Method for manufacturing molded article

Abstract

The present disclosure provides a method for manufacturing a molded article. A method for manufacturing a molded article includes stacking a first member and a second member such that the first member has an extended portion, and joining the first member and the second member to each other by welding a top plate corresponding portion in the stacked state; a bending step in which a mold is brought into contact with the protruding portion and the vertical wall corresponding portions of the plurality of plates and the protruding portion are bent toward the moving direction side; and pressing the vertical wall corresponding parts of the plurality of plates through the mold, thereby forming a top plate part and a vertical wall part.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a manufacturing method of a formed product. BACKGROUND

[0002] For example, Japanese Patent Publication No. 2002-192247 discloses a technique of obtaining a formed product by press-forming a plurality of sheet materials in a superposed state. SUMMARY

[0003] In the technique of the above document, when press-forming a plurality of sheet materials in a superposed state to obtain a formed product having a top plate portion and a vertical wall portion, there is a problem that a gap is easily generated between the plurality of sheet materials due to a bending springback of the material being bent in a direction in which the material attempts to return to the original shape. If the gap between the plurality of sheet materials becomes large after press-forming, it can cause inconvenience in subsequent welding and assembly operations and the like.

[0004] One aspect of the present disclosure is capable of reducing the amount of bending springback of a sheet material at the time of press-forming in a manufacturing method of a formed product, the manufacturing method of the formed product being to obtain a formed product having a top plate portion and a vertical wall portion by press-forming a plurality of sheet materials in a superposed state.

[0005] One aspect of the present disclosure is a manufacturing method of a formed product, the manufacturing method of the formed product being to obtain a formed product having a top plate portion and a vertical wall portion by press-forming a plurality of sheet materials in a superposed state. In the manufacturing method of the formed product, a first member and a second member are provided as the plurality of sheet materials.

[0006] The first member has a first top plate corresponding portion, a first vertical wall corresponding portion, and a protruding portion. The first top plate corresponding portion indicates a portion corresponding to a part of the top plate portion of the formed product. The first vertical wall corresponding portion indicates a portion corresponding to at least a part of the vertical wall portion of the formed product. The second member has a second top plate corresponding portion and a second vertical wall corresponding portion. The second top plate corresponding portion indicates a portion corresponding to another part of the top plate portion of the formed product. The second vertical wall corresponding portion indicates a portion corresponding to at least another part of the vertical wall portion of the formed product. The second top plate corresponding portion of the second member is superposed with the first member.

[0007] In addition, in any plane parallel to the plurality of sheet materials, a direction from the first vertical wall corresponding portion and the second vertical wall corresponding portion toward the first top plate corresponding portion and the second top plate corresponding portion is an inner side, and a direction from the first vertical wall corresponding portion and the second vertical wall corresponding portion toward the opposite side of the first top plate corresponding portion and the second top plate corresponding portion is an outer side. Further, an end portion of the first member located on the outer side is a first end portion, and an end portion of the second member located on the outer side is a second end portion. The first end portion is located at a position further outward than the second end portion. The protruding portion indicates a region of the first member from the first end portion to a portion superposed with the second end portion.

[0008] Further, a direction from the first member side toward the second member side is referred to as a moving direction. In the manufacturing method, the following process is performed, that is, the first member and the second member are stacked in a manner that the first member has the protruding portion, and the first member and the second member are joined to each other by welding the first ceiling corresponding portion and the second ceiling corresponding portion in the stacked state. Further, the following process is performed, that is, in a state that the joined first ceiling corresponding portion and the second ceiling corresponding portion are clamped, the mold is moved along the moving direction so that the mold contacts the protruding portion, and the first longitudinal wall corresponding portion, the second longitudinal wall corresponding portion, and the protruding portion of the plurality of sheet materials are bent toward the moving direction side.

[0009] Further, the following process is performed, that is, in a state that the mold bends the first longitudinal wall corresponding portion, the second longitudinal wall corresponding portion, and the protruding portion, the mold is further moved along the moving direction so that the mold presses the first longitudinal wall corresponding portion and the second longitudinal wall corresponding portion of the plurality of sheet materials, thereby forming the ceiling portion and the longitudinal wall portion.

[0010] According to the above manufacturing method, the ceiling portion and the longitudinal wall portion can be formed after the mold contacts the protruding portion so that the plurality of sheet materials are bent. That is, the ceiling portion and the longitudinal wall portion are formed after the plurality of sheet materials are slightly bent. Therefore, the longitudinal wall portion can be less likely to be bent back.

[0011] In one aspect of the present disclosure, the mold can include a longitudinal wall forming portion and a shoulder portion. The longitudinal wall forming portion is a portion for forming the longitudinal wall portion. The shoulder portion is a portion of the mold that initially contacts the blank (i.e., the first member and the second member). The shoulder portion is located at a position closer to the moving direction side than an end portion of the longitudinal wall forming portion located on the moving direction side, and the shoulder portion has a surface at a position closer to the outside than the longitudinal wall forming portion, the surface having an angle with respect to the moving direction that is larger than an angle of the longitudinal wall portion with respect to the moving direction. Further, when the bending is performed, the second end portion can be disposed at a position closer to the inside than the shoulder portion, and the first longitudinal wall corresponding portion, the second longitudinal wall corresponding portion, and the protruding portion of the plurality of sheet materials can be bent toward the moving direction side by the shoulder portion contacting the protruding portion.

