elongation of the press-formed product W2 and to suppress wrinkles and cracks in the press-formed product W2. Consequently, the manufacturing method of the press-formed product W2 of this embodiment can improve the yield and quality of the press-formed product W2 and reduce costs. Furthermore, the manufacturing method of the press-formed product W2 of the present invention allows the first drawing process, which is a shallow drawing process, to be performed on the blank W1 together with the bending process or after the bending process, so that the second drawing process can be performed with the blank W1 positioned in a predetermined position. Therefore, the manufacturing method of the press-formed product of the present invention can perform press processing with high precision. Here, the upper die punch 11 in the press apparatus 1 used in the present invention corresponds to the die. The lower die holding part 46 may be provided independently, similar to the upper die section 36, or it may be provided integrally with the lower die punch 20, for example.

[0046] (b) The method for manufacturing the press-molded product W2 of this embodiment described above is characterized in that the upper mold section 36 is divided into multiple parts.

[0047] The manufacturing method for the press-formed product W2 of this embodiment, as described above, allows for the formation of separate drawing allowances in the blank W1 by configuring it as shown in (b) above, thus enabling appropriate press processing according to the molding of complex shapes. As a result, the manufacturing method for the press-formed product W2 of this embodiment can further suppress localized elongation of the press-formed product W2, and can further suppress wrinkles and cracks in the press-formed product W2.

[0048] (c) In the method for manufacturing the press-formed product W2 of the above embodiment, the lower die holding portion 46 is provided in the lower die punch 20 so as to extend outward from the deep drawing portion 21 and to face the upper die split portion 36, and the bending process is characterized in that the blank W1 is held between the lower die holding portion 46 and the upper die split portion 36, thereby bending the blank W1 by the amount of the drawing allowance in the deep drawing portion 21.

[0049] As described above, the method for manufacturing the press-formed product W2 of this embodiment is configured as shown in (c) above. By clamping the blank W1 with the lower die holding part 46 and the upper die split part 36, the bending process for the drawing allowance in the deep drawing section 21 can be performed prior to deep drawing. Therefore, in the method for manufacturing the press-formed product W2 of this embodiment, the drawing process by the upper die punch 11 is not performed all at once, so the excess flow of the blank W1 into the processing area can be effectively suppressed. As a result, the method for manufacturing the press-formed product W2 of this embodiment can further suppress localized elongation of the press-formed product W2, and can further suppress wrinkles and cracks in the press-formed product W2.

[0050] (d) In the method for manufacturing the press-formed product W2 of this embodiment described above, the upper die section 36 is positioned at a location that is at least the amount of processing allowance by the upper die punch 11 in the outward direction of the deep drawing section 21.

[0051] The manufacturing method for the press-formed product W2 of this embodiment, as described above, is configured as shown in (d) above, so that the drawing process by the upper die punch 11 is not performed all at once, and thus the excess flow of the blank W1 into the processed area can be effectively suppressed. As a result, the manufacturing method for the press-formed product W2 of this embodiment can further suppress localized elongation of the press-formed product W2, and can further suppress wrinkles and cracks in the press-formed product W2.

[0052] (e) In the method for manufacturing the press-formed product W2 of the above embodiment, the bending step is characterized in that the blank W1 is bent in the deep drawing section 21 so as to be inclined downward toward the lower die holding section 46.

[0053] The manufacturing method for the press-formed product W2 of this embodiment, as described above, is configured as shown in (e) above, so that in the bending process, a minimum drawing allowance is secured in the blank W1, and the second drawing process as deep drawing can be executed, thereby reducing the clamping allowance of the blank W1. Therefore, the manufacturing method for the press-formed product W2 of this embodiment can further suppress localized elongation of the press-formed product W2, and can further suppress wrinkles and cracks in the press-formed product W2.

[0054] The above describes the configuration and effects of the method for manufacturing a press-molded product W2 according to the present invention. However, the method for manufacturing a press-molded product W2 according to the present invention is not limited to the embodiments and modifications described above, and various modifications can be made within the scope of the present invention. For example, the method for manufacturing a press-molded product W2 may be as described in (a) above, and can be configured in various forms and sequences. Furthermore, the method for manufacturing a press-molded product W2 according to the present invention may, for example, not include some or all of the configurations related to (b) to (e) above, or may include some or all of (b) to (e) above and other configurations.

[0055] In this embodiment, an upper punch 11 is used instead of a die, but the upper punch 11 may be formed as a die or together with the die. Furthermore, the upper punch 11 and the lower punch 20 can be formed in various shapes and sizes according to the shape and size of the press-formed product W2. Also, the blank holder 3 (upper blank holder 30 and lower blank holder 40) can be formed in various shapes and sizes according to the shape and size of the blank W1 and the press-formed product W2.

