Press molding method, press molding device and manufacturing method for press molded product

Abstract

To provide a press molding method, a press molding device and a manufacturing method for a press molded product which can suppress product defects.SOLUTION: In a press molding method according to the disclosure, which makes an upper die 11 and a lower die 12 relatively approach each other, while making the upper die 11 and the lower die 12 clamp a plate-like work-piece 50, so as to press mold the plate-like work-piece 50, a movable part 13 that can move in a pressing direction is provided on the lower die 12 so that the movable part can protrude from a surface of the lower die 12. When the upper die 11 and the lower die 12 are made to relatively approach each other, the movable part 13 is made to protrude from the surface of the lower die 12 so that a site 53 of the plate-like work-piece 50 protruded toward the upper die by the movable part 13 contacts the upper die 11 first.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a press molding method, a press molding apparatus, and a method for manufacturing a press-molded product. [Background technology]

[0002] Patent Document 1 discloses a press forming technique in which both ends of a workpiece are clamped while an upper die and a lower die are brought relatively close to each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-182920 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have found the following problems. When the upper die comes into contact with the workpiece, a molding mark is left. If the upper die and lower die have a complex shape, the workpiece may become misaligned during press molding, leaving a molding mark on the press-molded product, which may result in a defective product.

[0005] The present disclosure has been made in consideration of the above circumstances, and provides a press molding method, a press molding apparatus, and a method for manufacturing a press-molded product that can suppress product defects. [Means for solving the problem]

[0006] The press molding method according to the present disclosure includes: A press forming method for press-forming a plate-shaped workpiece by clamping the plate-shaped workpiece with an upper die and a lower die and bringing the upper die and the lower die relatively close to each other, a movable part that is movable in a pressing direction so as to be protruding from a surface of the lower die is provided on the lower die, When the upper mold and the lower mold are brought closer together, the movable part is made to protrude from the surface of the lower mold so that the portion of the plate-shaped workpiece protruding toward the upper mold by the movable part first abuts against the upper mold.

[0007] In the press molding method according to the present disclosure, the portion of the plate-shaped workpiece protruding toward the upper die side by the movable part first comes into contact with the upper die. As a result, molding marks are formed in the portion of the plate-shaped workpiece protruding toward the upper die side. Since the molding marks can be removed in the portion of the plate-shaped workpiece protruding toward the upper die side, the press molding method according to the present disclosure can suppress product defects.

[0008] The movable portion may be provided near a position where the length of the lower die in the pressing direction is the longest. With this configuration, the amount of deformation of the plate-shaped workpiece protruding toward the upper die is reduced, thereby suppressing damage to the plate-shaped workpiece. Therefore, the press molding method according to the present disclosure can suppress product defects.

[0009] The press molding apparatus according to the present disclosure is A press molding apparatus that press-forms a plate-shaped workpiece by clamping the plate-shaped workpiece with an upper mold and a lower mold while moving the upper mold and the lower mold relatively close to each other, the lower die includes a movable part movable in a pressing direction so as to be protruding from a surface of the lower die, When the upper mold and the lower mold are brought closer together, the movable part is made to protrude from the surface of the lower mold so that the portion of the plate-shaped workpiece protruding toward the upper mold by the movable part first abuts against the upper mold.

[0010] In the press molding apparatus according to the present disclosure, the portion of the plate-shaped workpiece protruding toward the upper die side by the movable part first comes into contact with the upper die. As a result, molding marks are formed in the portion of the plate-shaped workpiece protruding toward the upper die side. Since the molding marks can be removed in the portion of the plate-shaped workpiece protruding toward the upper die side, the press molding apparatus according to the present disclosure can suppress product defects.

[0011] The movable portion may be provided near a position where the length of the lower die in the pressing direction is the longest. With this configuration, the amount of deformation of the plate-shaped workpiece protruding toward the upper die is reduced, thereby suppressing damage to the plate-shaped workpiece. Therefore, the press molding apparatus according to the present disclosure can suppress product defects.

[0012] The method for producing a press-molded product according to the present disclosure includes: A method for manufacturing a press-molded product, comprising the steps of: clamping a plate-shaped workpiece by an upper mold and a lower mold; bringing the upper mold and the lower mold relatively close to each other; and press-molding the plate-shaped workpiece to form a press-molded product, a movable part that is movable in a pressing direction so as to be protruding from a surface of the lower die is provided on the lower die, When the upper mold and the lower mold are brought closer together, the movable part is made to protrude from the surface of the lower mold so that the portion of the plate-shaped workpiece protruding toward the upper mold by the movable part first abuts against the upper mold.

