Method for producing press-molded article

Abstract

The present disclosure relates to a method for manufacturing a press-molded article. The method for manufacturing a press-molded article includes: forming a through-hole in a workpiece; a bending step for bending the workpiece in which the through-hole part is formed, and molding an intermediate molded article in which the first wall part, the second wall part, and the bent part are formed; and obtaining a press-molded article by removing the excess portion from the intermediate molded article. The through portion is formed on the workpiece such that the through portion is located at a position where a boundary line between the second wall portion and the excess portion intersects the bent portion in the intermediate molded article. And cutting the intermediate molded article along a boundary line between the first wall portion and the excess portion from a direction intersecting the first wall portion, and cutting the intermediate molded article along a boundary line between the second wall portion and the excess portion from a direction intersecting the second wall portion, thereby removing the excess portion from the intermediate molded article.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a press-formed product including a first wall portion, a second wall portion intersecting the first wall portion, and a bent portion connecting the first wall portion and the second wall portion to each other. Background Art

[0002] After stamping, the ends of a stamped product may deviate from the target shape. For example, Japanese Patent Publication No. 2020-62664 proposes a method of forming an intermediate formed product with an excess portion at the end by stamping, and then removing the excess portion from the intermediate formed product by trimming. According to the method described in Japanese Patent Publication No. 2020-62664, it is easy to obtain a stamped product with a target shape. Summary of the invention

[0003] However, for example, the intermediate molded product described in Japanese Patent Publication No. 2020-62664 has a top plate portion and a vertical wall portion, and a portion of the vertical wall portion is included in the redundant portion. In this case, when the redundant portion is removed from the intermediate molded product by trimming, the load applied to the trimming blade is likely to increase.

[0004] One aspect of the present disclosure is intended to provide a technology for reducing the load applied to a trimming blade when removing excess portions from an intermediate formed product through trimming in a manufacturing method of a stamped product, wherein the stamped product has a first wall portion, a second wall portion intersecting the first wall portion, and a bent portion connecting the first wall portion and the second wall portion to each other.

[0005] One aspect of the present disclosure is a method for manufacturing a stamped product, the stamped product having a first wall portion, a second wall portion intersecting the first wall portion, and a bent portion connecting the first wall portion and the second wall portion. The method for manufacturing the stamped product includes the following (i) to (iii).

[0006] (i) A through portion penetrating the workpiece is formed in the workpiece.

[0007] (ii) The workpiece having the through portion formed therein is bent to produce an intermediate molded product having the first wall portion, the second wall portion, and the bent portion formed therein.

[0008] (iii) A press-formed product is obtained by removing an excess portion from the intermediate formed product, wherein the excess portion is a portion continuous with each of the first wall portion, the second wall portion, and the bent portion of the intermediate formed product.

[0009] The through portion is formed on the workpiece in such a manner that the through portion is located at a position where the boundary line between the second wall portion and the redundant portion intersects with the bent portion in the intermediate formed product. The intermediate formed product is cut along the boundary line between the first wall portion and the redundant portion from a direction intersecting with the first wall portion, and the intermediate formed product is cut along the boundary line between the second wall portion and the redundant portion from a direction intersecting with the second wall portion, thereby removing the redundant portion from the intermediate formed product.

[0010] According to the above configuration, in the method for manufacturing a press-formed product, when removing an excess portion from the intermediate formed product by the trimming process, the load applied to the trimming blade can be reduced.

[0011] In one embodiment of the present disclosure, the through-portion can be formed on the workpiece in such a manner that the region in the intermediate formed product where the through-portion is formed at least overlaps with the bent portion in a cross-sectional view perpendicular to the ridgeline of the workpiece. According to the above configuration, in the manufacturing method of a stamped product, when the excess portion is removed from the intermediate formed product by trimming, the load applied to the trimming blade can be further reduced.

[0012] In one embodiment of the present disclosure, at least a portion of the second wall portion may be bent in a manner protruding toward the first wall portion. In the above configuration, the problem of an increased load on the trimming blade is more likely to occur. Therefore, when the excess portion is removed from the intermediate molded product by trimming, it is more conducive to reducing the load on the trimming blade.

[0013] In one embodiment of the present disclosure, the intermediate formed product can be cut along the boundary line between the first wall portion and the redundant portion from a direction perpendicular to the first wall portion, and the intermediate formed product can be cut along the boundary line between the second wall portion and the redundant portion from a direction perpendicular to the second wall portion. According to the above configuration, in the manufacturing method of the stamped product, when the redundant portion is removed from the intermediate formed product by trimming, the load applied to the trimming blade can be further reduced.

[0014] In one aspect of the present disclosure, the workpiece may be made of high tensile strength steel. In the above configuration, the problem of the load applied to the trimming blade being easily increased is more likely to occur. Therefore, when the excess portion is removed from the intermediate formed product by trimming, it is easier to reduce the load applied to the trimming blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a perspective view of the press-formed product according to the first embodiment.

[0016] Figure 2 This is another perspective view of the press-formed product according to the first embodiment.

[0017] Figure 3 It is a front view of the press-formed product according to the first embodiment.

[0018] Figure 4 This is a flowchart of the method for manufacturing a press-formed product according to the first embodiment.

[0019] Figure 5 It is a plan view of the workpiece after the punching step of the first embodiment is performed.

[0020] Figure 6 It is a perspective view of an intermediate molded product molded in the intermediate molding step of the first embodiment.

[0021] Figure 7 This is another perspective view of the intermediate molded product formed in the intermediate molding step of the first embodiment.

[0022] Figure 8 yes Figure 7 Cross-sectional view along line VIII-VIII.

[0023] Fig. 9 This is a perspective view of the intermediate molded product after the first trimming step of the first embodiment has been performed.

