Molding manufacturing method

Abstract

To reduce a bending-back amount of a plate during pressing in a molding manufacturing method capable of providing a molding having a top plate and a vertical wall by pressing a plurality of stacked plates.SOLUTION: This manufacturing method performs twisting vertical wall equivalent parts and extensions of a plurality of plates to a moving-direction side by moving a mold in a moving direction to contact the mold with the extensions in a state where a top plate equivalent part after joining is pinched. The method further performs forming a top plate and a vertical plate by further moving the mold in the moving direction to press the vertical wall equivalent parts of the plates to the mold in a state where the vertical wall equivalent parts and the extensions are twisted by the mold.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a molded article. [Background technology]

[0002] For example, Patent Document 1 below discloses a technique for pressing a plurality of stacked plate materials to obtain a molded product. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-192247 Summary of the Invention [Problem to be solved by the invention]

[0004] When multiple stacked plate materials are pressed to obtain a molded product having a top plate portion and vertical wall portions, as in the technology of Patent Document 1, a problem has been found in that gaps are likely to occur between the multiple plate materials due to unbending, in which the bent material deforms in the direction in which it tries to return to its original shape. If the gaps between the multiple plate materials become large after pressing, problems may arise during subsequent work such as welding and assembly.

[0005] One aspect of the present disclosure is to provide a method for manufacturing a molded product in which multiple stacked plate materials are pressed to obtain a molded product having a top plate portion and a vertical wall portion, by which the amount of bending back of the plate materials during pressing can be reduced. [Means for solving the problem]

[0006] One aspect of the present disclosure is a method for manufacturing a molded product, which includes pressing a plurality of stacked plate materials to obtain a molded product having a top plate portion and a vertical wall portion. In the method for manufacturing a molded product, the plurality of plate materials include a first member and a second member.

[0007] The first member has a top plate equivalent portion, a vertical wall equivalent portion, and an extension portion. The top plate equivalent portion represents a portion corresponding to the top plate portion of the molded product. The vertical wall equivalent portion represents a portion corresponding to at least a part of the vertical wall portion of the molded product. The second member has a top plate equivalent portion and a vertical wall equivalent portion. The top plate equivalent portion of the second member is overlapped with the first member.

[0008] In any plane parallel to the multiple plate members, the direction from the vertical wall equivalent portion toward the top plate equivalent portion is referred to as the inside, and the direction from the vertical wall equivalent portion toward the opposite side of the top plate equivalent portion is referred to as the outside. The outer end of the first member is referred to as the first end, and the outer end of the second member is referred to as the second end. The first end is located further outward than the second end. The extension portion refers to the area from the first end of the first member to the overlapping portion of the second end.

[0009] In this manufacturing method, the direction from the first member side toward the second member side is set as the movement direction, and in a state where the first member is overlapped with the second member so that the first member has an extension portion, the top plate equivalent portion is welded to join the first member and the second member. In addition, by moving a mold along the movement direction while sandwiching the joined top plate equivalent portion, the mold is brought into contact with the extension portion, and the vertical wall equivalent portion and the extension portion of the multiple plate materials are deflected in the movement direction.

[0010] Furthermore, while the mold is bending the vertical wall equivalent portions and the extension portions, the mold is further moved along the movement direction, whereby the mold presses the vertical wall equivalent portions of the multiple plate materials to form the top plate portion and the vertical wall portion.

[0011] According to this manufacturing method, the top plate portion and the vertical wall portion can be formed after the die is brought into contact with the extension portion to bend the multiple plate materials. In other words, the top plate portion and the vertical wall portion are formed after the multiple plate materials are slightly bent. This makes it difficult for the vertical wall portions to bend back.

[0012] In one aspect of the present disclosure, the mold may include a vertical wall forming portion and a shoulder portion. The vertical wall forming portion is a portion for forming the vertical wall portion. The shoulder portion is a portion of the mold that first comes into contact with the blank (i.e., the first member and the second member). The shoulder portion is located closer to the movement direction than the end portion of the vertical wall forming portion on the movement direction side, and has a surface that is outside the vertical wall forming portion and has a larger angle with respect to the movement direction than the vertical wall portion. Furthermore, when bending, the second end portion may be located inside the shoulder portion, and the shoulder portion may come into contact with the extension portion, thereby bending the vertical wall corresponding portions and the extension portions of the multiple plate materials toward the movement direction.

[0013] This manufacturing method allows the shoulders to contact the extensions to deflect the plates, and by appropriately configuring the shape of the shoulders, the extent to which the first and second members are deflected can be appropriately set.

