A torsion beam semi-finished product and its stamping die

Abstract

This utility model relates to the field of torsion beam technology, specifically disclosing a torsion beam semi-finished product with a continuous variable cross-section structure along its length. The variable cross-section structure includes a cavity located on the product axis and flanges located on the left and right sides of the cavity. The height of the cavity gradually decreases from the middle to both ends of the variable cross-section structure along its length. The flanges and the cavity cooperate to make the cross-section of the variable cross-section structure W-shaped in the middle and U-shaped at both ends. The free ends of both flanges are provided with curved arc segments that move towards the middle of the product. A stamping die is also provided for stamping and forming a torsion beam semi-finished product, including a punch assembly and a die assembly. The die assembly includes a die core, which includes an inner concave cavity and guide surfaces on both sides. The guide surfaces are used to push the curved arc segments towards the centerline of the inner concave cavity. This solution is used to solve the problem in the prior art that the free ends of the flanges are easily scratched on the die guide surfaces during U-O forming, leading to a shortened die life.

Description

Technical Field

[0001] This utility model relates to the field of torsion beam technology, specifically to a torsion beam semi-finished product and its stamping die. Background Technology

[0002] In the automotive parts manufacturing industry, closed torsion beam crossbeams are widely used due to their good torsional stiffness and space utilization.

[0003] Taking the rolling of sheet metal into a torsion beam as an example, existing forming methods include the "Method for Manufacturing Bending Torsional Profiles" disclosed in patent publication number CN110038975B. Its process route includes: first, stamping the outline of the sheet blank and pre-defining the longitudinal edge curvature; then, gradually stamping and stretching the middle area to form end side legs; next, reverse stamping to form a central cavity on the product axis, the central cavity extending from the middle of the product to both ends along the product length, with the cavity height decreasing towards both ends until there are no cavities at the ends of the product length; then, flanging the side legs on both sides of the central cavity to obtain a semi-finished product with a W-shaped structure in the middle and a U-shaped structure at both ends; finally, welding the two side legs of the W-shaped semi-finished product together in the middle. This process gradually releases and adjusts stress through multi-step forming; however, this process route is lengthy, involving multiple stamping and reverse forming processes, requiring a large number of molds, resulting in high costs, long production cycles, and low efficiency.

[0004] Another existing patent, CN115890152B, entitled "Closed Torsion Beam Crossbeam Stamping and Welding Process," significantly simplifies the process. The steps are: stamping the central cavity in one go, trimming the edges, then directly flanging the planar structures on both sides of the cavity to obtain a W-shaped structure, and finally closing the two sides of the W-shaped structure towards the center to obtain the closed section of the torsion beam crossbeam. Theoretically, this method is simpler, eliminating the need for a single stamping die. However, the inventors encountered the following problem when using the UO forming method to close the flanged sections: If, during the UO (Uneven Ore) closing process, a guide surface is set on the die core to guide the two flanges to simultaneously approach each other, and UO forming is performed after the free ends of the two flanges abut against each other, then during the process of guiding the flanges with the guide surface, the free ends of the flanges (edges of the sheet metal) are prone to severe sliding friction and scratching with the guide surface of the closing die. This scratching can easily lead to wear, tear, or even damage to the guide surface, shortening the die's lifespan. Utility Model Content

[0005] The present invention aims to provide a torsion beam semi-finished product and its stamping die to solve the problem in the prior art that the free end of the flange is easily scratched on the guide surface of the die during UO forming, resulting in a shortened die life.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A torsion beam semi-finished product has a continuous variable cross-section structure along its length. The variable cross-section structure includes a cavity located on the product axis and flanges located on the left and right sides of the cavity. The height of the cavity gradually decreases from the middle to both ends of the variable cross-section structure along its length. The flanges and the cavity cooperate to make the cross-section of the variable cross-section structure W-shaped in the middle and U-shaped in the cross-section at both ends. The free ends of the two flanges are provided with curved arc segments that move towards the middle of the product.

[0007] The principle and advantages of this solution are as follows: This solution sets a curved arc segment on the flange of the torsion beam semi-finished product that moves towards the center of the product. This allows the free end of the flange to be introduced and begin closing movement in a smoother and more compliant manner with the guide surface of the die when the torsion beam semi-finished product is formed by stamping die. This reduces the direct impact and friction on the guide surface of the stamping die, improves the life of the stamping die, and makes the top shape of the flange of the product fuller after forming.

