Flat plate convex hull stamping process method

Abstract

The invention provides a flat plate convex hull stamping process method which comprises the following steps: performing primary stamping on a to-be-stamped plate to form a first convex hull on the to-be-stamped plate; the first convex hull is subjected to secondary back pressure to form a second convex hull, and a formed plate is obtained; the first convex hull depth is larger than the convex hull depth of a preset target, and the difference value between the first convex hull depth and the convex hull depth of the preset target is D1; the depth of the second convex hull is smaller than that of the first convex hull, the depth of the second convex hull is larger than or equal to the preset target convex hull depth, the difference value between the depth of the second convex hull and the preset target convex hull depth is D2, and D1 is larger than D2. Wherein in the secondary pressure return process, the first convex hulls are subjected to the new pressure effect to form the second convex hulls, so that the problem that after primary stamping, the residual stress direction of some areas possibly promotes outward expansion of materials during springback can be effectively solved, and redistribution and offset of the residual stress are achieved.

Description

Technical Field

[0001] This invention relates to the field of stamping technology, and mainly to a method for stamping a flat plate with a raised bulge. Background Technology

[0002] With the continuous development of automobiles, the requirements for the appearance quality of automotive exterior body panels, the reliability of automotive exterior body panel molds, and innovation are also increasing. Among them, automotive body panels refer to the functional components that constitute the automobile body (including interior and exterior trim) and serve as a covering structure. Moreover, as stamped parts, automotive body panels are the core appearance and assembly carrier of the automobile body.

[0003] In related technologies, lightweight materials such as low-density, high-strength magnesium alloys and carbon fiber composites are commonly used in the preparation of raw materials for automotive body panels. The material processing mainly involves stamping, using stamping equipment to stamp flat sheets of magnesium alloys and carbon fiber composites.

[0004] However, due to their low density, lightweight materials such as magnesium alloys and carbon fiber composites have a combination of high elastic modulus and low yield strength, resulting in significantly higher springback sensitivity than traditional metals. They also have poor plastic deformation ability and are prone to sudden twisting after the stress of compression is released, which affects the stability of the manufacturing process and reduces the manufacturing precision of the product. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that sudden twisting after stress release of materials after stamping affects the product manufacturing accuracy and stability, and to provide a flat plate convex stamping process method.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for stamping a flat sheet with a raised bump, comprising the following steps: stamping the sheet material to be stamped once to form a first raised bump on the sheet material; and stamping the first raised bump a second time to form a second raised bump, thereby obtaining a shaped sheet material; wherein, the depth of the first raised bump is greater than a preset target raised bump depth, and the difference between the depth of the first raised bump and the preset target raised bump depth is D1; ​​the depth of the second raised bump is less than the depth of the first raised bump, the depth of the second raised bump is greater than or equal to the preset target raised bump depth, and the difference between the depth of the second raised bump and the preset target raised bump depth is D2, where D1 > D2.

[0007] The above technical solution has the following advantages or beneficial effects: By first stamping the sheet metal and then performing a second back-pressing, a first convex bulge exceeding the preset depth is formed during the first stamping process. Due to the springback characteristics of lightweight materials, if the preset target depth is reached directly after the first stamping, the bulge depth is very likely to deviate from the target value due to springback during subsequent stress release. This solution sets the first bulge depth to be deeper than the preset target by a difference of D1, reserving adjustment space for subsequent springback. Then, the first bulge is subjected to a second back-pressing to form a second bulge. The depth of the second bulge is less than the depth of the first bulge, but greater than or equal to the preset target bulge depth, and the difference D2 between the depth of the second bulge and the preset target bulge depth is less than D1. During the secondary back-pressing process, the first convex bud is subjected to new pressure to form the second convex bud. This can effectively improve the problem that the residual stress direction in certain areas after the first stamping may cause the material to expand outward during springback. The secondary back-pressing can suppress the springback trend caused by this stress by changing the stress direction, and even produce small deformations in the opposite direction. This achieves the redistribution and cancellation of residual stress, effectively controlling the dimensional stability of the stamping convex bud affected by springback during the stamping process. After the secondary back-pressing, even if the material springs back to a certain extent, the depth of the second convex bud can be made as close as possible to or even reach the preset target value. This effectively overcomes the process instability problem caused by the high springback sensitivity of lightweight materials and improves the stability of the manufacturing process.