[0024] Fig.10 It is a perspective view of a press-formed product according to the second embodiment.

[0025] Fig.11 It is a perspective view of an intermediate molded product formed in the intermediate molding step of the second embodiment.

[0026] Fig. 12A It is a perspective view of an intermediate molded product for illustrating a modified example of the through portion.

[0027] Fig. 12B It is a perspective view of an intermediate molded product for illustrating another modified example of the through portion. DETAILED DESCRIPTION

[0028] Exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings.

[0029] [1. First embodiment]

[0030] [1-1. Composition of stamped products]

[0031] Figure 1 to Figure 3 The stamped product 1 shown is a component of the automobile body. The stamped product 1 is made of a high-tensile strength steel material with a relatively high tensile strength. For example, the stamped product 1 can be made of a high-tensile strength steel material with a tensile strength of 980 MPa or more, or can be made of a high-tensile strength steel material with a tensile strength of 1180 MPa or more. The stamped product 1 of this embodiment is made of a high-tensile strength steel material with a tensile strength of 1470 MPa.

[0032] The press-formed product 1 includes a first wall portion 11 , a second wall portion 12 , a third wall portion 13 , a first bent portion 14 , and a second bent portion 15 .

[0033] The first wall portion 11 is a plate-shaped portion extending in a predetermined direction. The first wall portion 11 has, for example, a flat plate shape. The first wall portion 11 has a fixed width portion 111 and a widened portion 112. The fixed width portion 111 and the widened portion 112 are continuous with each other in the extending direction of the first wall portion 11. The fixed width portion 111 is a portion having a fixed width. The widened portion 112 is a portion whose width increases as it moves away from the fixed width portion 111. The widths of the fixed width portion 111 and the widened portion 112 are the widths of the fixed width portion 111 and the widened portion 112. Figure 3 The lengths of the fixed width portion 111 and the widened portion 112 in the direction perpendicular to the center line W of the first wall portion 11 are shown. The center line W of the first wall portion 11 extends along the extension direction of the first wall portion 11. The center line W of the first wall portion 11 is bent toward the first bent portion 14 at the widened portion 112.

[0034] like Figure 1 and Figure 2 As shown, the second wall portion 12 is a plate-shaped portion intersecting the first wall portion 11. The second wall portion 12 is, for example, substantially perpendicular to the first wall portion 11. The second wall portion 12 is continuous with an edge of the first wall portion 11 on one side perpendicular to the direction of the center line W via the first curved portion 14. The second wall portion 12 extends along the edge of the first wall portion 11. In other words, the second wall portion 12 extends along the first curved portion 14. The length of the second wall portion 12 along the first curved portion 14 is shorter than the length of the first wall portion 11 along the first curved portion 14.

[0035] The third wall portion 13 is a plate-shaped portion intersecting with the first wall portion 11. The third wall portion 13 is, for example, substantially perpendicular to the first wall portion 11. The third wall portion 13 is opposed to the second wall portion 12. The third wall portion 13 is continuous with the other side edge of the first wall portion 11 in the direction perpendicular to the center line W (that is, the edge on the opposite side of the second wall portion 12) via the second curved portion 15. The third wall portion 13 extends along the edge of the first wall portion 11. In other words, the third wall portion 13 extends along the second curved portion 15. The length of the third wall portion 13 along the second curved portion 15 is substantially equal to the length of the first wall portion 11 along the second curved portion 15.

[0036] The first curved portion 14 is a portion extending between the first wall portion 11 and the second wall portion 12 along the edge of the adjacent first wall portion 11. The first curved portion 14 connects the first wall portion 11 and the second wall portion 12. The cross-sectional shape of the first curved portion 14 perpendicular to the extending direction is an arc shape.

[0037] like Figure 3As shown, at least a portion of the ridgeline of the first curved portion 14 is curved in a manner protruding toward the first wall portion 11. This can also be said to mean that at least a portion of the second wall portion 12 is curved in a manner protruding toward the first wall portion 11. In the present embodiment, the portion of the second wall portion 12 that is continuous with the widened portion 112 of the first wall portion 11 is curved in a manner protruding toward the first wall portion 11. That is, in the present embodiment, the ridgeline of the portion of the first curved portion 14 that connects the widened portion 112 of the first wall portion 11 and the second wall portion 12 to each other is curved in a manner protruding toward the first wall portion 11.

[0038] like Figure 1 and Figure 2 As shown, the second curved portion 15 is a portion extending along the edge of the adjacent first wall portion 11 between the first wall portion 11 and the third wall portion 13. The second curved portion 15 connects the first wall portion 11 and the third wall portion 13. The cross-sectional shape of the second curved portion 15 perpendicular to the extending direction is an arc shape.

[0039] [1-2. Method for manufacturing press-formed product]

[0040] like Figure 4 As shown, the method for manufacturing the press-formed product 1 includes a punching step S1 , an intermediate forming step S2 , a first trimming step S3 , and a second trimming step S4 .

[0041] [1-2-1. Punching process]

[0042] In the punching step S1, a punching process is performed on a workpiece 2. The workpiece 2 is a plate-shaped member that is a material of the press-formed product 1. The workpiece 2 before the punching step S1 is in the shape of a flat plate.

[0043] In the punching step S1, the following peripheral portion removal process and through-portion forming process are performed as one process. In other words, the above processes are performed simultaneously. Figure 5 The workpiece 2 is shown after the punching step S1 is performed (that is, after all the processing included in the punching step S1 is performed).

[0044] <Outer periphery removal processing>

[0045] In the peripheral portion removal process, the peripheral portion of the workpiece 2 is removed by punching. Thus, the workpiece 2 is formed into Figure 5 The workpiece 2 after the peripheral portion removal process includes a first formed portion 21 , a second formed portion 22 , a third formed portion 23 , and an excess portion 24 .

