Car door inner panel and its stamping and drawing forming method

Abstract

This invention relates to the field of vehicle technology, specifically providing a door inner panel and its stamping and drawing forming method, aiming to solve the problem that existing door inner panels cannot simultaneously meet the requirements of large stamping depth, full window closure, and lightweight construction. To this end, the door inner panel of this invention includes a first stamping area, a second stamping area, and a stepped stamping area disposed between the first and second stamping areas. The second stamping area surrounds the first stamping area. The stepped stamping area includes a first slope segment and a second slope segment that are smoothly connected. The first slope segment is smoothly connected to the first stamping area, and the second slope segment is smoothly connected to the second stamping area. The slope of the first slope segment is less than the slope of the second slope segment. The door inner panel is configured to be integrally stamped and drawn. The stepped stamping area enables the door inner panel to achieve a stamping depth of 200mm in a single stamping and drawing process while ensuring full window closure and using aluminum door inner panel material, and also prevents the door inner panel from cracking or wrinkling.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, specifically providing a door inner panel and its stamping and drawing forming method. Background Technology

[0002] With the rapid development of technology, users have higher and higher requirements for the overall shape and performance of vehicles. Among them, the greater the stamping depth of the rear door inner panel, the easier it is to set the internal structure of the door. However, the existing cold stamping and drawing process of the door inner panel cannot simultaneously meet the requirements of large stamping depth, full window lowering and lightweight.

[0003] Specifically, if existing technology allows the stamping depth of the door inner panel to reach 160 mm in a single operation, it would prevent the window from fully lowering, or it would require a glass-segmented or steel inner panel design to achieve the same result. Furthermore, to simultaneously achieve a large stamping depth, fully lowerable windows, and lightweight construction, some manufacturers employ a two-piece inner panel design. This solution solves the problem of one-time stamping of the inner panel, but it requires an additional set of mold and welding equipment in the stamping and drawing process. This increases vehicle production costs and makes it more difficult to control vehicle dimensions due to the segmented inner panel design, leading to significant challenges in dimensional accuracy and mass production stability. Additionally, some manufacturers use a multi-stage drawing process to meet these requirements; however, this stamping and drawing method makes it difficult to control the dimensional accuracy of the door inner panel, again posing significant challenges to dimensional accuracy and mass production stability.

[0004] Accordingly, there is a need in the field for a new door inner panel and its stamping and drawing forming method to solve or alleviate the above-mentioned technical problems to some extent. Summary of the Invention

[0005] The present invention aims to solve or alleviate to some extent the above-mentioned technical problems, namely, that existing car door inner panels cannot simultaneously meet the requirements of large stamping depth, full window folding and lightweight.

[0006] In a first aspect, the present invention provides a door inner panel, the door inner panel including a first stamping area, a second stamping area and a stepped stamping area, the second stamping area being disposed around the first stamping area, the stepped stamping area being disposed between the first stamping area and the second stamping area, the stepped stamping area including a first slope segment and a second slope segment that are smoothly connected, the first slope segment being smoothly connected to the first stamping area, the second slope segment being smoothly connected to the second stamping area, wherein the slope of the first slope segment is less than the slope of the second slope segment, and the door inner panel is configured to be integrally stamped and drawn.

[0007] In the above-mentioned optional technical solutions for the inner door panel, the total height of the first slope section and the second slope section along the drawing direction is greater than or equal to two-fifths of the total stamping depth of the inner door panel and less than or equal to three-fifths of the total stamping depth of the inner door panel; the width of the first slope section is greater than or equal to 15 mm and less than or equal to 35 mm.

[0008] In the above-mentioned optional technical solution for the inner door panel, the connection surface between the second slope section and the second stamping area is a flange bite surface, and the radius of the rounded corner of the flange bite surface is greater than or equal to 15 mm; the radius of the rounded corner at the connection between the first slope section and the second slope section is greater than or equal to 20 mm; and the radius of the rounded corner at the connection between the first slope section and the first stamping area is greater than or equal to 20 mm.

[0009] In the aforementioned optional technical solutions for the inner door panel, a lock hole is provided on the first stamping area, and the draft angle of the side wall of the lock hole along the drawing direction is greater than or equal to 10°. 0 The draft angle of the sidewall along the drawing direction of the second slope section near the flange seam surface is greater than or equal to 20°. 0 .

[0010] On another aspect, the present invention also provides a stamping and drawing method for a car door inner panel, the car door inner panel including a first stamping area, a second stamping area, and a stepped stamping area, the second stamping area surrounding the first stamping area, the stepped stamping area being disposed between the first stamping area and the second stamping area, the stepped stamping area including a first slope segment and a second slope segment smoothly transitioned together, the first slope segment smoothly transitioning to the first stamping area, the second slope segment smoothly transitioning to the second stamping area, wherein the slope of the first slope segment is less than the slope of the second slope segment, the stamping and drawing method... The forming method includes: determining the actual stamping and drawing parameter information of the first stamping area, the second stamping area, the stepped stamping area, the drawing supplementary surface stamping area, and the draw bead; wherein, at least a portion of the drawing supplementary surface stamping area is arranged along the circumference of the second stamping area, and the draw bead is arranged along the circumference of the drawing supplementary surface stamping area; and according to the actual stamping and drawing parameter information of the first stamping area, the second stamping area, the stepped stamping area, the drawing supplementary surface stamping area, and the draw bead, the inner door panel, the drawing supplementary surface stamping area, and the draw bead are stamped and drawn in one pass on the blank holder surface.

