A method of side wall pressing

Abstract

The application relates to a sharp-edged side wall stamping method. Since the sharp-edged round corner is small, corresponding amplification of the sharp-edged round corner needs to be carried out, and during the drawing, the over-drawing amount of the upper side of the sharp edge is equal to that of the lower side, so that the sharp-edged round corner after being drawn is similar to the sharp-edged round corner before being drawn, the shaping amount of the two sides of different parts is uniform, the drawing operation of the sharp edge is realized, the sharp edge is shaped in the subsequent process, and the stamping of the sharp edge is finally completed; in the above steps, a large-area modification of the original product modeling surface for drawing is not needed, the product quality is ensured, and the sliding and cracking phenomena in the drawing process are avoided. The whole side wall stamping is completed in four processes, no die is added, and the cost is reduced.

Description

Technical Field

[0001] This application relates to the field of automotive body panel stamping technology, and in particular to a method for stamping sharp-edged side panels. Background Technology

[0002] Currently, the integral side panel of a passenger vehicle is the most difficult part to manufacture among the body panels. This is because integral side panels are usually three-dimensional curved surfaces, and are large in size and complex in structure, making them prone to forming defects such as tearing and wrinkling. Moreover, integral side panels are geometrically asymmetrical outer body panels, and their edges are adjacent to multiple environmental components, resulting in extremely stringent requirements for assembly precision and surface quality.

[0003] In some related technologies, the exterior of a car can give consumers the most direct impression. A sharp design can highlight the car's ruggedness while also exuding a sporty feel. The feature lines of a car are key lines that determine its styling characteristics. Among them, sharp edges involve minimizing the rounded corners of the feature lines, using strong ridges to emphasize inner strength and penetrating power. Sharp edges: refer to the appearance ridge features on stamped parts with an outer rounded corner of less than 6.5mm and an arc length of less than 2.5mm. Because the small rounded corners of sharp edges violate conventional stamping principles, they are not conducive to the stretching and forming of sheet metal, and therefore mainly suffer from defects such as necking, tearing, slip lines, hidden pits, and springback.

[0004] In other related technologies, there are currently two known stamping process solutions for conventional sharp-edged parts:

[0005] Option 1: One-step drawing process for sharp edges. The product is directly drawn out during the drawing process. This option typically involves sharpening and compensating for the original sharp edges and rounded corners of the product to address the issue of dimensional discrepancies caused by the flattening of parts after forming sharp edges. For example, if a product has a sharp edge with a rounded corner of R6, a one-step drawing process might design the drawing punch rounded corner to be R2-R3, or even R0 for some manufacturers. In a one-step drawing process, the punch rounded corner R is extremely small, making it prone to slippage and cracking defects, and the die is also prone to wear.

[0006] Option 2: Secondary Forming Process for Sharp Edges. In the drawing process, the product's rounded corners are enlarged to R8 or higher. A subsequent shaping process is used to refine the rounded corners. This option generally has two forms: lower shaping and upper shaping. The lower shaping process typically involves trimming the product's surface and rounded corners during the drawing process, and then using a second mold insert in the shaping process to refine the edges. The upper shaping process typically only involves trimming the rounded corners during the drawing process, and then using secondary drawing or other mechanisms to shape them upwards in the shaping process. The secondary forming process avoids slippage and cracking issues, but it introduces drawing hardening marks, adds 1-2 sets of molds, increasing mold costs and the number of processes, and also requires additional press equipment. Furthermore, the process design significantly modifies the product's appearance, making it difficult to control the final product's appearance quality and lighting effects. Summary of the Invention

[0007] This application provides a method for stamping sharp-edged side panels to solve the problems in related technologies where, during the secondary forming process of sharp-edged edges, the forming amount at different parts of the sharp-edged edge line is inconsistent and uneven, and slippage and cracking occur during the drawing process when the sharp-edged edge with continuously changing fillet is drawn.

[0008] Firstly, a method for stamping sharp-edged side panels is provided, comprising:

[0009] In OP20, the stamped part is drawn to obtain a first-process part; the stamped part includes a sharp edge and a first target area, the first target area being the area on the stamped part excluding the sharp edge; the drawing step of the sharp edge includes:

[0010] According to the change value of the sharp edge fillet in the direction of the sharp edge trend, the sharp edge fillet is enlarged accordingly in the direction of the sharp edge trend, and the overdrawing amount on the upper side of the sharp edge is equal to the overdrawing amount on the lower side, so that the sharp edge fillet of the first process part and the sharp edge fillet of the stamped part are similar angles.

[0011] In the OP30 process, the sharp edges of the first workpiece are shaped, and the second target area is trimmed, shaped, and punched to obtain the second workpiece.

[0012] In the OP40 process, the third target area of ​​the second process part is trimmed, shaped, and punched to obtain the third process part;

[0013] In the OP50 process, the fourth target area of ​​the third process part is trimmed, shaped, and punched to obtain the target side panel.

[0014] In some embodiments, the sharp corner radius of the first process part is the rounded corner radius after the stamped part is drawn and enlarged, and is larger than the sharp corner radius of the target side panel.