[0014] In one aspect of the present disclosure, the mold may be a step shape having a top plate portion and multiple surfaces that are approximately horizontal. In this case, the mold may have a first surface and a second surface as the multiple surfaces. The first surface is a surface on the front side in the movement direction. The second surface is a surface on the rear side in the movement direction. When performing the bending, the second surface may contact the extension portion to bend the vertical wall equivalent portions and extension portions of the multiple plate materials toward the movement direction. Furthermore, when forming the top plate portion and the vertical wall portions, the first surface may contact the extension portion to form a flange portion extending outward from the vertical wall portion.

[0015] According to this manufacturing method, even when manufacturing a molded product having a flange portion, it is possible to bend a plurality of plate materials and then mold the top plate portion and the vertical wall portion. In one aspect of the present disclosure, when forming the top plate portion and the vertical wall portion, the forming of the flange portion may be completed inside the shoulder portion. Note that the forming of the flange portion may be started while the shoulder portion is in contact with the flange portion, and then the forming may be completed inside the shoulder portion.

[0016] According to this manufacturing method, the shoulder portion can be brought into contact with the multiple plate materials from a more outer side, so that the top plate portion, vertical wall portion, and flange portion can be formed after the multiple plate materials have been sufficiently bent.

[0017] In one embodiment of the present disclosure, the second member may have a thickness equal to or greater than that of the first member. According to this manufacturing method, the second moment of area of ​​the first member is likely to be equal to or less than the second moment of area of ​​the second member, which makes it easier to obtain the effect of bending the first member. As a result, the first member is less likely to bend back, and a gap between the first member and the second member is less likely to occur.

[0018] In one aspect of the present disclosure, after the top plate portion and the vertical wall portion are formed, the first member and the second member may be welded to the vertical wall portion. According to this manufacturing method, the vertical wall portion is configured to be less likely to bend back, so the gap between the first member and the second member is small, which allows for smooth welding.

[0019] In one aspect of the present disclosure, the molded article may be an automobile part. According to this manufacturing method, a molded article to be used as an automobile part can be successfully manufactured. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1A is a perspective view showing an example of a press-formed product, and FIG. 1B is a cross-sectional view of the press-formed product. [Figure 2] FIG. 2A is a cross-sectional view showing a state before press-molding in the method for manufacturing a press-molded product, and FIG. 2B is a cross-sectional view showing a state in which the top plate portion is held. [Figure 3] 1 is a flowchart showing a method for manufacturing a press-formed product. [Figure 4] 4A and 4B are plan and cross-sectional views of the plate material before press forming. [Figure 5] FIG. 5A is a cross-sectional view showing a state in which the press-molded product is bent in the manufacturing method thereof, and FIG. 5B is a cross-sectional view showing a state in which pressing is completed. [Figure 6] FIG. 6A is a cross-sectional view of the manufacturing device of the first modified example, showing the state before press molding, and FIG. 6B is a cross-sectional view showing the state after press molding. [Figure 7] FIG. 7A is a cross-sectional view of the manufacturing device of the second modified example, showing the state before press molding, and FIG. 7B is a cross-sectional view showing the state after press molding. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. Embodiment] [1-1. Composition of press-molded products] <Outline of press-molded products> The molded product 1 shown in Figures 1A and 1B is a press-molded product obtained by pressing a plurality of stacked plate materials. The molded product 1 is used as an automobile component such as a front pillar, rocker, or center pillar, or as other automobile pillar or frame part. The molded product 1 and its manufacturing method can be applied not only to automobile component parts, but also to various other parts and products.

[0022] The formed product 1 is obtained by performing press forming, including bending, on a first member 10 and a second member 20 made of steel plate. Before press forming, the first member 10 and the second member 20 are blanks obtained by cutting out, for example, a rolled steel plate. The first member 10 and the second member 20 are made of, for example, a cold-rolled steel plate, a hot-rolled steel plate, or a galvannealed steel plate. In this embodiment, a galvannealed steel plate is used. The first member 10 and the second member 20 may have a thickness of 0.6 mm to 2.0 mm. For example, the thickness of the first member 10 and the second member 20 is 1.0 mm. In the present disclosure, the applicable range of tensile strength for the first member 10 and the second member 20 is 270 MPa to 1470 MPa. Within this applicable range, the effects of the present disclosure can be obtained, and more preferably, a range of 980 MPa to 1470 MPa facilitates the generation of gaps and the benefits of the present disclosure. In this embodiment, the tensile strength of the first member 10 and the second member 20 is, for example, about 1470 MPa.

[0023] Here, the first member 10 and the second member 20 may be set to different thicknesses. In particular, the thickness of the second member 20 may be set to be thicker than the thickness of the first member 10. In this case, for example, the thickness of the first member 10 may be set to 0.8 mm, and the thickness of the second member 20 may be set to 1.2 mm, etc. Below, a configuration in which the thickness of the second member 20 is set to be thicker than the thickness of the first member 10 will be described.