[0011] In the optional technical solutions of the above-mentioned stamping and drawing forming method, the step of "determining the actual stamping and drawing parameter information of the first stamping area, the second stamping area, the stepped stamping area, the drawing supplementary surface stamping area, and the draw bead" specifically includes: setting preset stamping and drawing parameter information of the first stamping area, the second stamping area, the stepped stamping area, the drawing supplementary surface stamping area, and the draw bead; determining the forming model of the inner door panel according to the preset stamping and drawing parameter information; and determining the actual stamping and drawing parameter information of the first stamping area, the second stamping area, the stepped stamping area, the drawing supplementary surface stamping area, and the draw bead according to the forming model.

[0012] In the optional technical solution of the above-mentioned stamping and drawing forming method, the connection surface between the second slope section and the second stamping area is set as a flange biting surface, and a locking hole is set on the first stamping area. The step of "determining the actual stamping and drawing parameter information of the first stamping area, the second stamping area and the stepped stamping area according to the forming model" includes: determining the total height of the first slope section and the second slope section along the drawing direction and the width of the first slope section; determining the fillet radius of the flange biting surface, the fillet radius of the connection between the first slope section and the second slope section and the fillet radius of the connection between the first slope section and the first stamping area; determining the sidewall draft angle of the locking hole along the drawing direction and the sidewall draft angle of the second slope section near the flange biting surface along the drawing direction.

[0013] In the optional technical solution of the above-mentioned stamping and drawing forming method, the total height of the first slope section and the second slope section along the drawing direction is set to be greater than or equal to two-fifths and less than or equal to three-fifths of the total stamping depth of the inner door panel; the width of the first slope section is set to be greater than or equal to 15 mm and less than or equal to 35 mm; the fillet radius of the flange bite face is set to be greater than or equal to 15 mm; the fillet radius at the connection between the first slope section and the second slope section is set to be greater than or equal to 20 mm; the fillet radius at the connection between the first slope section and the first stamping area is set to be greater than or equal to 20 mm; the draft angle of the lock hole along the drawing direction is set to be greater than or equal to 10°. 0 The draft angle of the side wall along the drawing direction near the flange seam of the second slope section is set to be greater than or equal to 20°. 0 .

[0014] In the optional technical solution of the above-mentioned stamping and drawing forming method, a die is provided in the stamping area of ​​the drawing supplement surface, and an inner drawing bead and an outer drawing bead are provided, wherein the outer drawing bead is provided on the outer periphery of the inner drawing bead. The step of "determining the actual stamping and drawing parameter information of the stamping area of ​​the drawing supplement surface and the drawing bead according to the forming model" includes: determining the fillet radius of the die near the inner drawing bead, the fillet radius of the die near the inner panel of the door, and the fillet radius of the die; determining the spacing between the inner drawing bead and the outer drawing bead near the top and bottom sides of the vehicle, and the spacing between the inner drawing bead and the outer drawing bead near the B-pillar and C-pillar sides of the vehicle.

[0015] In the optional technical solution of the above-mentioned stamping and drawing forming method, the fillet radius of the die near the inner drawbeam is set to be greater than or equal to 15 mm and less than or equal to 25 mm, the fillet radius of the die near the inner door panel is set to be greater than or equal to 25 mm, and the fillet radius of the die is set to be greater than or equal to 20 mm and less than or equal to 30 mm; the distance between the inner drawbeam and the outer drawbeam near the top and bottom sides of the vehicle is set to be greater than or equal to 25 mm, and the distance between the inner drawbeam and the outer drawbeam near the B-pillar and C-pillar sides of the vehicle is set to be greater than or equal to 40 mm and less than or equal to 60 mm.

[0016] By adopting the above technical solution, the present invention, through the setting of the stepped stamping area, can ensure that the window is fully lowered and that aluminum door inner panel material is used, so that the stamping depth of the door inner panel can reach 200 mm in just one stamping and drawing process, and can also ensure that the door inner panel formed by stamping and drawing will not crack or wrinkle. Attached Figure Description

[0017] The disclosure of this invention will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Furthermore, similar numbers in the drawings are used to denote similar components, wherein:

[0018] Figure 1 A schematic diagram of the structure of the inner door panel of the present invention is shown;

[0019] Figure 2 It shows Figure 1 The cross section at point AA shows the width of the first slope segment and the total height of the first and second slope segments along the drawing direction at their maximum and minimum values, as well as the cross section comparison curve of the inner door panel without a stepped stamping area at point AA.

[0020] Figure 3 A flowchart illustrating the main steps of the stamping and drawing forming method of the present invention is shown.

[0021] Figure 4 A schematic diagram of the forming model of the inner door panel, the stamping area of ​​the drawing supplement surface, and the drawing bead on the blank holder surface of the present invention is shown.

