Manufacturing method for molded products

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 product.

Background Art

[0002] For example, Patent Document 1 below discloses a technique for obtaining a molded product by pressing a plurality of plate materials in a stacked state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When obtaining a molded product having a top plate portion and a vertical wall portion by pressing a plurality of plate materials in a stacked state as in the technique of Patent Document 1 above, there is a problem that a gap is likely to occur between the plurality of plate materials due to springback in which the bent material tends to deform in the direction of returning to its original state. If the gap between the plurality of plate materials becomes large after pressing, inconveniences may occur during subsequent operations such as welding and assembly.

[0005] One aspect of the present disclosure is to reduce the amount by which the plate material is springbacked during pressing in a method for manufacturing a molded product that presses a plurality of plate materials in a stacked state to obtain a molded product having a top plate portion and a vertical wall portion.

Means for Solving the Problems

[0006] One aspect of the present disclosure is a method for manufacturing a molded product that presses a plurality of plate materials in a stacked state to obtain a molded product having a top plate portion and a vertical wall portion. In the method for manufacturing a molded product, a first member and a second member are provided as the plurality of plate materials.

[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 the part corresponding to the top plate portion of the molded product. The vertical wall equivalent portion represents the part 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 in a state where it is superimposed on the first member.

[0008] In any plane parallel to multiple boards, the direction from the vertical wall portion toward the top plate portion is defined as the inside, and the direction from the vertical wall portion toward the opposite side of the top plate portion is defined as the outside. Furthermore, 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 out than the second end. The extension portion refers to the area from the first end of the first member to the overlapping part of the second end.

[0009] In this manufacturing method, the first and second members are joined by welding the top plate portion while the first member is superimposed on the second member so that the first member has an extended portion, with the direction of movement being from the first member to the second member. Furthermore, while the top plate portion after joining is held in place, the mold is moved along the direction of movement, causing the mold to come into contact with the extended portion and causing the vertical wall portions and extended portions of the multiple plate materials to bend in the direction of movement.

[0010] Furthermore, by moving the mold further along the direction of movement while the mold is flexing the vertical wall portion and the extended portion, the mold presses against the vertical wall portions of multiple sheet materials, thereby forming the top plate portion and the vertical wall portion.

[0011] This manufacturing method allows the top plate and vertical wall sections to be formed after the mold is brought into contact with the extension section and the multiple sheet metal pieces are bent. In other words, the top plate and vertical wall sections are formed after the multiple sheet metal pieces are slightly bent. This makes it less likely for the vertical wall sections to unbend.

[0012] In one aspect of this disclosure, the mold may include a vertical wall forming section and a shoulder section. The vertical wall forming section is the part for forming the vertical wall section. The shoulder section is the part of the mold that first comes into contact with the blank material (i.e., the first and second members). The shoulder section is located on the side of the direction of movement side of the end of the vertical wall forming section on the direction of movement side, and has a surface that is outside the vertical wall forming section and has an angle greater than that of the vertical wall section with respect to the direction of movement. Furthermore, when bending is performed, the second end may be positioned inside the shoulder section, and the shoulder section may come into contact with the extension section, thereby bending the vertical wall equivalent sections and extension sections of the multiple plate materials in the direction of movement.

[0013] This manufacturing method makes it possible to create a configuration in which multiple plate materials are bent by the shoulder portion touching the extended portion. Furthermore, by appropriately setting the shape of the shoulder portion, the degree to which the first and second members are bent can be precisely controlled.

[0014] In one aspect of this disclosure, the mold may have a stepped shape having a plurality of surfaces substantially horizontal to the top plate portion. In this case, the mold may have a first surface and a second surface as the plurality of surfaces. The first surface is the surface on the front side in the direction of movement. The second surface is the surface on the back side in the direction of movement. When bending is performed, the second surface may touch the extension portion, thereby bending the vertical wall portions and extension portions of the plurality of plate materials toward the direction of movement. Also, when forming the top plate portion and the vertical wall portion, the first surface may touch the extension portion, thereby forming a flange portion that extends outward from the vertical wall portion.