[0013] In the manufacturing method of the press-molded product according to the present disclosure, the portion of the plate-shaped workpiece protruding toward the upper die side by the movable part first comes into contact with the upper die. As a result, a molding mark is formed in the portion of the plate-shaped workpiece protruding toward the upper die side. Since the molding mark can be removed in the portion of the plate-shaped workpiece protruding toward the upper die side, the manufacturing method of the press-molded product according to the present disclosure can manufacture a press-molded product with reduced product defects. Effect of the Invention

[0014] The present disclosure makes it possible to provide a press molding method, a press molding apparatus, and a method for manufacturing a press-molded product that can suppress product defects. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a plan view of a plate-shaped workpiece and a press-formed product. [Diagram 2] 1 is a cross-sectional view of a press molding apparatus according to a first embodiment. [Diagram 3] 1 is a flowchart showing a press molding method according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view of a press molding apparatus according to a comparative example. [Diagram 5] FIG. 4 is a cross-sectional view of a press molding apparatus according to a comparative example. [Figure 6] 1 is a cross-sectional view of a press molding apparatus according to a first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the present disclosure will be described through the embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. In addition, all of the configurations described in the embodiments are not necessarily essential as means for solving the problems. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and repeated explanations are omitted as necessary. Naturally, the right-handed xyz Cartesian coordinate system shown in the drawings is for the convenience of explaining the positional relationship of the components. Usually, the positive direction of the z axis is vertically upward, and the xy plane is a horizontal plane.

[0017] (Embodiment 1) <Press-molded products> First, a press-molded product will be described with reference to Fig. 1. Fig. 1 is a plan view of a plate-shaped workpiece and a press-molded product. The upper part of Fig. 1 shows the plate-shaped workpiece before press molding. The lower part of Fig. 1 shows the plate-shaped workpiece (press-molded product) after press molding. The plate-shaped workpiece 50 shown in the upper part of Fig. 1 is press-molded into a plate-shaped workpiece (press-molded product 60) shown in the lower part of Fig. 1 by the press molding apparatus, press molding method, and manufacturing method of a press-molded product according to the first embodiment.

[0018] 1, the plate-shaped workpiece 50 has holes 51 and 52. The hole 51 is a hole for attaching a rear door, and the hole 52 is a hole for attaching a front door.

[0019] As shown in the lower part of Fig. 1, the press-molded product 60 has a protruding portion 61, a hole 51, and a hole 52. The protruding portion 61 is formed by the press molding apparatus, the press molding method, and the manufacturing method of the press-molded product according to embodiment 1. The protruding portion 61 shown in the lower part of Fig. 1 has a convex shape protruding in the positive direction of the z-axis.

[0020] The positive z-axis side of the protruding portion 61 is the outside of the vehicle body, and the negative z-axis side is the inside of the vehicle body. After press molding, the protruding portion 61 undergoes a predetermined process such as processing and painting to become a rear fender of the vehicle body. Therefore, the protruding portion 61 can also be said to be a design surface that improves the external design.

[0021] <Configuration of press molding equipment> Next, the configuration of the press molding apparatus according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a cross-sectional view of the press molding apparatus according to the first embodiment. The upper part of Fig. 2 is a diagram showing the press molding apparatus in a state where press molding is started. The lower part of Fig. 2 is a diagram showing the press molding apparatus in a state where press molding is completed. The plate-shaped workpiece 50 shown in Fig. 2 shows a portion that will become a protruding portion 61 of a press-molded product 60 by being press-molded.

[0022] As shown in the upper part of Fig. 2, the press molding apparatus 10 includes an upper die 11, a lower die 12, and a movable part 13. First, the upper die 11 and the lower die 12 will be described. As shown in the upper part of Fig. 2, the upper die 11 and the lower die 12 are a pair of press dies, and can be relatively displaced in the press direction (z-axis direction). The upper die 11 and the lower die 12 each have a non-linearly symmetrical shape with respect to a center line C1, and have a complex shape.

