A process optimization method for improving the inner recess of the wheelhouse side wall of a fender drawn part

Abstract

The application discloses a process optimization method for improving the inner recess of a wheel port sidewall of a fender drawn part, and the method comprises the following steps: uniformly increasing the convex modeling of a process supplement surface of a wheel port sidewall, controlling the wheel port drawing sidewall forming process of the fender, changing the die round corner of the wheel port sidewall and the contact point between the sheet metal and the convex and concave dies during the wheel port sidewall forming, changing the contact process of the sidewall draw surface, making the sheet metal not subjected to a single direction force during the forming process, and increasing the rigidity of the wheel port sidewall of the drawn part.

Description

Technical Field

[0001] This invention belongs to the field of automotive fender drawing technology, specifically relating to a process optimization method for improving the concave sidewall of the wheel well after fender drawing. Background Technology

[0002] As a common automotive exterior panel, the fender typically undergoes deep drawing to ensure sufficient forming. While the sidewall surface of the wheel arch area is usually made flat, the drawing depth of the fender's wheel arch is generally quite deep to guarantee adequate forming. Due to the material's forming characteristics, the flat section exhibits a concave center and outward curling bottom after springback release at the end of drawing, resulting in an overall appearance of a concave central area. Figure 1 , Figure 2 As shown.

[0003] Because the waste material in the wheel well area of ​​the fender is relatively large and the number of processes is limited, the trimming process will be segmented or a waste material cutter will be set. When the drawing process is completed and the part is placed on the second trimming die, the concave area will get stuck on the waste material cutter or trimming cutter in the wheel well area, causing the part to be suspended above the punch. Moreover, the part itself has limited weight and cannot fall onto the punch by its own weight, resulting in the part not fitting properly with the trimming punch.

[0004] If the concave issue is not resolved, during the trimming process, the workpiece will only be pressed onto the punch when the upper die pressure plate is fully depressed. During this process, the workpiece will shift on the punch, but this shift is uncontrollable, affecting the stability of the workpiece on the punch. Furthermore, jamming and clamping may occur during workpiece handling, negatively impacting the overall stability of the workpiece during the trimming process and increasing the dimensional stability and debugging difficulty of the final part. These unstable factors must be resolved during mold debugging before subsequent work can proceed. However, resolving this issue on-site increases processing costs, lengthens the debugging cycle, and ultimately increases the number of rectification rounds. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, this invention provides a process optimization method for improving the concave sidewall of the wheel well in fender parts after drawing. Based on conventional stamping processes, the drawing process design is optimized. Multiple protrusions are added to the process supplementary surface of the drawing wheel well sidewall during the drawing process. A reasonable process design and space allocation are designed according to different drawing depths. Simultaneously, CAE technology is applied for simulation analysis to adjust and optimize the process design. This invention can significantly improve the jamming and clamping problems caused by the springback concavity of the fender drawing wheel well sidewall during part handling, while also improving the stability of the final part's dimensions. It addresses potential problems in the design phase, reduces debugging cycles, and minimizes the number of rectification rounds.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A process optimization method for improving the concave sidewall of the wheel opening of a fender after drawing involves optimizing the process shape of the wheel opening sidewall of the fender: uniformly adding a convex shape to the process supplementary surface of the wheel opening sidewall to control the forming process of the wheel opening sidewall of the fender.

[0008] Furthermore, by uniformly adding convex shapes to the process supplementary surface of the wheel opening sidewall during the drawing process, changing the draft angle and radius of the convex plane, and controlling the spacing between the convexes, the contact point between the die radius of the wheel opening sidewall and the die during the forming of the wheel opening sidewall is changed during the drawing process. This changes the contact process of the draft surface of the sidewall, so that the sheet metal is no longer subjected to a force in a single direction during the forming process. After drawing to the bottom, it is fixed by the convex and concave radius of the convex ...

[0009] Furthermore, the optimization of the fender drawing wheel sidewall process shape specifically includes: uniformly adding convex humps to the process supplementary surface of the drawing wheel sidewall; setting the parameters and distribution position of the convex humps; and applying CAE for simulation analysis to adjust and optimize the process shape.