[0015] With this manufacturing method, even when manufacturing a molded product having a flange portion, multiple sheet metals can be bent before forming the top plate portion and vertical wall portion. In one aspect of this disclosure, when forming the top plate portion and the vertical wall portion, the flange portion may be formed inward of the shoulder portion. Alternatively, the flange portion may be formed while in contact with the shoulder portion, and then completed inward of the shoulder portion.

[0016] According to such a manufacturing method, since the shoulders can be brought into contact with the plurality of plate materials from the outside, the top plate portion, the vertical wall portion, and the flange portion can be formed after sufficiently bending the plurality of plate materials.

[0017] In one aspect of the present disclosure, the second member may have a plate thickness greater than or equal to that of the first member. According to such a manufacturing method, since the second moment of area of the first member is likely to be less than or equal to the second moment of area of the second member, the effect of bending the first member can be easily obtained. Therefore, the first member is less likely to experience springback, and a gap between the first member and the second member can be configured to be less likely to occur.

[0018] In one aspect of the present disclosure, after forming the top plate portion and the vertical wall portion, the first member and the second member may be welded at the vertical wall portion. According to such a manufacturing method, since the vertical wall portion is configured to be less likely to experience springback, the gap between the first member and the second member becomes small. Therefore, the welding operation can be performed well.

[0019] In one aspect of the present disclosure, the molded product may be an automotive part. According to such a manufacturing method, a molded product applied to automotive parts can be manufactured well.

Brief Description 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 the state before press forming in the manufacturing method of the press-formed product, and FIG. 2B is a cross-sectional view showing the state in which the top plate portion is held. [Figure 3] It is a flowchart showing a manufacturing method of a press-formed product. [Figure 4] FIG. 4A is a plan view showing a plate material before press forming. FIG. 4B is a cross-sectional view of the plate material before press forming. [Figure 5] FIG. 5A is a cross-sectional view showing the bent state in the manufacturing method of the press-formed product, and FIG. 5B is a cross-sectional view showing the state in which the press is completed. [Figure 6] FIG. 6A is a cross-sectional view showing a state before press forming of a manufacturing apparatus according to a first modification, and FIG. 6B is a cross-sectional view showing a state after press forming. [Figure 7] FIG. 7A is a cross-sectional view showing a state before press forming of a manufacturing apparatus according to a second modification, and FIG. 7B is a cross-sectional view showing a state after press forming.

Mode for Carrying Out the Invention

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

[0022] The molded product 1 is obtained by press forming, including bending, of a first member 10 and a second member 20 made of steel sheets. Before press forming, the first member 10 and the second member 20 are blank materials obtained, for example, by cutting out a roll of steel sheet. The first member 10 and the second member 20 are made of, for example, cold-rolled steel sheet, hot-rolled steel sheet, or alloyed zinc-plated steel sheet, and in this embodiment, alloyed zinc-plated steel sheet is used. The first member 10 and the second member 20 can have a plate thickness of 0.6 mm to 2.0 mm. For example, the plate thickness of the first member 10 and the second member 20 is 1.0 mm each. In this 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 this disclosure can be obtained, and more preferably, gaps tend to occur between 980 MPa and 1470 MPa, making it easier to obtain the contributions of this 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 greater than that of the first member 10. In this case, for example, the thickness of the first member 10 can be set to 0.8 mm and the thickness of the second member 20 can be set to 1.2 mm. Below, we will describe a configuration in which the thickness of the second member 20 is greater than that of the first member 10.

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

[0025] The molded product 1 is obtained by processing multiple sheet materials. The multiple sheet materials include a first member 10 and a second member 20. Hereafter, the first member 10 and the second member 20 will be referred to collectively as two sheet 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 positioned on top of the first member 10, and in Figure 1, for the sake 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 orientation. For example, the molded product 1 may be used in an orientation that is upside down from the orientation shown in Figure 1.

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

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

[0029] In addition, multiple welds 12J are formed on the vertical wall sections 12 and 22. Four welds 12J are formed on the vertical wall sections 12 and 22. The molded product 1 is joined by a total of six welds 11J and 12J, including the two welds 11J on the top plate sections 11 and 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 length of the flange portion 13 in the width direction is, for example, about 20 mm.

[0031] As shown in Figure 1B, the molded product 1 of this embodiment is symmetrical, so in the following description, we may focus on only one side. However, the molded product 1 does not have to be symmetrical. Here, as shown in Figure 1B, the end of the first member 10 in the width direction is designated as the first end 13E, and the end of the second member 20 in the width direction is designated as the 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 in the middle of 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 to be shorter than the vertical wall portion 12 of the first member 10.

