Springback force eliminating die set for bending forming of automobile stamping parts

Abstract

This invention discloses a springback elimination forming device for bending automotive stamping parts, belonging to the field of automotive parts processing technology. Specifically, it includes a base and a forming component and a springback elimination component rotatably mounted above the base. This invention synchronously triggers the first working state of the springback elimination component with the bending angle during the bending process, causing the floating pressure block to form a plastic indentation before the elastic stress on the inner side of the bent stamping part is released. This converts some elastic strain into permanent plastic deformation, fundamentally weakening the springback driving force. Combined with bending pre-compensation, it improves the accuracy of the final bending angle. Furthermore, it employs a bidirectional threaded rod and a single motor-driven slide to move synchronously in opposite directions, achieving mechanical linkage between the straight clamping plates, folding clamping plates, and floating pressure block on both sides. This ensures the consistency of the clamping force and the synchronicity of the movements at each point along the bending axis of the stamping part, avoiding the problem of asynchronous movement caused by multiple independent drive sources and eliminating the risk of localized torsional deformation.

Description

Technical Field

[0001] This invention relates to the field of automotive parts processing technology, and more specifically to a springback elimination forming device for bending and forming automotive stamping parts. Background Technology

[0002] Automotive stamping parts are core basic components that make up the structure of automobile body, chassis and interior. They cover a variety of types such as body panels, load-bearing frame parts and connecting parts, and are characterized by large batch production, high precision requirements and strong forming consistency.

[0003] Bending and forming is one of the core processes in automotive stamping. It involves using mold pressure to plastically bend metal sheets to achieve preset angles, curvatures, and dimensions. The forming accuracy directly determines the fit, structural stability, and appearance flatness of the subsequent vehicle assembly, making it a key link in ensuring the quality of automobile production.

[0004] Springback of stamped parts is an inherent technical defect in the metal sheet forming process. The technical essence is that when the sheet is plastically bent under the pressure of the mold, plastic deformation and elastic deformation occur simultaneously inside. When the mold is depressurized and the workpiece is removed from the forming load, the residual elastic stress inside is released, causing the workpiece to undergo reverse deformation, which ultimately leads to problems such as excessive forming angle, deviation of bending arc, and excessive dimensional deviation. For example, referring to the pressing device disclosed in patent publication number CN108672563A that eliminates the springback force of a product during bending, the springback force is slowly eliminated by the movement of the horizontal groove after the product is formed. When the inclined arc groove moves, it can be offset from the core block at an angle, which is convenient for picking up and putting down the parts. However, the existing springback elimination device after bending adopts an independent multi-drive source, fixed guide groove trajectory, and intervention only after bending is completed in a "post-bending slow release" mode. This results in the springback compensation being disconnected from the bending process, and it is impossible to actively intervene in the elastic stress generated during bending. At the same time, there is a lack of unified motion reference among multiple pressing components, making it difficult to ensure the synchronicity and consistency of springback elimination at each point along the bending axis, that is, it is difficult to effectively control the bending accuracy. Therefore, this invention proposes a solution. Summary of the Invention

[0005] The purpose of this invention is to provide a springback elimination forming device for bending and forming automotive stamping parts, in order to solve the above-mentioned technical problems.