[0015] In some embodiments, the sharp edges of the first workpiece are shaped in the OP30 process, specifically including the following steps:

[0016] A second mold is provided, comprising an upper mold and a lower mold. The lower mold includes a lower base plate and a punch. A sharp-edged punch insert is detachably connected to the punch, and the rounded corner of the top of the sharp-edged punch insert is the same as the rounded corner of the sharp edge of the target side panel. The upper mold includes an upper base plate and a pressure plate. A shaping insert is detachably connected to the pressure plate and located directly above the sharp-edged punch insert. A dead block is provided between the upper base plate and the pressure plate, arranged along the sharp edge direction and located above the shaping insert.

[0017] Place the first workpiece on the lower mold of the second mold, and make the rounded corner of the sharp edge of the first workpiece contact the rounded corner of the top of the sharp edge punch insert;

[0018] The upper base plate and the pressure plate move downwards and gradually press the first workpiece; when the pressure plate reaches the bottom, the pressure plate is locked in place, and the shaping insert shapes the sharp edge into position.

[0019] In some embodiments, the second target area includes the arc apex area of ​​the first process component, the doorway area of ​​the first process component, the taillight area of ​​the first process component, the outer periphery area of ​​the first process component, the triangular window area of ​​the first process component, and the fuel tank hole area of ​​the first process component;

[0020] In the OP30 process, the target area is trimmed, shaped, and punched, including the following steps:

[0021] Using the second mold, the arc-shaped top area, the doorway area, the outer perimeter area, and the taillight area of ​​the first workpiece are trimmed;

[0022] Using the second mold, punching is performed on the triangular window area and the oil tank hole area of ​​the first workpiece, wherein the punching operation of the triangular window area of ​​the first workpiece is a single punching operation, and the punching operation of the oil tank hole area of ​​the first workpiece is a rough punching operation.

[0023] The second mold is used to shape the doorway area and the triangular window area of ​​the first workpiece.

[0024] In some embodiments, a closed coarse punching trajectory is provided on the oil tank hole area of ​​the first workpiece; a design distance is provided between the side of the coarse punching trajectory near the sharp edge and the sharp edge;

[0025] Using the second mold, punching holes in the oil tank area of ​​the first workpiece includes the following steps:

[0026] In the direction of the upper and lower sides of the sharp edge, the cutting edge of the second mold on the side away from the sharp edge on the coarse punching trajectory cuts in first, and the cutting edge of the second mold on the side closer to the sharp edge on the coarse punching trajectory cuts in later to punch the hole.

[0027] In the direction of the sharp edge, the cutting edge of the second die at both ends of the coarse punching trajectory cuts in first, and the cutting edge of the second die in the middle of the coarse punching trajectory cuts in later.

[0028] In some embodiments, the second mold uses multiple first limiting pressure members to move the pressure plate downward; some of the first limiting pressure members are used to apply pressure to the areas on the upper and lower sides of the sharp edge; and other first limiting pressure members are used to apply pressure to the area around the coarse punching trajectory.

[0029] In some embodiments, the first process component doorway region includes a first process component front doorway region and a first process component rear doorway region;

[0030] The shaping of the doorway area of ​​the first workpiece using the second mold includes the following steps:

[0031] The second mold is used to shape the first shaping area of ​​the front door opening region of the first process part. The first shaping area is the area that extends from the front door opening flange to the side wall below the rounded corner of the appearance of the second process part.

[0032] The second mold is used to shape the second shaping area of ​​the rear door opening area of ​​the first process part. The second shaping area is the area around the rear door opening except for the disconnected area; the disconnected area is the area where the sharp edge meets the rear door opening.

[0033] In some embodiments, the third target area includes the second process component roof area, the second process component rear windshield area, the second process component front door opening area, the second process component rear door opening area, the second process component taillight area, the second process component A-pillar, the second process component B-pillar, the second process component door sill area, the second process component triangular window area, the second process component wheel cover area, the second process component rear bumper area, and the second process component fuel tank opening area;

[0034] In the OP40 process, the third target area of ​​the second process part is trimmed, shaped and punched, including the following steps;

[0035] Trim the lower part of the front door opening area of ​​the second process part, the lower part of the rear door opening area of ​​the second process part, and the taillight area of ​​the second process part; wherein the trimming of the taillight area of ​​the second process part is a fine trimming to remove the waste material remaining from the trimming of the taillight area of ​​the first process part in the OP30 process.

[0036] The second process component A column and the second process component B column are punched with straight holes;

[0037] The top cover area, rear windshield area, sill area, rear door opening area, rear bumper area, triangular window area, wheel cover area, and fuel tank hole area of ​​the second process component are shaped.

[0038] In some embodiments, before shaping the oil tank hole area of ​​the second workpiece, the following steps are also included:

[0039] In the OP40 process, the third mold is equipped with multiple second limiting pressure components for applying pressure to the oil tank hole area and sharp edge of the second workpiece; among them, some of the second limiting pressure components are arranged along the direction of the sharp edge, and the other part of the second limiting pressure components are arranged around the oil tank hole area of ​​the second workpiece.

[0040] In some embodiments, the fourth target area includes the third part top cover area, the third part fuel tank opening area, the third part A-pillar, the third part rear bumper area, the third part rear windshield area, and the third part taillight area;

[0041] In the OP50 process, the fourth target area of ​​the third process part is trimmed, shaped, and punched, including the following steps:

[0042] Trim the edges of the top cover area and the oil tank hole area of ​​the third process part;

[0043] Punching is performed on the A-pillar of the third process component and the rear guard area of ​​the third process component;

[0044] The flanges of the rear windshield area, taillight area, and A-pillar of the third process component are shaped.