[0046] The first formed portion 21 is a portion corresponding to the first wall portion 11 in the finished press-formed product 1. In other words, the first formed portion 21 is a portion that forms the first wall portion 11.

[0047] The second formed portion 22 is a portion corresponding to the second wall portion 12 in the finished press-formed product 1. In other words, the second formed portion 22 is a portion that forms the second wall portion 12. The second formed portion 22 is continuous with the first formed portion 21.

[0048] The third formed portion 23 is a portion corresponding to the third wall portion 13 in the finished press-formed product 1. In other words, the third formed portion 23 is a portion forming the third wall portion 13. The third formed portion 23 is continuous with the first formed portion 21 on the side opposite to the second formed portion 22 side.

[0049] The redundant portion 24 is a portion that is removed during the process of manufacturing the press-formed product 1 from the workpiece 2. The redundant portion 24 is provided at a corner of the workpiece 2. The redundant portion 24 is continuous with both the first formed portion 21 and the second formed portion 22. Specifically, the redundant portion 24 is continuous with both of the following two portions, the two portions including a portion of the first formed portion 21 corresponding to the widened portion 112 of the first wall portion 11, and a portion of the second formed portion 22 continuous with the portion of the first formed portion 21.

[0050] The boundary line X1 between the first molded portion 21 and the second molded portion 22 forms one line with the boundary line X2 between the first molded portion 21 and the redundant portion 24. The boundary line X3 between the second molded portion 22 and the redundant portion 24 intersects both the boundary line X1 between the first molded portion 21 and the second molded portion 22 and the boundary line X2 between the first molded portion 21 and the redundant portion 24.

[0051] <Through-portion forming process>

[0052] In the through-portion forming process, a through-portion is formed on the workpiece 2 by punching. Figure 5 The through-portion 25 shown in the figure is a hole that penetrates the workpiece 2 in the thickness direction. The through-portion 25 is, for example, a circular hole.

[0053] The through portion 25 is formed at a position where the boundary line X1 between the first formed portion 21 and the second formed portion 22 intersects with the boundary line X3 between the second formed portion 22 and the redundant portion 24 in the workpiece 2. In other words, the through portion 25 is formed at a position where the first formed portion 21, the second formed portion 22, and the redundant portion 24 are connected to each other in the workpiece 2.

[0054] [1-2-2. Intermediate forming process]

[0055] In the intermediate forming step S2, the workpiece 2 after the punching step S1 is subjected to a punching process. Figure 6 and Figure 7The intermediate formed product 3 shown in FIG. 1 is a workpiece 2 formed by a first bending process, a second bending process, a first wall portion forming process, a second wall portion forming process, and a third wall portion forming process. In other words, the above processes are performed simultaneously. The intermediate formed product 3 is the workpiece 2 after all the processes included in the intermediate forming process S2 have been performed (i.e., after the intermediate forming process S2 has been performed).

[0056] <First bending process>

[0057] In the first bending process, Figure 5 As shown by the hollow arrow in FIG, the workpiece 2 after the punching step S1 is bent by a stamping process along the boundary line X1 between the first formed portion 21 and the second formed portion 22. As a result, the first bent portion 14 is formed on the workpiece 2. The first bent portion 14 corresponds to the portion of the workpiece 2 that is bent along the boundary line X1 between the first formed portion 21 and the second formed portion 22.

[0058] In the present embodiment, the boundary line X1 between the first formed portion 21 and the second formed portion 22 and the boundary line X2 between the first formed portion 21 and the redundant portion 24 form a line. Therefore, in the present embodiment, the workpiece 2 after the punching step S1 is bent along the continuous boundary lines X1 and X2. Figure 6 The redundant curved portion 311a and the first curved portion 14 are shown. The redundant curved portion 311a is a portion linearly connected to the first curved portion 14. The redundant curved portion 311a corresponds to a portion of the workpiece 2 that is bent along the boundary line X2 between the first formed portion 21 and the redundant portion 24. The cross-sectional shape of the redundant curved portion 311a perpendicular to the extension direction is an arc shape.

[0059] <Second bending process>

[0060] In the second bending process, Figure 5 As shown by the hollow arrow in FIG, the workpiece 2 after the punching step S1 is bent by a stamping process along the boundary line X4 between the first formed portion 21 and the third formed portion 23. Thus, the second bent portion 15 is formed on the workpiece 2. The second bent portion 15 corresponds to the portion of the workpiece 2 that is bent along the boundary line X4 between the first formed portion 21 and the third formed portion 23.

[0061] <First Wall Forming Process>

[0062] In the first wall portion forming process, the first formed portion 21 is formed by press working into a shape designed as the first wall portion 11. Thus, the first wall portion 11 is formed on the workpiece 2.

[0063] <Second Wall Formation Process>

[0064] In the second wall portion forming process, the second formed portion 22 is formed by press working into a shape designed as the second wall portion 12 . Thus, the second wall portion 12 is formed on the workpiece 2 .

[0065] <Third wall forming process>

[0066] In the third wall portion forming process, the third formed portion 23 is formed into a shape designed as the third wall 13 by press working. Thus, the third wall portion 13 is formed on the workpiece 2.