[0006] The present invention provides the following apparatus: a springback elimination forming device for bending and forming automotive stamping parts, comprising a base and a forming component and a springback elimination component rotatably disposed above the base; The molding assembly includes a left bending seat and a right bending seat folded and disposed in the middle of the side plate; The bullet-absorbing assembly has a first working state and a second working state; it includes a mounting plate set on the upper side of the side plate, a bidirectional threaded rod rotatably set between the mounting plates, and a slide block sleeved on the outside of the bidirectional threaded rod with opposite spiral directions on both sides. A straight clamping plate and a folding clamping plate are respectively installed on the left and right sides of the slide block, and a floating pressure block pointing to the inside of the bending when the stamping part is bent is installed at the bottom of the straight clamping plate and the folding clamping plate. In the first working state, the slide moves in a close proximity, causing the straight clamping plate and the folding clamping plate to complete the lateral clamping of the stamped part, and the floating pressure block presses against the inner side of the bent part and forms a local plastic indentation; in the second working state, the slide moves in the opposite direction, causing the straight clamping plate and the folding clamping plate to disengage from the surface of the stamped part, and the floating pressure block disengages from the inner side of the bent part to release the clamping of the stamped part. Specifically, the motor drives the bidirectional threaded rod to rotate. Since the threads on the left and right sides rotate in opposite directions, the slides on both sides move closer to each other synchronously under the constraint of the guide rod. The slides drive the straight clamping plate and the folding clamping plate to move together: the straight clamping plate is located on the left side of the slide and the folding clamping plate is located on the right side. When the slides move close together, the straight clamping plate and the folding clamping plate clamp the bent part of the stamping part laterally from the left and right sides. At the same time, the floating pressure block is pushed by the spring and presses against the bent inner surface of the stamping part. Since the stamped part has been bent to the bending angle, its inner side of the bend is exactly below the floating pressure block. Therefore, the floating pressure block presses into the surface of the stamped part with a set pressure to form a local plastic indentation. This is the first working state: the slide moves close together, the straight clamping plate and the folding clamping plate complete the lateral clamping of the stamped part, and the floating pressure block presses against the inner side of the bend of the stamped part and forms a local plastic indentation. In the first working state, the motor maintains torque to keep the slide in the pressing position, while the oil cylinder maintains the bending angle and the pressure holding time lasts for a certain period of time. During this period, the elastic stress on the inner side of the bent part is partially released and locked due to the plastic deformation of the indentation, and the springback tendency is reduced.

[0007] Furthermore, the side plate is vertically set in the middle of the outer side of the base. A middle pressure column is set on the upper side of the side plate corresponding to the rotatable connection between the left and right bending seats. A pressure rod is set on the upper middle of both the left and right bending seats. The upper side of the pressure rod and the lower side of the middle pressure column together form the bending forming area of ​​the stamping part.

[0008] Furthermore, a base plate is installed on the upper end of the base corresponding to the left bending seat, and the upper end of the base plate is connected to the left bending seat. A hydraulic cylinder is hinged to the bottom of the base corresponding to the right bending seat, and the output end of the hydraulic cylinder is hinged to the bottom of the right bending seat.

[0009] Furthermore, a motor for driving the rotation of the bidirectional threaded rod is installed on one side of the mounting plate. The threads on the surface of the bidirectional threaded rod are arranged symmetrically in both directions, and a guide rod that is horizontally slidably connected to the slide is installed on the upper inner side of the mounting plate.

[0010] Furthermore, a rod seat is installed at the bottom of the slide block. Hanging holes are arranged along the bending axis on the lower center of the rod seat. A floating rod is hung on the rod seat through the hanging holes. The lower end of the floating rod is movably connected to a fork arm rod that is connected to the floating pressure block.

[0011] Furthermore, a threaded sleeve is installed on the external thread of the floating rod, and a spring connected to the upper side of the fork arm is installed at the bottom of the threaded sleeve.

[0012] Furthermore, a bottom support rod is installed at the rotatable connection of the right bending seat near the left bending seat, and the upper side of the bottom support rod contacts the bottom of the stamped part.

[0013] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. On the one hand, the first working state of the springback elimination component is triggered synchronously with the bending angle during the bending process, so that the floating pressure block forms a plastic indentation before the elastic stress on the inner side of the bent stamping part is released, converting part of the elastic strain into permanent plastic deformation, thereby weakening the springback driving force from the root. Combined with the bending pre-compensation, the accuracy of the final bending angle is improved.