[0023] As shown in the upper part of Fig. 2, the lower die 12 has a fixed die 16 and a movable die 17. In the press molding apparatus 10, typically, the fixed die 16 of the lower die 12 is fixed, and the upper die 11 is brought close to the movable die 17, and the movable die 17 is pressed by the upper die 11. That is, the movable die 17 is linked with the upper die 11 and moves in the pressing direction (z-axis direction). In general, the fixed die 16 is called a punch, and the movable die 17 is called a ring or blank holder.

[0024] As shown in the upper part of Fig. 2, upper die 11 has clamp portions 21 and 22 on both ends. Also, as shown in the upper part of Fig. 2, lower die 12 (movable die 17) has clamp portions 23 and 24 on both ends. As shown in the upper part of Fig. 2, clamp portions 21 and 23, and clamp portions 22 and 24 are structured so that they can clamp plate-shaped workpiece 50 by bringing them close to each other.

[0025] As described above, the movable die 17 is movable in the pressing direction (z-axis direction). A more detailed description will be given with reference to the upper part of FIG. 2. As shown in the upper part of FIG. 2, when the upper die 11 and the lower die 12 are brought relatively close to each other, the clamp part 21 and the clamp part 23, and the clamp part 22 and the clamp part 24 come into contact with each other via the plate-shaped workpiece 50. Then, as shown in the lower part of FIG. 2, the movable die 17 descends in the negative direction of the z-axis while maintaining this contact state. That is, with the operation of bringing the upper die 11 and the lower die 12 relatively close to each other, the movable die 17 is pushed in the negative direction of the z-axis by the clamp part 21 and the clamp part 22 of the upper die 11, and thus descends in the negative direction of the z-axis. In this way, the movable die 17 is linked with the upper die 11 and moves in the pressing direction (z-axis direction).

[0026] Next, the movable part 13 will be described. As shown in the upper part of Fig. 2, the movable part 13 is provided on the fixed die 16 of the lower die 12. The movable part 13 has a structure that is movable in the pressing direction (z-axis direction) so as to be able to protrude from the surface of the lower die 12. The movable part 13 is movable in the pressing direction (z-axis direction) by having, for example, a cylinder structure using nitrogen gas or an elastic structure using a spring.

[0027] As shown in the upper part of Fig. 2, the movable part 13 can be moved toward the positive direction of the z-axis from position L1, where the length of the fixed die 16 of the lower die 12 in the press direction is the longest. In other words, if the upper end position of the movable part 13 is position L2, the movable part 13 can be moved so that the height in the z-axis direction of position L2 is higher than the height in the z-axis direction of position L1. As shown in the upper part of Fig. 2, the part of the plate-shaped workpiece at position L1 is part 54. The part of the plate-shaped workpiece at position L2 is part 53.

[0028] 2, the movable part 13 comes into contact with the plate-shaped workpiece 50 clamped by the upper die 11 and the lower die 12 at position L2. When the upper die 11 and the lower die 12 are brought relatively close to each other, the movable part 13 descends in the negative direction of the z-axis while maintaining this contact state. Then, as shown in the lower part of FIG. 2, the movable part 13 is stored in the fixed die 16 of the lower die 12.

[0029] 2, when the movable part 13 is housed in the fixed part 16 of the lower die 12, the upper die 11 and the lower die 12 come into contact with each other via the plate-shaped workpiece 50. Therefore, it is preferable that the contact surface of the movable part 13 with the plate-shaped workpiece 50 has an inclination of the surface in the vicinity of the lower die 12 on which the movable part 13 is provided, in the xz cross-sectional view.

[0030] <Operation of press molding equipment> Next, the operation of the press molding apparatus according to the embodiment 1 will be described with reference to Fig. 2 and Fig. 3. Fig. 3 is a flowchart showing the press molding method according to the embodiment 1. In the description of Fig. 3, the symbols in Fig. 2 will be used as appropriate.

[0031] First, the plate-shaped workpiece 50 is placed between the upper mold 11 and the lower mold 12, and the plate-shaped workpiece 50 is clamped by using the upper mold 11 and the lower mold 12 (step ST1). More specifically, as shown in the upper part of Fig. 2, the plate-shaped workpiece 50 is clamped by using the clamp parts 21 and 23, and the clamp parts 22 and 24.

[0032] Next, the movable part 13 is caused to protrude from the surface of the fixed die 16 of the lower die 12 (step ST2). More specifically, as shown in the upper part of Fig. 2, the movable part 13 is caused to protrude from the surface of the fixed die 16 of the lower die 12 so that the height in the z-axis direction of position L2 is higher than the height in the z-axis direction of position L1. As a result, the plate-shaped workpiece 50 is lifted from the lower side (lower die 12 side) by the movable part 13 with both ends clamped, and the part 53 is formed.