[0008] In some embodiments of this application, a method for stamping a flat plate with a raised bulge is provided. In the step of stamping the sheet material to be stamped once, a first stamping die is used to stamp the sheet material to be stamped once. The bulge depth of the first stamping die is greater than the preset target bulge depth, so that the depth of the first bulge is greater than the preset target bulge depth.

[0009] Another technical solution in the above technical solution has the following advantages or beneficial effects: the convex depth of the concave cavity of the first stamping die is set to be greater than the preset target convex depth. After the stamping equipment is started, the punch of the first stamping die can be driven to press the sheet metal downward with a preset pressure. Under the constraint of the cavity of the first stamping die, the convex depth of the first convex formed on the sheet metal to be stamped can be greater than the preset target convex depth.

[0010] In some embodiments of this application, a method for stamping a flat convex bulge is provided. In the step of performing a second back press on the first convex bulge to form a second convex bulge, a second stamping die is used to perform a second back press on the first convex bulge. The convex bulge depth of the second stamping die is equal to the preset target convex bulge depth, so that the depth of the second convex bulge is equal to the preset target convex bulge depth.

[0011] Another technical solution described above has the following advantages or beneficial effects: the convex depth of the concave cavity of the second stamping die is set to be equal to the preset target convex depth. After step S20, the first stamping die can be replaced with the second stamping die, and then the punch of the second stamping die is driven to press the first convex downward with a preset pressure. During the above-mentioned secondary pressing process, under the constraint of the cavity of the second stamping die, the depth of the first convex gradually decreases until it conforms to the concave cavity of the second stamping die to form the second convex with the target convex contour.

[0012] In some embodiments of this application, a method for stamping a flat plate convex bulge is provided, wherein the difference D3 between the convex bulge depth of the first stamping die and the preset target convex bulge depth ranges from 1.8mm to 2.2mm. Another technical solution in the above-mentioned technical solution has the following advantages or beneficial effects: by controlling the difference D3 between the convex bulge depth of the first stamping die and the preset target convex bulge depth to a range of 1.8mm to 2.2mm, excessive deformation force during the first stamping can be avoided, reducing the thinning of the convex bulge bottom wall thickness, reducing the difficulty of secondary back-pressing, and simultaneously making the secondary back-pressing process more stable, reducing the generation of new stress, and improving the quality of stamping.

[0013] In some embodiments of this application, a method for stamping a flat plate convex bulge is provided, wherein the difference D3 between the bulge depth of the first stamping die and the preset target bulge depth is equal to 2mm. Another technical solution described above has the following advantages or beneficial effects: by controlling the difference D3 between the bulge depth of the first stamping die and the preset target bulge depth to 2mm, during the secondary back-pressing process, the first bulge is shallowed by 2mm through back-pressing, which can effectively redistribute and offset the residual stress after the first stamping, effectively control springback, and improve the stability of the stamping process.

[0014] In some embodiments of this application, a method for stamping a flat plate with a raised bump is provided. Before the step of stamping the sheet metal to be stamped once to form a first raised bump on the sheet metal to be stamped, the flat plate with a raised bump stamping process further includes: conveying the sheet metal to be stamped to a blanking die, and controlling the upper die of the blanking die to move toward the lower die of the blanking die to cut the sheet metal to be stamped into a preset shape.

[0015] Another technical solution in the above-mentioned technical solution has the following advantages or beneficial effects: The blanking die consists of an upper die and a lower die. The lower die of the blanking die can be provided with a cavity that matches the preset shape, and the upper die of the blanking die can be provided with a corresponding cutting edge. The equipment is started, and the upper die of the blanking die is controlled to move towards the lower die below. The cutting edge of the upper die cooperates with the cavity of the lower die to punch and cut the sheet metal to be stamped, ultimately cutting the sheet metal into a preset shape that matches the requirements of the convex forming of automotive body panels.