[0024] <Overall shape of press-molded product> The molded product 1 is formed into a tall saddle shape. The saddle shape has vertical wall portions 12, 22 extending on both sides of top plate portions 11, 21 in a direction intersecting the top plate portions 11, 21. The molded product 1 is used to cover long objects such as cables and pillar-like members along their length, or to be attached to another plate material to reinforce the plate material.

[0025] The molded product 1 is obtained by processing a plurality of plate materials. The plurality of plate materials include a first member 10 and a second member 20. Hereinafter, the first member 10 and the second member 20 will also be collectively referred to as two plate materials.

[0026] The first member 10 has a top plate portion 11, a vertical wall portion 12, and a flange portion 13. The second member 20 is placed under the first member 10 and stacked thereon, and in FIG. 1, for ease of explanation, the top plate portion 11 is shown as the upper part of the molded product 1. However, the molded product 1 can be used in any position. For example, the molded product 1 may be used in a position that is upside down from the position shown in FIG. 1.

[0027] The top plate portion 11 is generally flat and generally rectangular in plan view. The length of the top plate portion 11 in the width direction (i.e., the left-right direction in FIG. 1B) is, for example, about 150 mm, and the length in the depth direction (b in FIG. 4A) is, for example, about 350 mm. Two welds 11J are formed in the center of the top plate portion 11. At the welds 11J, the top plate portions 11, 21 of the first member 10 and the second member 20 are joined by spot welding. Note that the plane on which the top plate portion 11 is located may hereinafter be simply referred to as the top plate portion 11.

[0028] The top panel 11 has two folded portions along its two opposing sides. Each of these folded portions includes a vertical wall portion 12. The vertical wall portion 12 is flat and adjacent to the top panel 11, connecting to the top panel 11 and extending from the top panel 11 in a direction intersecting the plane on which the top panel 11 is located. The length of the vertical wall portion 12 (i.e., the height from the top panel 11 to the flange portion 13) is, for example, about 60 mm.

[0029] A plurality of welds 12J are also formed on the vertical wall portions 12, 22. Four welds 12J are formed on the vertical wall portions 12, 22. The molded product 1 is joined by a total of six welds 11J, 12J, including the two welds 11J on the top plate portions 11, 21.

[0030] The flange portion 13 is configured to protrude from the tip of the vertical wall portion 12. In other words, the flange portion 13 extends outward from the tip of the vertical wall portion 12. The flange portion 13 extends generally parallel to the top plate portion 11. The flange portion 13 is substantially flat and substantially rectangular in plan view. The width of the flange portion 13 is, for example, about 20 mm.

[0031] 1B, the molded article 1 of this embodiment is bilaterally symmetrical, and therefore the following description may focus on only one side. However, the molded article 1 does not have to be bilaterally symmetrical. 1B, the end of the first member 10 in the width direction is referred to as a first end 13E, and the end of the second member 20 in the width direction is referred to as a second end 22E. The second member 20 does not reach the flange portion 13 of the first member 10, and the second end 22E is located midway along the vertical wall portion 12 of the first member 10. In other words, the vertical wall portion 22 of the second member 20 is set shorter than the vertical wall portion 12 of the first member 10.

[0032] 1B, the region of the first member 10 from the first end 13E to the overlapping portion of the second end 22E is defined as the extension portion 14. The extension portion 14 includes a part of the vertical wall portion 12 of the first member 10 (i.e., the portion closer to the flange portion 13 than the second end 22E) and the flange portion 13.

[0033] Note that, with regard to the two plate materials, the portions corresponding to the entire top plate portions 11, 21 of the molded product 1 before the main molding (S50) described below are also referred to as "top plate corresponding portions." Similarly, the portions corresponding to a part of the vertical wall portion 12 of the molded product 1 (i.e., the portion closer to the top plate portion 11 than the second end portion 22E) and the entire vertical wall portion 22 are also referred to as "vertical wall corresponding portions."

[0034] As shown in Figure 1B, etc., in any plane parallel to two plate members (e.g., top plate portions 11, 21), the direction from the vertical wall equivalent portion toward the top plate equivalent portion is defined as the inside, and the direction from the vertical wall equivalent portion toward the opposite side of the top plate equivalent portion is defined as the outside.