[0022] Figure 5 It shows Figure 4 Cross-sectional view at point BB;

[0023] Figure 6 It shows Figure 4 Cross-sectional view at point C;

[0024] Figure 7 It shows Figure 4 Cross-sectional view at point DD;

[0025] Figure 8 A forming limit diagram of the inner door panel of the present invention is shown;

[0026] Figure 9 A forming model diagram of a car door inner panel according to a specific embodiment of the present invention is shown;

[0027] Figure 10 This illustrates a single-stage drawing (FLD) cloud diagram of the inner door panel according to a specific embodiment of the present invention.

[0028] Figure 11 The diagram shows a single-stage drawing (FLD) cloud image of the inner door panel of a comparative embodiment of the present invention.

[0029] Figure label:

[0030] 1. Door inner panel; 11. First stamping area; 111. Bottom stamping surface; 112. Side stamping surface; 113. Lock hole; 12. Second stamping area; 13. Step stamping area; 131. First slope section; 132. Second slope section;

[0031] 2. Stamping area of ​​the drawing supplementary surface; 21. First stamping area of ​​the drawing supplementary surface; 22. Second stamping area of ​​the drawing supplementary surface;

[0032] 3. Tie bars; 31. Inner tie bars; 32. Outer tie bars;

[0033] 4. Pressing surface; 41. Initial sheet outline; 42. Ending sheet outline;

[0034] 5. C-pillar seam line. Detailed Implementation

[0035] The following describes optional embodiments of the present invention with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely for explaining the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. For example, the present invention does not limit the specific application of the door inner panel; it can be used in sedans, commercial vehicles, buses, trucks, fuel-powered vehicles, electric vehicles, and hybrid electric vehicles. These are not limiting; those skilled in the art can set their own applications based on actual usage. Such changes in specific application do not deviate from the basic principles of the present invention and therefore fall within the scope of protection of the present invention.

[0036] It should be noted that in the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, terms such as "upper," "lower," "left," "right," "inner," and "outer," indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the structure must have a specific orientation, or be constructed and operated in a specific orientation; therefore, it should not be construed as a limitation of this invention. Additionally, it should be noted that the terms "B-pillar" and "C-pillar" refer to the B-pillar and C-pillar of a vehicle.

[0037] Furthermore, it should be noted that although the various steps of the stamping and drawing forming method of the present invention are described in a specific order in the description of the present invention, these orders are not restrictive. Without departing from the basic principles of the present invention, those skilled in the art can perform the steps in different orders.

[0038] First refer to Figure 1 and 2 ,like Figure 1 and 2 As shown, the inner door panel 1 of the present invention includes a first stamping area 11, a second stamping area 12, and a stepped stamping area 13. The second stamping area 12 is disposed around the first stamping area 11, and the stepped stamping area 13 is disposed between the first stamping area 11 and the second stamping area 12. The first stamping area 11, the stepped stamping area 13, and the second stamping area 12 are all smoothly transitioned. Furthermore, the C-pillar seam line 5 of the vehicle is disposed on the outer side of the second stamping area 12. The stepped stamping area 13 enables the inner door panel 1 to be integrally stamped and drawn, and ensures that the overall stamping depth of the inner door panel 1 reaches 200 mm.

[0039] Furthermore, the stepped stamping area 13 includes a first slope segment 131 and a second slope segment 132 that are smoothly connected. The first slope segment 131 is smoothly connected to the first stamping area 11, and the second slope segment 132 is smoothly connected to the second stamping area 12. The slope of the first slope segment 131 is less than the slope of the second slope segment 132. Setting both the first slope segment 131 and the second slope segment 132 as stamping surfaces with slopes can not only ensure the stamping depth of the inner door panel 1, but also effectively prevent the inner door panel 1 from deforming due to inertial rebound caused by the mold after stamping. That is, it can effectively prevent the inner door panel 1 from having inaccurate manufacturing dimensions and deformation in some areas, thereby effectively ensuring the stamping and drawing quality of the inner door panel 1.

[0040] It should be noted that the present invention does not impose any restrictions on the specific shape of the inner door panel 1, nor on the specific slope values ​​of the first slope section 131 and the second slope section 132. Those skilled in the art can set these values ​​according to actual conditions. Furthermore, regarding the C-pillar seam line 5 of the vehicle, in this preferred embodiment, the C-pillar seam line 5 is set to be convex, smooth, and nearly straight, and satisfies a radius of curvature greater than or equal to 8000 mm and less than or equal to 20000 mm.

[0041] Regarding the first slope section 131 and the second slope section 132, specifically, as follows: Figure 2 As shown, curve L is the cross-sectional curve of the inner door panel 1 excluding the step stamping area 13 at point AA; curve M is the cross-sectional curve of the point AA where the step size formed by the step stamping area 13 is the largest; and curve N is the cross-sectional curve of the point AA where the step size formed by the step stamping area 13 is the smallest. Specifically, the total height of the first slope segment 131 and the second slope segment 132 along the drawing direction ( Figure 2 The total stamping depth of the inner door panel 1 is greater than or equal to the middle h). Figure 2 The width of the first slope section 131 is two-fifths of the total stamping depth H of the inner door panel 1 and less than or equal to three-fifths of the total stamping depth H of the inner door panel 1; Figure 2 The thickness of the inner door panel 1 is greater than or equal to 15 mm and less than or equal to 35 mm. Based on the specific setting data of the first slope 131 and the second slope 132 mentioned above, it is possible to ensure that the stamping depth of the inner door panel 1 is around 200 mm, and also to fully guarantee the stamping and drawing quality of the inner door panel 1.