[0045] The beneficial effects of the technical solution provided in this application include:

[0046] This application provides a method for stamping sharp-edged side panels. Since the sharp-edged corner radius is small, it needs to be enlarged accordingly. Therefore, during the sharp-edged drawing process, the value of the sharp-edged corner radius change along the direction of the sharp-edged edge is correspondingly enlarged. Furthermore, during drawing, the overdrawing amount on the upper side of the sharp-edged edge is equal to the overdrawing amount on the lower side, so that the sharp-edged corner radius after drawing is similar to the sharp-edged corner radius between the drawn edges. This results in a uniform and consistent sharp-edged edge direction after drawing, and the shaping amount on both sides of different parts is consistent and uniform, thus achieving the drawing operation of the sharp-edged edge. The sharp-edged edge is then shaped in subsequent processes to finally complete the stamping of the sharp-edged edge. In the above steps, it is not necessary to modify the original product shape surface significantly during drawing, ensuring product quality and avoiding slippage and cracking during the drawing process. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A schematic diagram of the structure of the first process component provided in the embodiments of this application;

[0049] Figure 2 This is a schematic diagram of the structure of the second process component provided in an embodiment of this application;

[0050] Figure 3 A schematic diagram of the structure of the third process component provided in the embodiments of this application;

[0051] Figure 4 A schematic diagram of the structure of the fourth process component provided in the embodiments of this application;

[0052] Figure 5 This is a schematic diagram of the lower mold structure of the second mold provided in an embodiment of this application;

[0053] Figure 6 A schematic diagram of the upper mold structure of the second mold provided in the embodiments of this application;

[0054] Figure 7 A cross-sectional schematic diagram of the section used for sharp edge shaping in the second mold provided in an embodiment of this application;

[0055] Figure 8 A schematic diagram showing the state in which the sharp edges and rounded corners of the first workpiece provided in this application embodiment have not yet been stamped in the second mold;

[0056] Figure 9 This is a flowchart of the stamping process provided in the embodiments of this application.

[0057] In the diagram: 1. First process component; 2. Second process component; 3. Third process component; 4. Target side panel component; 5. Upper mold of the second mold; 501. Upper base plate; 502. Pressure plate; 503. Shaping insert; 504. Fixed block; 6. Lower mold of the second mold; 600. Sharp-edged punch insert. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] The technical background and reasons for solving the problems addressed in this application are explained in detail below:

[0060] ① The rounded corners of the sharp edges on the side panels that our company is producing are not uniform and fixed values; the size of the rounded corners varies along the direction of the sharp edges.

[0061] ②Our company's stamping workshop has 5 presses on line L1 and 4 presses on line L2. The molds for the new model must be compatible with both lines. Therefore, this side panel process plan needs to be designed to be completed in 4 processes.

[0062] In the traditional drawing process, by modifying the product's curved surface, one side of the product's shape is kept unchanged while the other side is reconstructed. This amplifies and softens the sharp edges of the product's edges during the drawing process. In subsequent processes, one or two sets of shaping dies are added to reshape the modified product's surface into the original product's surface, thus achieving the goal of processing the sharp edges.

[0063] This method, with one side having shaping allowance and the other side having zero shaping allowance, results in significant differences in the stress on the sheet metal during edge forming, leading to defects in the edge appearance. It directly causes inconsistent and uneven shaping allowances at different locations along sharp edges, as well as slippage and cracking during the drawing process. For example, in traditional solutions, the sharp edge radius varies from R2 to R5; during over-drawing, the radius is directly enlarged to R12, resulting in inconsistent shaping allowances along the edge direction and causing appearance defects.

[0064] In addition, according to conventional processes, the sharp edge shaping and the fuel tank punching cannot be completed in the same process. They must be separated into two steps. That is, the sharp edge shaping and the fuel tank punching need to be carried out in different processes. Furthermore, considering other shaping, trimming and punching operations, the traditional process cannot reduce the process to four steps.

[0065] Therefore, to ensure the quality of the sharp edges and ridges, without adding molds, and to complete the manufacturing of all parts of the side panel within four processes, the problem of significantly modifying the product's appearance and shape in the secondary forming process of sharp edges in related technologies, affecting the product's appearance quality, and leading to increased mold costs and processes can be solved.

[0066] Therefore, a sharp-edged side panel stamping method is proposed to solve the above problems, as detailed below:

[0067] Please see Figures 1-4 (in appendix) Figures 2-4 (The XZ marking in the figure indicates the stamping direction and is not redundant.) A method for stamping sharp-edged sidewalls includes the following steps:

[0068] In OP20, the stamped part is drawn to obtain part 1 of the first process; the stamped part includes sharp edges and a first target area, the first target area being the area on the stamped part excluding the sharp edges; the drawing step of the sharp edges includes:

[0069] According to the change value of the sharp edge fillet in the direction of the sharp edge trend, the sharp edge fillet is enlarged accordingly along the direction of the sharp edge trend, and the overdrawing amount on the upper side of the sharp edge is equal to the overdrawing amount on the lower side, so that the sharp edge fillet of the first process part 1 is similar to the sharp edge fillet of the stamped part.