[0067] like Figure 6 and Figure 7 As shown, the intermediate formed product 3 obtained by the intermediate forming step S2 includes the first wall portion 11, the second wall portion 12, the third wall portion 13, the first curved portion 14, the second curved portion 15, the redundant portion 31, and the through portion 25. The redundant portion 31 is a portion corresponding to the redundant portion 24 in the workpiece 2 before the intermediate forming step S2 is performed. The redundant portion 31 is provided at the end of the intermediate formed product 3. The redundant portion 31 includes the above-mentioned redundant curved portion 311a. The redundant portion 31 is continuous with each of the first wall portion 11, the second wall portion 12, and the first curved portion 14. The boundary line Y1 between the first wall portion 11 and the redundant portion 31 intersects with the boundary line Y2 between the second wall portion 12 and the redundant portion 31.

[0068] In the intermediate molded product 3, the through portion 25 is located at a position where the boundary line Y2 between the second wall portion 12 and the redundant portion 31 intersects with the first bent portion 14. In the through portion forming process of the above-mentioned punching step S1, the through portion 25 is formed on the workpiece 2 in such a manner that the through portion 25 is located at a position where the boundary line Y2 between the second wall portion 12 and the redundant portion 31 intersects with the first bent portion 14 in the intermediate molded product 3. The position where the boundary line Y2 between the second wall portion 12 and the redundant portion 31 intersects with the first bent portion 14 substantially coincides with the position where the boundary line Y1 between the first wall portion 11 and the redundant portion 31 intersects with the boundary line Y2 between the second wall portion 12 and the redundant portion 31.

[0069] In the following, in the cross-sectional view perpendicular to the ridge line of the first curved portion 14 (ie, Figure 8 The direction along the plate surface of the first curved portion 14 (as shown in FIG. 1 ) is referred to as the bending direction D of the first curved portion 14. In the intermediate formed product 3, the region where the through portion 25 is formed in the bending direction D of the first curved portion 14 includes the first curved portion 14. In the intermediate formed product 3 of the present embodiment, the region where the through portion 25 is formed in the bending direction D of the first curved portion 14 coincides with the first curved portion 14. In other words, in the intermediate formed product 3 of the present embodiment, the through portion 25 extends from one end of the first curved portion 14 in the bending direction D to the other end.

[0070] In the through-portion forming process of the above-mentioned punching step S1, the through-portion 25 is formed on the workpiece 2 in such a manner that the area where the through-portion 25 is formed in the intermediate molded product 3 at least overlaps with the first bent portion 14 in a cross-sectional view perpendicular to the ridgeline of the first bent portion 14.

[0071] [1-2-3. The first trimming process]

[0072] like Figure 6 As shown, the redundant portion 31 is composed of a first portion 311 and a second portion 312. The first portion 311 includes the above-mentioned redundant curved portion 311a. The first portion 311 is divided by the outer edge of the redundant portion 31, the boundary line Y1 between the first wall portion 11 and the redundant portion 31 (more specifically, the boundary line between the first wall portion 11 and the redundant curved portion 311a), and the cutting line Y3. The second portion 312 is divided by the outer edge of the redundant portion 31, the boundary line Y2 between the second wall portion 12 and the redundant portion 31, and the cutting line Y3. The cutting line Y3 is a virtual line extending from the through portion 25 to the outer edge of the redundant portion 31. The cutting line Y3 intersects with the boundary line Y1 between the first wall portion 11 and the redundant portion 31, and the boundary line Y2 between the second wall portion 12 and the redundant portion 31.

[0073] In the first trimming step S3, the intermediate molded product 3 formed in the intermediate molding step S2 is trimmed. Thus, the second portion 312 of the excess portion 31 is removed. In the first trimming step S3, the following first cutting and second cutting are performed as one step. In other words, the above-mentioned processes are performed simultaneously. Fig. 9 The intermediate molded product 3 is shown after the first trimming step S3 is performed (that is, after all the processing included in the first trimming step S3 is performed).

[0074] <1st cutting process>

[0075] In the first cutting process, the intermediate molded product 3 formed in the intermediate molding step S2 is cut along the boundary line Y2 between the second wall portion 12 and the excess portion 31 by trimming. The boundary line Y2 between the second wall portion 12 and the excess portion 31 corresponds to the line cut by the trimming process (the so-called trimming line). Figure 6 As shown by the hollow arrow in FIG. 1 , the intermediate formed product 3 formed in the intermediate forming step S2 is cut from a direction intersecting with the second wall portion 12. For example, the intermediate formed product 3 is cut in a direction perpendicular to the second wall portion 12. The cutting direction of the intermediate formed product 3 is consistent with the displacement direction of the trimming blade used for trimming. The same applies to the following.

[0076] <Second Cutting Process>

[0077] In the second cutting process, the intermediate formed product 3 formed in the intermediate forming step S2 is cut along a cutting line Y3 by trimming. The cutting line Y3 corresponds to a so-called trimming line. Figure 6 As shown by the hollow arrow in , the intermediate molded product 3 formed in the intermediate molding step S2 is cut from a direction intersecting with the second wall portion 12. For example, the intermediate molded product 3 is cut along a direction perpendicular to the second wall portion 12.

[0078] [1-2-4. Second trimming process]

[0079] In the second trimming step S4, Fig. 9 As shown, the intermediate molded product 3 after the first trimming step S3 is trimmed. Thus, the first portion 311 of the redundant portion 31 is removed. Specifically, the intermediate molded product 3 after the first trimming step S3 is cut along the boundary line Y1 between the first wall portion 11 and the redundant portion 31 by the trimming process. The boundary line Y1 between the first wall portion 11 and the redundant portion 31 corresponds to the so-called trimming line. Fig. 9 As shown by the hollow arrow in , the intermediate molded product 3 after the first trimming step S3 is cut from a direction intersecting the first wall portion 11. For example, the intermediate molded product 3 is cut along a direction perpendicular to the first wall portion 11.

[0080] The first trimming step S3 and the second trimming step S4 remove the excess portion 31 from the intermediate molded product 3. Figure 1 to Figure 3 The stamped product 1 is shown.

