Metal plate high-magnification deep drawing progressive composite forming device

By adopting a two-stage dynamic edge pressing force control method in metal sheet stretching and forming technology, the material flow state is monitored in real time and the edge pressing force is automatically adjusted, which solves the problem of difficulty in taking into account both wrinkle and cracking in the prior art, and significantly improves the forming quality and product pass rate.

CN120055112AActive Publication Date: 2025-05-30YUQIN PRECISION DRAWING TECH (SUZHOU) CO LTD
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Patent Information

Application Number
CN202510519615.3
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-04-24
Publication Date
2025-05-30
Estimated Expiration
2045-04-24

AI Technical Summary

Technical Problem

The existing metal sheet stretching and forming technology is difficult to take into account the dual requirements of anti-wrinkle and anti-cracking in the same process, resulting in limited product qualification rate.

Method used

The dual-stage dynamic edge pressure force control method is adopted. By setting a laser trigger component on the stretching path, the material flow state is monitored in real time, and the edge pressure force output mode is automatically switched: the minimum critical wrinkle prevention force is used in the initial stage, and the edge pressure force is dynamically compensated for the edge pressure force after the stretching, covering the critical interval (between the minimum edge pressure and the maximum edge pressure force) to achieve intelligent adaptation of the edge pressure force.

Benefits of technology

It significantly improves the forming quality of complex curved parts, avoids wrinkling and cracking, and improves the product's pass rate and flatness.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to the technical field of metal plate stretching, and discloses a metal plate high-magnification deep drawing progressive composite forming device which comprises a stretching male die and a stretching female die and further comprises a stretching unit arranged between the stretching male die and the stretching female die and a control center in the stretching male die. The stretching unit comprises a hydraulic cylinder arranged in the middle of the stretching male die, a pushing plate arranged at the bottom of the hydraulic cylinder, a stretching lower pressing block arranged at the bottom of the pushing plate, an edge pressing outer plate arranged at the bottom of the stretching male die, an edge pressing inner plate arranged on one side of the edge pressing outer plate and an edge pressing ring arranged on the top of the edge pressing inner plate. And the top of the blank pressing ring is limited and rotated in the stretching male die, and metal blank plate materials are arranged at the bottoms of the blank pressing outer plate and the blank pressing inner plate. Double-stage dynamic blank holder force control is utilized, the minimum blank holder force is adopted in the initial stage, the flange wrinkling risk is reduced, the blank holder force is automatically increased in the later stretching stage, thinning and cracking are restrained, the pressure adjusting range covers the critical interval, and the stretching quality is improved.
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Description

Technical Field

[0001] The present invention relates to the technical field of metal sheet stretching, and particularly to a high magnification deep drawing progressive composite forming device for metal sheets. Background Art

[0002] In the field of metal sheet stretching forming, the traditional process generally adopts a fixed blank holding force control method, applying a constant pressure to the blank through a fixed blank holder to suppress wrinkling. However, this method has significant technical defects: in the initial stage of stretching, the material flow resistance is small, and a small blank holding force can meet the anti-wrinkling requirements; but as the stretching process progresses, the material gradually flows into the die cavity. Especially when the material edge enters the die fillet area, the contact area decreases, resulting in stress concentration. At this time, if the initial blank holding force is maintained, local wrinkling is likely to occur. On the contrary, if the blank holding force is increased to avoid wrinkling, the material will bear excessive tensile stress at the die fillet, resulting in thinning and rupture.

[0003] Due to the lack of a dynamic adjustment mechanism in the prior art, it is difficult to balance the dual requirements of anti-wrinkling and anti-rupture in the same process, resulting in limited product qualification rate. The proposed two-stage dynamic blank holding force control method sets a laser trigger component on the stretching path to monitor the material flow state in real time. When it is detected that the material enters the critical deformation area, the control system automatically switches the blank holding force output mode: in the initial stage, the minimum critical anti-wrinkling force is adopted to reduce the risk of flange wrinkling; in the later stage of stretching, the blank holding force is dynamically compensated to the safety threshold according to the material contact state, effectively suppressing fillet rupture. This technology realizes the intelligent adaptation of the blank holding force during the stretching process by covering the critical area (Fmin - Fmax) through pressure adjustment, significantly improving the forming quality of complex curved parts. Summary of the Invention

[0004] In view of the problem in the prior art that it is impossible to balance anti-wrinkling and anti-rupture during the stretching of metal blank sheets, a high magnification deep drawing progressive composite forming device for metal sheets is proposed.

