Cold stamping part drawing forming structure, die and springback control method

Abstract

The invention discloses a cold stamping part drawing forming structure, a die and a springback control method, and belongs to the technical field of automobile cold stamping, and the cold stamping part drawing forming structure comprises a cold stamping part; the first end of the pre-forming model is arranged at the edge ridge of the cold stamping part; the first end of the craft model is arranged at the second end of the pre-forming model; and the flange edge is horizontally arranged at the second end of the craft model. The pre-forming model is designed at the edge ridge line of the cold stamping part, the pre-forming model converts elastic-plastic deformation of the open positive springback area of the curved surface of the cold stamping part into plastic deformation, closed control over the tangential ridge line is achieved, open positive springback within the contact angle range of the formed A surface is optimized, and the forming quality of the cold stamping part is improved. The open type positive springback within the 45-degree contact angle range of the forming A face is smaller than 1 degree, meanwhile, the overall open type positive springback of the forming A face is optimized, the forming quality of a cold stamping part is effectively improved, and therefore the quality of the whole automobile is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile cold stamping, and in particular to a cold stamping part drawing forming structure, a die and a springback control method. BACKGROUND

[0002] At present, the automobile industry is developing rapidly, and the development of domestic passenger cars pays more and more attention to the safety factor. With the development of automobile cold stamping technology, cold stamping parts currently use general plates and high-strength plates, many of which are curved surfaces. Due to the large difference in curvature and the relatively complex shape, the springback opening problem after cold stamping forming is serious, which directly affects the curved surface shape, the size qualification of cold stamping parts and the dimensional stability. The springback opening of the curved surface after the cold stamping of the curved surface with a radius of 500 mm or more is inevitable, and the springback of the A-surface angle around the vertex of the curved surface is the result of the springback opening of the curved surface, so it is difficult to control the springback.

[0003] The existing cold stamping part curved surface springback control method in the industry is that the pre-process design personnel designs the springback compensation, increases the positive thinning trend, and the later debugging personnel implements the feed control to relieve the springback trend, thereby optimizing the springback state. In these two ways, whether it is the springback compensation of the pre-process design personnel or the feed control of the later debugging personnel, it needs to be modified experimentally several times to effectively relieve the cold stamping part curved surface springback problem, and the cold stamping part curved surface springback problem cannot be completely solved. SUMMARY

[0004] The purpose of the present application is to provide a cold stamping part drawing forming structure, a die and a springback control method: in order to effectively solve the cold stamping part curved surface springback problem, the present application provides a cold stamping part curved surface springback control method, which effectively controls the closed forming of the forming A-surface, designs a pre-forming shape for the edge ridge line of the cold stamping part, realizes the closed control of the tangential ridge line, optimizes the open positive springback in the contact angle range of the forming A-surface, and optimizes the overall open positive springback of the forming A-surface, thereby effectively improving the cold stamping part forming quality and improving the overall vehicle quality.

[0005] The present application provides the following solutions:

[0006] In a first aspect, the present application discloses a cold stamping part drawing forming structure, comprising:

[0007] a cold stamping part;

[0008] a pre-forming shape, a first end of the pre-forming shape being arranged at a position of an edge ridge line of the cold stamping part;

[0009] a process shape, a first end of the process shape being arranged at a second end of the pre-forming shape;

[0010] a flange edge, the flange edge being horizontally arranged at a second end of the process shape.

[0011] Preferably, the pre-forming shape includes a first concave fillet R3 extending circumferentially at the edge ridge of the cold stamping part, so that the cold stamping part is closed by the first concave fillet R3.

[0012] Preferably, the radius of the first concave fillet R3 is 3-8 mm.

[0013] Preferably, the sheet thickness t1 of the pre-forming shape is less than the sheet thickness t of the cold stamping part.

[0014] Preferably, the process shape includes a first convex fillet, and a transition concave fillet is arranged between the process shape and the pre-forming shape.

[0015] In a second aspect, the application also discloses a cold stamping part forming die for processing the cold stamping part draw forming structure, comprising:

[0016] a forming concave die, a middle part of a lower curved surface of the forming concave die corresponds to an upper curved surface of the cold stamping part, a convex fillet curved surface shape is arranged at a position corresponding to the pre-forming shape, a first concave surface is arranged at a position corresponding to the process shape, and a first pressure surface is arranged at a position corresponding to the flange edge;

[0017] a forming convex die, a middle part of an upper curved surface of the forming convex die corresponds to a lower curved surface of the cold stamping part, a concave fillet curved surface shape is arranged at a position corresponding to the pre-forming shape, and a first convex surface is arranged at a position corresponding to the process shape;

[0018] a pressure body, the pressure body is arranged on both sides of the forming convex die, and a second pressure surface is arranged at a position corresponding to the flange edge at an upper end of the pressure body.