[0081] [1-3. Effect]

[0082] According to the first embodiment described in detail above, the following effects can be obtained.

[0083] (1a) The press-formed product 1 includes a first wall portion 11, a second wall portion 12, and a first bent portion 14. In the manufacturing method of the press-formed product 1 of the present embodiment, an intermediate formed product 3 having the first wall portion 11, the second wall portion 12, and the first bent portion 14 is formed by bending the workpiece 2. Thereafter, an excess portion 31 is removed from the intermediate formed product 3, thereby obtaining the press-formed product 1.

[0084] Here, as a method for manufacturing the stamped product 1, a method of directly forming the stamped product 1 by bending the workpiece 2 without providing the excess portion 24 on the workpiece 2 may also be considered. That is, a method of directly manufacturing the stamped product 1 from the workpiece 2 without passing through the intermediate formed product 3 may also be considered. However, in this case, in the finished stamped product 1, cracks may be generated from the end of the first bent portion 14 in the extension direction.

[0085] Compared with the case where the stamped product 1 is manufactured directly from the workpiece 2 without passing through the intermediate formed product 3, the manufacturing method of this embodiment can suppress the occurrence of cracks in the stamped product 1. Therefore, the stamped product 1 having the target shape can be easily obtained.

[0086] (1b) In the manufacturing method of the press-formed product 1 of the present embodiment, the intermediate formed product 3 is cut along the boundary line Y1 between the first wall portion 11 and the excess portion 31 from the direction intersecting the first wall portion. In addition, the intermediate formed product 3 is cut along the boundary line Y2 between the second wall portion 12 and the excess portion 31 from the direction intersecting the second wall portion 12. Thus, the excess portion 31 is removed from the intermediate formed product 3, thereby obtaining the press-formed product 1.

[0087] Compared to, for example, the case where the intermediate molded product 3 is cut from a direction parallel to the first wall portion 11 along the boundary line Y1 between the first wall portion 11 and the redundant portion 31, or compared to the case where the intermediate molded product 3 is cut from a direction parallel to the wall portion 12 along the boundary line Y2 between the second wall portion 12 and the redundant portion 31, the above-mentioned configuration can reduce the size of the cut portion in the intermediate molded product 3 along the cutting direction. That is, the size of the portion of the intermediate molded product 3 that the trimming blade should pass through can be reduced. Therefore, the load applied to the trimming blade can be reduced.

[0088] (1c) For example, the intermediate molded product 3 is cut along the boundary line Y1 between the first wall portion 11 and the redundant portion 31 from a direction perpendicular to the first wall portion 11. In addition, for example, the intermediate molded product 3 is cut along the boundary line Y2 between the second wall portion 12 and the redundant portion 31 from a direction perpendicular to the second wall portion 12. According to the above configuration, the load applied to the trimming blade can be further reduced.

[0089] (1d) In the manufacturing method of the stamped product 1 of the present embodiment, the through portion 25 is formed on the workpiece 2 before the workpiece 2 is bent. The through portion 25 is formed on the workpiece 2 in such a manner that the through portion 25 is located at a position where the boundary line Y2 between the second wall portion 12 and the redundant portion 31 intersects the first bent portion 14 in the intermediate formed product 3.

[0090] According to the above configuration, when the intermediate molded product 3 is cut along the boundary line Y1 between the first wall portion 11 and the redundant portion 31 from the direction intersecting with the first wall portion 11, it is possible to suppress the intermediate molded product 3 from being cut along the direction parallel to the first bent portion 14 at the edge of the first curved portion 14 located on the redundant portion 31 side. In addition, when the intermediate molded product 3 is cut along the boundary line Y2 between the second wall portion 12 and the redundant portion 31 from the direction intersecting with the second wall portion 12, it is possible to suppress the intermediate molded product 3 from being cut along the direction parallel to the first curved portion 14 at the edge of the first curved portion 14 located on the redundant portion 31 side. Therefore, the size of the cut portion in the intermediate molded product 3 along the cutting direction can be further reduced. Therefore, the load applied to the trimming blade can be further reduced.

[0091] (1e) In the manufacturing method of the stamped product 1 of the present embodiment, the through portion 25 is formed on the workpiece 2 in such a manner that the region in the intermediate formed product 3 where the through portion 25 is formed at least overlaps with the first bent portion 14 in a cross-sectional view perpendicular to the ridgeline of the first bent portion 14. According to the above configuration, the effect of (1d) above can be further enhanced.

[0092] (1f) In the manufacturing method of the stamped product 1 of the present embodiment, the peripheral portion removal process and the through-portion forming process are performed in one process called the punching process S1. According to the above configuration, the through-portion 25 can be formed on the workpiece 2 without increasing the number of processes. Therefore, the effects of (1d) and (1e) above can be obtained without increasing the number of processes.

[0093] (1g) At least a portion of the second wall portion 12 of the stamped product 1 is bent in a manner that protrudes toward the first wall portion 11. According to the above-mentioned structure, in the case where it is assumed that the stamped product 1 is manufactured directly from the workpiece 2 without passing through the intermediate formed product 3, cracks are likely to occur in the stamped product 1. Therefore, it is easy to adopt a method of manufacturing the stamped product 1 from the workpiece 2 via the intermediate formed product 3. On the other hand, the use of this method is prone to the problem that the load applied to the trimming blade is likely to increase when the excess portion 31 is removed from the intermediate formed product 3. Therefore, as described in (1b) above, the application of the manufacturing method of this embodiment is conducive to reducing the load applied to the trimming blade.