[0035] [1-2. Press forming equipment] 2A and 2B are cross-sectional views of a press forming apparatus 100 for forming the formed product 1. The press forming apparatus 100 includes a first mold 40 as a punch, a second mold 50 as a die, and a blank holder 60. The first mold 40 and the second mold 50 are configured to be relatively displaceable along the height direction of the formed product 1 by a drive mechanism (not shown). The height direction of the formed product 1 is, for example, a direction perpendicular to the top plate portion 11, which is the vertical direction in FIG. 2A. The press forming apparatus 100 is configured so that the second mold 50 displaces along the height direction without displacing the first mold 40. The direction in the height direction that the second mold 50 moves during pressing is referred to as the movement direction M. However, the first mold 40 may be displaced in the height direction, or both the second mold 50 and the first mold 40 may be displaced in the height direction.

[0036] The blank holder 60 is attached to the second die 50 so as to face the first die 40, and is disposed vertically above the first die 40. A mechanism such as a gas cylinder is built into the second die 50. The blank holder 60 is configured to be lowered by the mechanism such as the gas cylinder at the same time that the second die 50 starts to move vertically, so that the blank holder 60 can sandwich the first member 10 and the second member 20 before they are formed between the first die 40 and the blank holder 60 before the second die 50 comes into contact with the two plate materials.

[0037] The second die 50, the first die 40, and the blank holder 60 work together to perform press forming. The second die 50 and the first die 40 can be engaged with each other and face each other while being spaced apart before press forming. As an example, the second die 50 has a concave shape, and the first die 40 has a convex shape.

[0038] The first mold 40 and the second mold 50 each have a shape that follows the shape of the molded product 1. Specifically, the first mold 40 and the second mold 50 each include vertical wall molding portions 41, 51, flange molding portions 42, 52, depth extension portions 43, 53, and shoulder portions 44, 54. The vertical wall molding portions 41, 51 are portions for molding the vertical wall portions 12, 22. The flange molding portions 42, 52 are portions for molding the flange portion 13. The depth extension portions 43, 53 are wall-shaped portions that extend generally vertically and connect the flange molding portions 42, 52 and the shoulder portions 44, 54.

[0039] The shoulder portions 44, 54 are surfaces parallel to the flange molding portions 42, 52 and are located outward of the flange molding portions 42, 52 and toward the moving direction M. The shoulder portions 44, 54 are located closer to the moving direction than the end of the vertical wall molding portion 51 on the moving direction side, and are located outward of the vertical wall molding portions 41, 51.

[0040] Furthermore, the shoulder portions 44, 54 have surfaces that form a larger angle with respect to the movement direction M than the vertical wall portions 12, 22. In other words, the angle formed between the movement direction M (i.e., the vertical line) and the surface (e.g., a surface extending generally horizontally) that constitutes the shoulder portions 44, 54 is set to be larger than the angle formed between the movement direction M and the surface (e.g., a surface extending generally vertically) that constitutes the vertical wall portions 12, 22.

[0041] In this way, the second mold 50 is configured to have a step shape. The step shape is a shape having a plurality of surfaces (for example, a flange forming portion 52 and a shoulder portion 54) that are substantially horizontal to the top plate portions 11 and 21.

[0042] [1-3. Manufacturing methods for press-molded products] Next, a description will be given of a method for manufacturing the molded product 1. In this embodiment, the molded product 1 is manufactured by following the procedure shown in FIG.

[0043] 3, the manufacturing method of the molded product 1 begins with blanking in S10. Blanking is a process of cutting out a blank material that will be used to make the molded product 1, for example, by cutting out a rolled steel plate. At this time, the second member 20 is cut out so that it is shorter in length than the first member 10.

[0044] Next, in S20, the top plate portions 11, 21 of the two plate materials, i.e., the first member 10 and the second member 20, are joined by welding. Here, during welding, the two plate materials are arranged so that the second member 20 is hidden by the first member 10 in a plan view, as shown in FIG. 4A. Specifically, the second end 22E, which is an end of the second member 20, is arranged so as to be located more inward than the first end 13E, which is an end of the first member 10, and in this state, two welded portions 11J are formed.

[0045] In the configuration of this embodiment, the first member 10 and the second member 20 are made of the same material, and as shown in Fig. 4B, the thickness t1 of the second member 20 is set to be larger than the thickness t0 of the first member 10. In this case, when comparing the second moments of area, bt0 3 / 12≦bt1 3 / 12 and the second moment of area of ​​the first member 10 becomes equal to or less than the second moment of area of ​​the second member 20. At this time, it is believed that the effect of bending the first member 10 is more easily obtained. It is also believed that the amount of bending back of the first member 10 becomes equal to or less than the amount of bending back of the second member 20. Note that b is the width of the material (for example, the length in the depth direction in FIG. 2A). In other words, when the first member 10 and the second member 20 are made of the same material, it is believed that the gap between the vertical wall portions 12, 22 will become smaller if the thickness t1 of the second member 20 is equal to or greater than the thickness t0 of the first member 10.