[0032] Furthermore, as shown in Figure 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 on the flange portion 13 side of the second end 22E) and the flange portion 13.

[0033] Furthermore, for the two plate materials, the portion corresponding to all of the top plate portions 11 and 21 of the molded product 1 in the state prior to the main molding (S50) described later is also called the "top plate equivalent portion." Similarly, the portion 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 all of the vertical wall portion 22 is also called the "vertical wall equivalent portion."

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

[0035] [1-2. Press forming equipment] Figures 2A and 2B are cross-sectional views of a press forming apparatus 100 for forming a molded product 1. The press forming apparatus 100 comprises 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 displaceable relative to each other along the height direction of the molded product 1 by a drive mechanism (not shown). The height direction of the molded product 1 is, for example, the direction perpendicular to the top plate portion 11, and in Figure 2A, the vertical direction. The press forming apparatus 100 is configured so that the second mold 50 is displaced along the height direction without the first mold 40 being displaced. The direction in which the second mold 50 moves during pressing within the height direction 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 mounted to the second mold 50 so as to face the first mold 40, and is positioned vertically above the first mold 40. The second mold 50 has a built-in mechanism such as a gas cylinder. The blank holder 60 is configured to descend by the mechanism such as the gas cylinder at the same time as the second mold 50 begins to move vertically, so as to hold the first member 10 and the second member 20 before molding between the first mold 40 and the second mold 50 before the second mold 50 touches the two sheet metals.

[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 interlock with each other, and before press forming, they face each other in a separated state. For 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 conforms to the shape of the molded product 1. Specifically, the first mold 40 and the second mold 50 each include vertical wall molding sections 41 and 51, flange molding sections 42 and 52, depth extension sections 43 and 53, and shoulder sections 44 and 54. The vertical wall molding sections 41 and 51 are for molding the vertical wall sections 12 and 22. The flange molding sections 42 and 52 are for molding the flange section 13. The depth extension sections 43 and 53 are wall-like sections that extend generally in the vertical direction and connect the flange molding sections 42 and 52 with the shoulder sections 44 and 54.

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

[0040] Furthermore, the shoulder portions 44 and 54 have surfaces whose angle with respect to the direction of movement M is greater than that of the vertical wall portions 12 and 22. In other words, the angle between the direction of movement M (i.e., the vertical line) and the surfaces constituting the shoulder portions 44 and 54 (for example, surfaces that are roughly aligned horizontally) is set to be greater than the angle between the direction of movement M and the surfaces constituting the vertical wall portions 12 and 22 (for example, surfaces that are roughly aligned vertically).

[0041] Thus, the second mold 50 is configured in a stepped shape. A stepped shape is a shape having top plate portions 11, 21 and a plurality of substantially horizontal surfaces (for example, flange forming portion 52 and shoulder portion 54).

[0042] [1-3. Method for manufacturing press-formed products] Next, the method for manufacturing the molded product 1 will be described. In this embodiment, the procedure shown in Figure 3 is carried out to manufacture the molded product 1.

[0043] As shown in Figure 3, the manufacturing method for molded product 1 first involves blanking in S10. Blanking is the process of cutting out blank material, which will be the material for molded product 1, by cutting out a roll of steel sheet, etc. At this time, the second member 20 is cut to be shorter in length than the first member 10.

[0044] Next, in step S20, the top plate portions 11 and 21 of the two plate materials, namely the first member 10 and the second member 20, are joined by welding. During welding, the two plate materials are positioned such that, in a plan view, the second member 20 is hidden by the first member 10, as shown in Figure 4A. Specifically, the second end portion 22E of the second member 20 is positioned inward from the first end portion 13E of the first member 10, and in this state, two welded portions 11J are formed.