[0010] Preferably, the parameters and distribution positions of the convex shape are designed by varying the depth and width of the drawn sidewall to control the concave convex shape characteristics of the fender drawing wheel sidewall. The parameters of the convex shape should be set according to the specific parameters of the fender wheel sidewall plane, prioritizing the trimming line or scrap cutter line in the middle area of ​​the sidewall convex plane.

[0011] Preferably, the parameters and distribution positions of the convex bulge are set according to the specific parameters of the fender wheel well sidewall, specifically: the change in the width C of the sidewall determines whether to set the convex bulge; the position of the sidewall trimming line or scrap cutter line determines the initial position of the convex bulge; the convex bulge plane spacing E directly determines the density of the convex bulges on the sidewall; the draft angle α of the convex bulge sidewall determines the distance from the convex bulge high point to the wheel well sidewall; and the springback state of the concave shape is improved by adjusting the convex bulge draft angle and the size of the convex-concave R angle.

[0012] Preferably, the application of CAE for simulation analysis and adjustment of process design specifically refers to the application of CAE for simulation analysis to optimize the size of the convex hull R angle R2, the concave hull R1, the sidewall draft angle β, and the convex hull draft angle α parameters.

[0013] Preferably, the principles for setting the parameters and distribution positions of the convex hull shape include:

[0014] 1) Ensure that the scrap cutter cuts within the convex bulge plane area, and ensure that the cut is made in the middle of the convex bulge. The width of the convex bulge plane, D, is ≥ 40 mm.

[0015] 2) The R-angle connecting the convex hull plane and the side wall, where R2 of the convex hull is ≥8mm and R1 of the concave hull is ≥8mm. After the convex hull is rounded, the distance G between the R1 tangent and the R tangent of the concave die fillet is ≥5mm, and the distance F between the R1 tangent and the R tangent of the upper convex die is ≥5mm.

[0016] 3) The convex hull spacing E ≥ 80mm;

[0017] 4) When the width C of the fender wheel well sidewall is less than or equal to 50 mm, the convex bulge has a limited impact on the concave sidewall, so the convex bulge is no longer required.

[0018] 5) The draft angle β of the drawing sidewall is ≥10° and the draft angle α of the convex hull sidewall is ≥5°. The specific parameter settings are simulated and analyzed using CAE to determine the formability and finally determine the size of each parameter.

[0019] The present invention has the following beneficial effects:

[0020] 1. By studying the principle of the inward concavity in the middle and outward curl at the bottom that appears after the springback release after the end of the drawing process in the side wall area of ​​the fender wheel opening, the drawing process shaping is optimized, and an innovative convex shape is designed for the drawing forming process. This changes the forming contact state of the side wall of the fender wheel opening, making the forming process of the side wall area of ​​the wheel opening controllable and improving the final springback result.

[0021] 2. In the process design stage, CAE technology is used to conduct simulation analysis to fully demonstrate the rationality of the process shape. On the basis of ensuring the feasibility of drawing, the springback value of the side wall of the drawing wheel is controlled by adjusting the draft angle and width of the convex hull plane and the size of the convex and concave R angle of the convex hull.

[0022] 3. The present invention significantly improves the concave state at the fender drawing wheel opening. In the early process design stage, a convex bulge is used to improve the contact state of the fender wheel opening sidewall. The theoretical springback value is as follows: Figure 4 As shown, the ATOS scan results of the on-site shipment are compared as follows: Figure 5 The springback concavity trend has been significantly improved. When the springback-recovered part is placed in the second trimming process, the concavity and jamming of the sidewall caused by springback are basically eliminated. Figure 6 As shown. It basically solves the problems of part jamming and clamping during part handling caused by the concave wheel opening after the part is actually debugged on site. It improves the fit of the part on the trimming process during mold debugging, ensures the stability of the part on the mold, reduces the workload of on-site debugging personnel, shortens the mold development cycle, and reduces the overall mold manufacturing cost.

[0023] 4. This invention is applicable to solving most problems of concave sidewalls at the drawing wheel opening of fenders, and the results have been verified to be good. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0025] Figure 1 This refers to the concave area at the wheel arch of the fender after springback release during the drawing process in the background art.