[0019] Preferably, the concave fillet curved surface shape and the convex fillet curved surface shape are symbolically matched, the shape length direction of the convex fillet curved surface shape and the shape length direction of the concave fillet curved surface shape are symbolically matched, and the matching area covers the edge ridge of the cold stamping part.

[0020] In a third aspect, the application also discloses a cold stamping part curved surface springback control method, which is realized by the cold stamping part forming die and comprises the following steps:

[0021] S1: when the sheet is cold stamped and formed, the first pressure surface of the forming concave die and the second pressure surface of the pressure body press the flange edge of the sheet;

[0022] S2: the contact point of the sheet contacts the vertex of the forming convex die, the sheet is gradually bent to contact the whole area of the curved surface of the forming convex die, the middle part of the upper sheet reaches the theoretical position of the forming A surface through the forming concave die, and the theoretical product curved surface of the cold stamping part is formed on the sheet.

[0023] The concave round corner surface modeling and the convex round corner surface modeling form a pre-molding modeling on the sheet material, and the first convex surface and the first concave surface form a process modeling on the sheet material;

[0024] S3: after the forming is completed, the forming concave die is separated from the cold stamping part draw forming structure, and the cold stamping part presents only slight open positive springback after forming, the formed springback optimization curved surface open springback is slight, and the curved surface vertex periphery A surface angle springback is controlled to a controllable springback position of the forming A surface;

[0025] S4: cutting the pre-molding modeling, the process modeling and the flange edge part or all.

[0026] Preferably, the one-way linear length change optimization amount (1 / 2) ΔL5 of the cold stamping part is equal to the open positive springback optimization distance L4 of the curved surface vertex periphery A surface.

[0027] Preferably, the open positive springback of the forming A surface contact angle 45° of the cold stamping part is less than 1°.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] The present application designs a pre-molding modeling on the edge ridge line of the cold stamping part, the pre-molding modeling converts the elastic-plastic deformation of the cold stamping part curved surface open positive springback area into plastic deformation, realizes the closed control of the tangential ridge line, optimizes the open positive springback in the forming A surface contact angle range, the open positive springback in the forming A surface contact angle 45° range is less than 1°, and at the same time, the overall open positive springback of the forming A surface is optimized, the cold stamping part forming quality is effectively improved, and the whole vehicle quality is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0031] Figure 1 It is a schematic diagram of curved surface springback principle;

[0032] Figure 2 It is a schematic diagram of the springback control method principle of the present application;

[0033] Figure 3 It is a schematic diagram of the curved surface springback control process of the present application;

[0034] Figure 4A cross-sectional structure schematic diagram of a cold stamping part draw forming structure and die of the present application;

[0035] Figure 5 A schematic diagram of the curved surface springback control effect of the present application;

[0036] In the figure: 1. forming punch; 2. cold stamping part; 3. forming A face theoretical position; 4. forming A face springback position; 5. controllable springback position; 6. forming die; 7. blank holder; 8. second blank holder face; 9. cold stamping part flange edge; 10. first blank holder face; 11. process modeling; 12. pre-forming modeling; 13. edge line adjacent profile curved surface; 14. convex fillet curved surface modeling; 15. concave fillet curved surface modeling; D. forming punch vertex; D1. sheet metal contact point; L. profile straight line length; L1. profile straight line change length; L2. curved surface vertex peripheral A face open positive springback distance; AL0. one-way straight line length change amount; L3. profile straight line optimization length; L4. curved surface vertex peripheral A face open positive springback optimization distance; AL5. two-way change optimization amount; Q. forming punch curved surface; Q1. theoretical product curved surface; Q2. springback curved surface; Q3. springback optimization curved surface; R. concave fillet curved surface modeling main concave fillet modeling; R1 / R2. concave fillet curved surface modeling auxiliary transition convex fillet modeling; R3. first concave fillet; R4 / R5. pre-forming modeling 12 lower surface auxiliary transition convex fillet modeling; R6. convex fillet curved surface modeling main convex fillet modeling; R7 / R8. convex fillet curved surface modeling auxiliary transition concave fillet modeling; R9. pre-forming modeling 12 upper surface main concave fillet modeling; R10 / R11. pre-forming modeling 12 upper surface auxiliary transition convex fillet modeling; t. sheet metal thickness; t1. sheet metal thickness of pre-forming modeling 12. DETAILED DESCRIPTION

[0037] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0038] The terms used in the embodiments of the present application are merely for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. "Plural" generally includes at least two.