[0045] In this embodiment, the first member 10 and the second member 20 are made of the same material, and as shown in Figure 4B, the thickness t1 of the second member 20 is set to be greater than the thickness t0 of the first member 10. In this case, when comparing the second moment of area, bt0 3 / 12≦bt1 3 / 12 As a result, the second moment of area of ​​the first member 10 becomes less than or equal to the second moment of area of ​​the second member 20. In this case, it is considered that the effect of deflecting the first member 10 becomes easier to obtain. Also, it is considered that the amount of bending back of the first member 10 becomes less than or equal to 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 Figure 2A). In other words, if the first member 10 and the second member 20 are made of the same material, it is considered that the gap between the vertical wall portions 12 and 22 will become smaller if the thickness t1 of the second member 20 is greater than or equal to the thickness t0 of the first member 10.

[0046] Next, in S30, the top plates 11 and 21 of the two plate materials with the welded portion 11J formed are fixed. That is, with a gap formed between the blank holder 60 and the first mold 40, the two plate materials with the welded portion 11J formed are placed on the first mold 40 as shown in Figure 2A. At this time, the first member 10 is positioned closer to the second mold 50 (i.e., vertically upward) than the second member 20. In line of sight along the direction of movement M, the second end portion 22E is positioned inside the shoulder portion 54. This is so that the shoulder portion 54 touches the extension portion 14.

[0047] Then, as shown in Figure 2B, the blank holder 60 is moved along the direction of movement M to close the gap between it and the first mold 40. In this way, the top plates 11 and 21 of the two plate materials are fixed by the blank holder 60 and the first mold 40.

[0048] Next, in S40, the two plate materials are given a deflection. With the top plate portions 11 and 21 fixed using the blank holder 60, the second mold 50 is moved along the movement direction M, and as shown in Figure 2B, the shoulder portion 54 touches 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 touch the first member 10.

[0049] Then, from the state shown in Figure 2B, when the second mold 50 is moved further 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 Figure 5A. Next, the main molding process is carried out in S50. From the state shown in Figure 5A, as the second die 50 is moved further along the movement direction M, the deflection of the two sheet metals increases further, and eventually the vertical wall forming sections 41, 51 and the flange forming sections 42, 52 sandwich the two sheet metals, and the press working is completed as shown in Figure 5B.

[0050] Next, welding of the vertical wall sections 12 and 22 is performed in S60. That is, after bending of the vertical wall sections 12 and 22, multiple welded sections 12J are formed. Once the welding of the vertical wall sections 12 and 22 is complete, the molded product 1 is finished. Note that drilling, trimming, etc. may be performed after welding of the vertical wall sections 12 and 22.

[0051] [1-4. Consideration of mold shape] Here, while changing the length L of the flange forming sections 42 and 52 and the depth D of the depth extension sections 43 and 53 in the first mold 40 and the second mold 50, the size of the gap in the vertical wall sections 12 and 22 was measured and the results are shown in Table 1 below.

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

[0053] [Table 1]

[0054] As shown in Table 1, the results indicate that the gap size tends to increase as the length L increases. It is thought that a smaller length L allows for a greater amount of deformation when bending the two plates, resulting in a smaller gap.

[0055] Furthermore, these results showed a tendency for the size of the gap to decrease as the depth D increased. However, increasing the depth D leads to larger first molds 40 and second molds 50, resulting in increased costs. Therefore, it is preferable to set the depth D to approximately the vertical length of the vertical wall sections 12 and 22.

[0056] [1-5. Effects] The embodiments described in detail above produce the following effects. (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 portion while the first member 10 is stacked with the second member 20 such that the first member 10 has an extended portion 14. Furthermore, while the top plate equivalent portion is held in place after joining, the second mold 50 is moved along the movement direction M so that the second mold 50 comes into contact with the extended portion 14, causing the vertical wall equivalent portions and extended portions 14 of the multiple plate materials to bend toward the direction of movement. At this time, the second mold 50 comes into contact with the extended portion 14 without touching any part of the first member 10 other than the extended portion 14.

[0057] Furthermore, while the second mold 50 is bending the vertical wall portion and the extension portion 14, the second mold 50 is moved further along the direction of movement, thereby pressing the vertical wall portions of multiple plate materials with the second mold 50 to form 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 sheet metals, and then the top plate portions 11, 21 and the vertical wall portions 12, 22 are formed. In other words, the multiple sheet metals are slightly bent before the top plate portions 11, 21 and the vertical wall portions 12, 22 are formed. This makes it less likely for the vertical wall portions 12, 22 to unbend. By making it less likely for the vertical wall portions 12, 22 to unbend, the gaps between the vertical wall portions 12, 22 become smaller, allowing for better execution of welding and other operations after press working.