[0012] According to the above manufacturing method, a structure in which the plurality of sheet materials are bent by the shoulder portion contacting the protruding portion can be achieved. Further, by appropriately setting the shape of the shoulder portion, the degree of bending of the first member and the second member can be well set.

[0013] In one aspect of the present disclosure, the mold can be a stepped shape that is a shape having a plurality of planes substantially parallel to the top plate portion. In this case, the mold can have a first plane and a second plane as the plurality of planes. The first plane is a plane located on a proximal side in the moving direction. The second plane is a plane located on a distal side in the moving direction. When bending is performed, the first longitudinal wall corresponding portion, the second longitudinal wall corresponding portion, and the protruding portion of the plurality of sheets can be bent toward the moving direction side by the second plane contacting the protruding portion. Further, when the top plate portion and the longitudinal wall portion are formed, the flange portion extending outward from the longitudinal wall portion can be formed by the first plane contacting the protruding portion.

[0014] According to the manufacturing method described above, when a formed product having a flange portion is manufactured, the top plate portion and the longitudinal wall portion can be formed after the plurality of sheets are bent.

[0015] In one aspect of the present disclosure, when the top plate portion and the longitudinal wall portion are formed, the flange portion can be completed in a position inside the shoulder portion. In addition, the shoulder portion can start forming the flange portion while contacting the flange portion, and then the formation of the flange portion can be completed in a position inside the shoulder portion.

[0016] According to the manufacturing method described above, the shoulder portion can be contacted with the plurality of sheets from the outside, and thus the top plate portion, the longitudinal wall portion, and the flange portion can be formed after the plurality of sheets are sufficiently bent.

[0017] In one aspect of the present disclosure, the plate thickness of the second member can be greater than or equal to the plate thickness of the first member.

[0018] According to the manufacturing method described above, the second moment of area of the first member is easily equal to or less than the second moment of area of the second member, and thus the effect of bending the first member is easily obtained. As a result, a configuration in which the first member does not easily spring back and a gap between the first member and the second member does not easily occur can be achieved.

[0019] In one aspect of the present disclosure, the first member and the second member can be welded to each other at the longitudinal wall portion after the top plate portion and the longitudinal wall portion are formed.

[0020] According to the manufacturing method described above, since the configuration is such that the longitudinal wall portion does not easily spring back, a gap between the first member and the second member is reduced. Thus, the welding work can be performed favorably.

[0021] In one aspect of the present disclosure, the formed product can be a component of an automobile. According to the manufacturing method described above, the formed product that is a component of an automobile can be manufactured favorably. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1A is a perspective view showing one example of a formed product.

[0023] Figure 1B is a sectional view of the molded article.

[0024] Figure 2A is a sectional view of a press forming device indicating a state before press forming in the manufacturing method of the molded article.

[0025] Figure 2B is a sectional view of the press forming device showing a state where the top plate portion is held.

[0026] Figure 3 is a flowchart showing the manufacturing method of the molded article.

[0027] Figure 4A is a plan view showing the sheet before press forming.

[0028] Figure 4B is a sectional view of the sheet before press forming.

[0029] Figure 5A is a sectional view of the press forming device indicating a state where a plurality of sheets are bent in the manufacturing method of the molded article.

[0030] Figure 5B is a sectional view of the press forming device indicating a state where press forming of a plurality of sheets is completed.

[0031] Figure 6A is a sectional view showing a state of the press forming device of the first modification before press forming.

[0032] Figure 6B is a sectional view showing a state of the press forming device after press forming.

[0033] Figure 7A is a sectional view showing a state of the press forming device of the second modification before press forming.

[0034] Figure 7B is a sectional view showing a state of the press forming device after press forming. DETAILED DESCRIPTION

[0035] An exemplary embodiment of the present disclosure will be described below with reference to the accompanying drawings.

[0036] [1. First Embodiment]

[0037] [1-1. Configuration of Molded Article]

[0038] [Summary of Molded Article]

[0039] Figure 1A and Figure 1BThe shown formed product 1 is a press-formed product obtained by press-forming a plurality of sheet materials in a superposed state. The formed product 1 can be used as a constituent member of an automobile, for example, an automobile member such as a front pillar, a side panel, a center pillar, and the like, other pillar portions of an automobile, a frame portion, and the like. The formed product 1 and the manufacturing method thereof are not limited to the constituent member of an automobile, and can be applied to various other members and products.