[0039] It should be understood that, in the description herein, the term "and / or" is merely an association relationship used to describe associated objects, and indicates that there can be three relationships, for example, A and / or B can represent three cases of A existing alone, A and B existing simultaneously, and B existing alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after it.

[0040] It should be understood that, although the terms first, second, third, etc. can be used in embodiments of the present application to describe, these descriptions should not be limited to these terms. These terms are only used to distinguish the description. For example, without departing from the scope of the embodiments of the present application, the first can also be referred to as the second, and similarly, the second can also be referred to as the first.

[0041] Depending on the context, the word "if" as used herein can be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if it is determined" or "if (a stated condition or event) is detected" can be interpreted to mean "when it is determined" or "in response to determining" or "when (a stated condition or event) is detected" or "in response to detecting (a stated condition or event)".

[0042] It should also be noted that the terms "comprise", "comprising", or any other variant thereof are intended to cover non-exclusive inclusion, so that a product or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such product or device. Without more limitations, the element defined by the sentence "comprising a" does not exclude the existence of other identical elements in the product or device comprising the element.

[0043] It should be particularly noted that the symbols and / or numbers present in the description, if not marked in the description of the drawings, are not drawing marks.

[0044] As Figure 1As shown, when the cold stamping part 2 is manufactured by using the existing cold stamping method, after the cold stamping part 2 is formed, the open rebound of the rebound curved surface Q2 occurs, the angle rebound of the curved surface vertex peripheral A surface to the forming A surface rebound position 4, which seriously affects the forming quality of the cold stamping part. When the sheet metal is cold stamped and formed, the sheet metal contact point D1 contacts the vertex D of the forming punch 1, and then gradually contacts the forming punch curved surface Q full area after bending, and the curved surface vertex peripheral A surface reaches the forming A surface theoretical position 3 through the mold surface control, and the theoretical product curved surface Q1 is formed. When the forming is finished, the mold is separated from the cold stamping part 2, and the open positive rebound of the cold stamping part 2 occurs after the forming, forming the rebound curved surface Q2, and the angle rebound of the curved surface vertex peripheral A surface occurs, wherein the open positive rebound of the forming curved surface contact angle within the range of 45° is 5°, the open positive rebound distance L2 of the curved surface vertex peripheral A surface, due to the unbalanced stress of the inner and outer surfaces caused by the thickness t of the sheet metal, the overall contour straight line length L of the cold stamping part after forming changes to the contour straight line change length L1, the one-way straight line length change amount (1 / 2) ΔL0 is not equal to the open positive rebound distance L2 of the curved surface vertex peripheral A surface, and there is a rebound out-of-control difference.

[0045] Embodiment 1

[0046] Referring to Figures 2-5 As shown, the cold stamping part drawing forming structure provided by the embodiment of the application comprises:

[0047] The cold stamping part 2;

[0048] The pre-forming modeling 12 is arranged at the edge line position of the cold stamping part 2.

[0049] The process modeling 11 is arranged at the second end of the pre-forming modeling 12.

[0050] The flange edge 9 is horizontally arranged at the second end of the process modeling 11.

[0051] The cold stamping part 2 is located in the middle of the cold stamping part drawing forming structure, and the pre-forming modeling 12, the process modeling 11 and the flange edge 9 are sequentially arranged on the left and right sides. In the process of processing the cold stamping part 2, the cold stamping part drawing forming structure is first processed, and then the pre-forming modeling 12, the process modeling 11 and the flange edge 9 are cut off in a suitable process, so as to ensure that the open rebound of the rebound optimized curved surface Q3 of the produced cold stamping part 2 is slight.

[0052] Referring to Figures 2-5 As shown, the pre-forming modeling 12 comprises a first concave round corner R3, and the radius of the first concave round corner R3 is 3-8 mm, preferably 5 mm. The pre-forming modeling 12 extends in the circumferential direction at the edge line of the cold stamping part 2, so that the whole cold stamping part 2 is enclosed by the first concave round corner structure.

[0053] Referring toFigures 2-5 As shown, the plate thickness t1 of the pre-forming shape 12 is less than the plate thickness t of the cold stamping part 2.