[0046] Next, in S30, the top plate portions 11, 21 of the two plate materials on which the welded portion 11J has been formed are fixed. That is, with a gap formed between the blank holder 60 and the first die 40, the two plate materials on which the welded portion 11J has been formed are placed on the first die 40 as shown in FIG. 2A. At this time, the first member 10 is positioned closer to the second die 50 than the second member 20 (i.e., vertically above). When viewed along the movement direction M, the second end portion 22E is positioned more inward than the shoulder portion 54. This is so that the shoulder portion 54 comes into contact with the extension portion 14.

[0047] 2B, the blank holder 60 is moved along the movement direction M to close the gap between the blank holder 60 and the first die 40. In this way, the top plate portions 11, 21 of the two plate materials are fixed by the blank holder 60 and the first die 40.

[0048] Next, in S40, deflection is imparted to the two plate materials. With the top plate portions 11, 21 fixed using the blank holder 60, the second mold 50 is moved along the movement direction M, and as shown in FIG. 2B, the shoulder portion 54 comes into contact with the extension portion 14. At this time, the vertical wall forming portion 51, the flange forming portion 52, and the depth extension portion 53 do not come into contact with the first member 10.

[0049] Then, when the second mold 50 is further moved from the state of FIG. 2B along the movement direction M, the two plate materials are pressed by the second mold 50 and transition to a bent state as shown in FIG. 5A. Next, in S50, the actual forming is performed. When the second mold 50 is further moved from the state shown in Fig. 5A along the movement direction M, the deflection of the two plate materials becomes even greater, and eventually the vertical wall forming portions 41, 51 and the flange forming portions 42, 52 sandwich the two plate materials, and the press working is completed as shown in Fig. 5B.

[0050] Next, in S60, the vertical wall portions 12, 22 are welded. That is, after bending the vertical wall portions 12, 22, a plurality of welded portions 12J are formed. When the welding of the vertical wall portions 12, 22 is completed, the molded product 1 is completed. After welding the vertical wall portions 12, 22, drilling, trimming, etc. may be performed.

[0051] [1-4. Consideration of mold shape] Here, the length L of the flange molding portions 42, 52 in the first mold 40 and the second mold 50 and the depth D of the depth extension portions 43, 53 were changed, and the results of measuring the size of the gap between the vertical wall portions 12, 22 are shown in Table 1 below.

[0052] 2A, length L indicates the horizontal length of flange forming portions 42, 52, and depth D indicates the vertical length of depth extension portions 43, 53. The gap value was measured at the position of weld 12J.

[0053] [Table 1]

[0054] The results showed a tendency for the size of the gap to increase as the length L increased, as shown in Table 1. It is thought that a smaller length L allows for a larger amount of deformation when bending the two plate materials, resulting in a smaller gap.

[0055] Furthermore, the results of this study showed a tendency for the size of the gap to decrease as the depth D increases. However, increasing the depth D increases the size of the first mold 40 and the second mold 50, resulting in increased costs. For this reason, it is considered preferable to set the depth D to approximately the vertical length of the vertical wall portions 12, 22.

[0056] [1-5.Effects] According to the embodiment described above in detail, the following effects are achieved. (1a) In the manufacturing method of the molded product 1 described above, the first member 10 and the second member 20 are joined by welding the top plate-equivalent portions in a state where the first member 10 is overlapped with the second member 20 so that the first member 10 has the extension portions 14. Then, with the joined top plate-equivalent portions sandwiched between them, the second mold 50 is moved along the movement direction M, bringing the second mold 50 into contact with the extension portions 14, thereby deflecting the vertical wall-equivalent portions and the extension portions 14 of the multiple plate materials in the movement direction. At this time, the second mold 50 is brought into contact with the extension portions 14 without coming into contact with any portion of the first member 10 other than the extension portions 14.

[0057] Furthermore, while the second mold 50 is bending the vertical wall equivalent portions and the extension portions 14, the second mold 50 is further moved along the movement direction, whereby the second mold 50 presses the vertical wall equivalent portions of the multiple plate materials, thereby forming the top plate portions 11, 21 and the vertical wall portions 12, 22.

[0058] According to this manufacturing method, the second mold 50 is brought into contact with the extension portion 14 to bend the multiple plate materials, and then the top plate portions 11, 21 and the vertical wall portions 12, 22 are formed. In other words, the multiple plate materials are slightly bent before the top plate portions 11, 21 and the vertical wall portions 12, 22 are formed. This makes it possible to prevent the vertical wall portions 12, 22 from bending back. By preventing the vertical wall portions 12, 22 from bending back, the gap between the vertical wall portions 12, 22 becomes smaller, and operations such as welding after press working can be carried out smoothly.