[0040] The formed product 1 is obtained by press-forming the first member 10 and the second member 20 composed of steel sheets, including bending processing. The first member 10 and the second member 20 before the press-forming are, for example, blanks obtained by cutting a steel sheet in a roll shape. As one example, the first member 10 and the second member 20 include a cold-rolled steel sheet, a hot-rolled steel sheet, an alloyed galvanized steel sheet, and in the present embodiment, an alloyed galvanized steel sheet is used. The sheet thickness of the first member 10 and the second member 20 can be 0.6 mm to 2.0 mm. For example, the sheet thickness of each of the first member 10 and the second member 20 is 1.0 mm. In the present disclosure, the applicable range of the tensile strength of the first member 10 and the second member 20 is 270 MPa to 1470 MPa. If the tensile strength of the first member 10 and the second member 20 is within this applicable range, the effects of the present disclosure can be obtained, and more preferably, if the tensile strength is 980 MPa to 1470 MPa, a gap is easily generated between the first member 10 and the second member 20, and it is easy to obtain the contribution of the present disclosure. In the present embodiment, the tensile strength of the first member 10 and the second member 20 is, for example, about 1470 MPa.

[0041] Here, the first member 10 and the second member 20 can be set to different sheet thicknesses. In particular, the sheet thickness of the second member 20 can be set to be thicker than the sheet thickness of the first member 10. In this case, for example, the sheet thickness of the first member 10 can be set to 0.8 mm, the sheet thickness of the second member 20 can be set to 1.2 mm, and the like. In the following, a configuration in which the sheet thickness of the second member 20 is set to be thicker than the sheet thickness of the first member 10 is described.

[0042] <Overall shape of formed product>

[0043] The formed product 1 is formed to have a saddle shape having a certain height. The saddle shape refers to a shape in which the top panel portions 11, 21 have longitudinal wall portions 12, 22 on both sides thereof, and the longitudinal wall portions 12, 22 extend in a direction intersecting the top panel portions 11, 21. The formed product 1 is used to cover an object having an elongated shape such as a cable, a columnar member, and the like in the length direction, or is attached to another sheet material to reinforce the sheet material, and the like.

[0044] The molded article 1 is obtained by processing a plurality of sheets. The molded article 1 has the first member 10 and the second member 20 as the plurality of sheets. Hereinafter, the first member 10 and the second member 20 will also be collectively referred to as two sheets.

[0045] 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 arranged so as to overlap the lower side of the first member 10. In FIG. 1, the top plate portion 11 is shown as a portion on the upper side in the molded article 1 for ease of explanation. However, the molded article 1 can be used in any posture. For example, the molded article 1 can be used in a posture upside down from the posture shown in FIG. 1.

[0046] The top plate portion 11 is substantially flat and substantially rectangular in plan view. The length of the top plate portion 11 in the width direction (i.e., the left-right direction in the Figure 1B , for example, is about 150 mm, and the length of the top plate portion 11 in the depth direction (b in the Figure 4A , for example, is about 350 mm. Two weld portions 11J are molded at the center of the top plate portion 11. At the weld portions 11J, the respective top plate portions 11, 21 of the first member 10 and the second member 20 are joined to each other by spot welding. In addition, hereinafter, the plane on which the top plate portion 11 is located will be simply referred to as the top plate portion 11.

[0047] The portions of the top plate portion 11 along the two edges opposite to each other are respectively bent. The vertical wall portion 12 is included in both of the above-mentioned bent portions. The vertical wall portion 12 is flat and adjacent to and continuous with the top plate portion 11, and is a portion extending 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.

[0048] Further, a plurality of weld portions 12J are also molded on the vertical wall portions 12, 22. Two weld portions 12J are respectively molded at the vertical wall portions 12, 22 (i.e., a total of four weld portions 12J are molded in the molded article 1). The first member 10 and the second member 20 of the molded article 1 are joined to each other by a total of six weld portions 11J, 12J including the two weld portions 11J in the top plate portions 11, 21.

[0049] The flange portion 13 is configured to protrude from the front end of the vertical wall portion 12. In other words, the flange portion 13 extends from the front end of the vertical wall portion 12 toward the outside. The flange portion 13 extends substantially 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.

[0050] As Figure 1BAs shown, the molded article 1 of this embodiment is symmetrical from left to right. Therefore, in the following description, only one side of the molded article 1 will sometimes be emphasized. However, the molded article 1 may not be symmetrical from left to right.

[0051] Here, as Figure 1B As shown, the end of the first component 10 in the width direction is designated as the first end 13E, and the end of the second component 20 in the width direction is designated as the second end 22E. The second component 20 does not reach the flange portion 13 of the first component 10, and the second end 22E is located between the top plate portion 11 and the flange portion 13. That is, the longitudinal wall portion 22 of the second component 20 (i.e., the height from the top plate portion 21 to the second end 22E) is set to be shorter than the longitudinal wall portion 12 of the first component 10.