[0054] After the pre-forming shape 12 is formed, the plate thickness t1 in the pre-forming shape area is reasonably thinned, and the reasonable blanking gap effectively controls the feeding to ensure the reasonable internal forming.

[0055] Referring to Figures 2-5 As shown, the process shape 11 includes a first convex round corner, and a transition concave round corner is arranged between the first convex round corner and the first concave round corner R3. The radius of the first convex round corner and the transition concave round corner is 3-8 mm. The transition concave round corner is designed to meet the smoothness requirement of the process.

[0056] Embodiment 2

[0057] Referring to Figures 2-5 As shown, the cold stamping part forming die provided by the embodiment of the application is used for processing the cold stamping part draw forming structure described above, and includes:

[0058] The forming concave die 6, the middle part of the lower curved surface of the forming concave die 6 corresponds to the upper curved surface of the cold stamping part 2, the convex round corner curved surface shape 14 is arranged at the position corresponding to the pre-forming shape 12 on the lower curved surface of the forming concave die 6, the first concave surface is arranged at the position corresponding to the process shape 11, and the first blanking surface 10 is arranged at the position corresponding to the flange edge 9;

[0059] The forming convex die 1, the middle part of the upper curved surface of the forming convex die 1 corresponds to the lower curved surface of the cold stamping part 2, the concave round corner curved surface shape 15 is arranged at the position corresponding to the pre-forming shape 12 on the upper curved surface of the forming convex die 1, and the first convex surface is arranged at the position corresponding to the process shape 11;

[0060] The blanking body 7 is arranged on the left and right sides of the forming convex die 1, and the second blanking surface 8 is arranged at the position corresponding to the flange edge 9 on the upper end of the blanking body 7.

[0061] The cold stamping part forming curved surface springback control method needs the profile of the forming concave die 6 to forcibly control the cold stamping part in the forming standard position, wherein the full profile of the forming concave die 6 and the forming convex die 1 is arranged to be symmetrical to control the cold stamping part to the bottom of the gauge, to ensure that the elastic deformation of the curved surface area of the cold stamping part is changed into plastic deformation, so as to minimize the springback amount of the curved surface area and realize the control of the curved surface springback of the cold stamping part.

[0062] The concave round corner curved surface shape 15 is arranged at the position corresponding to the edge line of the cold stamping part on the upper curved surface of the forming convex die 1, the convex round corner curved surface shape 14 is arranged at the position corresponding to the edge line of the cold stamping part on the lower curved surface of the forming concave die 6, the concave round corner curved surface shape 15 and the convex round corner curved surface shape 14 are symmetrical in shape, and the shape length direction of the convex round corner curved surface shape 14 is symmetrical in shape with the shape length direction of the concave round corner curved surface shape 15. Referring to Figures 2-5As shown, the concave round corner surface modeling 15 is in symmetrical cooperation with the convex round corner surface modeling 14; the length direction of the convex round corner surface modeling 14 is in symmetrical cooperation with the length direction of the concave round corner surface modeling 15, and the cooperation area covers the edge ridge line of the cold stamping part 2 on the forming A surface.

[0063] The concave round corner surface modeling 15 is composed of a concave round corner surface modeling main body concave round corner modeling R and concave round corner surface modeling auxiliary transition convex round corner modelings R1 and R2 arranged on both sides of the concave round corner surface modeling main body concave round corner modeling R respectively, and the three round corner modelings jointly act on the sheet metal to form the pre-forming modeling 12 lower surface. The pre-forming modeling 12 lower surface is composed of a pre-forming modeling 12 lower surface main body convex round corner modeling R3 (i.e. a first concave round corner R3) and pre-forming modeling 12 lower surface auxiliary transition convex round corner modelings R4 and R5 arranged on both sides of the first concave round corner R3 respectively, and the three round corner modelings make the lower surface curve of the edge ridge line of the cold stamping part change from the elastic-plastic deformation of the open positive springback area to plastic deformation.

[0064] The convex round corner surface modeling 14 is composed of a convex round corner surface modeling main body convex round corner modeling R6 and convex round corner surface modeling auxiliary transition concave round corner modelings R7 and R8 arranged on both sides of the convex round corner surface modeling main body convex round corner modeling R6 respectively, and the three round corner modelings jointly act on the sheet metal to form the pre-forming modeling 12 upper surface, and the pre-forming modeling 12 upper surface is composed of a pre-forming modeling 12 upper surface main body concave round corner modeling R9 and pre-forming modeling 12 upper surface auxiliary transition convex round corner modelings R10 and R11 arranged on both sides of the upper surface main body concave round corner modeling R9 respectively, and the three round corner modelings make the upper surface curve of the edge ridge line of the cold stamping part change from the elastic-plastic deformation of the open positive springback area to plastic deformation.