[0059] (1b) In one aspect of the present disclosure, the shoulder portion 54 is located closer to the movement direction than the end of the vertical wall molding portion 51 on the movement direction side, and has a surface that is outside the vertical wall molding portion 51 and has a larger angle with respect to the movement direction than the vertical wall portions 12, 22. Furthermore, when bending, the second end portion 22E is located inside the shoulder portion 54, and the shoulder portion 54 comes into contact with the extension portion 14, thereby bending the vertical wall equivalent portions of the multiple plate materials and the extension portion 14 toward the movement direction. According to this manufacturing method, it is possible to realize a configuration in which the shoulder portion 54 comes into contact with the extension portion 14 to deflect the plurality of plate materials.

[0060] (1c) In one aspect of the present disclosure, the second mold 50 has a step shape. The second mold 50 also has a flange forming portion 52 and a shoulder portion 54 as multiple surfaces that form the step shape. When bending, the shoulder portion 54 comes into contact with the extension portion 14, thereby bending the vertical wall portions of the multiple plate materials and the extension portion 14 toward the movement direction. When forming the top plate portions 11, 21 and the vertical wall portions 12, 22, the flange forming portion 52 comes into contact with the extension portion 14, thereby forming the flange portion 13 that extends outward from the vertical wall portions 12, 22. According to this manufacturing method, even when manufacturing the molded product 1 having the flange portion 13, the top plate portions 11, 21 and the vertical wall portions 12, 22 can be formed after bending a plurality of plate materials.

[0061] (1d) In one aspect of the present disclosure, when forming the top plate portions 11, 21 and the vertical wall portions 12, 22, the flange portion 13 is completed forming inside the shoulder portion 54. Note that the flange portion 13 may be started forming while it is in contact with the shoulder portions 54, 72, 82, and then the forming may be completed inside the shoulder portions 54, 72, 82.

[0062] According to this manufacturing method, the shoulder portion 54 can be brought into contact with the plurality of plate materials from a more outer side, so that the top plate portions 11, 21 and the vertical wall portions 12, 22 can be formed after the plurality of plate materials have been sufficiently bent.

[0063] (1e) In one embodiment of the present disclosure, the second member 20 may have a thickness equal to or greater than that of the first member 10. According to this manufacturing method, the second moment of area of ​​the first member 10 tends to be equal to or less than the second moment of area of ​​the second member 20, which makes it easier to obtain the effect of bending the first member 10. Therefore, the first member 10 is less likely to bend back, and a configuration can be achieved in which a gap between the first member 10 and the second member 20 is less likely to occur.

[0064] (1f) In one aspect of the present disclosure, after the top plate portions 11, 21 and the vertical wall portions 12, 22 are formed, the first member 10 and the second member 20 are welded to the vertical wall portions 12, 22. According to this manufacturing method, the vertical wall portions 12, 22 are configured to be less likely to bend back, thereby reducing the gap between the first member 10 and the second member 20. This allows for smooth welding.

[0065] (1g) In one embodiment of the present disclosure, the molded article 1 may be an automobile part. According to this manufacturing method, it is possible to successfully manufacture the molded article 1 that is used as an automobile part.

[0066] 2. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0067] (2a) In the above embodiment, the press forming apparatus 100 of the embodiment is used. However, for example, a press forming apparatus 110 of a first modified example shown in FIGS. 6A and 6B may be used. In the press forming apparatus 100 of the embodiment, a configuration in which the second die 50 moves along the vertical direction is exemplified. However, the press forming apparatus 110 of the first modified example includes a second die 70 as a cam instead of the second die 50. The second die 70 includes a vertical wall forming portion 71 and a flange forming portion 72 (shoulder portion in the present disclosure). Furthermore, the first die 40 includes only the vertical wall forming portion 41 and the flange forming portion 42.

[0068] 6A, the second mold 70 is set so that the movement direction M approaches the two plate materials from diagonally above. That is, the movement direction M of the second mold 70 is a direction that combines a vertically downward component and a component in a direction from the outside to the inside.

[0069] In this configuration, when the second mold 70 moves along the movement direction M, the flange forming portion 72 first comes into contact with the extension portion 14 as shown by the two-dot chain line in Fig. 6A, and then the two plate materials are bent as the second mold 70 moves. Then, as shown in Fig. 6B, the vertical wall portions 12, 22 and the flange portion 13 are formed.

[0070] (2b) For example, a press forming apparatus 120 of a second modified example shown in Figures 7A and 7B may be used instead of the press forming apparatus 100 of the embodiment. The press forming apparatus 120 of the second modified example is an apparatus for obtaining a formed product without a flange portion 13, i.e., a formed product having only top plate portions 11, 21 and vertical wall portions 12, 22.