[0070] The first target area is the conventional drawing process in the OP20 process. Part of it is successfully drawn in one go, while the other part cannot be drawn in one go and is drawn again. It is then processed and shaped in subsequent processes.

[0071] In the OP30 process, the sharp edges of the first workpiece 1 are shaped, and the second target area is trimmed, shaped, and punched to obtain the second workpiece 2.

[0072] In the OP40 process, the third target area of ​​the second process part 2 is trimmed, shaped, and punched to obtain the third process part 3;

[0073] In the OP50 process, the fourth target area of ​​the third process part 3 is trimmed, shaped and punched to obtain the target side panel part 4.

[0074] It should be understood that the sharp edges of the stamped part do not have uniform, fixed fillet values. The fillet size varies depending on the design requirements. The main task of process OP20 is to draw out the majority of the product area of ​​the side panel part. For areas where the product cannot be drawn to its final position in one operation, over-drawing is implemented in this process. This involves modifying the product during drawing and considering further shaping in later processes to enlarge the sharp edges. The over-drawing design methods for other positions will not be elaborated upon; the over-drawing of sharp edges will be the primary focus.

[0075] Without altering the surface shape, the sharp edges and rounded corners of the product are enlarged. During overdrawing, instead of simply enlarging the rounded corner value at a certain point on the product's edge by a certain factor to obtain a fixed overdrawing rounded corner, it is enlarged according to the rounded corner variation value, ensuring that the shaping amount on the upper and lower sides of the sharp edge is the same (the shaping amount on both sides of the entire edge is almost symmetrical and consistent in the shaping stamping direction), and the shaping amount is very small. The maximum shaping amount of the overdrawing rounded corner and the product rounded corner does not exceed 0.5mm. The sharp edge rounded corner of the first process part 1 is the rounded corner of the stamped part after being enlarged by overdrawing, and it is larger than the sharp edge rounded corner of the target side panel part 4. That is, the overdrawing rounded corner is lower than the product sharp edge rounded corner, and does not exceed 0.5mm. The purpose is to ensure that the overdrawing process does not produce slippage defects or cracks. This ensures that subsequent shaping processes have small, easy-to-position, uniform, and less prone to defects such as deformation.

[0076] Therefore, this solves the problem in the secondary forming process of sharp edges in related technologies, where the forming amount of different parts of the sharp edge line is inconsistent and uneven when the sharp edge rounded corner is drawn in a constantly changing direction, as well as the problem of slippage and cracking during the drawing process.

[0077] In some preferred embodiments, the above steps, from the completion of the stamped part to the obtaining of the target side panel 4, are completed in four processes without the addition of a mold; the specific reason for this is that:

[0078] The sharp edge of the design is only 17mm away from the outline of the oil tank hole, less than 20mm. According to conventional processes, the sharp edge shaping and oil tank punching cannot be completed in one sequence; they must be done in two separate processes. Furthermore, the number of processes needs to be controlled to within four. Since the sharp edge needs to be shaped and the remaining parts need to be punched, adjustments to the processes following drawing are necessary. The subsequent steps of drawing can be referred to the following description:

[0079] refer to Figure 2 , Figure 5 , Figure 6 , Figure 7 and Figure 8 The OP30 process will be described as follows:

[0080] The first process component 1 includes a sharp edge and a second target area. The second target area includes the first process component's arc apex area b1, the first process component's doorway area, the first process component's taillight area b7, the first process component's outer perimeter area b2, the first process component's triangular window area b5, and the first process component's fuel tank hole area b6. The first process component's doorway area includes the first process component's front doorway area b3 and the first process component's rear doorway area b4. (Refer to...) Figure 1 The markings shown in the image. Figure 5 and Figure 6The second mold is not described in detail in this paper because the structure varies for different products. Therefore, only the structure related to the key process points of this application is introduced.

[0081] The OP30 process includes simultaneous trimming, punching, and shaping, with shaping encompassing the shaping of sharp edges and the second target area. Using the second die, the arc-shaped apex area, doorway area, outer perimeter area, and taillight area of ​​the first-process part are trimmed. Using the second die, the triangular window area and fuel tank hole area of ​​the first-process part are punched; the punching operation for the triangular window area is a single punching operation, while the punching operation for the fuel tank hole area is a rough punching operation. Using the second die, the doorway area and triangular window area of ​​the first-process part are shaped.

[0082] 1. Trimming operation

[0083] 1-1. In the first process, the arc-shaped top area mainly involves rough trimming of the front windshield, the side trimming of the front windshield, the rough trimming of the top cover, and the side trimming of the rear windshield. Among them, the rough trimming of the front windshield and the rough trimming of the top cover are straight trimming in this process. This process only removes the drawing waste material in the initial stage, but does not pinpoint the position required by the final product. These two positions will be finely trimmed in the final process, and this will be a side trimming.

[0084] 1-2. In the first process, the doorway area is cut off by straight trimming, but it is not completed in one go. Three pieces of waste are left in the front doorway and four pieces of waste are left in the back doorway to facilitate subsequent positioning.

[0085] 1-3. In the first process, the outer perimeter area of ​​the workpiece is trimmed along the circumference using a straight trimming method, and part of the drawing waste is removed;

[0086] 1-4. In the first process, the taillight area of ​​the component undergoes rough trimming on the side closest to the sharp edge to prevent the sharp edge shaping from intersecting with the trimming. The taillight area of ​​the first process is then finely trimmed in the next process.