[0016] In some embodiments of this application, a method for stamping a flat plate convex bulge is provided. After the step of performing a second back press on the first convex bulge to form a second convex bulge, the method for stamping a flat plate convex bulge further includes: trimming the edge of the formed plate and punching holes in a preset position of the formed plate using a punching die to form mounting holes in the formed plate.

[0017] Another technical solution described above has the following advantages or beneficial effects: the trimming process of the edge sheet of the formed sheet is carried out simultaneously with the punching process, thereby improving the overall stamping efficiency. Specifically, the lower die of the punching die is equipped with a locating pin and a die cavity that match the preset hole positions on the formed sheet, while the upper die is equipped with a corresponding punch. By starting the punching equipment, the upper die punch is controlled to punch downwards, forming the mounting hole at the preset position on the formed sheet.

[0018] In some embodiments of this application, a flat plate convex stamping process is provided. After the steps of trimming the edge sheet of the formed sheet and punching holes in the predetermined position of the formed sheet using a punching die, the flat plate convex stamping process further includes: bending the edge region of the formed sheet along a predetermined angle to form a flange structure on the formed sheet.

[0019] Another technical solution in the above-mentioned technical solution has the following advantages or beneficial effects: The sheet metal is transferred to the bending die station by a conveying mechanism. The bending die can be composed of an upper bending die, a lower bending die, and an angle positioning mechanism. The lower bending die is provided with a forming surface and a positioning groove that match the preset angle of the flange. The upper bending die is provided with a corresponding pressing and bending boss. By first placing the sheet metal into the positioning groove of the lower bending die and fixing it, it is ensured that the edge to be bent can be accurately aligned with the forming surface of the bending die. The bending equipment is started, and the upper bending die is controlled to move downward. Through the cooperation of the forming surfaces of the upper and lower bending dies, the edge area of ​​the formed sheet metal is bent along the preset angle, forming a flange structure on the formed sheet metal.

[0020] In some embodiments of this application, a flat plate convex stamping process method is provided. After the step of bending the edge region of the formed sheet material along a preset angle to form a flange structure on the formed sheet material, the flat plate convex stamping process method further includes: controlling a slider to shape the sheet material along the flange structure position at a preset speed.

[0021] Another technical solution in the above-mentioned technical solution has the following advantages or beneficial effects: After bending and flanging, the sheet material can be transferred to the forming station by a conveying mechanism, and a forming mold is provided at the forming station. Specifically, the sheet material with the flanged structure can be positioned on the positioning base of the forming mold, so that the flanged structure is aligned with the forming working surface of the slider. A preset speed for the slider movement can be set according to the thickness and material characteristics of the flanged material, and the slider is controlled to move uniformly in a straight line along the position of the flanged structure of the formed sheet material at the preset speed. Through the cooperation between the forming working surface of the slider and the positioning base, the flanged structure is formed in a conforming manner. During the forming process, the slider can apply uniform forming pressure to the flanged structure, thereby correcting minor angular deviations, edge warping, and other defects, and improving the flatness and perpendicularity of the flanged structure.

[0022] In some embodiments of this application, a flat plate convex stamping process is provided. After the steps of trimming the edge material of the formed plate and punching holes in a preset position of the formed plate using a punching die, the flat plate convex stamping process further includes: trimming the edge material of the formed plate a second time and punching another preset position of the formed plate using a punching die to form mounting holes in the formed plate.

[0023] Another technical solution in the above-mentioned technical solution has the following advantages or beneficial effects: the process of secondary trimming of the edge sheet of the formed sheet can be carried out simultaneously with the secondary punching process, thereby improving the overall stamping efficiency. In particular, through secondary trimming and punching, the risk of secondary springback or edge warping caused by stress affecting other parts of the formed sheet due to the large instantaneous punching force can be effectively reduced. Attached Figure Description

[0024] Figure 1 This is one of the schematic diagrams illustrating the specific steps of a flat plate convex hull stamping process according to an embodiment of the present invention; Figure 2 This is a sheet material formed by stamping a flat plate with a raised bulge, according to an embodiment of the present invention. Figure 3 yes Figure 2 A schematic diagram showing the process of forming medium-sized sheet metal through a single stamping and a second back pressing. Figure 4 This is a second schematic diagram illustrating the specific steps of a flat plate convex hull stamping process according to an embodiment of the present invention; Figure 5 This is the third schematic diagram of the specific steps of a flat plate convex stamping process according to an embodiment of the present invention.