[0059] (1b) In one aspect of the present disclosure, the shoulder portion 54 is located on the side of the direction of movement of the end of the vertical wall forming portion 51 on the direction of movement side, and has a surface that is on the side of the vertical wall forming portion 51 and has an angle with respect to the direction of movement that is greater than that of the vertical wall portions 12, 22. Furthermore, when bending is performed, the second end portion 22E is positioned inward of the shoulder portion 54, and the shoulder portion 54 comes into contact with the extension portion 14, thereby bending the vertical wall equivalent portion and the extension portion 14 of the multiple plate materials toward the direction of movement. This manufacturing method makes it possible to create a configuration in which multiple plate materials are bent by the shoulder portion 54 coming into contact with the extension portion 14.

[0060] (1c) In one aspect of the present disclosure, the second mold 50 is step-shaped. The second mold 50 also includes a flange forming portion 52 and a shoulder portion 54 as a plurality of surfaces for forming the step shape. When bending is performed, the shoulder portion 54 touches the extension portion 14, causing the vertical wall portions and extension portions 14 of the plurality of plate materials to bend in the direction of movement. Also, when forming the top plate portions 11, 21 and the vertical wall portions 12, 22, the flange forming portion 52 touches the extension portion 14, forming the flange portion 13 that extends outward from the vertical wall portions 12, 22. According to this manufacturing method, when manufacturing a molded product 1 having a flange portion 13, multiple sheet metals can be bent before forming the top plate portions 11, 21 and the vertical wall portions 12, 22.

[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 formed inside the shoulder portion 54. Alternatively, the molding of the flange portion 13 may begin with the shoulder portions 54, 72, 82 in contact, and then be completed inside the shoulder portions 54, 72, 82.

[0062] With this manufacturing method, the shoulder portion 54 can be brought into contact with multiple sheet metals from a more external position, allowing the top plate portion 11, 21 and the vertical wall portion 12, 22 to be formed after the multiple sheet metals have been sufficiently flexed.

[0063] (1e) In one aspect of the present disclosure, the second member 20 may have a thickness greater than or equal to that of the first member 10. With this manufacturing method, the second moment of area of ​​the first member 10 tends to be less than or equal to the second moment of area of ​​the second member 20, making it easier to achieve the effect of bending the first member 10. As a result, the first member 10 is less likely to straighten out, and a gap is less likely to form between it and the second member 20.

[0064] (1f) In one aspect of the present disclosure, the top plate portion 11, 21 and the vertical wall portion 12, 22 are formed, and then the first member 10 and the second member 20 are welded to the vertical wall portion 12, 22. This manufacturing method makes it difficult for the vertical wall sections 12 and 22 to bend back, thus reducing the gap between the first member 10 and the second member 20. Therefore, welding can be performed smoothly.

[0065] (1g) In one aspect of the present disclosure, the molded article 1 may be an automobile part. According to such a manufacturing method, a molded article 1 that is applied to an automobile part can be manufactured well.

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

[0067] (2a) In the above embodiment, the press forming apparatus 100 of the embodiment was used, but for example, the press forming apparatus 110 of the first modified example shown in Figures 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 was illustrated, but the press forming apparatus 110 of the first modified example is equipped with a second die 70 as a cam instead of the second die 50. The second die 70 is equipped with a vertical wall forming section 71 and a flange forming section 72 (shoulder section in this disclosure). The first die 40 is equipped with only a vertical wall forming section 41 and a flange forming section 42.

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

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

[0070] (2b) Alternatively, for example, instead of the press forming apparatus 100 of the embodiment, the press forming apparatus 120 of the second modified example shown in Figures 7A and 7B may be used. The press forming apparatus 120 of the second modified example is an apparatus for obtaining a molded product that does not have a flange portion 13, that is, a molded product that has only top plate portions 11, 21 and vertical wall portions 12, 22.