[0087] 2. Punching operation

[0088] All punching in this process involves straight punching. The punching primarily processes the mounting holes in the triangular window area of ​​the first-stage component and the fuel tank hole area of ​​the first-stage component. The mounting holes in the triangular window area of ​​the first-stage component are completed in a single punching operation, requiring no further processing. The fuel tank opening process is designed as rough finishing, shaping, and fine finishing; this process is only the first step, rough finishing. The subsequent steps will involve shaping and fine finishing.

[0089] 2-1. The punching of the oil tank hole area in the first process part is a rough punching operation in this sequence; a closed rough punching trajectory is provided on the oil tank hole area of ​​the first process part; a designed distance is provided between the side of the rough punching trajectory near the sharp edge and the sharp edge; using the second die, the oil tank hole area of ​​the first process part is punched, including the following steps:

[0090] In the direction of the sharp edge, the cutting edge of the second die on the side away from the sharp edge along the coarse punching trajectory cuts in first, followed by the cutting edge of the second die on the side closer to the sharp edge along the coarse punching trajectory, to perform punching; in the direction of the sharp edge, the cutting edges of the second die at both ends of the coarse punching trajectory cut in first, followed by the cutting edge of the second die in the middle of the coarse punching trajectory. The second die uses multiple first limiting pressure members to move the pressure plate 502 downward; some of the first limiting pressure members are used to apply pressure to the areas on the upper and lower sides of the sharp edge; other first limiting pressure members are used to apply pressure to the area around the coarse punching trajectory.

[0091] Specifically, the design distance between the side of the coarse punching trajectory near the sharp edge and the rounded corner of the sharp edge is greater than 40mm. This ensures sufficient pressure area on both sides of the sharp edge during shaping, preventing unstable pressure and inconsistent material flow during edge shaping, which could lead to defects in the edge's appearance. The pressure source arrangement near the tank opening and sharp edge must ensure sufficient pressure. The design principle is as follows: design two pressure sources (first limiting pressure components) within a 300mm area on each side of the sharp edge; design two pressure sources (first limiting pressure components) within a 300mm radius around the coarse punching trajectory, two vertically and one horizontally; considering that some pressure sources can be shared, a total of six pressure sources are arranged in this area, with a pressure of 2.4T. While ensuring sufficient total force, increasing the number of pressure sources reduces the pressure of individual sources, resulting in better pressure conditions. The design distance between the side of the coarse punching trajectory near the sharp edge and the rounded corner of the sharp edge is not necessarily better the larger it is. Excessively long trimming lines can cause cracking during the next process of shaping the tank opening.

[0092] The design principle for the second die in the fuel tank opening punching process is as follows: the cutting edge of the second die on the side furthest from the sharp edge cuts in first, followed by the cutting edge on the side closest to the sharp edge. On both the side closest to and furthest from the sharp edge, the cutting edges of the second die at both ends of the sharp edge cut in first, followed by the cutting edge in the middle of the sharp edge, meaning a clockwise cutting motion. This reduces the impact of the tensile force generated during punching on the sharp edge, further ensuring the formation effect of the sharp edge.

[0093] The principle is as follows: the blanking trimming force calculation F = material thickness * shear strength * trimming length. In principle, the fewer materials that are in contact with the trimming material at the same time, the smaller the trimming force generated, and the smaller the lateral drag force will also be. In addition, the farther apart the materials are, the smaller the influence of the force.

[0094] 3. Plastic surgery procedures

[0095] Shaping mainly involves shaping areas of the original product that could not be drawn to completion in one go during the previous drawing process, thus altering certain areas. This process primarily includes shaping the front doorway area, the rear doorway area, the triangular window area, and the sharp edge area of ​​the first-stage part. The doorway areas of the first-stage part include the front doorway area b3 and the rear doorway area b4.

[0096] 3-1. Shaping of the front door opening area of ​​the first process part: The first shaping area of ​​the front door opening area of ​​the first process part is shaped. The first shaping area is the area that extends from the front door opening flange to the side wall below the rounded corner of the appearance of the second process part. That is, the shaping parting line is designed at the rounded corner where the appearance and the structural surface meet.

[0097] 3-2. Shaping the rear doorway area in the first process: The second mold shapes the second shaping area of ​​the rear doorway area. The second shaping area is the periphery of the rear doorway excluding the disconnected area; the disconnected area is the area where the sharp edge meets the rear doorway. In other words, the shaping of the rear doorway is not closed along the periphery of the doorway, but is disconnected at the intersection of the sharp edge and the rear doorway to avoid shaping the sharp edge and the doorway at the same time. The length of the disconnected area is 500mm.

[0098] 3-3. First process component: triangular window shaping: general shaping.

[0099] 3-4. Sharp Edge Shaping

[0100] A second mold is provided, comprising an upper mold 5 and a lower mold 6. The lower mold 6 includes a bottom plate and a punch. A sharp-edged punch insert 600 is detachably connected to the punch. The rounded corner of the top of the sharp-edged punch insert 600 is the same as the rounded corner of the sharp edge of the target side panel 4. The upper mold 5 includes an upper bottom plate 501 and a pressure plate 502. A shaping insert 503 is detachably connected to the pressure plate 502 and located directly above the sharp-edged punch insert 600. A dead block 504 is provided between the upper bottom plate 501 and the pressure plate 502, arranged along the sharp edge direction and located above the shaping insert 503.