[0005] Its purpose is to utilize two-stage dynamic blank holding force control. In the initial stage, the minimum blank holding force is adopted to reduce the risk of flange wrinkling. In the later stage of stretching, it automatically switches to an enhanced blank holding force to suppress thinning and rupture. The pressure adjustment range covers the critical interval (between the minimum blank holding force and the maximum blank holding force), improving the quality of stretching.

[0006] The technical solution of the present invention is a high magnification deep drawing progressive composite forming device for metal sheets, including a stretching punch and a stretching die, and further including a stretching unit arranged between the stretching punch and the stretching die, and a control center in the stretching punch; The stretching unit includes a hydraulic cylinder disposed in the middle of the stretching punch, a pushing plate disposed at the bottom of the hydraulic cylinder, a stretching lower pressing block disposed at the bottom of the pushing plate, a blank holding outer plate disposed at the bottom of the stretching punch, a blank holding inner plate disposed on one side of the blank holding outer plate, a blank holding ring disposed at the top of the blank holding inner plate, the top of the blank holding ring being rotationally limited within the stretching punch, a metal blank sheet disposed at the bottoms of the blank holding outer plate and the blank holding inner plate, a progressive stretching groove opened in the middle of the stretching die, a blank holding force dynamic adjustment component arranged in a circular array inside the blank holding ring, and a laser component disposed on the surfaces of the blank holding outer plate, the blank holding inner plate, and the stretching die; The blank holding force dynamic adjustment component is used to dynamically adjust the magnitude of the blank holding force during the stretching process of the metal blank sheet, preventing the metal blank sheet from wrinkling and cracking; The laser component is used to trigger the blank holding force dynamic adjustment component to adjust the blank holding force.

[0007] Further, the blank holding force dynamic adjustment component includes a downward pressing component. The downward pressing component includes a limiting groove opened on the blank holding ring, a bearing plate disposed in the limiting groove, a limiting top column disposed at the bottom of the bearing plate, a spring disposed inside the limiting top column, a limiting bottom column disposed at the bottom of the spring, and an extrusion plate disposed at the bottom of the limiting bottom column.

[0008] Further, the limiting top column and the limiting bottom column are in a mutually matching staggered overlapping shape, the spring is disposed between them, and one side of the extrusion plate is also limitedly disposed in the limiting groove.

[0009] Further, the blank holding force dynamic adjustment component further includes a magnetic attraction component. The magnetic attraction component includes a circular magnet disposed on one side of the extrusion plate, an iron core disposed at the bottom of the stretching lower pressing block, a coil disposed outside the iron core, a power supply connected to the coil and disposed inside the stretching lower pressing block. The iron core and the coil are both disposed inside the stretching lower pressing block, and the stretching lower pressing block is integrally T-shaped.

[0010] Further, the blank holding force dynamic adjustment component further includes an annular cancellation component. The cancellation component includes a vertical groove opened on the blank holding ring, an arc groove communicating with the bottom of the vertical groove, an extrusion rod disposed on the side wall of the stretching lower pressing block, and an arc magnet disposed on the blank holding inner plate and located between two downward pressing components.

[0011] Further, the laser component includes an A laser group disposed between the blank holding outer plate and the stretching die, and B laser groups, C laser groups, and D laser groups sequentially disposed between the blank holding inner plate and the stretching die.

[0012] Further, the B laser group and the D laser group are respectively disposed on both sides of the bottom of the blank holding inner plate, and the C laser group is disposed in the middle thereof.

[0013] Furthermore, each of the A laser group, B laser group, C laser group, and D laser group is respectively composed of a laser generator and a laser receiver.

[0014] Furthermore, the progressive stretching groove includes two grooves with progressive depths in the vertical direction.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The dynamic blank holding force adjustment component can be used to control the blank holding force between the minimum blank holding force and the maximum blank holding force, which can not only avoid the wrinkling phenomenon of the metal blank sheet during the latter half of the drawing process, but also ensure that the bottom fillet of the metal blank sheet is not stretched and ruptured. The double-stage dynamic blank holding force control is utilized. In the initial stage, the minimum blank holding force is adopted to reduce the risk of flange wrinkling, and the blank holding force is automatically switched to an enhanced blank holding force in the later stage of stretching to inhibit thinning and rupture. The pressure adjustment range covers the critical interval (between the minimum blank holding force and the maximum blank holding force), improving the quality of stretching.