[0026] Figure 2 The theoretical springback value of the wheel end sidewall after drawing in the background technology (positive values ​​outward and negative values ​​inward in the figure);

[0027] Figure 3 In the process optimization method for improving the concave sidewall of the wheel hole of the fender after drawing, as described in this invention, multiple convex bulges are added to the process supplementary surface of the sidewall of the drawing wheel hole.

[0028] Figure 4 The theoretical springback value after adding a convex bulge to the side wall of the wheel opening using the process optimization method of this invention is shown in the figure (positive values ​​are outward and negative values ​​are inward).

[0029] Figure 5 The actual ATOS scanning results of the parts produced on-site using the process optimization method of this invention;

[0030] Figure 6 A schematic diagram illustrating the shape of the part placed in the variable process after adding the convex hull using the process optimization method of the present invention;

[0031] Figure 7 This is a schematic diagram illustrating the contact process between the drawing sidewall draft surface and the die in an embodiment of the present invention.

[0032] Figure 8 This is a schematic cross-sectional view of the concave area of ​​the wheel arch after the fender springback release in an embodiment of the present invention;

[0033] Figure 9 This is a schematic diagram of the convex bulge parameters added to the wheel arch sidewall of the fender in an embodiment of the present invention;

[0034] Figure 10 This is a schematic diagram of the draft angle parameters of the fender wheel arch sidewall protrusion in an embodiment of the present invention;

[0035] Figure 11(a) shows the process of the fender wheel well sidewall convex contacting the sheet metal in an embodiment of the present invention. Figure 1 Schematic diagram;

[0036] Figure 11(b) shows the process of the fender wheel well sidewall convex contacting the sheet metal in an embodiment of the present invention. Figure 2 Schematic diagram;

[0037] Figure 11(c) shows the process of the fender wheel well sidewall convex contacting the sheet metal in an embodiment of the present invention. Figure 3 Schematic diagram. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0039] A process optimization method for improving the concave sidewall of the wheel opening of a fender after drawing involves optimizing the process shape of the wheel opening sidewall of the fender: uniformly adding a convex shape to the process supplementary surface of the wheel opening sidewall to control the forming process of the wheel opening sidewall of the fender.

[0040] Furthermore, by uniformly adding convex shapes to the process supplementary surface of the wheel opening sidewall during the drawing process, changing the draft angle and radius of the convex plane, and controlling the spacing between the convexes, the contact point between the die radius of the wheel opening sidewall and the die during the forming of the wheel opening sidewall is changed during the drawing process. This changes the contact process of the draft surface of the sidewall, so that the sheet metal is no longer subjected to a force in a single direction during the forming process. After drawing to the bottom, it is fixed by the convex and concave radius of the convex ...

[0041] Furthermore, the optimization of the fender drawing wheel sidewall process shape specifically includes: uniformly adding convex humps to the process supplementary surface of the drawing wheel sidewall; setting the parameters and distribution position of the convex humps; and applying CAE for simulation analysis to adjust and optimize the process shape.

[0042] Preferably, the parameters and distribution positions of the convex shape are designed by varying the depth and width of the drawn sidewall to control the concave convex shape characteristics of the fender drawing wheel sidewall. The parameters of the convex shape should be set according to the specific parameters of the fender wheel sidewall plane, prioritizing the trimming line or scrap cutter line in the middle area of ​​the sidewall convex plane.

[0043] Preferably, the parameters and distribution positions of the convex bulge are set according to the specific parameters of the fender wheel well sidewall, specifically: the change in the width C of the sidewall determines whether to set the convex bulge; the position of the sidewall trimming line or scrap cutter line determines the initial position of the convex bulge; the convex bulge plane spacing E directly determines the density of the convex bulges on the sidewall; the draft angle α of the convex bulge sidewall determines the distance from the convex bulge high point to the wheel well sidewall; and the springback state of the concave shape is improved by adjusting the convex bulge draft angle and the size of the convex-concave R angle.

[0044] Preferably, the application of CAE for simulation analysis and adjustment of process design specifically refers to the application of CAE for simulation analysis to optimize the size of the convex hull R angle R2, the concave hull R1, the sidewall draft angle β, and the convex hull draft angle α parameters.

[0045] Preferably, the principles for setting the parameters and distribution positions of the convex hull shape include:

[0046] 1) Ensure that the scrap cutter cuts within the convex bulge plane area, and ensure that the cut is made in the middle of the convex bulge. The width of the convex bulge plane, D, is ≥ 40 mm.