[0052] In addition, such as Figure 1B As shown, the region in the first component 10 from the first end 13E to the portion where the second end 22E is superimposed is defined as the protrusion 14. The protrusion 14 includes a portion of the longitudinal wall portion 12 of the first component 10 (i.e., the portion of the longitudinal wall portion 12 located near the flange portion 13 relative to the second end 22E) and the flange portion 13.

[0053] Furthermore, for both sheet metal parts, the portions corresponding to the entire top plate portions 11 and 21 of the molded article 1 in the state before the main forming (S50) described later are also referred to as "top plate corresponding portions". The top plate corresponding portions include the top plate corresponding portion of the first component 10, i.e., the first top plate corresponding portion, and the top plate corresponding portion of the second component 20, i.e., the second top plate corresponding portion. Similarly, the portions corresponding to a portion of the longitudinal wall portion 12 of the molded article 1 (i.e., the portion located near the top plate portion 11 relative to the second end 22E) and the entire longitudinal wall portion 22 are also referred to as "longitudinal wall corresponding portions". The longitudinal wall corresponding portions include the longitudinal wall corresponding portion of the first component 10, i.e., the first longitudinal wall corresponding portion, and the longitudinal wall corresponding portion of the second component 20, i.e., the second longitudinal wall corresponding portion.

[0054] In addition, such as Figure 1B As shown, on any plane parallel to the two plates (e.g., top plate portions 11 and 21), the direction from the corresponding portion of the longitudinal wall toward the corresponding portion of the top plate is defined as the inner side, and the direction from the corresponding portion of the longitudinal wall toward the opposite side of the corresponding portion of the top plate is defined as the outer side.

[0055] [1-2. Stamping Forming Device]

[0056] Figure 2A and 2Bis a cross-sectional view of a press forming apparatus 100 for forming a shaped product 1. The press forming apparatus 100 is provided with a first die 40 as a punch, a second die 50 as a die, and a blank holder 60. The first die 40 and the second die 50 are configured to be relatively displaced along a height direction of the shaped product 1 by a driving mechanism not shown. In addition, the height direction of the shaped product 1 refers to, for example, a direction orthogonal to the ceiling portion 11, and is a vertical direction in Figure 2A the present embodiment. The press forming apparatus 100 is configured such that the second die 50 is displaced along the height direction, and the first die 40 is not displaced. In addition, a direction in which the second die 50 is moved along the height direction at the time of pressing is referred to as a moving direction M. However, the first die 40 can be displaced along the height direction instead of the second die 50, or both the second die 50 and the first die 40 can be displaced along the height direction.

[0057] The blank holder 60 is installed on the second die 50 in a manner opposed to the first die 40, and is disposed above the first die 40 in the vertical direction. A mechanism such as a cylinder is built in the second die 50. The blank holder 60 is configured such that, when the second die 50 starts to be moved along the vertical direction, the second die 50 is lowered by the mechanism such as a cylinder at the same time, and the first member 10 and the second member 20 before forming can be clamped between the blank holder 60 and the first die 40 before the second die 50 contacts the two sheet materials.

[0058] The second die 50, the first die 40, and the blank holder 60 cooperate to perform press forming. The second die 50 and the first die 40 can engage with each other, and are opposed in a state of being separated from each other before press working. As one example, the second die 50 is concave, and the first die 40 is convex.

[0059] The first die 40 and the second die 50 each have a shape similar to that of the shaped product 1. Specifically, the first die 40 and the second die 50 each have a vertical wall forming portion 41, 51, a flange forming portion 42, 52, a depth extension portion 43, 53, and a shoulder portion 44, 54. The vertical wall forming portion 41, 51 is a site for forming the vertical wall portion 12, 22. The flange forming portion 42, 52 is a site for forming the flange portion 13. The depth extension portion 43, 53 is a wall-like portion extending substantially along the vertical direction, and is a site connecting the flange forming portion 42, 52 and the shoulder portion 44, 54.

[0060] Shoulders 44 and 54 are planes parallel to flange forming portions 42 and 52, and are located on the outer side of flange forming portions 42 and 52, and on the side of the moving direction M. Shoulders 44 and 54 are located on the side of the moving direction M, closer to the end of the longitudinal wall forming portion 51 on the side of the moving direction M, and are located on the outer side of the longitudinal wall forming portions 41 and 51.

[0061] Furthermore, the shoulders 44 and 54 have surfaces whose angle with respect to the direction of movement M is greater than the angle with respect to the direction of movement M of the longitudinal walls 12 and 22. In other words, the angle between the direction of movement M (i.e., the vertical line) and the plane constituting the shoulders 44 and 54 (e.g., a plane that is approximately horizontal) is set to be greater than the angle between the direction of movement M and the plane constituting the longitudinal walls 12 and 22 (e.g., a plane that is approximately vertical).

[0062] As described above, the second mold 50 is configured in a stepped shape. A stepped shape refers to a shape having multiple generally horizontal planes (e.g., flange forming portion 52 and shoulder portion 54) that are generally parallel to the top plate portions 11 and 21.