[0014] 2. On the other hand, a bidirectional threaded rod and a slide driven by a single motor move synchronously in opposite directions to achieve mechanical linkage between the straight clamping plates, folding clamping plates and floating pressure blocks on both sides. This ensures the consistency of the clamping force and the synchronicity of the action at each point along the bending axis of the stamped part, avoids the problem of asynchronous movement caused by multiple independent drive sources, and eliminates the risk of local torsional deformation. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the rear view structure of the present invention; Figure 3 This is a schematic diagram of the installation of the molding component of the present invention; Figure 4 This is a structural diagram of the bullet-absorbing assembly of the present invention; Figure 5 This is a cross-sectional schematic diagram of the installation structure of the floating pressure block of the present invention; Figure 6 This is a schematic diagram of the installation of the slide block of the present invention; Figure 7 This is a side sectional view of the present invention.

[0016] In the diagram: 1. Base; 2. Side plate; 3. Left bending seat; 4. Right bending seat; 5. Mounting plate; 6. Slide seat; 7. Two-way threaded rod; 8. Straight clamping plate; 9. Folding clamping plate; 10. Motor; 11. Rod seat; 12. Floating pressure block; 13. Stamped part; 14. Pressure rod; 15. Hydraulic cylinder; 16. Bottom support plate; 17. Central pressure column; 18. Bottom support rod; 19. Guide rod; 20. Hanging hole; 21. Floating rod; 22. Screw sleeve; 23. Spring; 24. Fork arm rod. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the following description is provided in conjunction with embodiments and appendices. Figure 1-7 As shown, the present invention will be further described in detail. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0018] Example 1: A springback elimination forming device for bending and forming automotive stamping parts, comprising a base 1 and a forming component and a springback elimination component rotatably disposed above the base 1; The molding assembly includes a left bending seat 3 and a right bending seat 4 folded and disposed in the upper middle part of the side plate 2; The bullet-absorbing assembly has a first working state and a second working state; it includes a mounting plate 5 set on the upper side of the side plate 2, a bidirectional threaded rod 7 rotatably set between the mounting plates 5, and a slide block 6 sleeved on the outside of the bidirectional threaded rod 7 with opposite spiral directions on both sides. A straight clamping plate 8 and a folding clamping plate 9 are respectively installed on the left and right sides of the slide block 6. A floating pressure block 12 pointing to the inner side of the bending when the stamping part 13 is bent and formed is installed at the bottom of the straight clamping plate 8 and the folding clamping plate 9. In the first working state, the slide block 6 moves close to each other, causing the straight clamping plate 8 and the folding clamping plate 9 to complete the lateral clamping of the stamping part 13, and the floating pressure block 12 presses against the inner side of the bend of the stamping part 13 and forms a local plastic indentation; in the second working state, the slide block 6 moves in the opposite direction, causing the straight clamping plate 8 and the folding clamping plate 9 to disengage from the surface of the stamping part, and the floating pressure block 12 disengages from the inner side of the bend of the stamping part 13 to release the clamping of the stamping part 13; For the initial state of the forming component and the deforming component: the piston rod of the cylinder 15 is in the retracted state, the right bending seat 4 and the left bending seat 3 are opened to the maximum included angle of 180°, the stamping part 13 is placed above the left bending seat 3 and the right bending seat 4, the middle part is placed between the middle pressure column 17 and the pressure rod 14, the bottom is supported by the bottom support rod 18, the motor 10 is in the stopped state, the bidirectional threaded rod 7 is not rotated, the left and right sliding seats 6 are respectively located at the two ends of the bidirectional threaded rod 7 at positions far away from each other, the straight clamping plate 8, the folding clamping plate 9 and the floating pressure block 12 are all far away from the stamping part 13; The side plate 2 is vertically arranged in the middle of the outer side of the base 1. The side plate 2 is provided with a middle pressure column 17 on the upper side of the rotating connection between the left bending seat 3 and the right bending seat 4. The middle of the upper side of the left bending seat 3 and the right bending seat 4 are provided with pressure rods 14. The upper side of the pressure rods 14 and the lower side of the middle pressure column 17 together constitute the bending forming area of ​​the stamping part 13. A base plate 16 is installed on the upper end of the base 1 corresponding to the left bending seat 3. The upper end of the base plate 16 is connected to the left bending seat 3. A hydraulic cylinder 15 is hinged to the bottom of the base 1 corresponding to the right bending seat 4. The output end of the hydraulic cylinder 15 is hinged to the bottom of the right bending seat 4. A motor 10 for driving the rotation of the bidirectional threaded rod 7 is installed on one side of the mounting plate 5. The threads on the surface of the bidirectional threaded rod 7 are bidirectionally symmetrically arranged, and a guide rod 19 that is horizontally slidably connected to the slide block 6 is installed on the upper inner side of the mounting plate 5. During bending and forming: the piston rod of the oil cylinder 15 extends and pushes the right bending seat 4 to rotate upward around the axis. At this time, the pressure rod 14 and the middle pressure column 17 jointly squeeze the stamping part 13, causing the stamping part 13 to bend and deform.