[0025] The correspondence between the reference numerals and the component names is as follows: 100, sheet material to be stamped; 200, first convex bulge; 300, second convex bulge. Detailed Implementation

[0026] This invention provides a method for stamping a flat plate with a raised bulge. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the scope of protection of the invention.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] Currently, lightweight materials such as low-density, high-strength magnesium alloys and carbon fiber composites are commonly used in the preparation of automotive body panels. The material processing mainly involves stamping, using stamping equipment to stamp flat sheets of magnesium alloys and carbon fiber composites.

[0029] Among them, lightweight materials such as magnesium alloys and carbon fiber composites, due to their low density, have a combination of high elastic modulus and low yield strength, resulting in significantly higher springback sensitivity than traditional metals. They also have poor plastic deformation capacity and are prone to sudden twisting after the stress of compression is released. Moreover, during the production process, the stress concentration problem of traditional packaging processes exists, and the initial residual stress already exists during material processing (such as rolling and injection molding). The superposition of compression stress and this may trigger secondary deformation, resulting in poor process stability in the manufacturing of automotive body panels and reduced product manufacturing precision.

[0030] Therefore, it is necessary to design a method to solve the problem of sudden twisting of materials after stress release, which affects the product manufacturing accuracy and stability, and to provide a flat plate convex stamping process.

[0031] Figure 1 This is a schematic diagram illustrating one of the specific steps of a flat plate convex stamping process according to an embodiment of the present invention.

[0032] like Figure 1 As shown, one embodiment of the present invention provides a method for stamping a flat plate with a raised bulge, comprising the following steps: Step S20: The sheet metal 100 to be stamped is stamped once to form a first protrusion 200 on the sheet metal 100 to be stamped. Step S30: The first convex 200 is subjected to a second back press to form the second convex 300, thereby obtaining the shaped sheet material; Wherein, the depth of the first convex hull 200 is greater than the depth of the convex hull of the preset target, and the difference between the depth of the first convex hull 200 and the depth of the convex hull of the preset target is D1. The depth of the second convex hull 300 is less than the depth of the first convex hull 200. The depth of the second convex hull 300 is greater than or equal to the convex hull depth of the preset target, and the difference between the depth of the second convex hull 300 and the convex hull depth of the preset target is D2, where D1 > D2.

[0033] Figure 2 This is a sheet material formed by stamping a flat plate with a raised bulge, according to an embodiment of the present invention. Figure 3 yes Figure 2 A schematic diagram showing the process of forming medium-sized sheet metal through a single stamping and a second back-pressing; it should be noted that... Figure 3 Indicated as Figure 2 A partial schematic diagram of the structure at point AA, wherein... Figure 3 The depth of 2mm shown in the diagram can represent the back pressure depth after the first convex hull 200 undergoes a second back pressure.

[0034] like Figure 2 and Figure 3 As shown, in step S20, the sheet metal is first stamped to form a first protrusion 200. Specifically, the sheet metal to be stamped is first fixed on the stamping die to prevent the sheet metal from shifting during the stamping process. Then, the stamping equipment is started to press the sheet metal downwards, thereby forming the first protrusion 200 on the sheet metal. In this step, the sheet metal can form a preset intermediate transition first protrusion 200 with a relatively large depth from a flat state. In some specific embodiments, the first stamping process can simultaneously form multiple first protrusions 200 on the sheet metal.

[0035] In step S30, the material is stamped again. Specifically, a second back pressure can be applied to the first protrusion 200 on the sheet metal, so that the formed second protrusion 300 is closer to the preset target protrusion depth than the first protrusion 200. In this step, based on the first protrusion 200 with a relatively large depth formed by the first stamping, a reverse forming force can be applied to reduce the height of the first protrusion 200. Because lightweight materials have a high elastic modulus, they store a large amount of elastic strain energy after unloading. The formed product's accuracy is affected by severe springback. By applying a force opposite to the direction of the first stamping in step S30, the residual stress remaining in the material after the first forming is actively and controllably released and adjusted, thereby consuming the main elastic potential energy that leads to the final severe springback and sudden twisting.