[0071] The press forming apparatus 120 of the second modification includes a second mold 80 instead of the second mold 50. The second mold 80 includes a vertical wall forming section 81 and a shoulder section 82. While the shoulder section 54 of the embodiment extends horizontally, the shoulder section 82 of the second modification includes an inclined surface that slopes toward the direction of movement M as it moves outward. The shoulder section 82 is also configured to have a surface whose angle with respect to the direction of movement M is greater than that of the vertical wall sections 12 and 22. Even with this configuration, the shoulder portion 82 touches the two plate materials before the vertical wall forming portion 81 touches the two plate materials, so the two plate materials can be flexed before press forming. Therefore, it is possible to reduce the likelihood of bending back.

[0072] (2c) Alternatively, the second mold 50 may have a shoulder portion configured as a curved surface. In this case, it is preferable that the angle between the plane extending along the tangent to the curved surface and the direction of movement M be set to be greater than the angle between the plane extending along the vertical wall portions 12, 22 and the direction of movement M. Even with this configuration, the two sheet metal pieces can be bent before press forming.

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

[0074] (2e) Multiple functions of one component in the above embodiment may be realized by multiple components, or one function of one component may be realized by multiple components. Also, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, some of the configurations of the above embodiment may be omitted. Furthermore, at least some of the configurations of the above embodiment may be added to or replaced with the configurations of other above embodiments.

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

[0076] [Technical concepts disclosed in this specification] [Item 1] A method for manufacturing a molded product having a top plate portion and vertical wall portions, which involves pressing multiple stacked sheet materials together to obtain a molded product. The aforementioned plurality of plate materials include a first member and a second member, The first member has a top plate equivalent portion representing the top plate portion of the molded product, a vertical wall equivalent portion representing at least a part of the vertical wall portion of the molded product, and an extension portion. The second member is in a state where it is superimposed on the first member, and has a portion corresponding to the top plate and a portion corresponding to the vertical wall, In any plane parallel to the plurality of plate materials, the direction from the vertical wall portion toward the top plate portion is defined as the inside, and the direction from the vertical wall portion toward the opposite side of the top plate 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 out than the second end. The extension portion refers to the region of the first member from the first end to the overlapping portion of the second end. In this manufacturing method, the direction of movement is from the first member side toward the second member side, The first member and the second member are joined by welding the top plate-equivalent portion while the first member is superimposed on the second member such that the first member has the extended portion, With the top plate portion after joining being held in place, the mold is moved along the direction of movement to bring the mold into contact with the extension portion, thereby causing the vertical wall portions and extension portions of the multiple plate materials to bend toward the direction of movement. With the mold flexing the portion corresponding to the vertical wall and the portion corresponding to the extension, the mold is further moved along the direction of movement, thereby pressing the portion corresponding to the vertical wall of the plurality of plate materials with the mold, and forming the top plate portion and the vertical wall portion. A method for manufacturing molded products. [Item 2] A method for manufacturing a molded article as described in item 1, The aforementioned mold is A vertical wall molding section for forming the aforementioned vertical wall section, A shoulder portion located on the side of the movement direction of the end of the vertical wall molding portion on the movement direction side, and having a surface that is on the outside of the vertical wall molding portion and has an angle with respect to the movement direction that is greater than that of the vertical wall portion, Equipped with, When the bending described above is performed, the second end is positioned inward from the shoulder portion, and the shoulder portion touches the extension portion, thereby bending the portion corresponding to the vertical wall and the extension portion of the plurality of plate materials toward the direction of movement. A method for manufacturing molded products. [Item 3] A method for manufacturing a molded article as described in item 1 or item 2, The mold has a stepped shape, having multiple surfaces that are substantially horizontal to the top plate portion. The plurality of surfaces include a first surface on the front side in the direction of movement and a second surface on the back side in the direction of movement. When the bending described above is carried out, the second surface comes into contact with the extension portion, causing the portion of the plate material corresponding to the vertical wall and the extension portion to bend toward the direction of movement. When forming the top plate portion and the vertical wall portion, the first surface comes into contact with the extension portion, thereby forming the flange portion that extends outward from the vertical wall portion. A method for manufacturing molded products. [Item 4] A method for manufacturing a molded article as described in item 2 or item 3 which references item 2, When forming the top plate portion and the vertical wall portion, the flange portion extending outward from the vertical wall portion is formed on the inside of the shoulder portion. A method for manufacturing molded products. [Item 5] A method for manufacturing a molded article as described in any one of items 1 to 4, The second member has a plate thickness greater than or equal to that of the first member. A method for manufacturing molded products. [Item 6] A method for manufacturing a molded article as described in any one of items 1 to 5, After forming the top plate portion and the vertical wall portion, the first member and the second member are welded to the vertical wall portion. A method for manufacturing molded products that further implements this method. [Item 7] A method for manufacturing a molded article as described in any one of items 1 to 6, The aforementioned molded product is an automobile part. A method for manufacturing molded products. [Explanation of Symbols]