[0019] First, the motor 10 drives the bidirectional threaded rod 7 to rotate. Since the threads on the left and right sides rotate in opposite directions, the slides 6 on both sides move closer to each other synchronously under the constraint of the guide rod 19. The slides 6 drive the straight clamping plate 8 and the folding clamping plate 9 to move together: the straight clamping plate 8 is located on the left side of the slides 6, and the folding clamping plate 9 is located on the right side. When the slides 6 move close together, the straight clamping plate 8 and the folding clamping plate 9 clamp the bent part of the stamping part 13 laterally from the left and right sides. At the same time, the floating pressure block 12 is pushed by the spring 23 and presses against the bent inner surface of the stamping part 13. Since the stamped part 13 has been bent to the bending angle, its inner side of the bend is exactly below the floating pressure block 12. Therefore, the floating pressure block 12 presses into the surface of the stamped part 13 with a set pressure to form a local plastic indentation. This is the first working state: the slide block 6 moves close to each other, the straight clamping plate 8 and the folding clamping plate 9 complete the lateral clamping of the stamped part 13, and the floating pressure block 12 presses against the inner side of the bend of the stamped part 13 and forms a local plastic indentation. In the first working state, the motor 10 maintains torque to keep the slide 6 in the pressing position, while the oil cylinder 15 maintains the bending angle and the pressure holding time lasts for a certain period of time. During this period, the elastic stress on the inner side of the bent part 13 is partially released and locked due to the plastic deformation of the indentation, and the springback tendency is reduced.

[0020] Subsequently, after the pressure holding is completed, the piston rod of the hydraulic cylinder 15 retracts, driving the right bending seat 4 to rotate in the opposite direction, causing the included angle of the bending seat to revert from the over-bending angle to the target bending angle. At this time, the stamped part 13 springs back, but due to the combined effect of over-bending pre-compensation and indentation plastic locking, the final angle after springback is exactly equal to the target angle. The motor 10 rotates in the opposite direction, driving the bidirectional threaded rod 7 to rotate in the opposite direction. The two slide blocks 6 move in opposite directions synchronously, and the straight clamping plate 8 and the folding clamping plate 9 release their lateral clamping on the stamping part 13. The floating pressure block 12 disengages from the curved inner surface of the stamping part 13. This is the second working state: the slide block 6 moves in opposite directions, causing the straight clamping plate 8 and the folding clamping plate 9 to disengage from the surface of the stamping part, and the floating pressure block 12 disengages from the curved inner surface of the stamping part 13 and releases its clamping. Finally, the formed stamped part 13 is taken out, completing one work cycle.

[0021] The principle of springback elimination in this invention is as follows: by synchronously triggering the first working state of the springback elimination component with the bending angle during the bending process, the floating pressure block 12 forms a plastic indentation before the elastic stress on the inner side of the bent part 13 is released, converting part of the elastic strain into permanent plastic deformation, thereby weakening the springback driving force from the root. Combined with the bending pre-compensation, the accuracy of the final bending angle is improved.