[0071] The press molding apparatus 120 of the second modified example includes a second mold 80 instead of the second mold 50. The second mold 80 includes a vertical wall molding portion 81 and a shoulder portion 82. While the shoulder portion 54 of the embodiment extends horizontally, the shoulder portion 82 of the second modified example includes an inclined surface that slopes outward toward the movement direction M. The shoulder portion 82 is also configured to have a surface that forms a larger angle with respect to the movement direction M than the vertical wall portions 12, 22. Even with this configuration, the shoulder portion 82 comes into contact with the two plate materials before the vertical wall forming portion 81 comes into contact with the two plate materials, so the two plate materials can be bent before press forming, thereby making it possible to make it less likely for unbending to occur.

[0072] (2c) Alternatively, the second mold 50 may have a shoulder portion configured as a curved surface. In this case, the angle between a plane extending along a tangent to the curved surface and the movement direction M may be set to be larger than the angle between a plane extending along the vertical wall portions 12, 22 and the movement direction M. Even with this configuration, the two plate materials can be bent and then press-formed.

[0073] (2d) Although the molded article 1 has been illustrated as having a saddle-shaped configuration with vertical wall portions 12, 22 on both sides of the top plate portions 11, 21, the configuration is not limited to this. For example, the molded article 1 may have a one-sided bent shape with vertical wall portions 12, 22 on only one side of the top plate portions 11, 21.

[0074] (2e) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0075] (2f) The present disclosure is not limited to the manufacturing method of the molded product described above, and can be realized in various forms, such as a molded product having a top plate portion and a vertical wall portion.

[0076] [Technical idea disclosed in this specification] [Item 1] A method for manufacturing a molded product, in which a plurality of stacked plate materials are pressed to obtain a molded product having a top plate portion and a vertical wall portion, The plurality of plate members include a first member and a second member, The first member has a top plate equivalent portion that represents a portion that corresponds to a top plate portion of the molded product, a vertical wall equivalent portion that represents a portion that corresponds to at least a part of a vertical wall portion of the molded product, and an extension portion, The second member is in a state of being stacked on the first member, and has the top plate equivalent portion and the vertical wall equivalent portion, In any plane parallel to the plurality of plate members, the direction from the vertical wall equivalent portion toward the top plate equivalent portion is defined as the inside, and the direction from the vertical wall equivalent portion toward the opposite side of the top plate equivalent portion is defined as the outside, and the outer end of the first member is defined as the first end, and the outer end of the second member is defined as the second end, the first end is located further outward than the second end, the extension portion indicates a region of the first member from the first end portion to a portion where the second end portion overlaps, The manufacturing method includes: a moving direction from the first member side toward the second member side; In a state where the first member is overlapped with the second member so as to have the extension portion, the top plate equivalent portion is welded to join the first member and the second member; a mold is moved along the movement direction while clamping the top plate equivalent portion after the joining, so that the mold comes into contact with the extension portion, thereby bending the vertical wall equivalent portion and the extension portion of the plurality of plate materials toward the movement direction; In a state where the mold bends the vertical wall equivalent portions and the extension portions, the mold is further moved along the movement direction, thereby pressing the vertical wall equivalent portions of the plurality of plate materials with the mold to form the top plate portion and the vertical wall portion; A method for manufacturing a molded product in which the above is carried out. [Item 2] A method for producing a molded article according to item 1, The mold is a vertical wall molding portion for molding the vertical wall portion; a shoulder portion that is located closer to the moving direction than the end of the vertical wall molding portion that is closer to the moving direction, and that has a surface that is at a larger angle with respect to the moving direction than the vertical wall portion, on the outer side of the vertical wall molding portion; Equipped with When the bending is performed, the second end portion is disposed on the inner side of the shoulder portion, and the shoulder portion comes into contact with the extension portion, thereby bending the vertical wall equivalent portions and the extension portions of the plurality of plate materials toward the movement direction. Manufacturing method of molded products. [Item 3] A method for producing a molded article according to item 1 or 2, the mold has a step shape having a plurality of surfaces that are substantially horizontal to the top plate portion, The plurality of surfaces include a first surface on the front side in the movement direction and a second surface on the back side in the movement direction, When the bending is performed, the second surface contacts the extension portion, thereby bending the vertical wall equivalent portions and the extension portions of the plurality of plate materials toward the movement direction, When the top plate portion and the vertical wall portion are formed, the first surface comes into contact with the extension portion, thereby forming a flange portion extending outward from the vertical wall portion. Manufacturing method of molded products. [Item 4] A method for producing a molded article according to item 2 or item 3 that references item 2, When the top plate portion and the vertical wall portion are formed, the flange portion extending outward from the vertical wall portion is completed to be formed on the inner side of the shoulder portion. Manufacturing method of molded products. [Item 5] A method for producing a molded article according to any one of items 1 to 4, The second member has a thickness equal to or greater than that of the first member. Manufacturing method of molded products. [Item 6] A method for producing a molded article according to any one of items 1 to 5, After forming the top plate portion and the vertical wall portion, welding the first member and the second member to the vertical wall portion; A method for manufacturing a molded article, further comprising the steps of: [Item 7] A method for producing a molded article according to any one of items 1 to 6, The molded article is an automobile part. Manufacturing method of molded products. [Explanation of symbols]