[0016] 2. During the stretching process of the metal blank sheet, the rotation of the inner blank holding plate can further avoid the generation of wrinkles at the edge of the metal blank sheet, making it smoother and improving the flatness and stretching quality after stretching.

[0017] 3. Through the two grooves with progressive depths, the compressive stress during the stretching process of the metal blank sheet can be dispersed, further improving its stretching quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic three-dimensional structure diagram of the whole of the present invention; Figure 2 is a schematic cross-sectional structure diagram of the whole of the present invention; Figure 3 is of the present invention Figure 2 is an enlarged schematic structure diagram of part A in Figure 4 is a schematic structure diagram of the whole internal structure of the present invention; Figure 5 is a schematic structure diagram of the whole of the lower pressing assembly of the present invention; Figure 6 is a schematic cross-sectional structure diagram of the whole of the lower pressing assembly of the present invention; Figure 7 is a schematic three-dimensional structure diagram of the inner blank holding plate and the outer blank holding plate of the present invention; Figure 8 is a schematic structure diagram of the whole force-bearing structure of the metal blank sheet of the present invention after entering the inner blank holding plate.

[0019] In the figure: 1. Drawing punch; 2. Drawing die; 3. Hydraulic cylinder; 4. Pushing plate; 5. Drawing lower pressing block; 6. Blank holder outer plate; 7. Blank holder inner plate; 8. Blank holder ring; 9. Metal blank sheet; 10. Progressive drawing groove; 11. Limit groove; 12. Bearing plate; 13. Limit top column; 14. Spring; 15. Limit bottom column; 16. Extrusion plate; 17. Circular magnet; 18. Iron core; 19. Coil; 20. Vertical groove; 21. Arc groove; 22. Extrusion rod; 23. Arc magnet; 24. A laser group; 25. B laser group; 26. C laser group; 27. D laser group. Specific implementation mode

[0020] To make the above objects, features, and advantages of the present invention more obvious and understandable, the specific implementation mode of the present invention will be described in detail below with reference to the accompanying drawings of the specification.

[0021] Example 1, referring to Figures 1-8 , which is the first embodiment of the present invention, provides a high magnification drawing progressive compound forming device for metal sheet, including a drawing punch 1 and a drawing die 2. A downward pressing mechanism is also installed on the drawing punch 1, which is a prior art and can be a hydraulically driven downward pressing device. It also includes a drawing unit installed between the drawing punch 1 and the drawing die 2, and a control center inside the drawing punch 1; the drawing unit includes a hydraulic cylinder 3 installed in the middle of the drawing punch 1, a pushing plate 4 fixedly connected to the bottom of the hydraulic cylinder 3, a drawing lower pressing block 5 fixedly connected to the bottom of the pushing plate 4, a blank holder outer plate 6 fixedly connected to the bottom of the drawing punch 1, a blank holder inner plate 7 clamped on one side of the blank holder outer plate 6, a blank holder ring 8 fixedly connected to the top of the blank holder inner plate 7, the top of the blank holder ring 8 is rotationally limited inside the drawing punch 1, a metal blank sheet 9 abutted against the bottoms of the blank holder outer plate 6 and the blank holder inner plate 7, a progressive drawing groove 10 opened in the middle of the drawing die 2, a blank holder force dynamic adjustment component annularly arranged inside the blank holder ring 8, and a laser component installed on the surfaces of the blank holder outer plate 6, the blank holder inner plate 7, and the drawing die 2; the blank holder force dynamic adjustment component is used to dynamically adjust the magnitude of the blank holder force during the stretching process of the metal blank sheet 9 to prevent the metal blank sheet 9 from wrinkling and cracking; the laser component is used to trigger the blank holder force dynamic adjustment component to adjust the blank holder force.