[0036] In this design, the depth of the second convex 300 is less than the depth of the first convex 200, and the depth of the second convex 300 is greater than or equal to the depth of a preset target convex 200. Furthermore, the difference between the depth of the second convex 300 and the depth of the preset target convex 200 is D2, where D1 > D2. Thus, the difference between the depth of the first convex 200 formed by a single stamping and the depth of the preset target convex 200 is greater than the difference between the depth of the second convex 300 formed by a second back stamping and the depth of the preset target convex 200. The depth of the second convex 300 is closer to the preset target. In some specific embodiments, the depth of the second convex 300 can be equal to the preset target.

[0037] Specifically, this solution involves forming the sheet metal through a first stamping followed by a second back-pressing. During the first stamping, a first protrusion 200 exceeding a preset depth is formed. Due to the springback characteristics of lightweight materials, if the preset target depth is reached directly after the first stamping, the protrusion depth is highly likely to deviate from the target value during subsequent stress release due to springback. This solution sets the depth of the first protrusion 200 to be deeper than the preset target by a difference of D1, reserving adjustment space for subsequent springback. Next, the first protrusion 200 is subjected to a second back-pressing to form a second protrusion 300. The depth of the second protrusion 300 is less than the depth of the first protrusion 200, but greater than or equal to the preset target protrusion depth, and the difference D2 between the depth of the second protrusion 300 and the preset target protrusion depth is less than D1. During the secondary back-pressing process, the first convex 200 is subjected to new pressure to form the second convex 300. This can effectively improve the problem that the residual stress direction in certain areas after the first stamping may cause the material to expand outward during springback. The secondary back-pressing can suppress the springback trend caused by this stress by changing the stress direction, and even produce small deformations in the opposite direction, thereby achieving the redistribution and cancellation of residual stress. This effectively controls the dimensional stability of the stamping convex due to springback during the stamping process. After the secondary back-pressing, even if the material springs back to a certain extent, the depth of the second convex 300 can be made as close as possible to or even reach the preset target value. This effectively overcomes the process instability caused by the high springback sensitivity of lightweight materials and improves the stability of the manufacturing process.

[0038] It should be noted that, in some specific embodiments, the depth of the second convex 300 can be equal to the preset target convex depth. In this way, the load can be directly applied to the first convex 200 through one or two back pressures to form a convex convex of the preset depth, thereby improving the efficiency of the stamping process.

[0039] In some other specific implementations, by setting multiple secondary back pressures, the newly formed second convex 300 can continuously approach the convex 300 at a preset depth.

[0040] In some embodiments, in the step of stamping the sheet metal 100 to be stamped once, the sheet metal 100 to be stamped is stamped once using a first stamping die, and the convex depth of the first stamping die is greater than a preset target convex depth, so that the depth of the first convex 200 is greater than the preset target convex depth.

[0041] In the first stamping process of step S20, the first stamping die is used to stamp the sheet metal 100 to be stamped. Specifically, the convex depth of the concave cavity of the first stamping die is set to be greater than the preset target convex depth. After the stamping equipment is started, the punch of the first stamping die can be driven to stamp the sheet metal downward with a preset pressure. Under the constraint of the cavity of the first stamping die, the convex depth of the first convex 200 formed on the sheet metal 100 to be stamped can be greater than the preset target convex depth.

[0042] In some embodiments, in the step of performing a second back press on the first convex 200 to form the second convex 300, the first convex 200 is subjected to a second back press using a second stamping die, and the convex depth of the second stamping die is equal to a preset target convex depth, so that the depth of the second convex 300 is equal to the preset target convex depth.

[0043] In the secondary back-pressing process of step S30, the second stamping die is used to reverse-press the second protrusion 300. Specifically, the protrusion depth of the concave cavity of the second stamping die is set to be equal to the preset target protrusion depth. After step S20, the first stamping die can be replaced with the second stamping die, and then the punch of the second stamping die is driven to press the first protrusion 200 downward with a preset pressure. In the above-mentioned secondary back-pressing process, under the constraint of the cavity of the second stamping die, the depth of the first protrusion 200 gradually decreases until it conforms to the concave cavity of the second stamping die to form the second protrusion 300 with the target protrusion contour.