[0063] [1-3. Manufacturing methods for molded articles]

[0064] Next, the manufacturing method of the molded article 1 will be described. In this embodiment, according to... Figure 3 The steps shown are performed to manufacture the molded article 1.

[0065] like Figure 3 As shown, in the manufacturing method of the formed article 1, blanking is first performed in S10. Blanking refers to the operation of cutting a blank of material used as the formed article 1 by cutting a coiled steel sheet or the like. At this time, the second part 20 is cut in such a way that the length of the second part 20 in the width direction is shorter than the length of the first part 10 in the width direction.

[0066] Next, in S20, the top plate portions 11 and 21 of the two plates, namely the first component 10 and the second component 20, are joined together by welding. Here, when welding is performed, as follows... Figure 4A As shown, the two plates are arranged such that, when viewed from above, the second component 20 is covered by the first component 10. Specifically, the end of the second component 20, i.e., the second end 22E, is positioned inside the end of the first component 10, i.e., the first end 13E, and in this state, two welded portions 11J are formed.

[0067] Furthermore, in this embodiment, the first component 10 and the second component 20 are made of the same material, and as... Figure 4BAs shown, the plate thickness t1 of the second member 20 is set to be larger than the plate thickness t0 of the first member 10. In this case, the sectional second moments of the two sheets are compared as shown in the following mathematical expression,

[0068] bt0 3 / 12≤bt1 3 / 12

[0069] The sectional second moment of the first member 10 is smaller than or equal to the sectional second moment of the second member 20. At this time, it can be considered that the effect of bending the first member 10 is more easily obtained. Further, it can be considered that the amount of bending springback of the first member 10 is smaller than or equal to the amount of bending springback of the second member 20. In addition, b is the width of the material (for example, Figure 2A That is, when the first member 10 and the second member 20 are of the same material, if the plate thickness t1 of the second member 20 is larger than or equal to the plate thickness t0 of the first member 10, it can be considered that the gap between the vertical wall portion 12 and the vertical wall portion 22 is reduced.

[0070] Then, in S30, the top plate portions 11, 21 of the two sheets shaped with the two welds 11J are fixed. That is, as shown in Figure 2A the two sheets shaped with the two welds 11J are placed on the first mold 40. At this time, the first member 10 is disposed at a position closer to the second mold 50 side (i.e., the upper side in the vertical direction) than the second member 20. In the line of sight along the moving direction M, the second end portion 22E is disposed at a position closer to the inside than the shoulder portion 54. This is to ensure that the shoulder portion 54 contacts the extension portion 14.

[0071] Then, as shown in Figure 2B the gap between the blank holder 60 and the first mold 40 is closed. Thus, the top plate portions 11, 21 of the two sheets are fixed by the blank holder 60 and the first mold 40.

[0072] Next, in S40, bending is applied to the two sheets. The second mold 50 is moved along the moving direction M in a state where the top plate portions 11, 21 are fixed using the blank holder 60. Then, as shown in Figure 2B the shoulder portion 54 contacts 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 contact the first member 10.

[0073] Then, when the second mold 50 is further moved along the moving direction M from Figure 2B the state shown in Figure 5A the two sheets are pressed by the second mold 50 and are transformed into a bent state.

[0074] Next, in S50, main forming is implemented. When the first mold 40 is further moved along the moving direction M from the state shown in FIG. 6, the two sheet materials are further bent, and the longitudinal wall forming portions 41, 51 and the flange forming portions 42, 52 sandwich the two sheet materials, as shown in FIG. 7. Figure 5A When the second mold 50 is further moved along the moving direction M from the state shown in FIG. 6, the two sheet materials are further bent, and the longitudinal wall forming portions 41, 51 and the flange forming portions 42, 52 sandwich the two sheet materials, as shown in FIG. 7. Figure 5B As shown in FIG. 8, the press working is completed.

[0075] Next, in S60, the longitudinal wall portions 12, 22 are welded. That is, after the longitudinal wall portions 12, 22 are bent, a plurality of welding portions 12J are formed. When the welding of the longitudinal wall portions 12, 22 is completed, the formed product 1 is completed. In addition, drilling, trimming, and the like can be implemented after the welding of the longitudinal wall portions 12, 22 is completed.

[0076] [1-4. Analysis of mold shape]

[0077] Here, the length L of the flange forming portions 42, 52 and the depth D of the depth extension portions 43, 53 in the first mold 40 and the second mold 50 were changed, and the results of the gap size between the longitudinal wall portions 12, 22 were measured and are shown in Table 1 below.

[0078] As shown in Table 1, the length L indicates the length of the flange forming portions 42, 52 in the horizontal direction, and the depth D indicates the length of the depth extension portions 43, 53 in the vertical direction. The value of the gap is a value measured at the position of the welding portion 12J. Figure 2A

[0079] [Table 1]

[0080] L [mm] D [mm] Gap [mm] Example 1 30 45 1.61 Example 2 45 45 1.67 Example 3 60 45 1.95 Example 4 30 60 1.59 Example 5 30 90 1.54

[0081] As shown in Table 1, from the results, as the length L increases, there is a tendency for the size of the gap to increase. It can be considered that the smaller the length L, the greater the amount of deformation when the two sheet materials are bent, and thus the gap decreases.