[0022] Specifically, when stretching the metal blank sheet 9, the downward pressing mechanism pushes the overall stretching punch 1 downward, causing the stretching punch 1 to drive the outer blank-holding plate 6 and the inner blank-holding plate 7 to press downward synchronously, pressing the metal blank sheet 9 to prevent wrinkling during the stretching process. When the stretching punch 1 drives the outer blank-holding plate 6 to extrude the metal blank sheet 9 in place, at this time, the hydraulic cylinder 3 moves under the control of the control center, pushing the plate 4 to press down the stretching lower block 5, and the lower block stretches the metal blank sheet 9. The metal blank sheet 9 moves into the progressive stretching groove 10 under the stretching action. At this time, the metal blank sheet 9 will pass through the laser assembly, triggering the laser assembly. The laser assembly and the control center are connected by instructions. After receiving the instructions, the control center controls the blank-holding force dynamic adjustment component to adjust the blank-holding force on the metal blank sheet 9. The control center is used to receive instructions and control the operation of each functional component. When the metal blank sheet 9 passes through the outer blank-holding plate 6, it is defaulted that the blank-holding force at this time is the minimum blank-holding force (the minimum blank-holding force to avoid wrinkling). At this time, the inner blank-holding plate 7 does not apply additional blank-holding force to the metal blank sheet 9, and since the outer blank-holding plate 6 presses against the inner blank-holding plate 7, the blank-holding force of the inner blank-holding plate 7 is also the minimum blank-holding force at this time. When the edge of the metal blank sheet 9 reaches the inner blank-holding plate 7, the laser group is triggered. During the continuous downward pressing of the stretching lower block 5, an additional force is applied to the inner blank-holding plate 7 through the downward pressing component. Since the metal blank sheet 9 is being stretched, the smaller its contact area with the inner blank-holding plate 7, the greater its compressive stress and the easier it is to wrinkle. At this time, it is necessary to increase the blank-holding force to avoid wrinkling, and this additional applied force cannot exceed the maximum blank-holding force (which is likely to cause thinning and cracking at the rounded corners of the metal blank sheet 9). At this time, the dynamic blank-holding force adjustment component can be used to control the blank-holding force between the minimum blank-holding force and the maximum blank-holding force, which can not only avoid wrinkling of the metal blank sheet 9 in the latter half of the stretching process but also ensure that the bottom rounded corners of the metal blank sheet 9 are not stretched and cracked. The double-stage dynamic blank-holding force control is utilized. The minimum blank-holding force is adopted in the initial stage to reduce the risk of convex wrinkling, and the blank-holding force is automatically switched to an enhanced blank-holding force in the later stage of stretching to inhibit thinning and cracking. The pressure adjustment range covers the critical interval (between the minimum blank-holding force and the maximum blank-holding force), improving the quality of stretching.

[0023] Referring to Figures 1-5 , the blank-holding force dynamic adjustment component includes a downward pressing component. The downward pressing component includes a limiting groove 11 opened on the blank-holding ring 8, a bearing plate 12 slidably connected in the limiting groove 11, a limiting top column 13 fixedly connected to the bottom of the bearing plate 12, a spring 14 fixedly connected inside the limiting top column 13, a limiting bottom column 15 fixedly connected to the bottom of the spring 14, and an extrusion plate 16 fixedly connected to the bottom of the limiting bottom column 15.

[0024] Specifically, when the metal blank sheet 9 passes through the A laser group 24, that is, after the laser emitter in the A laser group 24 emits laser, the laser receiver cannot receive the laser. At this time, the A laser group 24 is triggered and sends a power-on instruction to the control center, causing the coil 19 to be powered on, so that the magnetic attraction component generates a magnetic force, thereby adsorbing the circular magnet 17, causing the pressing plate 16 to move upward along the limiting groove 11 and compress the spring 14. At this time, the pressing plate 16 is adsorbed and does not press the inner pressing edge plate 7. When the metal blank sheet 9 passes through the B laser group 25 (the same as above), the B laser group 25 sends a power-off instruction to the control center. At this time, the magnetic attraction component no longer has a magnetic force, and the spring 14 resets, causing the pressing plate 16 to press the inner pressing edge plate 7. And since the stretching lower pressing block 5 continues to move downward, at this time, its side will press down the bearing plate 12, and the bearing plate 12 presses the spring 14 and the pressing plate 16. The lower the stretching lower pressing block 5 moves, the more the edge of the metal blank sheet 9 moves into the stretching progressive groove, the smaller its contact area with the inner pressing edge plate 7, the greater the degree of compression of the spring 14, and the greater the pressing force of the pressing plate 16 on the inner pressing edge plate 7, which can better avoid wrinkling.