[0101] Place the first workpiece 1 on the lower mold 6 of the second mold, and make the rounded corner of the sharp edge of the first workpiece 1 contact the rounded corner of the top of the sharp edge punch insert 600;

[0102] The upper base plate 501 and the pressure plate 502 move downwards and gradually press the first workpiece 1; when the pressure plate 502 reaches the bottom, the pressure plate 502 is locked in place, and the shaping insert 503 shapes the sharp edge into place.

[0103] Specifically:

[0104] Because the sharp-edged fillets are enlarged during the drawing process, the enlarged drawing fillets have a shaping allowance of 0.5mm compared to the fillets of the product (target side panel 4). At the start of shaping, the first workpiece after OP20 drawing is placed on the punch of this process. The fillet at the top of the sharp-edged punch insert 600 is the same as the sharp-edged fillet of the target side panel 4, and the fillet is held in place by the punch. Although the product surfaces on both sides of the sharp edge of the first workpiece are exactly the same as the punch shape (only the sharp edge is enlarged differently), at this time, the sharp-edged fillet of the enlarged sharp-edged punch insert 600 is larger than the original sharp-edged fillet of the product.

[0105] Subsequently, the pressure plate 502 descends, and under the force of the elastic element, the pressure plate 502 gradually presses the first workpiece 1. Upon reaching the bottom, the pressure plate 502 locks in place, shaping the sharp edge. That is, the sharp edge is shaped by the pressure plate 502, but since the pressure plate 502 locks in place, the forming force comes from the press slide. Correspondingly, some key points regarding sharp edge shaping are:

[0106] I. The pressure plate part at the corresponding sharp edge of the upper mold 5 of the second mold is not a whole with the pressure plate of the whole mold. Instead, a separate shaping insert 503 is separated. This shaping insert 503 serves both the pressing function and the shaping function.

[0107] II. The shaping insert 503 is positioned directly above the sharp edge. It is mounted on the pressure plate 502. The pressure plate 502 has supporting ribs at its lower part, and a retaining block 504 is designed between the supporting ribs and the upper base plate 501 to ensure that the shaping force of the sharp edge comes from the press slide when forming to the bottom. This retaining block 504 differs from the retaining block on the pressure plate 502; it is arranged along the sharp edge direction and positioned directly above it. For this side panel, the sharp edge length is approximately 460mm, and four retaining blocks are arranged along the edge direction. This ensures uniform force distribution along the entire sharp edge, preventing edge defects caused by deflection or deformation of the pressure plate 502 during shaping. Similarly, the lower die shaping area is also designed as an insert structure, mounted on the punch body (i.e., a detachable sharp edge punch insert 600), facilitating the adjustment and subsequent maintenance of the sharp edge.

[0108] In some preferred embodiments, reference Figure 3 The OP40 process is described in detail below:

[0109] The third target area includes the second-process component roof area c1, the second-process component rear windshield area c3, the second-process component front door opening area c9, the second-process component rear door opening area c11, the second-process component taillight area c4, the second-process component A-pillar c10, the second-process component B-pillar c12, the second-process component door sill area c8, the second-process component triangular window area c2, the second-process component wheel arch area c7, the second-process component rear bumper area c5, and the second-process component fuel tank opening area c6; (Reference) Figure 2 The markings shown.

[0110] The third target area of ​​the second process part 2 is trimmed, shaped and punched, including the following steps;

[0111] Trim the lower part of the front door opening area, the lower part of the rear door opening area, and the taillight area of ​​the second process component; the trimming of the taillight area of ​​the second process component is a fine trimming to remove the waste material remaining from the trimming of the taillight area of ​​the first process component in process OP30; make straight punch holes in the A pillar and B pillar of the second process component 2; shape the roof area, rear windshield area, door sill area, rear door opening area, rear bumper area, triangular window area, wheel arch area, and fuel tank hole area of ​​the second process component.

[0112] The specific steps mentioned above are as follows:

[0113] 1. Trimming operation

[0114] This sequence consists entirely of straight trimming, including trimming and removing some waste material from the lower part of the front door opening area of ​​the second process part; trimming and removing some waste material from the lower part of the rear door opening area of ​​the second process part; trimming of the taillight area of ​​the second process part, the taillight trimming is a fine trimming, removing the remaining waste material from the taillight area trimming of the OP30 process.

[0115] 2. Punching operation: The second workpiece A column and the second workpiece B column are punched directly.

[0116] 3. Plastic surgery procedures

[0117] 3-1. The second process involves shaping the top cover area, which is entirely side-shaped. The shaping range covers the entire top area, and the shaping method is internal and external pressing. That is, the inner pressing plate presses on the profile on one side of the door opening, and the outer pressing plate presses on the waste material left over from the rough trimming process OP30 on the top cover side.

[0118] 3-2. The second process involves straightening the rear window area of ​​the component. At this point, the shaping is not yet complete. The next process will involve side shaping.

[0119] 3-3. The second process involves straightening the threshold area, including the lower threshold and the lower area of ​​the A-pillar.