[0042] Furthermore, the second slope section 132 and the second stamping area 12 are connected by a flange interlocking surface, the radius of the flange interlocking surface R1 being greater than or equal to 15 mm; the radius of ... More preferably, a locking hole 113 is provided on the first stamping area 11. The locking hole 113 is located at the connection between the bottom stamping surface 111 and the side stamping surface 112. The draft angle A1 of the side wall of the locking hole 113 along the drawing direction (i.e., the draft angle of the side stamping surface 112) is greater than or equal to 10°. 0 The draft angle A2 of the second slope section 132 near the flange seam surface along the drawing direction is greater than or equal to 20°. 0 .

[0043] The setting range of the above-mentioned multiple fillet radii and side wall draft angles can effectively increase the stamping depth of the inner door panel 1, making H between 160 mm and 205 mm. It can also ensure that the blank holder surface 4 of the inner door panel 1 will not be lifted by the mold when the drafting is completed by setting appropriate side wall draft angles A1 and A2. That is, it can effectively avoid the problem of bending and deformation of some areas of the inner door panel 1 during the drafting process, and fully guarantee the stamping and drawing quality of the inner door panel 1, so as to facilitate the vehicle assembly process.

[0044] Furthermore, the present invention also claims a stamping and drawing method for a door inner panel 1, see reference. Figure 3 , Figure 3 A flowchart illustrating the main steps of the stamping and drawing forming method of the present invention is shown. Figure 3 As shown, based on the inner door panel described in the above embodiments, the stamping and drawing forming method of the present invention mainly includes the following steps:

[0045] S1: Determine the actual stamping and drawing parameters of the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead;

[0046] S2: Based on the actual stamping and drawing parameters of the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead, the inner door panel, the drawing supplementary surface stamping zone, and the draw bead are stamped and drawn on the blanking surface in one pass.

[0047] First, in step S1, the actual stamping and drawing parameters of the first stamping zone 11, the second stamping zone 12, the stepped stamping zone 13, the drawing supplementary surface stamping zone 2, and the draw bead 3 are determined. At least a portion of the drawing supplementary surface stamping zone 2 is arranged along the circumference of the second stamping zone 12, and the draw bead 3 is arranged along the circumference of the drawing supplementary surface stamping zone 2.

[0048] Of course, this invention does not impose any restrictions on the specific type of the actual stamping and drawing parameter information. For example, the actual stamping and drawing parameter information can be the draft angle, stamping width, stamping depth, etc., which are not limiting and can be set by those skilled in the art according to the actual situation. In addition, it should be noted that this invention does not impose any restrictions on the specific determination method of the actual stamping and drawing parameter information of the first stamping area 11, the second stamping area 12, the stepped stamping area 13, the drawing supplementary surface stamping area 2, and the draw bead 3. Those skilled in the art can set it by themselves according to the actual situation.

[0049] Next, in step S2, based on the actual stamping and drawing parameters of the first stamping area 11, the second stamping area 12, the stepped stamping area 13, the drawing supplementary surface stamping area 2, and the draw bead 3, the inner door panel 1, the drawing supplementary surface stamping area 2, and the draw bead 3 are stamped and drawn in one pass on the blanking surface 4. Specifically, the operator can import the actual stamping and drawing parameters of the first stamping area 11, the second stamping area 12, the stepped stamping area 13, the drawing supplementary surface stamping area 2, and the draw bead 3 into the stamping and drawing forming equipment. The stamping and drawing forming equipment stamps and draws in one pass on the blanking surface 4 according to the imported data to form the inner door panel 1, the drawing supplementary surface stamping area 2, and the draw bead 3. After that, the drawing supplementary surface stamping area 2 and the draw bead 3 are cut off to obtain the inner door panel 1.

[0050] Further, before step S1, the C-pillar seam line 5 is adjusted so that it is convex and smooth, almost straight. Specifically, the C-pillar seam line 5 is set to be convex, smooth, and almost straight, and its radius of curvature is greater than or equal to 8000 mm and less than or equal to 20000 mm.

[0051] See next. Figures 4 to 7 ,like Figures 4 to 7As shown, in an optional implementation, at least a portion of the drawing supplementary stamping area 2 is arranged along the circumference of the inner door panel 1, and the drawing rib 3 is arranged along the circumference of the drawing supplementary stamping area 2. Those skilled in the art can customize this arrangement according to actual conditions. In this optional embodiment, the drawing supplementary stamping area 2 includes a first drawing supplementary stamping area 21 and a second drawing supplementary stamping area 22. An opening is provided at the center of the inner door panel 1, and the first drawing supplementary stamping area 21 covers the opening. The second drawing supplementary stamping area 22 surrounds the inner door panel 1 and has a die formed therein. Those skilled in the art should understand that the arrangement of at least a portion of the drawing supplementary stamping area 2 along the inner door panel 1 can be either such that the drawing supplementary stamping area 2 completely covers the circumference of the inner door panel 1, or it can only cover a portion of the circumference of the inner door panel 1. Those skilled in the art can customize this arrangement according to the actual requirements of the inner door panel 1 for use in a vehicle.