[0044] In some embodiments, the difference D3 between the bulge depth of the first stamping die and the preset target bulge depth can be greater than 1.8 mm. By setting the difference D3 between the bulge depth of the first stamping die and the preset target bulge depth to be greater than 1.8 mm, the problem of insufficient compensation for springback deformation during the sheet metal stamping bulge process due to an excessively small difference can be avoided, which would require greater pressure or more adjustments during secondary back pressure, thereby improving the efficiency of the stamping forming process.

[0045] In some embodiments, the difference D3 between the bulge depth of the first stamping die and the preset target bulge depth can be less than 2.2 mm. Excessive stretching at the bottom of the bulge can easily lead to thinning of the wall thickness, thus increasing the difficulty of secondary back-pressing. By setting the difference D3 between the bulge depth of the first stamping die and the preset target bulge depth to less than 2.2 mm, the problem of wall thinning due to increased deformation force on the sheet metal 100 during the first stamping due to a large difference can be avoided. Simultaneously, it avoids the need to apply a larger back-press load during the secondary stamping process to correct the bulge depth to the preset target, as a large back-press load can easily create new stress in the sheet metal, affecting the stamping effect.

[0046] In some embodiments, the difference D3 between the bulge depth of the first stamping die and the bulge depth of the preset target can be in the range of 1.8mm to 2.2mm.

[0047] By controlling the difference D3 between the convex depth of the first stamping die and the convex depth of the preset target to a range of 1.8mm to 2.2mm, excessive deformation force during the first stamping can be avoided, the thinning of the bottom wall thickness of the convex can be reduced, the difficulty of the second back pressing can be reduced, and the second back pressing process can be made more stable, reducing the generation of new stress and improving the quality of stamping.

[0048] like Figure 3 As shown, in some embodiments, the difference D3 between the convex depth of the first stamping die and the preset target convex depth is equal to 2mm. By controlling the difference D3 between the convex depth of the first stamping die and the preset target convex depth to 2mm, the first convex 200 is shallowed by 2mm during the secondary back-pressing process. This effectively redistributes and offsets the residual stress after the first stamping, effectively controls springback, and improves the stability of the stamping process.

[0049] Figure 4 This is the second schematic diagram of the specific steps of a flat plate convex stamping process according to an embodiment of the present invention.

[0050] like Figure 4 As shown, in some embodiments, prior to the step of stamping the sheet metal 100 to form a first protrusion 200 on the sheet metal 100, the flat plate protrusion stamping process further includes: Step S10: The sheet metal 100 to be stamped is conveyed to the blanking die, and the upper die of the blanking die is controlled to move toward the lower die of the blanking die so as to cut the sheet metal 100 to be stamped into a preset shape.

[0051] Before step S20, a blanking, cutting, and shaping step is also included. Specifically, the sheet metal 100 to be stamped can be conveyed to the blanking die via an automated conveying mechanism such as a conveyor belt or a robotic arm. The blanking die consists of an upper die and a lower die. The lower die of the blanking die can be provided with a cavity matching a preset shape, and the upper die of the blanking die can have a corresponding cutting edge. The equipment is started, and the upper die of the blanking die is controlled to move towards the lower die below. By utilizing the cutting edge of the upper die and the cavity of the lower die, the sheet metal 100 to be stamped is punched and cut, ultimately cutting the sheet metal into a preset shape that matches the requirements of the convex forming of the automotive body panel. After the above cutting is completed, the upper die of the blanking die is reset, and the cut sheet metal can be transferred to the primary stamping station via a conveying mechanism.

[0052] Figure 5 This is the third schematic diagram of the specific steps of a flat plate convex stamping process according to an embodiment of the present invention.

[0053] like Figure 5 As shown, in some embodiments, after the step of performing a second back press on the first convex 200 to form the second convex 300, the flat convex convex stamping process further includes: Step S40: Trim the edge of the formed sheet and punch holes in the preset position of the formed sheet using a punching die to form mounting holes in the formed sheet.