[0120] 3-4. Second process: Straightening of the rear door opening area. To avoid overlap with the sharp edge shaping, the remaining area of ​​the door opening that needs shaping will be shaped in this process. At the same time, the remaining part of the rear door opening will be shaped together with the triangular window area, wheel arch area, and upper rear bumper area.

[0121] 3-5. The lower part of the back-protection area of ​​the second process component is straightened.

[0122] 3-6. Second Process Part: Oil Tank Hole Area; The oil tank hole area, after rough finishing in the previous process, is shaped. After shaping, all surfaces are in place, except for the trimming lines, which require fine finishing in the final OP50 process. To prevent the shaping from dragging the already formed sharp edges, pressure sources need to be strategically placed on the sharp edges and the oil tank opening: four nitrogen cylinders (second limiting pressure components) are evenly arranged above the sharp edge along the edge direction; three nitrogen cylinders are arranged around the oil tank opening. That is, multiple second limiting pressure components are set on the third mold used in the OP40 process to apply pressure to the oil tank hole area and sharp edges of the second process part; some of the second limiting pressure components are arranged along the direction of the sharp edge, and the other part is arranged around the oil tank hole area of ​​the second process part.

[0123] The reason for the reasonable arrangement of pressure sources is that the shaping force is greater in the oil tank hole area of ​​the second process part, and there will be material flow during the shaping process. The oil tank opening is very close to the sharp edge, the pressing area is very small, and the pressing effect is poor. This will cause the second process part 2 to move, which will lead to defects. Therefore, more nitrogen cylinders are designed to press the second process part 2 firmly and ensure the pressing effect.

[0124] In some preferred embodiments, reference Figure 4 The OP50 process is explained in detail below:

[0125] The fourth target area includes the third-process component roof area d1, the third-process component fuel tank opening area d3, the third-process component A-pillar d6, the third-process component rear bumper area d5, the third-process component rear windshield area d2, and the third-process component taillight area d4; such as Figure 3 The markings shown.

[0126] The fourth target area of ​​the third process part 3 is trimmed, shaped, and punched, including the following steps:

[0127] 1. Trim the edges of the top cover area and the fuel tank hole area of ​​the third-process component; that is, trim the side edges of the top cover area; trim the side edges above the A-pillar of the third-process component; trim the remaining scrap edges in other areas; perform a fine trimming on the fuel tank hole area of ​​the third-process component in this step. Then, remove all remaining scrap from the other areas from the previous three processes.

[0128] 2. Punch holes in the A-pillar and rear guard area of ​​the third process component; that is, all remaining holes are punched in this process; the punching and flipping holes in the A-pillar and rear guard area of ​​the third process component are completed in one step using a continuous punching and flipping mode.

[0129] 3. Perform final shaping on the rear windshield area, taillight area, and A-pillar flange of the third-stage component.

[0130] It should be understood that in the above four processes OP20-OP50, each process corresponds to a set of molds, namely the first mold, the second mold, the third mold, and the fourth mold. In this application, only the structure of the second mold is given. The other molds are molds made for the above processes. Since this application focuses on protecting the stamping process steps, not all mold diagrams are given.

[0131] Furthermore, through the explanation of all the above processes, it is possible to complete the stamping of the sharp-edged side panel product in four processes, and it can be used interchangeably between our stamping workshop's L1 and L2 lines.

[0132] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0133] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0134] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for stamping sharp-edged side panels, characterized in that, It includes: In the OP20 process, the stamped part is drawn to obtain the first part (1). The stamped part includes a sharp edge and a first target area, the first target area being the area on the stamped part excluding the sharp edge; The drawing step of the sharp edge includes: According to the change value of the sharp edge fillet in the direction of the sharp edge trend, the sharp edge fillet is enlarged accordingly along the direction of the sharp edge trend, and the overdrawing amount on the upper side of the sharp edge is equal to the overdrawing amount on the lower side, so that the sharp edge fillet of the first process part (1) and the sharp edge fillet of the stamped part are similar angles. In the OP30 process, the sharp edges of the first process part (1) are shaped, and the second target area is trimmed, shaped and punched to obtain the second process part (2). In the OP40 process, the third target area of ​​the second process part (2) is trimmed, shaped and punched to obtain the third process part (3). In the OP50 process, the fourth target area of ​​the third process part (3) is trimmed, shaped and punched to obtain the target side panel (4); the sharp corner of the first process part (1) is the rounded corner after being drawn and enlarged by the stamping part, and is larger than the sharp corner of the target side panel (4); there is a shaping amount of 0.5mm between the sharp corner of the first process part (1) and the sharp corner of the target side panel (4); In the OP30 process, the sharp edges of the first workpiece (1) are shaped, specifically including the following steps: A second mold is provided, comprising an upper mold (5) and a lower mold (6). The lower mold (6) comprises a bottom plate and a punch. A sharp-edged punch insert (600) is detachably connected to the punch. The rounded corner of the top of the sharp-edged punch insert (600) is the same as the rounded corner of the sharp edge of the target side panel (4). The upper mold (5) comprises an upper bottom plate (501) and a pressure plate (502). A shaping insert (503) is detachably connected to the pressure plate (502) and directly above the sharp-edged punch insert (600). The upper bottom plate (501) and Between the pressure plates (502) there is a stop block (504) arranged along the sharp edge direction and located above the shaping insert (503); the first workpiece (1) is placed on the lower mold (6) of the second mold, and the rounded corner of the sharp edge of the first workpiece (1) contacts the rounded corner of the top of the sharp edge punch insert (600); the upper base plate (501) and the pressure plate (502) move downward and gradually press the first workpiece (1); when the pressure plate (502) reaches the bottom, the pressure plate (502) stops, and the shaping insert (503) shapes the sharp edge into place.