[0008] This utility model also provides a stamping die for stamping and forming the aforementioned torsion beam semi-finished product.

[0009] Preferably, as an improvement, the assembly includes a punch assembly and a die assembly. The punch assembly includes a punch core, which engages with the cavity of the torsion beam semi-finished product. The die assembly includes a die core, which includes an inner concave cavity located at the center of the axis. The die core has guide surfaces on both sides of the inner concave cavity. The guide surfaces are used to push the curved arc segment of the torsion beam semi-finished product toward the centerline of the inner concave cavity during the mold closing process. The inner concave cavity is used to fit against the flange of the torsion beam semi-finished product.

[0010] Beneficial effects: This solution, through the design of the stamping die, enables the stamping die to perform UO forming on the torsion beam semi-finished product with a W-shaped cross section in the middle and U-shaped cross sections at both ends, thereby realizing the flange closure of the torsion beam product.

[0011] Preferably, as an improvement, the tangent direction of the curved segment at its free end is consistent with the tangent direction of the guide surface, so as to further reduce wear on the guide surface.

[0012] Preferably, as an improvement, after the punch assembly and the die assembly are closed, the flange is attached to the inner concave cavity, and the concave cavity is attached to the punch core.

[0013] Preferably, as an improvement, the concave cavity and guide surface of the die core are provided with a TD treatment layer to further improve the surface hardness, wear resistance and anti-galling properties, thereby extending the service life of the die under harsh working conditions by several times.

[0014] Preferably, as an improvement, the punch assembly further includes a base plate, and the punch core is detachably connected to the base plate to facilitate the replacement of the corresponding punch core according to the specific product.

[0015] Preferably, as an improvement, the punch core and the base plate have a concave-convex mating section to facilitate accurate and rapid installation of the punch core on the base plate.

[0016] Preferably, as an improvement, the die assembly further includes a base plate two, and the die core is detachably connected to the base plate two to facilitate the replacement of the corresponding die core according to the specific product. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of Embodiment 1 of the present invention.

[0018] Figure 2 for Figure 1 The left view (showing the U-shaped cross-section at the end).

[0019] Figure 3 for Figure 1 A left sectional view of the torsion beam semi-finished product, cut in the middle (showing the W-shaped section in the middle and the U-shaped section at the end).

[0020] Figure 4 for Figure 1 A schematic diagram of the axial section.

[0021] Figure 5 This is a cross-sectional view of the second embodiment of the utility model at the initial mold closing stage.

[0022] Figure 6 This is a cross-sectional view of the second embodiment of the utility model after the mold is closed.

[0023] Figure 7 This is a schematic diagram of the forming process of the torsion beam crossbeam formed by this utility model.

[0024] The reference numerals in the accompanying drawings include: torsion beam semi-finished product 10, cavity 11, flange 12, bending arc segment 121, punch assembly 20, base plate one 21, punch core 22, protrusion 221, die assembly 30, base plate two 31, die core 32, inner concave cavity 321, guide surface 322, and torsion beam product 100 with a closed cross section after UO forming. Detailed Implementation

[0025] The following detailed description illustrates the specific implementation method: Example 1 Combination Figures 1 to 4A torsion beam semi-finished product 10 is formed by stamping metal sheet and has a continuous variable cross-section structure along its length. The variable cross-section structure includes a cavity 11 located on the product axis and flanges 12 located on the left and right sides of the cavity 11. The height of the cavity 11 gradually decreases from the middle to both ends of the variable cross-section structure along its length. The flanges 12 and the cavity 11 cooperate to make the cross-section of the variable cross-section structure W-shaped in the middle and U-shaped at both ends. The free ends of the two flanges 12 are provided with curved arc segments 121 that move towards the middle of the product.

[0026] In this embodiment, by setting a curved arc segment 121 on the flange 12 of the torsion beam semi-finished product and moving towards the center of the product, the free end of the flange 12 can be introduced and begin to close in a smoother and more compliant manner with the mold guide surface 322 when the torsion beam semi-finished product is formed by stamping die. This reduces the direct impact and friction on the guide surface 322 of the stamping die, improves the life of the stamping die, and makes the top shape of the flange 12 of the product more full after forming.

[0027] Example 2 Combination Figures 5 to 7 This embodiment two provides a stamping die for stamping and forming the torsion beam semi-finished product of embodiment one.