[0022] Example 2: A rod seat 11 is installed at the bottom of the slide 6. Hanging holes 20 are arranged in the middle of the lower side of the rod seat 11 along the bending axis. A floating rod 21 is hung on the rod seat 11 through the hanging holes 20. The lower end of the floating rod 21 is movably connected to a fork arm rod 24 connected to the floating pressure block 12. The floating rod 21 is threaded with a threaded sleeve 22. The bottom of the threaded sleeve 22 is fitted with a spring 23 that is connected to the upper side of the fork arm rod 24. The right bending seat 4 is fitted with a bottom support rod 18 near the rotating connection of the left bending seat 3. The upper side of the bottom support rod 18 is in contact with the bottom of the stamping part 13.

[0023] By rotating the screw sleeve 22, the initial compression of the spring 23 can be changed, thereby independently adjusting the maximum clamping force of each floating pressure block 12. This allows it to automatically adapt to the curved surface shape of the inner side of the stamped part 13, ensuring uniform indentation. When the slide block 6 moves to make the floating pressure block 12 contact the stamped part 13, the spring 23 is compressed as it continues to move, and the clamping force gradually increases. The indentation depth is determined by the stiffness and compression of the spring 23, and the final indentation depth can be precisely controlled by the preset initial compression of the screw sleeve 22. Furthermore, different numbers of pressure bar assemblies can be selected according to the length of the stamped part 13 to ensure that indentation is applied evenly along the entire length of the bend.

[0024] Example 3: This example combines the technical content of Examples 1 and 2 to form a method for eliminating the bending springback of stamped parts using this device: Step 1: Based on the thickness of the stamped part 13, the yield strength of the material, and the target bending angle, the over-bending compensation angle Δ (take 3°~10°) is preset by the controller, and the initial compression of the spring 23 corresponding to each floating pressure block 12 is adjusted by rotating the screw sleeve 22 so that the preset indentation depth is 0.2~0.6 times the plate thickness; Step 2: Place the stamped part 13 above the left bending seat 3 and the right bending seat 4, so that its middle part is located between the middle pressure column 17 and the pressure rod 14, and its bottom is supported by the bottom support rod 18. Step 3: Start the hydraulic cylinder 15 to push the right bending seat 4 to rotate, so that the stamped part 13 bends to the preset bending angle; Step 4: When the bending seat reaches the bending angle, start the motor 10 to drive the bidirectional threaded rod 7 to rotate, so that the two sliding seats 6 on both sides move towards each other. The straight clamping plate 8 and the folding clamping plate 9 clamp the stamping part 13 laterally. At the same time, the floating pressure block 12 presses into the inner bending surface of the stamping part 13 to form a plastic indentation and holds the pressure for a period of time. Step 5: After the pressure holding is completed, the hydraulic cylinder 15 is driven in the reverse direction, causing the bending seat to retract to the target bending angle, and the stamped part 13 springs back and stabilizes at the target angle; Step 6: The motor 10 rotates in the opposite direction, driving the slide 6 to move backward, so that the straight clamping plate 8, the folding clamping plate 9 and the floating pressure block 12 are completely separated from the stamping part 13, and the formed part is taken out.

[0025] The results of the solution are as follows: On the one hand, the first working state of the springback elimination component is triggered synchronously with the bending angle during the bending process, so that the floating pressure block 12 forms a plastic indentation before the elastic stress on the inner side of the bending of the stamped part 13 is released, converting part of the elastic strain into permanent plastic deformation, thereby weakening the springback driving force from the root. Combined with the bending pre-compensation, the final bending angle accuracy is improved. On the other hand, the bidirectional threaded rod 7 and the slide block 6 driven by a single motor 10 move synchronously in opposite directions, realizing the mechanical linkage of the straight clamping plates 8, folding clamping plates 9 and floating pressure blocks 12 on both sides. This ensures the consistency of the clamping force and the synchronicity of the action at each point along the bending axis of the stamping part 13, avoids the problem of asynchronous movement caused by multiple independent drive sources, and effectively eliminates the risk of local torsion and deformation.