[0052] Furthermore, the drawbead 3 includes an inner drawbead 31 and an outer drawbead 32. The inner drawbead 31 is disposed between the end sheet contour 42 and the second drawing supplement surface stamping area 22, and the outer drawbead 32 is disposed between the starting sheet contour 41 and the end sheet contour 42. It should be noted that the specific shapes of the drawing supplement surface stamping area 2 and the drawbead 3 are not limiting, and those skilled in the art can adjust them according to the actual adaptation requirements of the vehicle door.

[0053] Based on the structure of the inner door panel 1, the stamping area 2 of the drawing supplement surface, and the drawing bead 3 described above, step S1 includes:

[0054] S11: Set the preset stamping and drawing parameters for the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead;

[0055] S12: Determine the forming model of the inner door panel based on the preset stamping and drawing parameters;

[0056] S13: Based on the forming model, determine the actual stamping and drawing parameters of the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead.

[0057] In step S11, those skilled in the art can preliminarily set the preset stamping and drawing parameters of the first stamping zone 11, the second stamping zone 12, the stepped stamping zone 13, the drawing supplementary surface stamping zone 2, and the drawing bead 3 based on experience.

[0058] In step S12, the preset stamping and drawing parameter information is imported into the drawing forming model to determine the forming model of the inner door panel 1.

[0059] Regarding step S13, step S13 further includes:

[0060] S131: Based on the forming model, determine the forming limit diagram of the inner door panel;

[0061] S132: Based on the forming limit diagram, adjust the preset stamping and drawing parameters of the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead to determine the actual stamping and drawing parameters of the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead.

[0062] In step S131, based on the forming model of the inner door panel 1, the shape of the inner door panel 1 is determined as follows: Figure 8 The forming limit diagram is shown.

[0063] In step S132, based on the forming limit diagram, it is determined whether the obtained forming limit diagram of the inner door panel 1 meets the following conditions: under the condition of a strain of 0.03, the maximum thinning of the blank holder 4 in area A is ≤18%, and the maximum failure is ≤0.7; the maximum thinning of the blank holder 4 in area B is ≤20%, and the maximum failure is ≤0.8, and does not exceed area C. If the obtained forming limit diagram of the inner door panel 1 does not meet the above conditions, the preset stamping and drawing parameters of the first stamping area 11, the second stamping area 12, the stepped stamping area 13, the drawing supplementary surface stamping area 2, and the draw bead 3 are repeatedly adjusted to meet the above conditions. If the above conditions are met, the set value range of the actual drawing and stamping parameters of the inner door panel 1, the drawing supplementary surface stamping area 2, and the draw bead 3 is determined to adapt to the manufacturing process of different types of vehicle doors.

[0064] Specifically, the actual stamping and drawing parameters for the first stamping zone 11, the second stamping zone 12, the stepped stamping zone 13, the drawing supplementary surface stamping zone 2, and the draw bead 3 are as follows:

[0065] "Determining the actual stamping and drawing parameters of the first stamping zone 11, the second stamping zone 12, and the stepped stamping zone 13 based on the forming model" includes:

[0066] Determine the total height h of the first slope section 131 and the second slope section 132 along the drawing direction and the width w of the first slope section 131; determine the fillet radius R1 of the flange bite surface, the fillet radius R2 of the connection between the first slope section 131 and the second slope section 132, the fillet radius R3 of the connection between the first slope section 131 and the first stamping area 11, and the fillet radius R4 of the connection between the bottom stamping surface 111 and the side stamping surface 112; determine the sidewall draft angle A1 of the lock hole 113 along the drawing direction and the sidewall draft angle A2 of the second slope section 132 near the flange bite surface along the drawing direction.

[0067] "Based on the forming model, determining the actual stamping and drawing parameters of the drawing supplementary surface stamping zone 2 and the draw bead 3 includes:"

[0068] Determine the fillet radius R5 of the die near the inner drawing bead 31, the fillet radius R6 of the die near the inner door panel 1, the fillet radius R7 of the die, and the draft angle A of the sidewall of the second drawing supplementary surface stamping area 22;

[0069] Determine the sides near the top and bottom of the vehicle (see) Figure 4 The spacing w2 of the inner drawbar 31 and outer drawbar 32 on the upper and lower sides, and the distance between them and the sides near the B-pillar and C-pillar of the vehicle (see...) Figure 4 The spacing w1 between the inner tie bars 31 and the outer tie bars 32 on the left and right sides.

[0070] Based on the conditions met by the forming limit diagram of the inner door panel 1, the actual stamping and drawing parameters of the first stamping area 11, the second stamping area 12, the stepped stamping area 13, the drawing supplementary surface stamping area 2, and the drawing bead 3 are repeatedly adjusted to meet the conditions that the inner door panel 1 will not crack or wrinkle and that the total stamping depth H of the inner door panel 1 can reach 200 mm.