[0033] Next, the upper die 11 and the lower die 12 are brought relatively close to each other (step ST3). In step ST2, the movable part 13 is protruded from the surface of the fixed die 16 of the lower die 12, so that in step ST3, the portion 53 of the plate-shaped workpiece 50 first comes into contact with the upper die 11. Then, while maintaining this contact state, the movable part 13 descends in the negative direction of the z axis, to reach the state shown in the lower part of Fig. 2. In this manner, the press-molded product 60 shown in the lower part of Fig. 1 is molded.

[0034] Following step ST3, the upper die 11 is released. At this time, in order to suppress deformation of the press-molded product 60, the movable part 13 may be configured to maintain a stored state in the fixed die 16 of the lower die 12. Of course, when the upper die 11 is released, the projection amount of the movable part 13 from the fixed die 16 can be set arbitrarily.

[0035] In the manufacturing method of a press-formed product, steps ST1 to ST3 are executed as in Fig. 3. In the manufacturing method of a press-formed product, steps ST1 to ST3 are executed, whereby a plate-shaped workpiece 50 shown in the upper part of Fig. 1 is press-formed to form a press-formed product 60 shown in the lower part of Fig. 1.

[0036] <Press forming device according to comparative example> Next, a press forming apparatus according to a comparative example will be described with reference to Figs. 4 and 5. Figs. 4 and 5 are cross-sectional views of the press forming apparatus according to the comparative example. The upper part of Fig. 4 is a diagram showing the press forming apparatus according to the comparative example in a press forming start state. The lower part of Fig. 4 is a diagram showing the press forming apparatus according to the comparative example in a press forming end state. The upper part of Fig. 5 is a diagram showing the press forming apparatus according to the comparative example in a press forming start state. The lower part of Fig. 5 is a diagram showing the press forming apparatus according to the comparative example in a press forming end state.

[0037] In the press molding apparatus according to the comparative example shown in Fig. 4 and Fig. 5, the same components as those in the press molding apparatus according to the embodiment 1 shown in Fig. 2 are denoted by the same reference numerals. Here, components different from those in the press molding apparatus according to the embodiment 1 will be described. Note that in Fig. 4 and Fig. 5, the press molded products are referred to as 70 and 80 in order to distinguish them from the press molded product 60 in Fig. 2.

[0038] A press molding apparatus according to a comparative example shown in Fig. 4 will be described. As shown in Fig. 4, a press molding apparatus 30 according to the comparative example includes an upper die 11 and a lower die 32. The lower die 32 has a similar shape to the lower die 12 of the press molding apparatus 10 shown in Fig. 2, but does not include a movable part 13.

[0039] 4, when the plate-shaped work 50 is clamped by the upper die 11 and the lower die 32, the lower die 32 and the plate-shaped work 50 come into contact with each other at position L1 of the lower die 32. Therefore, when the upper die 11 and the lower die 32 are brought relatively close to each other, a portion 54 of the plate-shaped work 50 comes into contact with the upper die 11 first. As a result, a molding mark is formed on the portion 54 of the plate-shaped work 50.

[0040] Here, the lower die 32 has a complex shape that is asymmetric with respect to the center line C1. Therefore, the plate-shaped workpiece 50 provided between the upper die 11 and the lower die 32 is displaced in its forming position during press forming. Accordingly, the forming marks formed on the portion 54 of the plate-shaped workpiece 50 are displaced in the direction of the arrow shown in the lower part of FIG. 4 (the negative direction of the x-axis). In this way, forming marks remain on the protruding portion of the press-formed product 70. The protruding portion of the press-formed product 70 becomes the rear fender of the vehicle body and is required to have an attractive appearance, so if the press forming device 30 is used, the product will be defective.

[0041] Next, a press molding apparatus according to a comparative example shown in FIG. 5 will be described. As shown in FIG. 5, the press molding apparatus 40 includes an upper mold 41 and a lower mold 42. The lower mold 42 includes a convex portion 43, as compared to the lower mold 12 of the press molding apparatus 10 shown in FIG. 2. The convex portion 43 protrudes from the lower mold 42 toward the upper mold 41. The tip of the convex portion 43 corresponds to the position L2 shown in FIG. 2. As described above in FIG. 2, the height of the position L2 in the z-axis direction is higher in FIG. 5 than the height of the position L1 in the z-axis direction. As shown in FIG. 5, in the press molding apparatus 40, the upper mold 41 includes a concave portion 44 so that the convex portion 43 fits into it.