[0054] Following the secondary stamping step in step S30, an edge trimming and punching step is also included. Specifically, after the secondary back-pressing obtains the formed sheet material, the edge of the formed sheet material is trimmed to meet the assembly requirements of automotive body panels. The formed sheet material after secondary back-pressing can be transferred to the trimming die station via a conveying mechanism. The upper die of the trimming die has a cutting edge that matches the final contour of the product, and the lower die of the trimming die has a corresponding positioning and support structure. The equipment is started, and the upper die is controlled to move to the lower die, precisely trimming the excess edge of the formed sheet material to remove edge burrs or excess material generated during stamping and back-pressing.

[0055] In the above process, the trimming of the edge material of the formed sheet can be carried out simultaneously with the punching process, thereby improving the overall stamping efficiency. Specifically, the lower die of the punching die has mounting hole positions corresponding to the preset hole positions on the formed sheet, locating pins of matching dimensions, and die holes, while the upper die has corresponding punches. By starting the punching equipment, the upper die punch is controlled to punch downwards, forming mounting holes at the preset positions on the formed sheet. like Figure 5 As shown, in some embodiments, after trimming the edge of the formed sheet and punching holes at preset positions on the formed sheet using a punching die, the flat plate convex stamping process further includes: Step S50: Trim the edge of the formed sheet material a second time, and use a punching die to punch a second hole at another preset position of the formed sheet material to form mounting holes in the formed sheet material.

[0056] The process includes a second trimming and punching step after the trimming and punching step in step S40. Specifically, step S40 trims a portion of the area, and step S50 can trim the remaining portion. This avoids excessive instantaneous punching force on the formed sheet material caused by cutting a large area of ​​the edge at once, and reduces the risk that other parts of the formed sheet material may be affected by stress due to the large instantaneous punching force, leading to secondary springback or edge warping.

[0057] In the above process, the secondary trimming of the edge material of the formed sheet can be performed simultaneously with the secondary punching process, thereby improving the overall stamping efficiency. The punching steps are similar to those in step S40. The secondary punching applies pressure to the remaining pre-defined positions that require punching, thus avoiding excessive instantaneous punching force on the formed sheet caused by creating multiple holes in a single punching operation. In this embodiment, through secondary trimming and punching, the risk of secondary springback or edge warping caused by excessive instantaneous punching force in other parts of the formed sheet is effectively reduced.

[0058] like Figure 5 As shown, in some embodiments, after trimming the edge of the formed sheet and punching holes at preset positions on the formed sheet using a punching die, the flat sheet convex stamping process further includes: Step S60: Bend the edge area of ​​the formed sheet material at a preset angle to form a flange structure on the formed sheet material.

[0059] The process includes a bending and flanging step after the trimming and punching steps in step S40. Specifically, step S60, following the secondary trimming and punching steps in step S50, involves transferring the sheet metal to the bending die station via a conveying mechanism. The bending die consists of an upper bending die, a lower bending die, and an angle positioning mechanism. The lower bending die has a forming surface and a positioning groove that match the preset flanging angle. The upper bending die has corresponding pressing and bending bosses. By first placing the sheet metal into the positioning groove of the lower bending die and fixing it, it is ensured that the edge to be bent can be precisely aligned with the forming surface of the bending die. The bending equipment is started, and the upper bending die is controlled to move downward. Through the cooperation of the forming surfaces of the upper and lower bending dies, the edge area of ​​the formed sheet metal is bent along the preset angle, forming a flanging structure on the formed sheet metal.

[0060] like Figure 5 As shown, in some embodiments, after the step of bending the edge region of the formed sheet at a preset angle to form a flange structure on the formed sheet, the flat sheet stamping process further includes: Step S70: Control the slider to shape along the flange structure position of the forming sheet at a preset speed.