[0056] Furthermore, in this embodiment, the bending process involves bending the blank W1 by the amount of the drawing allowance in the deep drawing section 21, but the drawing allowance can be set to various amounts depending on the shape, size, and material of the press-formed product W2. Also, in the bending process of this embodiment, the blank W1 is bent in the deep drawing section 21 so that it slopes downward toward the lower die holding section 46, but the present invention is not limited to this. For example, the bending process may be performed in a form other than in which the blank W1 slopes downward toward the lower die holding section 46 in the deep drawing section 21. That is, in the bending process, it is sufficient if a bending process without deep drawing is performed in the deep drawing section 21 prior to the deep drawing of the blank W1.

[0057] Furthermore, in this embodiment, the first drawing process is performed together with the bending process, but the first drawing process may be performed after the bending process. The drawing allowance for shallow drawing in the first drawing process can be set to various allowances depending on the shape, size, material, etc., of the press-formed product W2. Also, the first drawing process may be performed only as needed, and may be omitted. Furthermore, in this embodiment, one deep drawing section 21 is set on the blank W1, but multiple deep drawing sections 21 may be set. Furthermore, in this embodiment, the deep drawing section 21 is set at a position where it is drawn relatively deeply with respect to the blank W1, but the deep drawing section 21 does not necessarily have to be set at the position where it is drawn the deepest. In short, the deep drawing section 21 should be set at a position where it is drawn relatively deeply with respect to other parts during the drawing process, for example, it should be set at a location in the press-formed product W2 where localized stretching is not desired, or where wrinkles or cracks are not desired.

[0058] In this embodiment, the upper die section 36 is exemplified as being divided into three parts in the width direction of the blank W1, but the present invention is not limited thereto. For example, the upper die section 36 may be divided into one, two, or four or more parts. Furthermore, the upper die section 36 can be formed into various shapes and sizes. Also, when the upper die section 36 is divided into two or more parts, each part may not be divided into the same shape, but may be divided into different shapes and sizes. In such cases, the lower die holder 46 may also be divided into various quantities, shapes, and sizes to match the upper die section 36. Furthermore, the lower die holder 46 does not have to be divided. Also, in this embodiment, the lower die holder 46 is formed integrally with the lower die punch 20, but the lower die holder 46 may be formed independently of the lower die punch 20, not just integrally.

[0059] In this embodiment, the upper die section 36 is positioned at a location at least the amount of processing allowance by the upper die punch 11 in the outward direction of the deep drawing section 21, but is not limited to this, and the upper die section 36 can be positioned at various locations depending on the shape of the desired press-formed product W2.

[0060] The above describes various embodiments and modifications of the method for manufacturing press-molded products according to the present invention. However, the present invention is not limited to those exemplified in the embodiments and modifications described above, and it will be readily apparent to those skilled in the art that other embodiments may exist in the spirit and nature of the teachings, without departing from the scope of the claims. [Industrial applicability]

[0061] The present invention can be suitably used as a method for manufacturing press-formed products by deep drawing. Furthermore, the present invention can be suitably used as a method for manufacturing various parts (press-formed products) in automobiles and the like. [Explanation of symbols]

[0062] 1: Pressing device 3: Blank holder 10: Punch 11: Top-type punch 20: Lower punch 21: Deep drawing section 30: Upper blank holder 31: Upper main body 36: Upper body section 36a: Upper mold split part 36b: Upper mold split part 36c: Upper mold division part 40: Lower blank holder 41: Lower body part 46: Lower mold holding part W1: Blank W2: Press-formed product

Claims

1. A method for manufacturing press-formed products, in which a blank is formed using a press device, The aforementioned press device is A punch for press-forming the aforementioned blank, A blank holder for holding the blank, It has, The punch has an upper die punch and a lower die punch. The blank holder comprises an upper blank holder and a lower blank holder. The upper mold blank holder is divided into an upper mold main body and at least one upper mold sub-body, The upper mold section is positioned outward from the deep drawing section that draws the blank relatively deeper. The lower mold blank holder has a lower mold body portion provided so as to face the upper mold body portion, and a lower mold holding portion facing the upper mold section portion. A bending process in which the blank is bent in the drawing direction by clamping the blank with the upper die section and the lower die holding section, A first drawing step is performed in conjunction with the bending step, or after the bending step, in which the blank is clamped between the upper die body and the lower die body, and the blank is pressed against the lower die punch, It has, A second drawing process is performed after the first drawing process using the upper die punch and the lower die punch, A method for manufacturing a press-molded product, characterized by having the following:

2. The method for manufacturing a press-molded product according to claim 1, characterized in that the upper mold portion is divided into a plurality of parts.

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