[0047] 2) The R-angle connecting the convex hull plane and the side wall, where R2 of the convex hull is ≥8mm and R1 of the concave hull is ≥8mm. After the convex hull is rounded, the distance G between the R1 tangent and the R tangent of the concave die fillet is ≥5mm, and the distance F between the R1 tangent and the R tangent of the upper convex die is ≥5mm.

[0048] 3) The convex hull spacing E ≥ 80mm;

[0049] 4) When the width C of the fender wheel well sidewall is less than or equal to 50 mm, the convex bulge has a limited impact on the concave sidewall, so the convex bulge is no longer required.

[0050] 5) The draft angle β of the drawing sidewall is ≥10° and the draft angle α of the convex hull sidewall is ≥5°. The specific parameter settings are simulated and analyzed using CAE to determine the formability and finally determine the size of each parameter.

[0051] Example

[0052] A process optimization method for improving the concave sidewall of the wheel opening in the drawn fender is based on the conventional fender drawing scheme (deep drawing at the wheel opening sidewall, with a straight sidewall). The following optimizations are made to the process shape of the wheel opening sidewall of the drawn fender:

[0053] S1. Research on the generation principle of the inward concavity in the middle and outward curl at the bottom that occurs after the springback release following the completion of the drawing process in the side wall area of ​​the fender wheel well:

[0054] Based on long-term accumulated experience, the simulation and verification results of changing the convex bulge shape of the fender wheel arch sidewall during drawing were analyzed. It was found that when the fender wheel arch sidewall is flat, the springback surface of the drawn wheel arch sidewall will exhibit an inward concave phenomenon. The principle behind this phenomenon was analyzed: during drawing, the wheel arch area of ​​the sheet metal contacts the rounded corner of the die, and the sheet metal flows inward through the rounded corner of the die during the forming process. Figure 7 As shown, at the end of the drawing process, due to the single contact point and continuous sliding of the sheet metal, the theoretical springback value of the sidewall area at the end of the final forming is negative, resulting in a concave sidewall and a part state as shown. Figure 8 As shown.

[0055] S2. Uniformly add raised bulges to the process supplementary surface of the drawing wheel edge sidewall to control the forming process of the fender drawing wheel edge sidewall:

[0056] By adding a convex shape to the sidewall, changing the draft angle and radius of the convex plane, and controlling the spacing between the convexes, the radius of the die on the wheel opening sidewall is changed during the drawing process, and the contact point between the sheet metal and the die is adjusted during sidewall forming. Adding a convex to the sidewall can change the contact process of the draft surface of the sidewall, so that the sheet metal is no longer subjected to a force in a single direction during the forming process. After drawing to the bottom, the convex and concave radius of the convex ...

[0057] S3. Parameters and distribution of the convex hull: A reasonable convex hull process shape is designed by varying the depth and width of the drawn sidewalls. CAE technology is used to simulate and analyze the rationality of the process shape and whether the theoretical springback value after drawing meets the requirements, while ensuring the feasibility of formability after adding the convex hull.

[0058] To control the convex bulge process characteristics of the concave sidewall of the fender drawing wheel opening, it is necessary to set the specific parameters of the fender wheel opening sidewall, prioritizing ensuring that the trimming line or scrap cutter line is in the middle area of ​​the convex bulge plane: the change in the width C of the sidewall determines whether to set the convex bulge; the position of the trimming line or scrap cutter line determines the initial position of the convex bulge; the spacing E between the convex bulge planes directly determines the density of the convex bulges on the sidewall; the draft angle α of the convex bulge sidewall determines the distance from the convex bulge high point to the wheel opening sidewall; the springback state of the concavity can be improved by adjusting the draft angle of the convex bulge and the size of the convex-concave R angle, reducing other defects caused by complex rectification methods such as welding and downmilling during the part quality improvement process, greatly reducing the difficulty of part quality improvement, and reducing the increase in processing and manufacturing difficulty and cost.

[0059] The size of the convex hull radius R2 and concave hull radius R1, the sidewall draft angle β, the convex hull draft angle α, and other key parameters need to be simulated and verified using CAE technology to obtain the most reasonable size and arrangement.