[0071] Specifically, the total height h of the first slope section 131 and the second slope section 132 along the drawing direction is set to be greater than or equal to two-fifths of the total stamping depth H of the inner door panel 1 and less than or equal to three-fifths of the total stamping depth H of the inner door panel 1; the width w of the first slope section 131 is set to be greater than or equal to 15 mm and less than or equal to 35 mm; the fillet radius R1 of the flange bite face is set to be greater than or equal to 15 mm; the fillet radius R2 at the connection between the first slope section 131 and the second slope section 132 is set to be greater than or equal to 20 mm; the fillet radius R3 at the connection between the first slope section 131 and the first stamping area 11 is set to be greater than or equal to 20 mm; the fillet radius R4 at the connection between the bottom stamping surface 111 and the side stamping surface 112 is set to be greater than or equal to 10 mm; the draft angle A1 of the side wall of the lock hole 113 along the drawing direction is set to be greater than or equal to 10°. 0 The draft angle A2 of the sidewall along the drawing direction near the flange bite face of the second slope section 132 is set to be greater than or equal to 20°. 0 .

[0072] Furthermore, the fillet radius R5 of the die near the inner draw bead 31 is set to be greater than or equal to 15 mm and less than or equal to 25 mm; the fillet radius R6 of the die near the inner door panel 1 is set to be greater than or equal to 25 mm; the fillet radius R7 of the die is set to be greater than or equal to 20 mm and less than or equal to 30 mm; and the draft angle A of the sidewall of the stamping area 22 of the second drawing supplement surface is set to be greater than or equal to 12°. 0 And less than or equal to 18 0Of course, those skilled in the art should understand that the value of a certain parameter of the die formed on the second drawing supplementary stamping area 22 is not the same at all locations of the die. For example, in the same product, the fillet radius R5 of the die near the inner drawing bead 31 is not completely consistent at all locations of the die near the inner drawing bead 31. It needs to be set with different values ​​at different locations according to the actual structure required by the vehicle. As long as the overall fillet radius R5 of the die near the inner drawing bead 31 is greater than or equal to 15 mm and less than or equal to 25 mm, it is acceptable.

[0073] In addition, the spacing w2 between the inner drawbar 31 and the outer drawbar 32 near the top and bottom sides of the vehicle is set to be greater than or equal to 25 mm, and the spacing w1 between the inner drawbar 31 and the outer drawbar 32 near the B-pillar and C-pillar sides of the vehicle is set to be greater than or equal to 40 mm and less than or equal to 60 mm.

[0074] Setting the spacing of the inner drawbars 31 and outer drawbars 32 near the B-pillar and C-pillar sides of the vehicle to be greater than the spacing of the inner drawbars 31 and outer drawbars 32 near the top and bottom sides of the vehicle can effectively control the material flow in the second drawing supplementary surface stamping area 22 near the B-pillar and C-pillar sides of the vehicle. At the beginning of drawing, both the inner drawbars 31 and outer drawbars 32 can increase the drawing resistance, effectively preventing wrinkling of the blank holder surface 4. When the drawing stroke reaches its maximum value by about 50 mm, it is necessary to reduce the drawing resistance to improve the formability of the blank holder surface 4. This requirement can be achieved when w1 = 40~60 mm. This is because when the drawing stroke reaches its maximum value by about 50 mm, the blank holder surface 4 has already flowed past the outer drawbars 32. At this time, only the inner drawbars 31 are effective, and the drawing resistance is halved. This can accelerate the material flow of the blank holder surface 4, thereby improving the drawing formability.

[0075] Finally, based on the numerical range of the actual drawing and stamping parameters determined above, the final forming model of the inner door panel 1 is determined, and the inner door panel 1 is obtained by one-time stamping and drawing on the blank holder surface 4 according to the forming model and shearing.

[0076] The above-mentioned stamping and drawing parameters can produce aluminum door inner panels with a total stamping depth of 200 mm that allow the windows to be fully lowered.

[0077] Based on the above steps, in order to achieve a total stamping depth of 200 mm for the inner door panel 1, a possible stamping and drawing method for the inner door panel includes:

[0078] S21: Set the preset stamping and drawing parameters for the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead;

[0079] S22: Determine the forming model of the inner door panel based on the preset stamping and drawing parameters;

[0080] S23: Determine the forming limit diagram of the inner door panel based on the forming model;

[0081] S24: Based on the forming limit diagram, adjust the preset stamping and drawing parameter information of the first stamping area, the second stamping area, the stepped stamping area, the drawing supplementary surface stamping area, and the draw bead, so as to determine the actual stamping and drawing parameter information of the first stamping area, the second stamping area, the stepped stamping area, the drawing supplementary surface stamping area, and the draw bead;

[0082] The actual stamping and drawing parameters satisfy the following:

[0083] The total height h of the first slope section 131 and the second slope section 132 along the drawing direction is greater than or equal to two-fifths of the total stamping depth H of the inner door panel 1 and less than or equal to three-fifths of the total stamping depth H of the inner door panel 1; the width w of the first slope section 131 is greater than or equal to 15 mm and less than or equal to 35 mm; the fillet radius R1 of the flange bite face is greater than or equal to 15 mm; the fillet radius R2 at the connection between the first slope section 131 and the second slope section 132 is greater than or equal to 20 mm; the fillet radius R3 at the connection between the first slope section 131 and the first stamping area 11 is greater than or equal to 20 mm; the fillet radius R4 at the connection between the bottom stamping surface 111 and the side stamping surface 112 is greater than or equal to 10 mm; the draft angle A1 of the side wall of the lock hole 113 along the drawing direction is greater than or equal to 10°. 0 The draft angle A2 of the sidewall along the drawing direction of the second slope section 132 near the flange seam surface is greater than or equal to 20°. 0 The fillet radius R5 of the die near the inner draw bead 31 is greater than or equal to 15 mm and less than or equal to 25 mm; the fillet radius R6 of the die near the inner door panel 1 is greater than or equal to 25 mm; the fillet radius R7 of the die is greater than or equal to 20 mm and less than or equal to 30 mm; and the draft angle A of the sidewall of the stamping area 22 of the second drawing supplement surface is greater than or equal to 12°. 0 And less than or equal to 18 0 The spacing w2 between the inner drawbars 31 and outer drawbars 32 near the top and bottom of the vehicle is greater than or equal to 25 mm, and the spacing w1 between the inner drawbars 31 and outer drawbars 32 near the B-pillar and C-pillar of the vehicle is greater than or equal to 40 mm and less than or equal to 60 mm. The above settings enable the total stamping depth H of the aluminum door inner panel 1 to be between 160 mm and 205 mm, and enable the window to be fully lowered without the door inner panel 1 wrinkling or cracking.

[0084] As an example, the present invention provides a specific embodiment, see below. Figures 9 to 11 In this specific embodiment:

[0085] The C-pillar seam line is smooth and convex, with a radius of curvature of 8025 mm.

[0086] For the inner door panel 1: the total height h of the first slope section 131 and the second slope section 132 along the drawing direction is 0.533 times the total stamping depth H of the inner door panel 1; the minimum width w of the first slope section 131 is 20 mm; the minimum fillet radius R1 of the flange bite surface between the second slope section 132 and the second stamping area 12 is 15 mm; the minimum fillet radius R2 at the connection between the first slope section 131 and the second slope section 132 is 23 mm; the minimum fillet radius R3 at the connection between the first slope section 131 and the first stamping area 11 is 30 mm; and the minimum draft angle A1 of the side wall of the lock hole 113 along the drawing direction is 12.3 mm. 0 The minimum draft angle A2 of the sidewall near the flange seam surface of the second slope section 132 along the drawing direction is 23°. 0 The minimum radius of the fillet R4 at the connection between the bottom stamping surface 111 and the side stamping surface 112 is 10 mm.

[0087] For the stamping area 2 of the drawing supplement surface: the fillet radius R5 of the die near the inner drawing bead 31 is 20 mm, the fillet radius R6 of the die near the inner door panel 1 is greater than or equal to 45 mm, and the fillet radius R7 of the die is 25 mm.

[0088] For the drawbar 3: the spacing w1 between the inner drawbar 31 and the outer drawbar 32 near the B-pillar and C-pillar of the vehicle is 50mm.

[0089] Based on the above data, the stamping depth H of the inner door panel 1 is 197 mm.

[0090] Based on the above data, we obtain the following: Figure 9 The forming model of the inner door panel 1 shown is further subjected to forming limit analysis, such as... Figure 10 As shown, the maximum thinning of the obtained inner door panel 1 in area A is 17.5%, and the maximum failure is 0.7; the maximum thinning in area B is 19.6%, and the maximum failure is 0.785; none of the points exceed those in area C. As a comparative example, the FLD contour plot of the forming model of the inner door panel 1 obtained using conventional data is shown below. Figure 11 As shown, the inner door panel 1 exhibits severe cracking and wrinkling, which significantly reduces the manufacturing quality of the door according to conventional data. Therefore, the inner door panel 1 manufactured using the forming model determined by the relevant data of the inner door panel 1, the drawing supplementary stamping area 2, and the drawing bead 3 provided in this invention will not easily wrinkle or crack, and will also have a large stamping depth of 197 mm.

[0091] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A door inner panel, characterized in that, The inner door panel includes a first stamping area, a second stamping area, and a stepped stamping area. The second stamping area is arranged around the first stamping area, and the stepped stamping area is arranged between the first stamping area and the second stamping area. The stepped stamping area includes a first slope section and a second slope section that are smoothly connected. The first slope section is smoothly connected to the first stamping area, and the second slope section is smoothly connected to the second stamping area. The slope of the first slope section is less than the slope of the second slope section. The inner panel of the door is configured to be integrally stamped and drawn. The total height of the first slope section and the second slope section along the drawing direction is greater than or equal to two-fifths of the total stamping depth of the inner door panel and less than or equal to three-fifths of the total stamping depth of the inner door panel. The inner door panel is made of aluminum. The total stamping depth of the inner door panel is between 160mm and 205mm.

2. The inner door panel according to claim 1, characterized in that, The width of the first slope segment is greater than or equal to 15 mm and less than or equal to 35 mm.