[0082] In addition, from the results, as the depth D increases, there is a tendency for the size of the gap to decrease. However, if the depth D is increased, this leads to the large-scale of the first mold 40 and the second mold 50, and thus leads to an increase in cost. Therefore, it can be considered that it is preferable that the depth D be substantially the same as the length of the longitudinal wall portions 12, 22 in the vertical direction.

[0083] [1-5. Effects]

[0084] According to the embodiments described above, the following effects can be obtained.

[0085] ​(1a) In the manufacturing method of the above-mentioned shaped product 1, the following process is implemented, that is, the first member 10 and the second member 20 are stacked in a manner that the first member 10 has the protruding portion 14, and the first member 10 and the second member 20 are joined to each other by welding the roof corresponding portion in the stacked state. Further, the following process is implemented, that is, in a state that the roof corresponding portion after the joining is clamped, the second mold 50 is moved along the moving direction M, the second mold 50 is brought into contact with the protruding portion 14, and the longitudinal wall corresponding portions of the plurality of sheet materials and the protruding portion 14 are bent toward the moving direction M side. At this time, the second mold 50 is brought into contact with the protruding portion 14, and the second mold 50 is not brought into contact with any portion of the first member 10 except the protruding portion 14.

[0086] Further, the following process is implemented, in a state that the second mold 50 bends the longitudinal wall corresponding portions and the protruding portion 14, the second mold 50 is further moved along the moving direction M, and the second mold 50 presses the longitudinal wall corresponding portions of the plurality of sheet materials, thereby forming the roof portions 11, 21 and the longitudinal wall portions 12, 22.

[0087] According to the above-mentioned manufacturing method, the roof portions 11, 21 and the longitudinal wall portions 12, 22 can be formed after the second mold 50 is brought into contact with the protruding portion 14 so as to bend the plurality of sheet materials. That is, the roof portions 11, 21 and the longitudinal wall portions 12, 22 are formed after the plurality of sheet materials are slightly bent. Therefore, the longitudinal wall portions 12, 22 can be less likely to be bent back. By making the longitudinal wall portions 12, 22 less likely to be bent back, the gap between the longitudinal wall portions 12, 22 can be reduced, and thus the work such as welding after the press working can be favorably implemented.

[0088] (1b) In one aspect of the present disclosure, the shoulder portion 54 is located at a position on the moving direction M side than an end portion of the longitudinal wall forming portion 51 on the moving direction side, and the shoulder portion 54 has a surface at a position on the outer side than the longitudinal wall portion 51, the surface having an angle with respect to the moving direction M larger than an angle of the longitudinal wall portions 12, 22 with respect to the moving direction M. Further, when the bending is implemented, the second end portion 22E is disposed at a position on the inner side than the shoulder portion 54, and the longitudinal wall corresponding portions of the plurality of sheet materials and the protruding portion 14 are bent toward the moving direction M side by the shoulder portion 54 contacting the protruding portion 14.

[0089] According to the above-mentioned manufacturing method, the structure in which the plurality of sheet materials are bent by the shoulder portion 54 contacting the protruding portion 14 can be achieved.

[0090] (1c) In one aspect of the present disclosure, the second mold 50 is stepped. Further, the second mold 50 has a flange forming portion 52 and a shoulder portion 54 as the plurality of planes forming the stepped shape. When bending is performed, the plurality of plate members are bent toward the moving direction M side by the shoulder portion 54 contacting the protruding portion 14. Further, when the top plate portions 11, 21 and the vertical wall portions 12, 22 are formed, the flange portions 13 extending outward from the vertical wall portions 12, 22 are formed by the flange forming portion 52 contacting the protruding portion 14.

[0091] According to the above manufacturing method, when the formed product 1 having the flange portions 13 is manufactured, the top plate portions 11, 21 and the vertical wall portions 12, 22 can be formed after the plurality of plate members are bent.

[0092] (1d) In one aspect of the present disclosure, when the top plate portions 11, 21 and the vertical wall portions 12, 22 are formed, the flange portions 13 are completed at a position inside the shoulder portions 54. Alternatively, the shoulder portions 54, 72, 82 start forming the flange portions 13 while contacting the flange portions 13, and then the flange portions 13 can be completed at a position inside the shoulder portions 54, 72, 82.

[0093] According to the above manufacturing method, the shoulder portions 54 can be contacted with the plurality of plate members from the outside, and thus the top plate portions 11, 21 and the vertical wall portions 12, 22 can be formed after the plurality of plate members are sufficiently bent.

[0094] (1e) In one aspect of the present disclosure, the plate thickness of the second member 20 is greater than or equal to the plate thickness of the first member 10.