[0065] Embodiment 3

[0066] The embodiment of the present application provides a cold stamping part curved surface springback control method, which is realized by the above-mentioned cold stamping part forming die and comprises the following steps.

[0067] S1: When the sheet metal is cold stamped and formed, the first pressure surface 10 of the forming concave die 6 and the second pressure surface 8 of the pressure body 7 press the flange edge 9 of the sheet metal tightly;

[0068] S2: The sheet metal contact point D1 contacts the vertex D of the forming convex die, and the sheet metal is gradually contacted with the whole area of the forming convex die curve Q after being bent, and the upper sheet metal is made to reach the theoretical position 3 of the forming A surface by the forming concave die 6, so that the theoretical product curve Q1 of the cold stamping part 2 is formed on the sheet metal;

[0069] The concave round corner surface modeling 15 and the convex round corner surface modeling 14 make the sheet metal form the pre-forming modeling 12, and the first convex surface and the first concave surface make the sheet metal form the process modeling 11;

[0070] S3: After the forming is completed, the forming concave die 6 is separated from the cold stamping part draw forming structure, and the cold stamping part 2 after forming only presents a slight open positive springback, and the formed springback optimized curved surface Q3 open springback is slight, and the curved surface vertex peripheral A surface angle springback to the forming A surface controllable springback position 5;

[0071] S4: According to the requirements of process design, the pre-formed modeling 12, process modeling 11 and flange edge 9 are all cut off in the subsequent suitable process, which can be cut off at one time or cut off in multiple times.

[0072] The one-way linear length change optimization amount (1 / 2) ΔL5 of the cold stamping part 2 is equal to the open positive springback optimization distance L4 of the curved surface vertex peripheral A surface.

[0073] The open positive springback of the forming A surface of the cold stamping part 2 within the 45° range is less than 1°.

[0074] When the sheet metal is cold-stamped, the flange edge 9 of the cold-stamped part is controlled by the first pressing surface 10 of the forming concave die 6 and the second pressing surface 8 of the pressing body 7, the feeding of the sheet metal is effectively controlled to ensure reasonable internal forming, and the internal forming is ensured by the process modeling 11 in the process design to ensure uniform expansion of the internal material. When the contact point D1 of the sheet metal contacts the vertex D of the forming convex die 1, the sheet metal is gradually contacted with the full area of the curved surface Q of the forming convex die, and the curved surface vertex peripheral surface A is controlled by the forming concave die 6 to reach the theoretical position 3 of the forming A surface (the forming A surface or A surface refers to the smooth surface linked by the curvature of the outer surface of the cold-stamped part 2, which can be considered as the entire curved surface of the cold-stamped part 2 after forming), forming the theoretical product curved surface Q1, the profile of the edge line forms the curved surface 13, the concave fillet curved surface modeling 15 and the convex fillet curved surface modeling 14 jointly form the pre-forming modeling 12, which converts the elastic-plastic deformation of the open positive springback area of the curved surface of the cold-stamped part into plastic deformation, and when the forming is completed, the forming concave die 6 is separated from the cold-stamped part 2, and the cold-stamped part only presents a slight open positive springback after forming, forming the springback optimized curved surface Q3, which drives the curved surface vertex peripheral surface A to appear a slight angle springback, wherein the open positive springback of the curved surface vertex peripheral surface A in the range of 45° contact angle of the forming curved surface is 1°, the open positive springback optimized distance L4 of the curved surface vertex peripheral surface A, due to the unbalanced stress between the inner and outer surfaces caused by the thickness t of the sheet metal, the overall profile straight line length L of the cold-stamped part after forming becomes the profile straight line optimized length L3, the bidirectional variation optimization amount ΔL5, the unidirectional straight line length variation optimization amount (1 / 2) ΔL5 is equal to the open positive springback optimized distance L4 of the curved surface vertex peripheral surface A, and there is no difference in springback out of control. Although there is a slight open positive springback optimized distance L4, the 1° open positive springback in the range of 45° contact angle of the forming curved surface can be ignored, and the cold-stamped part 2 after forming has a slight open springback of the springback optimized curved surface Q3, and the angle springback of the curved surface vertex peripheral surface A reaches the controllable springback position 5 of the forming A surface, which controls the open positive springback of the curved surface of the cold-stamped part after forming, thereby ensuring the smooth progress of the control process of the curved surface springback of the cold-stamped part.