[0094] (1h) The workpiece 2 is made of high tensile strength steel. In the above configuration, when the excess portion 31 is removed from the intermediate formed product 3, the load applied to the trimming blade is prone to occur. Therefore, as described in (1b) above, the manufacturing method of this embodiment is more conducive to reducing the load applied to the trimming blade.

[0095] [2. Second embodiment]

[0096] [2-1. Composition of stamped products]

[0097] Fig.10 The press-formed product 4 of the second embodiment shown includes first to fifth wall portions 41 to 45 and first to fourth bent portions 46 to 49 .

[0098] The first wall portion 41, the second wall portion 42, and the first curved portion 46 have substantially the same structure as the first wall portion 11, the second wall portion 12, and the first curved portion 14 of the first embodiment. However, in their respective top views, the first wall portion 41 and the second wall portion 42 are substantially rectangular flat plates. The length of the first wall portion 41 along the first curved portion 46 is equal to the length of the second wall portion 42 along the first curved portion 46. The ridgeline of the first curved portion 46 is straight.

[0099] The third wall portion 43 is a flat plate-shaped portion parallel to the first wall portion 41. The third wall portion 43 intersects with the second wall portion 42. The third wall portion 43 is continuous with the edge of the second wall portion 42 on the side opposite to the first wall portion 41 via the second curved portion 47. The third wall portion 43 extends along the second curved portion 47. The length of the third wall portion 43 along the second curved portion 47 is equal to the length of the second wall portion 42 along the second curved portion 47. The third wall portion 43 is arranged on the side opposite to the first wall portion 41 side across the second wall portion 42.

[0100] The fourth wall portion 44 is a flat plate-shaped portion parallel to the second wall portion 42. The fourth wall portion 44 intersects with the third wall portion 43. The fourth wall portion 44 is continuous with the edge of the third wall portion 43 on the side opposite to the second wall portion 42 via the third curved portion 48. The fourth wall portion 44 extends along the third curved portion 48. The length of the fourth wall portion 44 along the third curved portion 48 is equal to the length of the third wall portion 43 along the third curved portion 48. The fourth wall 44 is arranged on the side opposite to the second wall portion 42 side across the third wall 43.

[0101] The fifth wall portion 45 is a flat plate-shaped portion parallel to the third wall portion 43. The fifth wall portion 45 intersects with the fourth wall portion 44. The fifth wall portion 45 is continuous with the edge of the fourth wall portion 44 on the side opposite to the third wall portion 43 via the fourth curved portion 49. The fifth wall portion 45 extends along the fourth curved portion 49. The length of the fifth wall portion 45 along the fourth curved portion 49 is equal to the length of the fourth wall portion 44 along the fourth curved portion 49. The fifth wall 45 is arranged on the side opposite to the third wall 43 side across the fourth wall 44.

[0102] The second curved portion 47 is a portion extending between the second wall portion 42 and the third wall portion 43 along the edge of the adjacent second wall portion 42. The second curved portion 47 connects the second wall portion 42 and the third wall portion 43. The cross-sectional shape of the second curved portion 47 perpendicular to the extending direction is an arc shape.

[0103] The third curved portion 48 is a portion extending between the third wall portion 43 and the fourth wall portion 44 along the edge of the adjacent third wall portion 43. The third curved portion 48 connects the third wall portion 43 and the fourth wall portion 44. The cross-sectional shape of the third curved portion 48 perpendicular to the extending direction is an arc shape.

[0104] The fourth curved portion 49 is a portion extending between the fourth wall portion 44 and the fifth wall portion 45 along the edge of the adjacent fourth wall portion 44. The fourth curved portion 49 connects the fourth wall portion 44 and the fifth wall portion 45. The cross-sectional shape of the fourth curved portion 49 perpendicular to the extending direction is an arc shape.

[0105] The ridgelines of the second to fourth curved portions 47 to 49 are all straight lines. The ridgelines of the second to fourth curved portions 47 to 49 are parallel to the ridgeline of the first curved portion 46 .

[0106] [2-2. Method for manufacturing press-formed product]

[0107] The method for manufacturing the press-formed product 4 according to the second embodiment is substantially the same as the method for manufacturing the press-formed product 1 according to the first embodiment.

[0108] First, a blanking process and an intermediate forming process are performed to form a flat workpiece 2. Fig.11 The intermediate molded product 5 is shown. The intermediate molded product 5 includes the first wall portion 41 to the fifth wall portion 45 , the first bent portion 46 to the fourth bent portion 49 , the redundant portion 51 , and the first through portion 52 to the fourth through portion 55 .

[0109] The redundant portion 51 is provided at the end of the intermediate molded product 5. The redundant portion 51 is continuous with the first wall portion 41 to the fifth wall portion 45. The boundary line Z1 between the first wall portion 41 and the redundant portion 51, the boundary line Z3 between the third wall portion 43 and the redundant portion 51, and the boundary line Z5 between the fifth wall portion 45 and the redundant portion 51 are parallel to each other. The boundary line Z2 between the second wall portion 42 and the redundant portion 51 and the boundary line Z4 between the fourth wall portion 44 and the redundant portion 51 are parallel to each other. The boundary line Z2 between the second wall portion 42 and the redundant portion 51 intersects with the boundary line Z1 between the first wall portion 41 and the redundant portion 51 and the boundary line Z3 between the third wall portion 43 and the redundant portion 51. The boundary line Z4 between the fourth wall portion 44 and the redundant portion 51 , the boundary line Z3 between the third wall portion 43 and the redundant portion 51 , and the boundary line Z5 between the fifth wall portion 45 and the redundant portion 51 .