[0095] According to the above manufacturing method, the second moment of area of the first member 10 is easily equal to or less than the second moment of area of the second member 20, and thus the effect of bending the first member 10 is easily obtained. As a result, a configuration in which the first member 10 is less likely to be bent and return, and a gap between the first member 10 and the second member 20 is less likely to occur, can be achieved.

[0096] (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 each other at the vertical wall portions 12, 22.

[0097] According to the above manufacturing method, since the vertical wall portions 12, 22 are less likely to be bent and return, a gap between the first member 10 and the second member 20 is reduced. Thus, the welding work can be performed favorably.

[0098] (1g) In one aspect of the present disclosure, the formed product 1 can be a member of an automobile. According to the above manufacturing method, the formed product 1, which is a member of an automobile, can be manufactured favorably.

[0099] [2. Other Embodiments]

[0100] The above describes embodiments of the present disclosure, but the present disclosure is not limited to the above-described embodiments and can be implemented in various modifications.

[0101] (2a) In the above-described embodiment, the press forming device 100 is used, but for example, a press forming device 110 of a first modified example as shown in Figs. 10A and 10B can be used. In the press forming device 100 of the above-described embodiment, the configuration in which the second die 50 moves in the vertical direction is exemplified, but in the press forming device 110 of the first modified example, the second die 70 as a cam is provided instead of the second die 50. The second die 70 has a longitudinal wall forming portion 71 and a flange forming portion 72 (shoulder portion in the present disclosure). In addition, the first die 40 has only the longitudinal wall forming portion 41 and the flange forming portion 42. Figure 6A and 6B In the press forming device 110 of the first modified example, the second die 70 is provided instead of the second die 50. The second die 70 has a longitudinal wall forming portion 71 and a flange forming portion 72 (shoulder portion in the present disclosure). In addition, the first die 40 has only the longitudinal wall forming portion 41 and the flange forming portion 42.

[0102] As shown in Figs. 10A and 10B, the moving direction M of the second die 70 is set to a direction from obliquely above the two sheets toward the two sheets. That is, the moving direction M of the second die 70 is a direction in which a downward component in the vertical direction and a component in a direction from the outer side to the inner side are combined. Figure 6A According to the above-described configuration, when the second die 70 moves in the moving direction M, as shown by the double-dotted line in Fig. 10A, the flange forming portion 72 first contacts the protruding portion 14, and the two sheets are bent as the second die 70 further moves. Further, as shown in Fig. 10B, the longitudinal wall portions 12, 22 and the flange portion 13 are formed.

[0103] Figure 6A According to the above-described configuration, when the second die 70 moves in the moving direction M, as shown by the double-dotted line in Fig. 10A, the flange forming portion 72 first contacts the protruding portion 14, and the two sheets are bent as the second die 70 further moves. Further, as shown in Fig. 10B, the longitudinal wall portions 12, 22 and the flange portion 13 are formed. Figure 6B

[0104] (2b) In addition, for example, a press forming device 120 of a second modified example as shown in Figs. 11A and 11B can be used instead of the press forming device 100 of the above-described embodiment. The press forming device 120 of the second modified example is a device for obtaining a formed product that does not have the flange portion 13, that is, a device for obtaining a formed product that has only the ceiling portions 11, 21 and the longitudinal wall portions 12, 22. Figure 7A and Figure 7B The press forming device 120 of the second modified example is a device for obtaining a formed product that does not have the flange portion 13, that is, a device for obtaining a formed product that has only the ceiling portions 11, 21 and the longitudinal wall portions 12, 22.

[0105] The press forming device 120 of the second modified example has a second die 80 instead of the second die 50. The second die 80 has a longitudinal wall forming portion 81 and a shoulder portion 82. The shoulder portion 54 of the above-described embodiment extends in the horizontal direction, but the shoulder portion 82 of the second modified example has an inclined surface that inclines toward the moving direction M side as it tends toward the outer side. The shoulder portion 82 is also configured to have a surface that has an angle with respect to the moving direction M that is larger than an angle of the longitudinal wall portions 12, 22 with respect to the moving direction M.​​

[0106] According to the above configuration, the shoulder portion 82 also contacts the two boards before the longitudinal wall forming portion 81 contacts the two boards, so the two boards can be bent first and then subjected to press forming. Thus, bending springback is less likely to occur.

[0107] (2c) Alternatively, the second mold 50 can have a shoulder portion configured as a curved surface. In this case, the angle between a plane extending along the tangent line of the curved surface and the moving direction M can be set to be larger than the angle between a plane extending along the longitudinal wall portion 12, 22 and the moving direction M.

[0108] According to the above configuration, the two boards can be bent first and then subjected to press forming.

[0109] (2d) The formed product 1 is exemplified as a saddle shape having the longitudinal wall portions 12, 22 on both sides of the top plate portions 11, 21, but the configuration of the formed product 1 is not limited thereto. For example, the formed product 1 can be configured as a shape having a single-side bend, i.e., having the longitudinal wall portions 12, 22 on only one side of the top plate portions 11, 21.