[0075] Finally, it should be noted that: the various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0076] The above examples are only used to illustrate the technical solutions of the present application, but not to limit the same; although the present application has been described in detail with reference to the foregoing examples, it should be understood by those of ordinary skill in the art that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A cold-stamped draw-forming structure, characterized by, Comprise: A cold stamping part (2); A pre-forming shape (12) arranged at the edge ridge line of the cold stamping part (2); A process shape (11) arranged at the second end of the pre-forming shape (12); A flange (9) arranged horizontally at the second end of the process shape (11).

2. The cold stamping part draw forming structure according to claim 1, wherein the pre-forming shape (12) comprises a first concave round corner (R3) extending circumferentially at the edge ridge line of the cold stamping part (2), so that the cold stamping part (2) is enclosed by the first concave round corner (R3).

3. The cold stamping part draw forming structure according to claim 2, wherein the radius of the first concave round corner (R3) is 3-8mm.

4. The cold stamping part draw forming structure according to claim 1, wherein the sheet thickness t1 of the pre-forming shape (12) is less than the sheet thickness t of the cold stamping part (2).

5. The cold stamping part draw forming structure according to claim 1, wherein the process shape (11) comprises a first convex round corner, and a transition concave round corner is arranged between the process shape (11) and the pre-forming shape (12). Comprise: A forming concave die (6) with a lower curved surface corresponding to the upper curved surface of the cold stamping part (2), wherein a convex round corner surface shape (14) is arranged at the position corresponding to the pre-forming shape (12), a first concave surface is arranged at the position corresponding to the process shape (11), and a first pressure surface (10) is arranged at the position corresponding to the flange (9); A forming convex die (1) with an upper curved surface corresponding to the lower curved surface of the cold stamping part (2), wherein a concave round corner surface shape (15) is arranged at the position corresponding to the pre-forming shape (12), and a first convex surface is arranged at the position corresponding to the process shape (11); A pressure body (7) arranged on the left and right sides of the forming convex die (1), wherein a second pressure surface (8) is arranged at the position corresponding to the flange (9) at the upper end of the pressure body (7).

6. A cold-stamping die for forming the cold-stamped draw-formed structure of any one of claims 1-5, wherein, 7. The cold stamping part forming die according to claim 6, wherein the concave round corner surface shape (15) and the convex round corner surface shape (14) are symbolically matched; the shape length direction of the convex round corner surface shape (14) and the shape length direction of the concave round corner surface shape (15) are symbolically matched, and the matching area covers the edge ridge line of the cold stamping part (2). Comprise the following steps: S1: When the sheet is cold stamped and formed, the first pressure surface (10) of the forming concave die (6) and the second pressure surface (8) of the pressure body (7) press the flange (9) of the sheet; ​ ​ ​ 8. A method for controlling springback of a curved surface of a cold-stamped part, realized by the cold-stamped part forming die according to claim 6 or 7, characterized in that, ​ ​ S2: the plate contact point (D1) contacts the forming punch vertex (D), the plate is bent and gradually contacts the forming punch curved surface Q full area, the upper plate middle part reaches the forming A surface theoretical position (3) through the forming die (6), and the plate forms a theoretical product curved surface Q1 of the cold stamping part (2); The concave fillet curved surface modeling (15) and the convex fillet curved surface modeling (14) form a pre-forming modeling (12) on the plate, and the first convex surface and the first concave surface form a process modeling (11) on the plate; S3: after forming, the forming die (6) is separated from the cold stamping part drawing forming structure, the cold stamping part (2) is slightly open after forming, and the formed rebound optimization curved surface Q3 is slightly open, the curved surface vertex peripheral A surface angle rebounds to the forming A surface controllable rebound position (5); S4: cut off part or all of the pre-forming modeling (12), the process modeling (11) and the flange edge (9).

9. The cold stamping part curved surface rebound control method according to claim 8, wherein the one-way linear length change optimization amount (1 / 2) ΔL5 of the cold stamping part (2) is equal to the open positive rebound optimization distance L4 of the curved surface vertex peripheral A surface.

10. The cold stamping part curved surface rebound control method according to claim 8, wherein the open positive rebound of the cold stamping part (2) in the 45° contact angle range of the forming A surface is less than 1°. ​ ​

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