[0042] As shown in Fig. 5, when the plate-shaped work 50 is clamped by the upper die 41 and the lower die 42, the lower die 32 and the plate-shaped work 50 are in contact with each other at positions L1 and L2 of the lower die 32. Since the height in the z-axis direction at position L2 is higher than the height in the z-axis direction at position L1, the portion 53 protrudes toward the upper die 41 more than the portion 54. Therefore, when the upper die 11 and the lower die 12 are brought relatively closer to each other, the portion 53 of the plate-shaped work 50 is first in contact with the upper die 11. As a result, a molding mark is formed on the portion 53 of the plate-shaped work 50, but a molding mark is not formed on the portion 54 of the plate-shaped work 50.

[0043] Here, the protruding portion of the press-molded product 80 becomes the rear fender of the vehicle body, and is required to have an attractive appearance, but the portion 53 is a position where molding marks can be removed later. Therefore, even if molding marks are formed on the portion 53 of the plate-shaped workpiece 50, it does not result in a defective product.

[0044] Furthermore, in the press forming apparatus 40, the plate-shaped workpiece 50 is supported at two points at positions L1 and L2 of the lower die 42. Therefore, in the press forming apparatus 40, even if the upper die 41 and the lower die 42 are brought relatively close to each other, the surface pressure of the upper die 41 against the plate-shaped workpiece 50 is distributed to two points, so that the size of the contact mark formed on the portion 53 can be reduced. Furthermore, by adjusting the press speed and press load of the press forming apparatus 40, the formation of the contact mark on the portion 53 can be suppressed.

[0045] Furthermore, in the press forming apparatus 40, the plate-shaped workpiece 50 is supported from the lower side (the lower die 32 side) at positions L1 and L2 of the lower die 32. That is, in the press forming apparatus 40, the plate-shaped workpiece 50 is press-formed while being supported at two points, so that deviation of the forming position of the plate-shaped workpiece 50 can be suppressed.

[0046] Here, in the press-molding apparatus 40, the plate-shaped workpiece 50 is pressed against the lower die 42 by the upper die 41, so that the portion 53 is formed with a shape similar to that of the protrusion 43 during press molding. In the press-molding apparatus 40, tensile stress is applied to the tip of the portion 53 in the direction from the tip of the portion 53 to the base of the portion 53 during press molding, and there is a risk of cracks occurring at the tip of the portion 53. As a result, using the press-molding apparatus 40 will result in a defective product.

[0047] <Suppression of molding marks> Here, the press forming apparatus 10 shown in Fig. 2 will be compared with the press forming apparatus 30 shown in Fig. 4. As described above, in the press forming apparatus 30, a forming mark is formed on the portion 54, and the forming mark is shifted in the negative direction of the x-axis during press forming.

[0048] On the other hand, in the press molding apparatus 10, the portion 53 of the plate-shaped workpiece 50 protrudes toward the upper die 11 by the movable portion 13. The portion 53 of the plate-shaped workpiece 50 comes into contact with the upper die 11 first. As a result, a molding mark is formed on the portion 53 of the plate-shaped workpiece 50, but a molding mark is not formed on the portion 54 of the plate-shaped workpiece 50. The portion 53 is a position where the molding mark can be removed later. Therefore, even if a molding mark is formed on the portion 53 of the plate-shaped workpiece 50, it does not result in a defective product.

[0049] 2, in the press molding apparatus 10, when the upper die 11 and the lower die 12 are brought relatively close to each other during press molding, the movable part 13 descends in the negative direction of the z-axis while maintaining the contact state between the part 53 and the movable part 13. That is, in the press molding apparatus 10, during press molding, the plate-shaped workpiece 50 is supported at two points at positions L1 and L2 of the lower die 12, and position L2 descends in the negative direction of the z-axis. For this reason, in the press molding apparatus 10, when the upper die 11 and the lower die 12 are brought relatively close to each other, the surface pressure of the upper die 11 against the plate-shaped workpiece 50 is distributed to two points, so that the size of the contact mark formed on the part 53 can be reduced. In addition, by adjusting the press speed and press load of the press molding apparatus 10, the formation of the contact mark on the part 53 can be suppressed.