[0025] Referring to Figures 1-5 , the limiting top column 13 and the limiting bottom column 15 are in a mutually matching staggered overlapping state, the spring 14 is arranged between the two, and one side of the pressing plate 16 is also limited and slides in the limiting groove 11.

[0026] Specifically, the staggered shape can ensure that the spring 14 will not deform when being compressed, and can also protect the spring 14, avoid the spring 14 being damaged by compression, ensure the service life of the spring 14, and enhance the stability of the pressure exerted on the inner pressing edge plate 7 when the spring 14 is pressed down.

[0027] Embodiment 2, referring to Figure 7 , which is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the pressing force dynamic adjustment component further includes a magnetic attraction component. The magnetic attraction component includes a circular magnet 17 fixedly connected to one side of the pressing plate 16, an iron core 18 installed at the bottom of the stretching lower pressing block 5, a coil 19 wound around the outer side of the iron core 18, and a power supply (not shown in the figure) connected to the coil 19 and installed inside the stretching lower pressing block 5. The iron core 18 and the coil 19 are both installed inside the stretching lower pressing block 5, and the stretching lower pressing block 5 is integrally T-shaped.

[0028] Specifically, as shown above, when the magnetic attraction component is used for the metal blank sheet 9 passing through the A laser group 24, a magnetic attraction force is generated to adsorb the extrusion plate 16, so that no additional force is applied to the extrusion plate 16. When the metal blank sheet 9 passes through the B laser group 25, no magnetic attraction force is generated, so that the downward pressing component can extrude the inner pressing edge plate 7, thereby enabling the bearing plate 12 to be extruded, realizing the extrusion of the extrusion plate 16 on the inner pressing edge plate 7, and this process is mutually influential, that is, the more the metal blank sheet 9 is stretched, the greater the pressing edge force it exerts, and the more wrinkles can be avoided. The remaining structures are the same as those of Embodiment 1.

[0029] Embodiment 3, refer to Figures 1-6 , which is the third embodiment of the present invention. The difference between this embodiment and the second embodiment is that the pressing edge force dynamic adjustment component further includes a cancellation component installed annularly. The cancellation component includes a vertical groove 20 opened on the pressing edge ring 8, an arc groove 21 communicating with the bottom of the vertical groove 20, a pressing rod 22 slidably connected to the side wall of the stretching and downward pressing block 5, and an arc magnet 23 fixedly connected to the inner pressing edge plate 7 and located between the two downward pressing components.

[0030] Specifically, the cancellation component is used to ensure that the additional pressing edge force exerted by the downward pressing component on the inner pressing edge plate 7 is too large, exceeding the maximum pressing edge force and causing the corner of the metal blank sheet 9 to rupture. When the metal blank sheet 9 moves at the bottom of the outer pressing edge plate 6, the pressing rod 22 always moves downward in the vertical groove 20. When the edge of the metal blank sheet 9 reaches the position of the B laser group 25, at this time, the pressing rod 22 reaches the intersection of the vertical groove 20 and the arc groove 21. At this time, the spring 14 is released and reset to extrude the inner pressing edge plate 7. During the continuous downward stretching process, the pressing rod 22 begins to enter the arc groove 21, causing the pressing edge ring 8 to start rotating. And when the edge of the metal blank sheet 9 reaches the C laser group 26, the C laser group 26 is triggered to send a power-on instruction to the control center, so that the electromagnet composed of the iron core 18 and the coil 19 regenerates a magnetic attraction force to adsorb the arc magnet 23. Since the arc magnet 23 is fixed on the inner pressing edge plate 7, an upward adsorption force is applied to the inner pressing edge plate 7, and the lower the stretching and downward pressing block 5 moves, the stronger the adsorption force between it and the arc magnet 23, which is used to cancel the additional pressure generated on the inner pressing edge plate 7 by continuously pressing the spring 14, in order to avoid the spring 14 being continuously pressed down, resulting in the pressing edge force of the inner pressing edge plate 7 exceeding the maximum pressing edge force, thereby causing the corner at the bottom of the metal blank sheet 9 to rupture. In addition, during the stretching process, the rotation of the inner pressing edge plate 7 can further avoid wrinkles at the edge of the metal blank sheet 9, making it more flat and improving the flatness and stretching quality after stretching. The remaining structures are the same as those of Embodiment 2.