3. The inner door panel according to claim 2, characterized in that, The connection surface between the second slope section and the second stamping area is a flange seam surface, and the radius of the fillet of the flange seam surface is greater than or equal to 15 mm; The radius of the fillet at the connection between the first slope segment and the second slope segment is greater than or equal to 20 mm; The radius of the fillet at the connection between the first slope section and the first stamping zone is greater than or equal to 20 mm.

4. The inner door panel according to claim 3, characterized in that, The first stamping area is provided with a locking hole, and the draft angle of the side wall of the locking hole along the drawing direction is greater than or equal to 10°; The draft angle of the sidewall along the drawing direction of the second slope section near the flange bite face is greater than or equal to 20°.

5. A method for stamping and drawing an inner door panel, used to manufacture the inner door panel according to any one of claims 1 to 4, characterized in that, The inner door panel includes a first stamping area, a second stamping area, and a stepped stamping area. The second stamping area surrounds the first stamping area. The stepped stamping area is located between the first and second stamping areas. The stepped stamping area includes a first slope segment and a second slope segment that are smoothly connected. The first slope segment is smoothly connected to the first stamping area, and the second slope segment is smoothly connected to the second stamping area. The slope of the first slope segment is less than the slope of the second slope segment. The total height of the first slope segment and the second slope segment along the drawing direction is set to be greater than or equal to two-fifths and less than or equal to three-fifths of the total stamping depth of the inner door panel. The inner door panel is made of aluminum. The total stamping depth of the inner door panel is between 160mm and 205mm. The stamping and drawing forming method includes: Determine the actual stamping and drawing parameters of the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead; Wherein, at least a portion of the drawing supplement surface stamping area is arranged along the circumference of the second stamping area, and the drawing bead is arranged along the circumference of the drawing supplement surface stamping area. Based on the actual stamping and drawing parameter information of the first stamping area, the second stamping area, the stepped stamping area, the drawing supplementary surface stamping area, and the drawing bead, the inner door panel, the drawing supplementary surface stamping area, and the drawing bead are stamped and drawn in one pass on the blank holder surface.

6. The stamping and drawing forming method according to claim 5, characterized in that, The steps of "determining the actual stamping and drawing parameters of the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead" specifically include: Set preset stamping and drawing parameter information for the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead; Based on the preset stamping and drawing parameters, the forming model of the inner door panel is determined; Based on the forming model, the actual stamping and drawing parameters of the first stamping zone, the second stamping zone, the stepped stamping zone, the drawing supplementary surface stamping zone, and the draw bead are determined.

7. The stamping and drawing forming method according to claim 6, characterized in that, The connection surface between the second slope section and the second stamping area is set as a flange seam surface, and a locking hole is provided on the first stamping area. The step of "determining the actual stamping and drawing parameters of the first stamping zone, the second stamping zone, and the stepped stamping zone based on the forming model" includes: Determine the total height of the first slope segment and the second slope segment along the drawing direction, and the width of the first slope segment; Determine the fillet radius of the flange seam, the fillet radius at the connection between the first slope segment and the second slope segment, and the fillet radius at the connection between the first slope segment and the first stamping area; Determine the draft angle of the sidewall of the lock hole along the drawing direction and the draft angle of the sidewall of the second slope section near the flange bite surface along the drawing direction.

8. The stamping and drawing forming method according to claim 7, characterized in that, The width of the first slope section is set to be greater than or equal to 15 mm and less than or equal to 35 mm; The radius of the fillet on the flange bite surface is set to be greater than or equal to 15 mm, the radius of the fillet at the connection between the first slope section and the second slope section is set to be greater than or equal to 20 mm, and the radius of the fillet at the connection between the first slope section and the first stamping area is set to be greater than or equal to 20 mm. The draft angle of the sidewall of the lock hole along the drawing direction is set to be greater than or equal to 10°, and the draft angle of the sidewall of the second slope section near the flange bite surface along the drawing direction is set to be greater than or equal to 20°.

9. The stamping and drawing forming method according to claim 6, characterized in that, A die is provided in the stamping area of ​​the drawing supplement surface, and inner and outer draw beads are provided, wherein the outer draw bead is provided on the outer periphery of the inner draw bead. The step of "determining the actual stamping and drawing parameters of the drawing supplementary surface stamping zone and the drawing bead based on the forming model" includes: Determine the fillet radius of the die near the inner drawbeam, the fillet radius of the die near the inner door panel, and the fillet radius of the die. The spacing between the inner and outer drawbars near the top and bottom sides of the vehicle, as well as the spacing between the inner and outer drawbars near the B-pillar and C-pillar sides of the vehicle, are determined.

10. The stamping and drawing method according to claim 9, characterized in that, The radius of the fillet near the inner drawbar of the die is set to be greater than or equal to 15 mm and less than or equal to 25 mm, the radius of the fillet near the inner door panel of the die is set to be greater than or equal to 25 mm, and the radius of the fillet of the die is set to be greater than or equal to 20 mm and less than or equal to 30 mm. The spacing between the inner and outer drawbars near the top and bottom sides of the vehicle is set to be greater than or equal to 25 mm, and the spacing between the inner and outer drawbars near the B-pillar and C-pillar sides of the vehicle is set to be greater than or equal to 40 mm and less than or equal to 60 mm.

Images