[0050] Furthermore, in the press forming apparatus 10, the plate-shaped workpiece 50 is supported at positions L1 and L2 of the lower die 12, and press forming is performed while position L2 is lowered in the negative direction of the z-axis. That is, in the press forming apparatus 10, since the plate-shaped workpiece 50 is press-formed while being supported at two points, it is possible to suppress deviation of the forming position of the plate-shaped workpiece 50 during press forming. As a result, the position of the forming mark of the portion 53 does not shift, and by removing the forming mark later, it is possible to ensure the appearance design and suppress product defects.

[0051] <Suppression of cracks> Here, the press forming apparatus 10 shown in Fig. 2 will be compared with the press forming apparatus 40 shown in Fig. 5. As described above, in the press forming apparatus 40, there is a risk of cracks occurring at the tip portion of the portion 53.

[0052] On the other hand, in the press forming apparatus 10, when the upper die 11 and the lower die 12 are brought relatively closer to each other, the movable part 13 and the plate-shaped workpiece 50 (part 53) maintain their abutting state at position L2, while the movable part 13 descends in the negative direction of the z axis. That is, in the press forming apparatus 10, the tip of part 53 descends in the negative direction of the z axis during press forming, and a shape similar to that of the protrusion 43 (see FIG. 5) is not formed for part 53. Therefore, in the press forming apparatus 10, tensile stress is not applied to the tip of part 53 in the direction from the tip of part 53 to the base of part 53 during press forming, and cracks at the tip of part 53 can be suppressed.

[0053] When a shape similar to the protrusion 43 is formed, as in the case of the press-molded product 80 produced by the press molding apparatus 40, the shape similar to the protrusion 43 is removed in the press molding in the next process, and therefore a new part cannot be molded from that location. On the other hand, in the press-molded product 60 produced by the press molding apparatus 10, a shape similar to the protrusion 43 is not formed and the product is flat, so that a new part can be molded from the flat location in the press molding in the next process.

[0054] In this way, in the press molding apparatus 10 according to the first embodiment, the portion 53 of the plate-shaped workpiece 50 protruding toward the upper die 11 side by the movable portion 13 first comes into contact with the upper die 11. As a result, a molding mark is formed in the portion 53 of the plate-shaped workpiece 50 protruding toward the upper die 11 side, but no molding mark is formed in the portion 54. The protruding portion 61 (see FIG. 1) becomes the rear fender of the vehicle body, and is required to have an appearance design. The portion 54 is the most protruding portion in the protruding portion 61 (see FIG. 1), and is required to have an appearance design, so it is a position where the molding mark cannot be removed later. On the other hand, the portion 53 is a position where the molding mark can be removed later. Since it is difficult to avoid the formation of molding marks in press molding, in the press molding apparatus 10 according to the first embodiment, a molding mark is intentionally formed in the portion 53, and the molding mark of the portion 53 is removed, thereby ensuring the appearance design of the rear fender of the vehicle body. In this way, in the press molding apparatus 10 according to the first embodiment, the appearance design can be ensured and product defects can be suppressed.

[0055] In other words, in the press-molding apparatus 10 according to the first embodiment, it is possible to prevent molding marks from being formed in areas where aesthetic design is required, and further, it is possible to prevent cracks in the plate-shaped workpiece 50.

[0056] <Position of moving parts> Here, it is preferable that the above-mentioned movable part 13 is provided in the vicinity of a position L1 where the length of the fixed die 16 of the lower die 12 in the pressing direction is the longest. A more specific explanation will be given with reference to Fig. 6. Fig. 6 is a cross-sectional view of the press molding device according to the first embodiment. Fig. 6 is a view showing a state in which a plate-shaped workpiece 50 is clamped.

[0057] As shown in Fig. 6, when the plate-shaped workpiece 50 is clamped between the upper die 11 and the lower die 12, the movable part 13 is stored in the lower die 12. That is, Fig. 6 is a diagram showing the movable part 13 before it is protruded from the surface of the lower die 12 to reach the state shown in the upper part of Fig. 2. In Fig. 6, a portion 53 formed in the plate-shaped workpiece 50 by the movable part 13 is indicated by a dotted line.

