Drawing forming process, production process and mold for body panel

Abstract

The present application relates to a drawing process for body panels, in which a blank is placed on a lower die, and a blank holder is first brought close to the lower die and formed together with the lower die into a first preset shape located at the edge of the blank; then the upper die is closed with the lower die and formed into a second preset shape; wherein the first preset shape and the second preset shape are both structures on the body panel; wherein, when the upper die is closed with the lower die, the blank holder is located around the upper die, and the blank holder and the lower die are in a closed state. According to the above-mentioned forming process, during the forming process of the upper die and the lower die, the first preset shape formed on the blank by the blank holder and the lower die can play a certain role in controlling the material flow and ensuring the quality of the product. Therefore, it is possible to achieve the reduction of process supplementary parts and save production costs by eliminating the draw ribs set on the blank.

Description

Technical Field

[0001] The present application relates to the field of automobile manufacturing, and more specifically, to a drawing forming process, a production process, and a mold for a vehicle body panel. Background Art

[0002] Currently, in the draw-forming process for automotive body panels, such as the rear floor, upper and lower dies are used to form the recessed and raised structures on the rear floor, and a blank holder and lower die are used to form draw ribs on the raw material to prevent material slippage during the forming process. The curve formed by projecting the intersection of the upper die and the blank holder onto the blank is the parting line of the product during the forming process. The blank includes a process supplement portion and a product portion. The boundary between the process supplement portion and the product portion is the product line on the blank. The area surrounded by the product line on the blank becomes the desired product after all forming processes are completed. In existing production processes, the product line is located within the parting line. In the process of obtaining the final rear floor product, the process supplements outside the product line need to be removed, resulting in low material utilization. Summary of the Invention

[0003] One of the objectives of the present application is to provide a body panel draw forming process, which can reduce waste generated during the production of body panels.

[0004] A second object of the present application is to provide a mold that produces less waste when molding vehicle body panels.

[0005] The third object of the present application is to provide a production process for vehicle body panels, which can reduce the waste generated during the production process of vehicle body panels.

[0006] One of the objectives of this application is achieved by the following technical solution:

[0007] A drawing forming process for a body panel comprises placing a blank on a lower die, first placing a blank holder close to the lower die and forming a first preset shape at the edge of the blank together with the lower die; then closing the upper die and forming a second preset shape; wherein the first preset shape and the second preset shape are both structures on the body panel; wherein, when the upper die and the lower die are closed, the blank holder is located around the upper die, and the blank holder and the lower die are in a closed state.

[0008] According to the above-mentioned forming process, during the forming process of the body panel, the pressure ring is first in contact with the lower die so that the sides of the blank are pressed, and at the same time, the pressure ring and the lower die form a first preset shape on part of the sides or all of the sides of the blank according to the structure on the body panel; then the upper die and the lower die form a second preset shape according to the structure on the body panel. During the forming process of the upper die and the lower die, the first preset shape formed on the blank by the pressure ring and the lower die can play a certain role in controlling the material flow and ensuring the quality of the product. Therefore, it is possible to achieve the reduction of the process supplement part and save production costs by eliminating the draw ribs set on the blank.

[0009] Furthermore, the first preset shape is a pit and boss structure with an edge depth of less than 10 mm on the vehicle body panel.

[0010] When forming pits or protrusions with a forming depth of less than 10 mm, it is only achieved by plastic deformation of the material, and no material flow occurs. Therefore, there is no need to set a structure for controlling material flow on the blank, and the blank holder and the lower die can be used for forming.

[0011] Furthermore, according to simulation analysis, if there is material slipping during the process of the upper mold and the lower mold forming the second preset shape, a molding structure for forming an anti-material slipping structure is designed between the pressure ring and the lower mold, and the molding structure is used to form the anti-material slipping structure on the side of the blank where material flows into.

[0012] Furthermore, parts of the blank located on both sides of the anti-slip structure have a height difference.