[0031] Embodiment 4, refer to Figures 1-3, which is the fourth embodiment of the present invention. The difference between this embodiment and the third embodiment is that the laser assembly includes an A laser group 24 installed between the blank holder outer panel 6 and the drawing die 2, and a B laser group 25, a C laser group 26, and a D laser group 27 that are sequentially installed between the blank holder inner panel 7 and the drawing die 2.

[0032] Specifically, the A laser group 24, the B laser group 25, the C laser group 26, and the D laser group 27 are triggered unidirectionally in sequence once. When the drawing is completed and the next drawing is performed, the above commands will be repeated for triggering.

[0033] Refer to Figure 3 , the B laser group 25 and the D laser group 27 are respectively installed on both sides of the bottom of the blank holder inner panel 7, and the C laser group 26 is installed in the middle thereof.

[0034] Specifically, they are triggered in sequence. When passing through the D laser group 27, after it is triggered, it sends a power-off command, so that the electromagnet composed of the iron core 18 and the coil 19 loses magnetic attraction and no longer adsorbs the arc magnet 23. After the drawing is completed, the drawing lower pressing block 5 resets, driving the extrusion rod 22 and the blank holder ring 8 to reset synchronously.

[0035] Refer to Figures 1-3 , the A laser group 24, the B laser group 25, the C laser group 26, and the D laser group 27 are each composed of a laser generator and a laser receiver.

[0036] Specifically, the laser generator therein continuously emits laser to the laser receiver. When any one of them fails to receive laser (when the metal blank sheet 9 passes through any of them), it is default that the laser group is triggered, and they each send commands to the control center respectively.

[0037] Refer to Figure 3 , the progressive drawing groove 10 includes two grooves with progressive depths in the vertical direction.

[0038] Specifically, through the two grooves with progressive depths, the compressive stress during the drawing process of the metal blank sheet 9 can be dispersed.

[0039] Combining Embodiments 1-4, the working principle of the present invention is as follows: When stretching the metal blank sheet 9, the pressing mechanism pushes the overall stretching punch 1 downward, causing the stretching punch 1 to drive the blank holder outer plate 6 and the blank holder inner plate 7 to press downward synchronously, pressing the metal blank sheet 9 to prevent wrinkling of the metal blank sheet 9 during the stretching process. When the stretching punch 1 drives the blank holder outer plate 6 to squeeze the metal blank sheet 9 in place, at this time, the hydraulic cylinder 3 moves under the control of the control center, pushing the plate 4 to press down the stretching lower block 5, and the lower block stretches the metal blank sheet 9. The metal blank sheet 9 moves into the progressive stretching groove 10 under the stretching action. At this time, the metal blank sheet 9 will pass through the laser assembly, triggering the laser assembly. The laser assembly and the control center are connected by instructions. After receiving the instructions, the control center controls the blank holding force dynamic adjustment component to adjust the blank holding force of the metal blank sheet 9. The control center is used to receive instructions and control the operation of each functional component. When the metal blank sheet 9 passes through the blank holder outer plate 6, it is defaulted that the blank holding force at this time is the minimum blank holding force (the minimum blank holding force to avoid wrinkling). At this time, the blank holder inner plate 7 does not apply additional blank holding force to the metal blank sheet 9, and since the blank holder outer plate 6 presses against the blank holder inner plate 7, the blank holding force of the blank holder inner plate 7 is also the minimum blank holding force at this time. When the edge of the metal blank sheet 9 reaches the blank holder inner plate 7, the laser group is triggered. During the continuous downward pressing of the stretching lower block 5, an additional force is applied to the blank holder inner plate 7 through the pressing component. Since the contact area between the metal blank sheet 9 and the blank holder inner plate 7 becomes smaller during the stretching process of the metal blank sheet 9, the compressive stress is greater and it is more likely to wrinkle. At this time, it is necessary to increase the blank holding force to avoid wrinkling, and this additional applied force cannot exceed the maximum blank holding force (which is likely to cause thinning and cracking at the rounded corners of the metal blank sheet 9). At this time, the dynamic blank holding force adjustment component can be used to control the blank holding force between the minimum blank holding force and the maximum blank holding force, which not only avoids wrinkling of the metal blank sheet 9 in the second half of the stretching process but also ensures that the bottom rounded corners of the metal blank sheet 9 are not stretched and cracked. The dual-stage dynamic blank holding force control is utilized. The minimum blank holding force is adopted in the initial stage to reduce the risk of convex wrinkling, and the blank holding force is automatically switched to an enhanced blank holding force in the later stage of stretching to inhibit thinning and cracking. The pressure adjustment range covers the critical interval (between the minimum blank holding force and the maximum blank holding force), improving the quality of stretching.