[0058] As shown in Fig. 6, when the plate-shaped workpiece 50 is clamped by the upper mold 11 and the lower mold 12, the workpiece is inclined on both sides from the portion 54, with the portion 54 being the apex. The inclination from the portion 54 to the clamp portion 21 and the clamp portion 23 has a positive inclination. As shown in Fig. 6, the inclination from the portion 54 to the clamp portion 22 and the clamp portion 24 has a negative inclination.

[0059] As described above, in order to form a molding mark on portion 53, movable portion 13 is caused to protrude from the surface of lower mold 12 so that the height of upper end position L2 of movable portion 13 is higher than the height of position L1 of lower mold 12. In other words, movable portion 13 is caused to protrude from the surface of lower mold 12 so that the height of portion 53 in the z-axis direction is higher than the height of portion 54 in the z-axis direction.

[0060] 6, the inclination from the portion 54 to the clamp portion 24 has a negative inclination, so that the length by which the movable portion 13 protrudes from the surface of the lower die 12 increases as the movable portion 13 approaches the clamp portion 22 and the clamp portion 24. In other words, the deformation amount of the plate-shaped workpiece 50 when the portion 53 is formed increases.

[0061] On the other hand, as the movable part 13 approaches position L1, the length by which the movable part 13 protrudes from the surface of the lower die 12 becomes shorter. That is, the amount of deformation of the plate-shaped workpiece 50 when forming the portion 54 becomes smaller. In the example shown in Fig. 2, the movable part 13 is provided on the clamp part 22 / 24 side, but the same can be said about the amount of deformation of the plate-shaped workpiece 50 even if the movable part 13 is provided on the clamp part 21 / 23 side.

[0062] In this way, by providing the movable part 13 near the position L1 where the length of the lower die 12 in the pressing direction is the longest, the amount of deformation of the plate-shaped workpiece 50 protruding toward the upper die 11 is reduced. This makes it possible to suppress damage to the plate-shaped workpiece 50. As a result, the press forming apparatus 10 can suppress product defects.

[0063] The present disclosure is not limited to the above-described embodiment, and may be modified as appropriate without departing from the spirit and scope of the present disclosure. [Explanation of symbols]

[0064] 10, 30, 40 Press molding equipment 11, 41 upper mold 12, 32, 42 lower mold 13 Moving parts 16 Fixed type 17 Movable type 21, 22, 23, 24 Clamp section 43 Convex 44 Recess 50 Plate-shaped workpiece 51, 52 holes 53, 54 parts 60, 70, 80 Press-molded products 61 Overhang C1 center line L1, L2 position

Claims

1. A press forming method for press-forming a plate-shaped workpiece by clamping the plate-shaped workpiece with an upper die and a lower die and bringing the upper die and the lower die relatively close to each other, a movable part that is movable in a pressing direction so as to be protruding from a surface of the lower die is provided on the lower die, When the upper mold and the lower mold are brought relatively close to each other, the movable part is caused to protrude from a surface of the lower mold so that a portion of the plate-shaped workpiece protruding toward the upper mold by the movable part first comes into contact with the upper mold. Press molding method.

2. The press molding method according to claim 1 , wherein the movable portion is provided in the vicinity of a position where the length of the lower die in the pressing direction is the longest.

3. A press molding apparatus that press-forms a plate-shaped workpiece by clamping the plate-shaped workpiece with an upper mold and a lower mold while moving the upper mold and the lower mold relatively close to each other, the lower die includes a movable part movable in a pressing direction so as to be protruding from a surface of the lower die, When the upper mold and the lower mold are brought relatively close to each other, the movable part is caused to protrude from a surface of the lower mold so that a portion of the plate-shaped workpiece protruding toward the upper mold by the movable part first comes into contact with the upper mold. Press forming equipment.

4. The press molding apparatus according to claim 3 , wherein the movable portion is provided in the vicinity of a position where the length of the lower die in the pressing direction is the longest.

5. A method for manufacturing a press-molded product, comprising the steps of: clamping a plate-shaped workpiece by an upper mold and a lower mold; bringing the upper mold and the lower mold relatively close to each other; and press-molding the plate-shaped workpiece to form a press-molded product, a movable part that is movable in a pressing direction so as to be protruding from a surface of the lower die is provided on the lower die, When the upper mold and the lower mold are brought relatively close to each other, the movable part is caused to protrude from a surface of the lower mold so that a portion of the plate-shaped workpiece protruding toward the upper mold by the movable part first comes into contact with the upper mold. A manufacturing method for press-molded products.

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