[0028] The stamping die includes a punch assembly 20 and a die assembly 30. The die assembly 30 is located above the punch assembly 20. The punch assembly 20 is fixedly installed, and the die assembly 30 closes downward to perform stamping.

[0029] The punch assembly 20 includes a base plate 21 and a punch core 22 bolted to the top of the base plate 21.

[0030] The working surface of the punch core 22 is designed as a protrusion 221 that mates with the concave cavity 11 surface of the torsion beam semi-finished product, thereby positioning the torsion beam semi-finished product before stamping. To further ensure assembly stability, a convex-concave mating section is provided between the punch core 22 and the base plate 21.

[0031] The die assembly 30 includes a base plate 31 and a die core 32 bolted to the bottom of the base plate 31. The die core 32 has a concave cavity 321 in the middle. The concave cavity 321 is used to bend the flange 12 of the torsion beam semi-finished product to fit into the concave cavity 321 when the mold is closed. The concave cavity 321 has a cross-section that changes along its length. The middle cross-section of the concave cavity 321 is inverted V-shaped, and the cross-sections at both ends of the concave cavity 321 are inverted U-shaped. The cross-section of the concave cavity 321 gradually transitions from the inverted V-shape in the middle to the inverted U-shape at the ends. The surface of the concave cavity 321 is formed by contouring according to the design shape of the outer surface of the final torsion beam product.

[0032] On the left and right sides of the concave cavity 321, the die core 32 is provided with inclined guide surfaces 322. The guide surfaces 322 are used to push the curved arc segment 121 of the torsion beam semi-finished product toward the centerline of the concave cavity 321 during the mold closing process. The tangent direction of the curved arc segment 121 of the torsion beam semi-finished product at its free end is consistent with the tangent direction of the guide surface 322 to reduce scratching and wear.

[0033] To improve the durability of stamping dies, TD treatment was performed on the surface of the inner cavity 321 of the die core 32 and the guide surface 322 to form a surface hardened layer with ultra-high hardness, high wear resistance and anti-galling properties.

[0034] In this embodiment, during the die closing process, the concave die core 32 moves downward toward the convex die core 22, and the guide surface 322 of the concave die core 32 pushes against the curved arc segment 121 of the free end of the flange 12 of the torsion beam semi-finished product, so that it moves smoothly toward the centerline of the concave cavity 321.

[0035] After the tops of the two flanges 12 abut together, the continued downward movement of the die core 32 will cause the material of the flanges 12 to adhere to the inner concave cavity 321 under its own material flow, thereby realizing the UO forming of the torsion beam crossbeam.

[0036] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A torsion beam semi-finished product, having a continuous variable cross-section structure along its length, characterized in that: The variable cross-section structure includes a cavity located on the product axis and flanges located on the left and right sides of the cavity. The height of the cavity gradually decreases from the middle to both ends along the length direction of the variable cross-section structure. The flanges and the cavity work together to make the cross-section of the variable cross-section structure W-shaped in the middle and U-shaped at both ends. The free ends of the two flanges are provided with curved arc segments that move towards the middle of the product.

2. A stamping die, characterized in that, Used for stamping and forming the semi-finished torsion beam as described in claim 1.

3. A stamping die according to claim 2, characterized in that: The device includes a punch assembly and a die assembly. The punch assembly includes a punch core, which engages with the cavity of the torsion beam semi-finished product. The die assembly includes a die core, which includes an inner concave cavity located in the middle of the axis. The die core has guide surfaces on both sides of the inner concave cavity. The guide surfaces are used to push the curved arc of the torsion beam semi-finished product toward the centerline of the inner concave cavity during the mold closing process. The inner concave cavity is used to fit against the flange of the torsion beam semi-finished product.

4. A stamping die according to claim 3, characterized in that: The tangent direction of the curved arc segment at its free end is consistent with the tangent direction of the guide surface.

5. A stamping die according to claim 3, characterized in that: After the punch assembly and the die assembly are closed, the flange is attached to the inner concave cavity, and the concave cavity is attached to the punch core.

6. A stamping die according to claim 3, characterized in that: The concave cavity and guide surface of the die core are both provided with a TD treatment layer.

7. A stamping die according to claim 3, characterized in that: The punch assembly also includes a base plate, and the punch core is detachably connected to the base plate.

8. A stamping die according to claim 7, characterized in that: The punch core and the base plate have a concave-convex mating section.

9. A stamping die according to claim 3, characterized in that: The die assembly also includes a base plate 2, and the die core is detachably connected to the base plate 2.

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