[0061] The process includes a flanging and shaping step following the bending and flanging step in step S60. Specifically, after the bending and flanging are completed, the sheet metal can be transferred to the shaping station via a conveying mechanism. The shaping station is equipped with a shaping mold. In step S70, the sheet metal with the flanged structure can be positioned on the positioning base of the shaping mold, aligning the flanged structure with the shaping working surface of the slider. A preset speed for the slider movement can be set according to the thickness and material characteristics of the flanged material. The slider is controlled to move in a uniform linear motion along the flanged structure position of the formed sheet metal at the preset speed. Through the cooperation between the shaping working surface of the slider and the positioning base, the flanged structure is shaped in a conforming manner. During the shaping process, the slider can apply uniform shaping pressure to the flanged structure, thereby correcting minor angular deviations, edge warping, and other defects, and improving the flatness and perpendicularity of the flanged structure. After shaping is completed, the slider is controlled to reset, ultimately forming the process of flat plate convex stamping.

[0062] It is understood that those skilled in the art can make equivalent substitutions or changes to the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A method for stamping a flat plate with a raised bulge, characterized in that, Includes the following steps: The sheet metal to be stamped is stamped once to form the first bulge on the sheet metal to be stamped; The first convex bulge is subjected to a second back press to form a second convex bulge, thereby obtaining a shaped sheet material; Wherein, the first convex hull depth is greater than the convex hull depth of the preset target, and the difference between the first convex hull depth and the convex hull depth of the preset target is D1; The depth of the second convex hull is less than the depth of the first convex hull, the depth of the second convex hull is greater than or equal to the convex hull depth of the preset target, and the difference between the depth of the second convex hull and the convex hull depth of the preset target is D2, where D1 > D2.

2. The flat plate convex stamping process method according to claim 1, characterized in that, In the step of stamping the sheet metal to be stamped once, the sheet metal to be stamped is stamped once using a first stamping die. The convex depth of the first stamping die is greater than the preset target convex depth, so that the depth of the first convex is greater than the preset target convex depth.

3. The flat plate convex stamping process method according to claim 2, characterized in that, In the step of performing a second back press on the first convex hull to form a second convex hull, the first convex hull is subjected to a second back press using a second stamping die. The convex hull depth of the second stamping die is equal to the preset target convex hull depth, so that the depth of the second convex hull is equal to the preset target convex hull depth.

4. The flat plate convex stamping process method according to claim 3, characterized in that, The difference D3 between the convex depth of the first stamping die and the convex depth of the preset target is in the range of 1.8mm to 2.2mm.

5. The flat plate convex stamping process method according to claim 4, characterized in that, The difference D3 between the convex depth of the first stamping die and the convex depth of the preset target is equal to 2mm.

6. The flat plate convex stamping process method according to claim 1, characterized in that, Before the step of stamping the sheet metal to be stamped once to form the first convex bump on the sheet metal to be stamped, the flat convex bump stamping process further includes: The sheet metal to be stamped is conveyed to the blanking die, and the upper die of the blanking die is controlled to move toward the lower die of the blanking die so as to cut the sheet metal to be stamped into a preset shape.

7. The flat plate convex stamping process method according to claim 1, characterized in that, After the step of performing a second back press on the first convex hull to form the second convex hull, the flat convex hull stamping process further includes: The edge of the formed sheet is trimmed, and a punching die is used to punch holes at preset positions on the formed sheet to form mounting holes.

8. The flat plate convex stamping process method according to claim 7, characterized in that, After the steps of trimming the edge sheet of the formed sheet and punching holes at preset positions on the formed sheet using a punching die, the flat plate convex stamping process further includes: The edge area of ​​the molded sheet is bent at a preset angle to form a flange structure on the molded sheet.

9. The flat plate convex stamping process method according to claim 8, characterized in that, After the step of bending the edge region of the formed sheet at a preset angle to form a flange structure on the formed sheet, the flat plate convex stamping process further includes: The slider is controlled to shape the sheet metal along the flange structure at a preset speed.

10. The flat plate convex stamping process method according to claim 7, characterized in that, After the steps of trimming the edge sheet of the formed sheet and punching holes at preset positions on the formed sheet using a punching die, the flat plate convex stamping process further includes: The edge of the formed sheet is trimmed a second time, and a punching die is used to punch a second hole at another preset position of the formed sheet to form the mounting hole of the formed sheet.

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