[0060] The design principles of convex hull shapes include:

[0061] 1. See reference Figure 9 The schematic diagram of the sidewall convex hull parameters shows that, firstly, it is necessary to ensure that the waste cutting tool cuts within the convex hull plane area, and to ensure that it cuts in the middle of the convex hull as much as possible. The width of the convex hull plane D ≥ 40mm.

[0062] 2. See reference Figure 9 The diagram shows the parameters of the sidewall convex hull. The R-angle connecting the convex hull plane and the sidewall is shown. The convex R2 ≥ 8mm and the concave R1 ≥ 8mm. After the convex hull is rounded, the distance G between the R1 tangent and the R tangent of the concave die rounded corner is ≥ 5mm, and the distance F between the R1 tangent and the R tangent of the upper convex die is ≥ 5mm.

[0063] 3. See reference Figure 9 The diagram shows the parameters of the sidewall protrusions. The protrusion spacing is generally E≥80mm to avoid the protrusions being too dense and increasing the processing cost.

[0064] 4. See reference Figure 9 The diagram shows the sidewall convex hull parameters. When the sidewall width C≤50mm, the space is small, and the convex hull setting has a limited impact on the sidewall concavity, so no convex hull is set.

[0065] 5. See Figure 10 The schematic diagram of the sidewall convex hull parameters is shown. The draft angle β of the drawn sidewall is ≥10° and the draft angle α of the convex hull sidewall is ≥5°. The specific parameter settings need to be simulated and analyzed using CAE technology to determine the formability and finally determine the size of each parameter.

[0066] 6. Referring to Figure 11(a), it is a schematic diagram of the sheet metal forming process after adding a bulge to the side wall of the fender wheel opening. At this time, only the fillet of the die cavity and the fillet of the punch contact the sheet metal. Figure 11(b) shows that the fillet of the punch, the fillet of the die cavity, and the bulge R all contact the sheet metal. Figure 11(c) shows that the fillet of the punch, the fillet of the die cavity, and the bulge R all contact the sheet metal.

[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process optimization method for improving the concave sidewall of the wheel well after fender drawing, characterized in that, The process shape of the fender drawing wheel sidewall is optimized: a raised bulge is uniformly added to the process supplementary surface of the drawing wheel sidewall to control the forming process of the fender drawing wheel sidewall. The optimization of the fender drawing wheel hole sidewall process includes: uniformly adding convex humps to the process supplementary surface of the drawing wheel hole sidewall; setting the parameters and distribution position of the convex humps; using CAE for simulation analysis to adjust and optimize the process design; uniformly adding convex humps to the process supplementary surface of the drawing wheel hole sidewall, by adding convex humps to the sidewall, changing the draft angle of the convex hump plane and the size of the convex and concave radius, and controlling the spacing between the convex humps, changing the contact point between the wheel hole sidewall concave die radius and the sheet metal and convex and concave dies during the wheel hole sidewall forming process, changing the contact process of the sidewall draft surface, so that the sheet metal is no longer subjected to a single-direction force during the forming process, and after drawing to the bottom, it is fixed by the convex and concave radius of the convex humps, increasing the rigidity of the wheel hole sidewall after drawing, making the sidewall forming process controllable, and reducing the free springback tendency of the wheel hole sidewall; the setting of convex humps The parameters and distribution positions refer to designing the convex bulge process shape by varying the depth and width of the drawn sidewall, controlling the concave convex bulge process shape characteristics of the fender drawn wheel opening sidewall, and setting specific parameters based on the fender wheel opening sidewall plane. Specifically, the change in the sidewall width C determines whether to set a convex bulge; the location of the sidewall trimming line or scrap cutter line determines the initial convex bulge location; the convex bulge plane spacing E determines the density of the sidewall convex bulges; the draft angle α of the convex bulge sidewall determines the distance from the convex bulge high point to the wheel opening sidewall; the springback state of the concave area is improved by adjusting the convex bulge draft angle and the size of the convex and concave R angles; the application of CAE for simulation analysis to adjust and optimize the process shape specifically refers to applying CAE for simulation analysis to optimize the size of the convex and concave R angles (i.e., convex R2 and concave R1), the sidewall draft angle β, and the convex bulge draft angle α.

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