[0110] (2e) One of the constituent elements in the above-described embodiments can have a plurality of functions, or one function, which can be realized by a plurality of constituent elements. In addition, a plurality of constituent elements in the above-described embodiments can have a plurality of functions, or one function, which can be realized by one constituent element. Furthermore, a part of the configuration of the above-described embodiments can be omitted. Furthermore, at least a part of the configuration of the above-described embodiments can be added to, or replaced with, the configuration of the other embodiments, and the like.

[0111] (2f) The present disclosure can be realized by various means other than the above-described method of manufacturing a formed product, such as a formed product having a top plate portion and a longitudinal wall portion.

Claims

1. A method of manufacturing a formed product by press-forming a plurality of panels in a stacked state to obtain a formed product having a top panel portion and a vertical wall portion, the method of manufacturing a formed product characterized by comprising the steps of: stacking a first member and a second member in such a manner that the first member has a protruding portion, and joining the first member and the second member to each other by welding a first top panel corresponding portion and a second top panel corresponding portion in the stacked state; bending, in a state in which the first top panel corresponding portion and the second top panel corresponding portion after the joining are clamped, a first vertical wall corresponding portion, a second vertical wall corresponding portion, and the protruding portion of the plurality of panels toward a side of a moving direction by moving a mold along the moving direction so that the mold contacts the protruding portion; and forming the top panel portion and the vertical wall portion by further moving the mold along the moving direction in a state in which the first vertical wall corresponding portion, the second vertical wall corresponding portion, and the protruding portion are bent by the mold so that the mold presses the first vertical wall corresponding portion and the second vertical wall corresponding portion of the plurality of panels, wherein the first member and the second member are provided as the plurality of panels, the first member has the first top panel corresponding portion, the first vertical wall corresponding portion, and the protruding portion, the first top panel corresponding portion indicates a portion corresponding to a part of a top panel portion of a formed product, the first vertical wall corresponding portion indicates a portion corresponding to at least a part of a vertical wall portion of the formed product, the second member is in a state of being stacked with the first member and has the second top panel corresponding portion and the second vertical wall corresponding portion, the second top panel corresponding portion indicates a portion corresponding to another part of the top panel portion of the formed product, the second vertical wall corresponding portion indicates a portion corresponding to at least another part of the vertical wall portion of the formed product, in any plane parallel to the plurality of panels, a direction from the first vertical wall corresponding portion and the second vertical wall corresponding portion toward the first top panel corresponding portion and the second top panel corresponding portion is an inner side, and a direction from the first vertical wall corresponding portion and the second vertical wall corresponding portion toward an opposite side of the first top panel corresponding portion and the second top panel corresponding portion is an outer side, in addition, an end portion of the first member located on the outer side is a first end portion, an end portion of the second member located on the outer side is a second end portion, the first end portion is located at a position closer to the outer side than the second end portion, the protruding portion indicates a region of the first member from the first end portion to a portion up to which the second end portion is stacked, and the moving direction is a direction from the first member side toward the second member side.

2. The method of manufacturing a formed product according to claim 1, wherein the mold has: a vertical wall forming portion for forming the vertical wall portion; and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ a shoulder portion located at a position closer to the moving direction side than an end portion of the longitudinal wall portion on the moving direction side, and having a surface at a position closer to the outer side than the shoulder portion, the surface making an angle with the moving direction larger than an angle made by the longitudinal wall portion with the moving direction, the second end portion is arranged at a position closer to the inner side than the shoulder portion when the bending is performed, the first longitudinal wall corresponding portion, the second longitudinal wall corresponding portion, and the protruding portion of the plurality of plates are bent toward the moving direction side by the shoulder portion contacting the protruding portion when the bending is performed.

3. The method of manufacturing a formed product according to claim 1 or 2, wherein the mold is a stepped shape that is a shape having a plurality of planes substantially parallel to the top plate portion, the plurality of planes include a first plane on a proximal side of the moving direction and a second plane on a distal side of the moving direction, the first longitudinal wall corresponding portion, the second longitudinal wall corresponding portion, and the protruding portion of the plurality of plates are bent toward the moving direction side by the second plane contacting the protruding portion when the bending is performed, a flange portion extending from the longitudinal wall portion toward the outer side is formed by the first plane contacting the protruding portion when the top plate portion and the longitudinal wall portion are formed.

4. The method of manufacturing a formed product according to claim 2, wherein a flange portion extending from the longitudinal wall portion toward the outer side is completed at a position closer to the inner side than the shoulder portion when the top plate portion and the longitudinal wall portion are formed.

5. The method of manufacturing a formed product according to any one of claims 1 to 4, wherein a plate thickness of the second member is larger than or equal to a plate thickness of the first member.

6. The method for producing a shaped article according to any one of claims 1 to 5, characterized in that, the following process is further performed: the first member and the second member are welded at the longitudinal wall portion after the top plate portion and the longitudinal wall portion are formed.

7. The method of manufacturing a formed product according to any one of claims 1 to 6, wherein the formed product is a member of an automobile.

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