[0110] The first through portion 52 to the fourth through portion 55 each have a structure substantially the same as the through portion 25 of the first embodiment. However, the first through portion 52 is located at a position where the boundary line Z2 between the second wall portion 42 and the redundant portion 51 intersects with the first curved portion 46. The second through portion 53 is located at a position where the boundary line Z3 between the third wall portion 43 and the redundant portion 51 intersects with the second curved portion 47. The third through portion 54 is located at a position where the boundary line Z4 between the fourth wall portion 44 and the redundant portion 51 intersects with the third curved portion 48. The fourth through portion 55 is located at a position where the boundary line Z5 between the fifth wall portion 45 and the redundant portion 51 intersects with the fourth curved portion 49.

[0111] The position where the boundary line Z2 between the second wall portion 42 and the redundant portion 51 intersects with the first curved portion 46 substantially coincides with the position where the boundary line Z1 between the first wall portion 41 and the redundant portion 51 intersects with the boundary line Z2 between the second wall portion 42 and the redundant portion 51. The position where the boundary line Z3 between the third wall portion 43 and the redundant portion 51 intersects with the second curved portion 47 substantially coincides with the position where the boundary line Z2 between the second wall portion 42 and the redundant portion 51 intersects with the boundary line Z3 between the third wall portion 43 and the redundant portion 51. The position where the boundary line Z4 between the fourth wall portion 44 and the redundant portion 51 intersects with the third curved portion 48 substantially coincides with the position where the boundary line Z3 between the third wall portion 43 and the redundant portion 51 intersects with the boundary line Z4 between the fourth wall portion 43 and the redundant portion 51. The position where the boundary line Z5 between the fifth wall portion 45 and the redundant portion 51 intersects with the fourth curved portion 49 roughly coincides with the position where the boundary line Z4 between the fourth wall portion 44 and the redundant portion 51 intersects with the boundary line Z5 between the fifth wall portion 45 and the redundant portion 51 .

[0112] After the intermediate forming process, the trimming process is carried out. In the trimming process, Fig.11As shown by the hollow arrow in , the intermediate molded product 5 obtained in the intermediate molding process is trimmed. Specifically, the intermediate molded product 5 is cut along the boundary line Z1 between the first wall portion 41 and the redundant portion 51 from the direction intersecting with the first wall portion 41 (for example, a direction perpendicular to the first wall portion 41). The intermediate molded product 5 is cut along the boundary line Z2 between the second wall portion 42 and the redundant portion 51 from the direction intersecting with the second wall portion 42 (for example, a direction perpendicular to the second wall portion 42). The intermediate molded product 5 is cut along the boundary line Z3 between the third wall portion 43 and the redundant portion 51 from the direction intersecting with the third wall portion 43 (for example, a direction perpendicular to the third wall portion 43). The intermediate molded product 5 is cut along the boundary line Z4 between the fourth wall portion 44 and the redundant portion 51 from the direction intersecting with the fourth wall portion 44 (for example, a direction perpendicular to the fourth wall portion 44). The intermediate molded product 5 is cut along a boundary line Z5 between the fifth wall portion 45 and the excess portion 51 from a direction intersecting the fifth wall portion 45 (eg, a direction perpendicular to the fifth wall portion 45). The boundary lines Z1 to Z5 correspond to so-called trimming lines.

[0113] The excess portion 51 is removed from the intermediate molded product 5 by the trimming step, thereby obtaining Fig.10 The stamped product 4 is shown.

[0114] [2-3. Effect]

[0115] According to the second embodiment described in detail above, the same effects as those of (1a) to (1f) and (1h) described above can be obtained.

[0116] [3. Other embodiments]

[0117] The embodiments of the present disclosure have been described above; however, the present disclosure is not limited to the above embodiments, and may take various forms.

[0118] (3a) In the method for producing the press-formed products 1 and 4 of the above-mentioned embodiments, the through-portions 25 and 52 to 55 are formed in the workpiece 2 by the punching step. When the through-portions are formed in the workpiece in the above-mentioned manner, the size of the through-portions is not particularly limited.

[0119] However, it is preferred to make the size of the through portion as large as possible within a range that does not affect the strength and other properties of the finished stamped product. For example, in the intermediate formed product, in the cross-sectional view perpendicular to the ridgeline of the first bent portion 14, the range where the through portion is formed overlaps with the first bent portion, and further, the size of the range where the through portion is formed can reach an overlap with at least one of a portion of the first wall portion and a portion of the second wall portion. If the through portion is large, even if an intermediate formed product having an appearance slightly deviating from the design is formed in the intermediate forming process, and in the subsequent trimming process, the position where the trimming blade passes through the intermediate formed product slightly deviates from the position designed as the trimming line, it is possible to prevent the position of the trimming blade passing through the intermediate formed product from deviating from the through portion. In other words, it is possible to prevent the intermediate formed product from being cut along a line that deviates from the through portion. Therefore, the above-mentioned effect (1d) can be more easily obtained.

[0120] On the other hand, when a through portion is formed on a workpiece, when the workpiece is subsequently bent, deformation of the through portion or cracks starting from the through portion may occur. For example, in the first embodiment described above, when the workpiece 2 is bent along the boundary line X1 between the first formed portion 21 and the second formed portion 22 in the first bending process of the intermediate forming step S2, the through portion 25 is stretched toward the bending direction D of the first bent portion 14. Therefore, it can be considered that there is a situation where the through portion 25 extends along the bending direction D of the first bent portion 14, or cracks are generated from the through portion 25 in a direction perpendicular to the bending direction D of the first bent portion 14. From the viewpoint of suppressing the deformation of the through portion when the workpiece is bent and suppressing the generation of cracks starting from the through portion, it is preferred that the size of the through portion is not too large.