2. The sharp-edged side panel stamping method as described in claim 1, characterized in that: The second target area includes the arc apex area of ​​the first process component, the doorway area of ​​the first process component, the taillight area of ​​the first process component, the outer perimeter area of ​​the first process component, the triangular window area of ​​the first process component, and the fuel tank hole area of ​​the first process component; In the OP30 process, the target area is trimmed, shaped, and punched, including the following steps: Using the second mold, the arc-shaped top area, the doorway area, the outer perimeter area, and the taillight area of ​​the first workpiece are trimmed; Using the second mold, punching is performed on the triangular window area and the oil tank hole area of ​​the first workpiece, wherein the punching operation of the triangular window area of ​​the first workpiece is a single punching operation, and the punching operation of the oil tank hole area of ​​the first workpiece is a rough punching operation. The second mold is used to shape the doorway area and the triangular window area of ​​the first workpiece.

3. The sharp-edged side panel stamping method as described in claim 2, characterized in that: The first workpiece has a closed coarse punching trajectory in the oil tank hole area; the side of the coarse punching trajectory closest to the sharp edge has a designed distance from the sharp edge; Using the second mold, punching holes in the oil tank area of ​​the first workpiece includes the following steps: In the direction of the upper and lower sides of the sharp edge, the cutting edge of the second mold on the side away from the sharp edge on the coarse punching trajectory cuts in first, and the cutting edge of the second mold on the side closer to the sharp edge on the coarse punching trajectory cuts in later to punch the hole. In the direction of the sharp edge, the cutting edge of the second die at both ends of the coarse punching trajectory cuts in first, and the cutting edge of the second die in the middle of the coarse punching trajectory cuts in later.

4. The sharp-edged side panel stamping method as described in claim 3, characterized in that: The second mold uses multiple first limiting pressure components to make the pressure plate (502) move downward; some of the first limiting pressure components are used to apply pressure to the areas on the upper and lower sides of the sharp edge; and other first limiting pressure components are used to apply pressure to the area around the coarse punching trajectory.

5. The method for stamping sharp-edged side panels as described in claim 2, characterized in that: The first process component doorway area includes the first process component front doorway area and the first process component rear doorway area; The shaping of the doorway area of ​​the first workpiece using the second mold includes the following steps: The second mold is used to shape the first shaping area of ​​the front door opening region of the first process part. The first shaping area is the area that extends from the front door opening flange to the side wall below the rounded corner of the appearance of the second process part. The second mold is used to shape the second shaping area of ​​the rear door opening area of ​​the first process part. The second shaping area is the area around the rear door opening except for the disconnected area; the disconnected area is the area where the sharp edge meets the rear door opening.

6. The method for stamping sharp-edged side panels as described in claim 1, characterized in that: The third target area includes the second process component roof area, the second process component rear windshield area, the second process component front door opening area, the second process component rear door opening area, the second process component taillight area, the second process component A pillar, the second process component B pillar, the second process component door sill area, the second process component triangular window area, the second process component wheel cover area, the second process component rear bumper area, and the second process component fuel tank opening area; In the OP40 process, the third target area of ​​the second process part (2) is trimmed, shaped and punched, including the following steps; Trim the lower part of the front door opening area of ​​the second process part, the lower part of the rear door opening area of ​​the second process part, and the taillight area of ​​the second process part; wherein the trimming of the taillight area of ​​the second process part is a fine trimming to remove the waste material remaining from the trimming of the taillight area of ​​the first process part in the OP30 process. The second process component (2) is punched with straight holes in its second process component A column and second process component B column; The top cover area, rear windshield area, sill area, rear door opening area, rear bumper area, triangular window area, wheel cover area, and fuel tank hole area of ​​the second process component are shaped.

7. The method for stamping sharp-edged side panels as described in claim 6, characterized in that: Before shaping the oil tank hole area of ​​the second workpiece, the following steps are also included: In the OP40 process, the third mold is equipped with multiple second limiting pressure components for applying pressure to the oil tank hole area and sharp edge of the second workpiece; among them, some of the second limiting pressure components are arranged along the direction of the sharp edge, and the other part of the second limiting pressure components are arranged around the oil tank hole area of ​​the second workpiece.

8. The method for stamping sharp-edged side panels as described in claim 1, characterized in that: The fourth target area includes the third-process component roof area, the third-process component fuel tank hole area, the third-process component A-pillar, the third-process component rear bumper area, the third-process component rear windshield area, and the third-process component taillight area; In the OP50 process, the fourth target area of ​​the third process part (3) is trimmed, shaped, and punched, including the following steps: Trim the edges of the top cover area and the oil tank hole area of ​​the third process part; Punching is performed on the A-pillar of the third process component and the rear guard area of ​​the third process component; The flanges of the rear windshield area, taillight area, and A-pillar of the third process component are shaped.

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