[0077] 1...Molded product, 10...First component, 11,21...Top plate section, 11J,12J...Welded section, 12,22...Vertical wall section, 13...Flange section, 13E...First end section, 14...Extension section, 20...Second component, 22E...Second end section, 40,70...First mold, 41,51,71,81...Vertical wall molding section, 42,52,72...Flange molding section, 43,53...Extension section, 44,54,82...Shoulder section, 50,70...Second mold, 60...Blank holder, 100,110,120...Press molding device.

Claims

1. A method for manufacturing a molded product having a top plate portion and vertical wall portions, which involves pressing multiple stacked sheet materials together to obtain a molded product. The aforementioned plurality of plate materials include a first member and a second member, The first member has a top plate equivalent portion representing the top plate portion of the molded product, a vertical wall equivalent portion representing at least a part of the vertical wall portion of the molded product, and an extension portion. The second member is in a state where it is superimposed on the first member, and has a portion corresponding to the top plate and a portion corresponding to the vertical wall, In any plane parallel to the plurality of plate materials, the direction from the vertical wall portion toward the top plate portion is defined as the inside, and the direction from the vertical wall portion toward the opposite side of the top plate 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 out than the second end. The extension portion refers to the region of the first member from the first end to the overlapping portion of the second end. In this manufacturing method, the direction of movement is from the first member side toward the second member side, The first member and the second member are joined by welding the top plate-equivalent portion while the first member is superimposed on the second member such that the first member has the extended portion, With the top plate portion after joining being held in place, the mold is moved along the direction of movement to bring the mold into contact with the extension portion, thereby causing the vertical wall portions and extension portions of the multiple plate materials to bend toward the direction of movement. With the mold flexing the portion corresponding to the vertical wall and the portion corresponding to the extension, the mold is further moved along the direction of movement, thereby pressing the portion corresponding to the vertical wall of the plurality of plate materials with the mold, and forming the top plate portion and the vertical wall portion. A method for manufacturing molded products.

2. A method for manufacturing a molded article according to claim 1, The aforementioned mold is A vertical wall molding section for forming the aforementioned vertical wall section, A shoulder portion located on the side of the movement direction of the end of the vertical wall molding portion on the movement direction side, and having a surface that is on the outside of the vertical wall molding portion and has an angle with respect to the movement direction that is greater than that of the vertical wall portion, Equipped with, When the bending described above is performed, the second end is positioned inward from the shoulder portion, and the shoulder portion touches the extension portion, thereby bending the portion corresponding to the vertical wall and the extension portion of the plurality of plate materials toward the direction of movement. A method for manufacturing molded products.

3. A method for manufacturing a molded article according to claim 1 or claim 2, The mold has a stepped shape, having multiple surfaces that are substantially horizontal to the top plate portion. The plurality of surfaces include a first surface on the front side in the direction of movement and a second surface on the back side in the direction of movement. When performing the aforementioned bending, the second surface comes into contact with the extension portion, causing the portion of the plate material corresponding to the vertical wall and the extension portion to bend toward the direction of movement. When forming the top plate portion and the vertical wall portion, the first surface comes into contact with the extension portion, thereby forming the flange portion that extends outward from the vertical wall portion. A method for manufacturing molded products.

4. A method for manufacturing a molded article according to claim 2, When forming the top plate portion and the vertical wall portion, the flange portion extending outward from the vertical wall portion is formed on the inside of the shoulder portion. A method for manufacturing molded products.

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

6. A method for manufacturing a molded article according to claim 1 or claim 2, After forming the top plate portion and the vertical wall portion, the first member and the second member are welded to the vertical wall portion. A method for manufacturing molded products that further implements this method.

7. A method for manufacturing a molded article according to claim 1 or claim 2, The aforementioned molded product is an automobile part. A method for manufacturing molded products.

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