[0013] The aforementioned technical solution utilizes a height difference between the blanks on either side of the anti-slip structure, which facilitates material flow. Compared to the prior art, which uses semicircular drawbeads to prevent slippage, this solution reduces process replenishment and waste.

[0014] Furthermore, the anti-material slippage structure is a curved surface structure.

[0015] The second purpose of this application is achieved by the following technical solution:

[0016] A mold comprises an upper mold, a lower mold and a pressure ring, wherein the upper mold is located inside the pressure ring, and the pressure ring is provided with a cavity for forming the first preset shape.

[0017] Furthermore, the blank holder and the lower die are provided with a structure for forming drawbeads.

[0018] The third objective of this application is achieved by the following technical solution:

[0019] A production process for vehicle body panels, using the mold provided in the embodiment of the present application to complete the process of forming the vehicle body panels on the blank according to the above-mentioned forming process.

[0020] Furthermore, after all the forming processes of the body panels are completed on the blank, the processes on the blank are additionally cut off along the product line.

[0021] Furthermore, the blank is an aluminum structural part.

[0022] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a schematic diagram of the positions of the product line and the parting line when molding the existing rear floor;

[0025] Figure 2 for Figure 1 Cross-sectional view in ;

[0026] Figure 3 for Figure 2 Enlarged view of point B in the middle;

[0027] Figure 4 A schematic diagram showing the positions of the product line and parting line of the rear floor molding process provided in Example 2 of the present application;

[0028] Figure 5 for Figure 4 Cross-sectional view in ;

[0029] Figure 6 for Figure 5 The enlarged image in ;

[0030] Figure 7 A schematic structural diagram of a drawing threshold provided in one embodiment of the present application;

[0031] Figure 8 Schematic diagram of the structure of the existing drawbead;

[0032] Figure 9 This is a structural diagram of an existing rear floor;

[0033] Figure 10A schematic diagram showing the positions of the product line and parting line of the rear floor molding process provided in Example 1 of the present application;

[0034] Figure 11 Schematic diagram of the results of simulation analysis of the molding process of Example 2;

[0035] Figure 12 Schematic diagram of the position of the product line and parting line of the rear floor molding process provided in Example 3 of the present application.

[0036] Icons: 10-blank; 11-product line; 12-parting line; 13-drawbead; 14-drawing sill; 20-rear floor. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0038] In the description of this application, it should be noted that the terms "inner" and "outer" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended solely to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" and the like are used solely for distinction and should not be construed as indicating or implying relative importance.

[0039] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0040] Currently, in the molding process of vehicle body panels, the arrangement of a product line 11 and a parting line 12 on a blank 10 is involved.

[0041] Take the rear floor 20 of the molded vehicle body as an example, please refer to Figures 1 to 3 , Figures 1 to 3This is a schematic diagram of the existing molding process for the rear floor 20. In the existing molding process for the rear floor 20, the parting line 12 during the molding process is located outside the product line 11. For the existing production process, the portion of the blank 10 outside the product line 11 is a process supplement. The process supplement is used to form a material-slipping prevention structure between the blank holder and the lower mold, namely, a draw rib 13. The existing draw rib 13 is a semicircular rib protruding from the surface of the blank 10. The draw rib 13 prevents the product from slipping during the molding process. After the rear floor 20 is molded, the process supplement needs to be removed along the product line 11 to obtain the final product and waste. That is, the more process supplements outside the product line 11, the more waste is generated. And according to the current molding process for the rear floor 20, in order to obtain a qualified product, it is necessary to set draw ribs 13 on the sides of the blank 10, which further causes material waste.

[0042] After analysis, the inventors of this application discovered that, according to existing processes, the blank holder is only used to form the drawbead 13 on the blank 10. To ensure product quality, the drawbead 13 is an essential structure. Therefore, according to existing production processes, it is impossible to solve the problem of large amounts of material waste by reducing process steps.