[0040] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A high-ratio deep-drawing progressive composite forming device for metal sheets, comprising a drawing punch and a drawing die, characterized in that: It also includes a stretching unit disposed between the stretching punch and the stretching die, and a control center in the stretching punch; The stretching unit includes a hydraulic cylinder arranged in the middle of the stretching punch, a push plate arranged at the bottom of the hydraulic cylinder, a stretching lower pressing block arranged at the bottom of the push plate, a blanking outer plate arranged at the bottom of the stretching punch, a blanking inner plate arranged at one side of the blanking outer plate, a blanking ring arranged at the top of the blanking inner plate, the top of the blanking ring limitedly rotates in the stretching punch, a metal blank sheet arranged at the bottom of the blanking outer plate and the blanking inner plate, a progressive stretching groove opened in the middle of the stretching die, a blanking force dynamic adjustment component arranged in an annular array inside the blanking ring, and a laser component arranged on the blanking outer plate, the blanking inner plate and the surface of the stretching die; The blank holder force dynamic adjustment component is used to dynamically adjust the size of the blank holder force as the metal blank sheet is stretched, so as to prevent the metal blank sheet from wrinkling and cracking; The laser assembly is used to trigger the blank holding force dynamic adjustment component to adjust the blank holding force.

2. The high-ratio deep drawing progressive composite forming device for metal sheets according to claim 1 is characterized in that: The dynamic adjustment component of the clamping force includes a pressing assembly, which includes a limiting groove opened on the clamping ring, a pressure plate arranged in the limiting groove, a limiting top column arranged at the bottom of the pressure plate, a spring arranged inside the limiting top column, a limiting bottom column arranged at the bottom of the spring, and an extrusion plate arranged at the bottom of the limiting bottom column.

3. The high-ratio deep drawing progressive composite forming device for metal sheets according to claim 2, characterized in that: The limiting top column and the limiting bottom column are in a mutually matching staggered overlapping state, a spring is arranged between the two, and one side of the extrusion plate is also limitedly arranged in the limiting groove.

4. The high-ratio deep drawing progressive composite forming device for metal sheets according to claim 2, characterized in that: The clamping force dynamic adjustment component also includes a magnetic attraction component, which includes a circular magnet arranged on one side of the extrusion plate, an iron core arranged at the bottom of the stretching lower pressure block, a coil arranged on the outside of the iron core, and a power supply connected to the coil and arranged inside the stretching lower pressure block. The iron core and the coil are both arranged inside the stretching lower pressure block, and the stretching lower pressure block is T-shaped as a whole.

5. The high-ratio deep drawing progressive composite forming device for metal sheets according to claim 1, characterized in that: The dynamic adjustment component of the clamping force also includes a ring-shaped offset component, which includes a vertical groove opened on the clamping ring, an arc groove connected to the bottom of the vertical groove, an extrusion rod arranged on the side wall of the stretching lower pressure block, and an arc magnet arranged on the inner plate of the clamping and located between the two lower pressure components.

6. The high-ratio deep drawing progressive composite forming device for metal sheets according to claim 5, characterized in that: The laser assembly comprises an A laser group arranged between the edge holding outer plate and the stretching die, and a B laser group, a C laser group and a D laser group arranged in sequence between the edge holding inner plate and the stretching die.

7. The high-ratio deep drawing and progressive composite forming device for metal sheets according to claim 6, characterized in that: The B laser group and the D laser group are respectively arranged on both sides of the bottom of the edge pressing inner plate, and the C laser group is arranged in the middle thereof.

8. The high-ratio deep drawing and progressive composite forming device for metal sheets according to claim 6, characterized in that: The A laser group, the B laser group, the C laser group and the D laser group are respectively composed of a laser generator and a laser receiver.

9. The high-ratio deep drawing and progressive composite forming device for metal sheets according to claim 1, characterized in that: The progressive stretching groove comprises two grooves with progressive depths in the vertical direction.

Citation Information

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