[0121] (3b) When a through portion is formed on a workpiece in the above-mentioned embodiment, the shape of the through portion is not particularly limited. For example, the through portion may be a circular hole or a polygonal hole. For example, compared with a case where the through portion is a circular hole, in a case where the through portion is a polygonal hole, it is easier to suppress deformation of the through portion when the workpiece is bent. For example, the through portion may also have a shape extending along the outer shape of the finished stamped product.

[0122] As an example, Fig. 12AAn intermediate formed product 3A is shown in which a through portion 25A is formed. The through portion 25A is a triangular hole which is a type of polygonal hole. Except for the shape of the through portion 25A, the intermediate formed product 3A has the same structure as the intermediate formed product 3 of the first embodiment described above. In the intermediate formed product 3A, it is preferred that the corner of the through portion 25A faces the redundant portion 31. According to the above structure, since the corner of the through portion 25A which is more likely to become the starting point of the crack faces the redundant portion 31, even if a crack starting from the through portion 25A is generated when the workpiece is bent, the crack is likely to be generated in the redundant portion 31. Therefore, the generation of cracks in the finished stamped product 1 can be further suppressed.

[0123] (3c) In the above-mentioned embodiments and Fig. 12A In the example shown, the through-portions 25, 25A, 52 to 55 are holes that penetrate the workpiece 2 in the thickness direction. However, the through-portions are not necessarily holes. Fig. 12B As shown, the through portion 25B may be a cut that penetrates the workpiece 2 in the thickness direction. As an example, Fig. 12B An intermediate molded product 3B in which a through portion 25B is formed is shown.

[0124] (3d) In the first embodiment, a plurality of processes are performed simultaneously in each of the punching process S1, the intermediate forming process S2, and the first trimming process S3. However, the plurality of processes included in each of the processes S1 to S3 are not necessarily performed simultaneously, and may be performed in sequence, for example. When the plurality of processes included in each of the processes S1 to S3 are performed sequentially, the order of the plurality of processes is not particularly limited.

[0125] (3e) In the first embodiment, the through-portion forming process is performed in the punching step S1. However, the through-portion forming process is not necessarily performed in the punching step S1, and may be performed in the subsequent intermediate forming step S2, for example.

[0126] (3f) In the first embodiment described above, the second trimming step S4 is performed after the first trimming step S3, but the order of the first trimming step S3 and the second trimming step S4 is not particularly limited. For example, the second trimming step S4 may be performed before the first trimming step S3. That is, for example, the intermediate molded product 3 is cut along the boundary line Y1 between the first wall portion 11 and the excess portion 31, and then the intermediate molded product 3 is cut along the boundary line Y2 between the second wall portion 12 and the excess portion 31, thereby removing the excess portion 31 from the intermediate molded product 3. For example, the first trimming step S3 and the second trimming step S4 may be performed as one process instead of separate processes.

[0127] (3g) In the first cutting process of the first trimming step S3 of the first embodiment, the intermediate molded product 3 is cut from the direction intersecting the second wall portion 12 along the boundary line Y2 between the second wall portion 12 and the redundant portion 31. The first cutting process can be achieved, for example, by a device configured to displace the trimming blade in the direction intersecting the second wall portion 12 using a cam mechanism. The first cutting process can be achieved, for example, by a person adjusting the direction of the intermediate molded product 3 so that the second wall portion 12 is oriented to intersect with the displacement direction of the trimming blade. This method is also applicable to the second cutting process in the first trimming step S3 of the first embodiment, the second trimming step S4, and each cutting process in the trimming step of the second embodiment.

[0128] (3h) The functions of one component in the above embodiment may be dispersed among multiple components, or the functions of multiple components in the above embodiment may be integrated into one component. In addition, a part of the components of the above embodiment may be omitted. At least a part of the components of the above embodiment may be added to the components of the above other embodiments, or at least a part of the components of the above embodiment may be replaced with the components of the above other embodiments.

Claims

1. A method for manufacturing a stamped product, the stamped product having a first wall portion, a second wall portion intersecting the first wall portion, and a bent portion connecting the first wall portion and the second wall portion to each other, the method for manufacturing the stamped product being characterized by comprising: forming a through portion on the workpiece that penetrates the workpiece; The workpiece having the through portion formed therein is subjected to bending processing to form an intermediate formed product on which the first wall portion, the second wall portion, and the bent portion are formed; as well as The press-formed product is obtained by removing a redundant portion from the intermediate formed product, wherein the redundant portion is a portion continuous with each of the first wall portion, the second wall portion, and the bent portion of the intermediate formed product, and The through-portion is formed on the workpiece in such a manner that the through-portion is located at a position where a boundary line between the second wall portion and the redundant portion intersects with the bent portion in the intermediate molded product, The intermediate molded product is cut along a boundary line between the first wall portion and the excess portion from a direction intersecting the first wall portion, and the intermediate molded product is cut along a boundary line between the second wall portion and the excess portion from a direction intersecting the second wall portion, thereby removing the excess portion from the intermediate molded product.

2. The method for manufacturing a press-formed product according to claim 1, wherein: The through portion is formed on the workpiece so that a region of the intermediate molded product where the through portion is formed at least overlaps with the bent portion in a cross-sectional view perpendicular to a ridgeline of the bent portion.

3. The method for manufacturing a press-formed product according to claim 1 or 2, characterized in that: At least a portion of the second wall portion is curved so as to protrude toward the first wall portion.

4. The method for manufacturing a press-formed product according to any one of claims 1 to 3, characterized in that: The intermediate molded product is cut along a boundary line between the first wall portion and the redundant portion from a direction perpendicular to the first wall portion, and the intermediate molded product is cut along a boundary line between the second wall portion and the redundant portion from a direction perpendicular to the second wall portion.

5. The method for manufacturing a press-formed product according to any one of claims 1 to 4, characterized in that: The workpiece is composed of high tensile strength steel.

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