[0043] Based on this, the inventors of this application have provided a process for draw-forming a body panel, in which a blank holder is provided with a cavity for forming the structure of the body panel. During the body panel forming process, the blank holder surrounds the upper die inside. The blank holder first closes with the lower die, pressing the sides of the blank 10. Simultaneously, the blank holder and the lower die form a first predetermined shape along some or all of the sides of the blank 10. The upper die then closes with the lower die to form a second predetermined shape. Both the first and second predetermined shapes are structures on the body panel.

[0044] During the forming process between the upper and lower dies, the first predetermined shape of the blank 10 formed by the blank holder and the lower die can play a certain role in controlling the material flow and ensuring the quality of the product. Therefore, by eliminating the drawbead 13 provided on the blank 10, it is possible to reduce the process supplementary part and save production costs.

[0045] Please refer to Figures 4 to 6 According to the molding process provided by the above embodiment of the present application, since the blank holder is provided with a cavity for molding the structure of the body panel, the parting line 12 is located inside the product line 11 during the molding process of the body panel in the molding process adopted by the present application. For the molding process provided by the present application, the part outside the product line 11 on the blank 10 is a process supplement. Figure 3 and Figure 6It is not difficult to understand that the molding process in which the parting line 12 is located inside the product line 11 can reduce the use of process supplements, thereby reducing waste generation and saving production costs.

[0046] It should be noted that the above technical solution does not cancel the anti-slip structure of all sides of the stock 10. After determining the structure of the blank holder, it is still necessary to perform simulation analysis on the forming process of the body panel, and calculate whether the first preset shape formed by the blank holder and the lower die can play the role of controlling slip in the process of the upper die and the lower die being molded. After calculation, if there is still a situation of slip on a certain side of the stock 10, for the side where material flows in, the structure of the blank holder can be further adjusted so that more structures of the body panel on this side are formed by the blank holder and the lower die, so as to meet the first preset shape and play the role of controlling slip in the process of the upper die and the lower die being molded; the flow of material can also be controlled by forming the anti-slip structure on this side of the stock 10 by the blank holder and the lower die, that is, after the blank holder and the lower die are molded, in addition to forming the first preset shape, the anti-slip structure is also formed. For the side where slip does not occur in the stock 10, there is no need to set the anti-slip structure, which reduces process replenishment, saves waste material that needs to be cut off, and can play the role of saving cost.

[0047] Of course, in some cases, even if a blank holder and a lower die are first used to form a portion of the body panel structure, the already formed structure on the body panel cannot prevent any side of the blank 10 from slipping during the subsequent molding process. In this case, it is still necessary to provide an anti-slip structure on each side of the blank 10.

[0048] In view of the above situation, the inventor of this application also provides a drawing threshold 14 as a material-slip prevention structure. Figure 6 As shown, the drawing threshold 14 provided in the present application is a curved surface structure connecting two planes with a height difference on the blank 10. That is, during the process of forming the drawing threshold 14, the area where the product is located on the blank 10 is elevated relative to the area where the process supplement is located. The drawing threshold 14 is a curved surface transitioning from the process supplement area to the product area. The cross section of the drawing threshold 14 can be a straight line or two tangent arcs, such as Figure 7 As shown, or a combination of arc and straight line. The cross section of the existing drawbead 13 structure is semicircular (as shown Figure 8 As shown) and trapezoids, etc. Figure 6 、 7 and Figure 8As shown, under the condition of the same horizontal dimensions, the cross-sectional perimeter of the draw sill 14 provided by the inventors of the present application is smaller. Accordingly, the material required to form the draw sill 14 provided by the present application is less than the material required to form the draw bead 13 in the prior art. In other words, even if the forming process provided by the present application fails to achieve the goal of saving material by reducing the number of anti-slip structures, the goal of saving material can still be achieved through the shape of the anti-slip structure provided by the present application (i.e., the draw sill 14).

[0049] The drawing threshold 14 provided in the present application has a weaker ability to control material slipping than the drawing rib 13 in the prior art. However, according to the forming process provided in the present application, a first preset shape is formed on the blank 10 while the drawing threshold 14 is formed. The anti-material slipping structure provided in the present application works together with the first preset shape on the blank 10 to avoid material slipping during the forming process of the upper and lower dies.