[0026] In summary, this invention organically integrates over-bending compensation and synchronous indentation locking through the coordinated work of the forming component and the springback elimination component, thereby solving the problems of springback compensation and bending process separation, poor synchronization of multiple drive sources, and inability to independently adjust clamping force in the prior art. It is particularly suitable for mass precision bending forming of high-strength steel stamping parts for automobiles.

[0027] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A springback-eliminating forming device for bending and forming automotive stamping parts, comprising a base (1) and a forming assembly and a springback-eliminating assembly rotatably disposed above the base (1), characterized in that: The molding assembly includes a left bending seat (3) and a right bending seat (4) folded and disposed in the upper middle part of the side plate (2). The bullet-absorbing assembly has a first working state and a second working state; it includes a mounting plate (5) set on the upper side of the side plate (2), a bidirectional threaded rod (7) rotatably set between the mounting plates (5), and a slide (6) sleeved on the outside of the bidirectional threaded rod (7) with opposite spiral directions on both sides. A straight clamping plate (8) and a folding clamping plate (9) are respectively installed on the left and right sides of the slide (6). A floating pressure block (12) pointing to the inner side of the bending when the stamping part (13) is bent is installed at the bottom of the straight clamping plate (8) and the folding clamping plate (9). In the first working state, the slide (6) moves close to each other, causing the straight clamp (8) and the folding clamp (9) to complete the lateral clamping of the stamping part (13), and the floating pressure block (12) presses against the inner side of the bent part (13) and forms a local plastic indentation; in the second working state, the slide (6) moves in the opposite direction, causing the straight clamp (8) and the folding clamp (9) to detach from the surface of the stamping part, and the floating pressure block (12) detaches from the inner side of the bent part (13) to release the clamping of the stamping part (13).

2. The springback elimination forming device for bending and forming automotive stamping parts according to claim 1, characterized in that, The side plate (2) is vertically set in the middle of the outer side of the base (1). The side plate (2) is provided with a middle pressure column (17) on the upper side of the rotating connection between the left bending seat (3) and the right bending seat (4). The middle of the upper side of the left bending seat (3) and the right bending seat (4) are provided with pressure rods (14). The upper side of the pressure rod (14) and the lower side of the middle pressure column (17) together constitute the bending forming area of ​​the stamping part (13).

3. The springback elimination forming device for bending and forming automotive stamping parts according to claim 2, characterized in that, The base (1) is fitted with a base plate (16) at the upper end of the left bending seat (3). The upper end of the base plate (16) is connected to the left bending seat (3). The base (1) is hinged to the bottom of the right bending seat (4). The output end of the oil cylinder (15) is hinged to the bottom of the right bending seat (4).

4. The springback elimination forming device for bending and forming automotive stamping parts according to claim 1, characterized in that, A motor (10) for driving the rotation of the bidirectional threaded rod (7) is installed on one side of the mounting plate (5). The threads on the surface of the bidirectional threaded rod (7) are bidirectionally symmetrically arranged, and a guide rod (19) that is horizontally slidably connected to the slide (6) is installed on the upper inner side of the mounting plate (5).

5. The springback elimination forming device for bending and forming automotive stamping parts according to claim 1, characterized in that, A rod seat (11) is installed at the bottom of the slide (6). A hanging hole (20) is arranged in the middle of the lower side of the rod seat (11) along the bending axis. A floating rod (21) is hung on the rod seat (11) through the hanging hole (20). The lower end of the floating rod (21) is movably connected to a fork arm rod (24) connected to the floating pressure block (12).

6. The springback elimination forming device for bending and forming automotive stamping parts according to claim 5, characterized in that, The floating rod (21) is threaded with a sleeve (22), and the bottom of the sleeve (22) is fitted with a spring (23) that is connected to the upper side of the fork arm rod (24).

7. The springback elimination forming device for bending and forming automotive stamping parts according to claim 1, characterized in that, A bottom support rod (18) is installed at the rotating connection of the right bending seat (4) near the left bending seat (3), and the upper side of the bottom support rod (18) is in contact with the bottom of the stamping part (13).

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