[0077] 1...molded product, 10...first member, 11,21...top plate portion, 11J,12J...welded portion, 12,22...vertical wall portion, 13...flange portion, 13E...first end portion, 14...extension portion, 20...second member, 22E...second end portion, 40,70...first die, 41,51,71,81...vertical wall forming portion, 42,52,72...flange forming portion, 43,53...extension portion, 44,54,82...shoulder portion, 50,70...second die, 60...blank holder, 100,110,120...press forming device.

Claims

1. A method for manufacturing a molded product, in which a plurality of stacked plate materials are pressed to obtain a molded product having a top plate portion and a vertical wall portion, The plurality of plate members include a first member and a second member, The first member has a top plate equivalent portion that represents a portion that corresponds to a top plate portion of a molded product, a vertical wall equivalent portion that represents a portion that corresponds to at least a part of a vertical wall portion of the molded product, and an extension portion, the second member is in a state of being stacked on the first member, and has the top plate equivalent portion and the vertical wall equivalent portion; In any plane parallel to the plurality of plate members, the direction from the vertical wall equivalent portion toward the top plate equivalent portion is defined as the inside, and the direction from the vertical wall equivalent portion toward the opposite side of the top plate equivalent portion is defined as the outside, and the outer end of the first member is defined as the first end, and the outer end of the second member is defined as the second end, the first end is located further outward than the second end, the extension portion indicates a region of the first member from the first end portion to a portion where the second end portion overlaps, The manufacturing method includes: defining a direction from the first member side toward the second member side as a movement direction; In a state where the first member is overlapped with the second member so as to have the extension portion, the top plate equivalent portion is welded to join the first member and the second member; a mold is moved along the movement direction while clamping the top plate equivalent portion after the joining, so that the mold comes into contact with the extension portion, thereby bending the vertical wall equivalent portion and the extension portion of the plurality of plate materials toward the movement direction; In a state where the mold bends the vertical wall equivalent portions and the extension portions, the mold is further moved along the movement direction, thereby pressing the vertical wall equivalent portions of the plurality of plate materials with the mold to form the top plate portion and the vertical wall portion; A method for manufacturing a molded product in which the above is carried out.

2. A method for producing the molded article according to claim 1, The mold is a vertical wall molding portion for molding the vertical wall portion; a shoulder portion that is located closer to the moving direction than the end of the vertical wall molding portion that is closer to the moving direction, and that has a surface that is at a larger angle with respect to the moving direction than the vertical wall portion, on the outer side of the vertical wall molding portion; Equipped with When the bending is performed, the second end portion is disposed on the inner side of the shoulder portion, and the shoulder portion comes into contact with the extension portion, thereby bending the vertical wall equivalent portion and the extension portion of the plurality of plate materials toward the movement direction. Manufacturing method of molded products.

3. A method for producing the molded article according to claim 1 or claim 2, the mold has a step shape having a plurality of surfaces that are substantially horizontal to the top plate portion, The plurality of surfaces include a first surface on a front side in the movement direction and a second surface on a rear side in the movement direction, When the bending is performed, the second surface contacts the extension portion, thereby bending the vertical wall equivalent portions and the extension portions of the plurality of plate materials toward the movement direction, When the top plate portion and the vertical wall portion are formed, the first surface comes into contact with the extension portion, thereby forming a flange portion extending outward from the vertical wall portion. Manufacturing method of molded products.

4. A method for producing the molded product according to claim 2, When the top plate portion and the vertical wall portion are formed, the flange portion extending outward from the vertical wall portion is completed to be formed on the inner side of the shoulder portion. Manufacturing method of molded products.

5. A method for producing the molded article according to claim 1 or claim 2, The second member has a thickness equal to or greater than that of the first member. Manufacturing method of molded products.

6. A method for producing the molded article according to claim 1 or claim 2, After forming the top plate portion and the vertical wall portion, welding the first member and the second member to the vertical wall portion; A method for manufacturing a molded article, further comprising the steps of:

7. A method for producing the molded article according to claim 1 or claim 2, The molded article is an automobile part. Manufacturing method of molded products.

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