[0050] According to the inventor's practice, in actual production, for pits and bosses with a depth of less than 10 mm on the body panel, a pressure ring can be used for forming; for pits and bosses with a depth greater than 10 mm, an upper mold and a lower mold should be used for forming.

[0051] According to the molding process provided by the present application, when the blank holder and the lower die are used to form the first preset shape, there is no existing anti-material slipping structure for controlling material slipping. For boss and pit structures with a depth of less than 10 mm, they can be obtained by plastic deformation of the blank 10 material itself, without the need for material to flow in from other positions of the blank 10. Therefore, when molding boss and pit structures with a depth of less than 10 mm, there is no need to first set a structure for controlling material slipping on the blank 10. Only pits and bosses with a depth of less than 10 mm on the body panel are molded using the blank holder and the lower die, which can prevent the edge of the blank 10 from being located within the product line 11 due to material slipping during the molding process of the blank holder and the lower die, thereby preventing the molded product from being incomplete. That is, in the molding process provided by the present application, the first preset shape only includes pits and bosses with a depth of less than 10 mm.

[0052] In accordance with the body panel forming process provided herein, this application also provides a forming mold comprising an upper mold, a lower mold, and an annular blank holder, with the upper mold positioned within the annular blank holder. The blank holder is provided with a cavity for forming recesses and bosses with a depth of less than 10 mm on the outer edge of the body panel. In some embodiments, the blank holder and the lower mold are also provided with forming structures for forming a draw threshold 14.

[0053] Example 1

[0054] This embodiment adopts the molding process provided by the above technical solution to form the rear floor 20 of the automobile. The structure of the rear floor 20 is as follows: Figure 9As shown, the blank 10 used to form the rear floor panel 20 is a square aluminum plate with a thickness of 1.4 mm. The blank 10 used in this embodiment has good rigidity, can be fully formed, and is not prone to deformation after forming. The rear floor panel 20 comprises a first region and a second region. The first region contains only recesses and protrusions with a depth of less than 10 mm; the second region contains recesses and protrusions with a depth of at least 10 mm. Part of the structure in the first region is located on both sides of the second region.

[0055] During the forming process, the structure in the first area can be formed by using a blank holder and a lower die; the structure in the second area can be formed by using an upper die and a lower die.

[0056] like Figure 9 As shown, in this embodiment, only the third area included in the first area shown in the figure is formed by the blank holder and the lower mold. According to the molding process of this embodiment, the positions of the product line 11 and the parting line 12 are as shown in FIG. Figure 10 It should be noted that Figure 10 What is shown is only the blank 10 after the completion of forming all the pits and protrusion structures of the rear floor 20, the purpose is to facilitate the demonstration of the depth relationship between the pits and protrusion structures between various areas on the rear floor 20; on the upper side of the blank 10 shown in the figure, although the parting line 12 is located on the outside of the product line 11, during the forming process of the pressure ring and the lower mold, the parting line 12 is completely located on the inside of the product line 11. In the subsequent process, due to the bending and other processing of the blank 10, part of the edge of the rear floor 20 shown in the figure (that is, the product line 11) is located within the parting line 12.

[0057] Computer simulation software analysis shows that when the upper and lower dies form the remaining structure of the rear floor panel 20, due to the large deformation in the second region, material slippage occurs on all four sides of the blank 10. Therefore, when customizing the molding process of the rear floor panel 20, anti-slip structures are also installed on all four sides of the blank 10.

[0058] Since in this embodiment, the third area is formed by using a pressure ring, that is, during the forming process of the upper mold and the lower mold, the structure of the third area of ​​the rear floor 20 (that is, the first preset shape) that has been formed on the blank 10 and the anti-material slippage structure formed on the blank 10 jointly play a role in controlling material slippage. Therefore, the anti-material slippage structure on this side can adopt the drawing threshold 14 provided in the embodiment of the present application.

[0059] Example 2

[0060] In view of the problem that the structure of the third area formed on the blank 10 by the blank holder and the lower die in Example 1 cannot control the material slipping during the process of the upper and lower dies forming the remaining structure, this embodiment makes further improvements through the molding process. In this embodiment, Figure 9 The structure in the fourth area shown is formed by the blank holder and the lower mold. The fourth area is also included in the first area. Compared with the third area, the fourth area contains more structures. Accordingly, there are more cavities on the blank holder for forming. Figure 4 As shown, compared with embodiment 1, the parting line 12 in this embodiment is further reduced inward (similarly, Figure 4 The blank 10 shown is the state after the pits and protrusions on the rear floor 20 are formed, not the state when the pressure ring and the lower mold are formed. Therefore, the parting line 12 shown is located outside the product line 11).

[0061] According to the analysis of computer simulation software, when the upper and lower molds are forming the structure outside the fourth area on the product, the material is only moved on the three sides of the blank 10, and the direction of the material is as follows: Figure 11 Therefore, according to the analysis results, during the molding process, it is only necessary to provide anti-slip structures on three sides of the blank 10. For the sides of the blank 10 where slipping does not occur, the anti-slip structure can be eliminated, and slip control can be achieved solely by using the structure already formed in the fourth region of the blank 10 (i.e., the first preset shape).

[0062] Example 3

[0063] According to the molding process provided in this application, this embodiment illustrates the positional relationship between the parting line 12 and the product line 11 in the molding process for a rear floor panel 20 structure different from that in Example 1.

[0064] like Figure 12 As shown, the first area only includes pits and boss structures with a depth of less than 10 mm; the second area includes pits and boss structures with a depth of not less than 10 mm.

[0065] For the rear floor 20 structure designed in this embodiment, the parting line 12 can be Figure 12 The position arrangement shown in FIG is then analyzed and determined by computer simulation software to be necessary to set an anti-material slip structure on the side of the blank 10.

[0066] It should be noted that, unless there is any conflict, the features in the embodiments of this application can be combined with each other.

[0067] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A vehicle body panel drawing process, characterized in that: The blank is placed in a lower die, and a blank holder is first brought close to the lower die and formed together with the lower die into a first preset shape at the edge of the blank; the first preset shape is a pit and boss structure at the edge of the body panel; Then, the upper mold and the lower mold are closed to form a second preset shape; Wherein, the first preset shape and the second preset shape are both structures on the vehicle body panel; Wherein, when the upper mold and the lower mold are clamped, the pressure ring is located around the upper mold, and the pressure ring and the lower mold are in a clamped state.

2. A vehicle body panel drawing process according to claim 1, characterized in that: The first preset shape has a depth less than 10 mm.

3. The vehicle body panel drawing process according to claim 1, characterized in that: According to simulation analysis, if there is material slipping during the process of the upper mold and the lower mold forming the second preset shape, a forming structure for forming an anti-material slipping structure is designed between the pressure ring and the lower mold, and the forming structure is used to form the anti-material slipping structure on the side of the blank where material flows into.

4. The vehicle body panel drawing process according to claim 3, characterized in that: Parts of the blank located on both sides of the anti-slip structure have a height difference.

5. The vehicle body panel drawing process according to claim 4, characterized in that: The anti-material slipping structure is a curved surface structure.

6. A mold for implementing a molding process according to any one of claims 3 to 5, comprising an upper mold, a lower mold and a blank holder, wherein the upper mold is located inside the blank holder, and is characterized in that: The blank holder is provided with a cavity for forming the first preset shape.

7. A mold according to claim 6, characterized in that: The pressure ring and the lower die are provided with a structure for forming the anti-material slip structure.

8. A process for producing a vehicle body panel, characterized in that: The process of forming the body panel on the blank is completed by using the mold described in claim 6 or 7 and the body panel drawing forming process described in any one of claims 1 to 5.

9. The process for producing a vehicle body panel according to claim 8, characterized in that: After all the forming processes of the body panels are completed on the blank, the additional processes on the blank are cut off along the production line.

10. The process for producing a vehicle body panel according to claim 8, wherein: The blank is an aluminum structural part.

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