Plate flanging forming method and device based on convex magnetic collector

Abstract

The invention relates to a plate flanging forming method based on a convex magnetic collector, which comprises the following steps of: determining parameters of a driving coil according to a plate forming specification, selecting a corresponding wire rod and a corresponding wire diameter, and winding the driving coil through a winding machine; determining the material and size parameters of the convex magnetic collector; manufacturing a convex magnetic collector; after the to-be-formed plate is subjected to annealing pretreatment, the middle of the to-be-formed plate is fixed through a mold; a convex magnetic collector is arranged in the opposite direction of a flanging area of a to-be-formed plate, a protrusion of the convex magnetic collector is aligned with the middle of the flanging area of the to-be-formed plate, and a driving coil is arranged at the bottom of the convex magnetic collector and connected with a pulse power source through a switch. And supplying power to the driving coil, controlling the discharge time of the pulse power supply, and flanging the to-be-formed plate. The magnetic field distribution of the flanging area of the plate is improved through the convex magnetic collector, the flatness and the uniformity of the formed flanging area of the plate are improved, and the problem that the flanging buckling phenomenon of the plate is caused by non-uniform electromagnetic force distribution due to the end effect is solved.

Description

Technical Field

[0001] The invention belongs to the field of metal forming and manufacturing, and in particular relates to a plate flanging forming method and device based on a convex magnetic collector. Background Art

[0002] In the fields of aerospace, automotive industry, etc., flanging process is very important in the processing of light alloys, which directly affects the forming accuracy of parts and components and the subsequent assembly and welding quality. Light alloys have low forming plasticity at room temperature and have disadvantages such as easy springback and tearing, which leads to bottlenecks in the field of material processing for traditional flanging process. Therefore, how to improve the forming performance of light alloy plates by improving the flanging process has become a key research direction.

[0003] Traditional plate flanging processes often face problems such as wrinkling and cracking in practical applications, especially in the flanging process of high-strength alloy plates. Since the plates often produce local buckling and wrinkling in the stress concentration area, the quality of the parts is reduced. In response to this problem, Li Jianwei et al. proposed a method to reduce wrinkling by optimizing process parameters in the "Research on Wrinkling Problems in Aluminum Alloy Plate Flanging Process" published in "Forging Technology". It significantly reduces wrinkling in flanging and improves the flatness of flanging by reasonably adjusting the flanging height and pressing force. However, this method is mainly aimed at aluminum alloy plates with simple geometric shapes. For more complex and variable-shaped parts, the improvement effect is limited. [1] In the article “Research on Optimization of Plate Flanging Process Based on Dynamic Forming” published in Mechanical Engineering Materials, Wang Wei et al. introduced dynamic loading to enhance the plasticity of the material during the flanging process, targeting the cracking problem of high-strength alloy plates. This significantly reduced the probability of cracks during the forming process and improved the surface quality and precision of the formed parts. This method further solves the problem of local cracking during plate flanging through the technical path of dynamic deep drawing, but its complex process flow and equipment requirements increase production costs, making it difficult to apply in large-scale industrial production. [2] .

[0004] In summary, the current research on the improvement of sheet metal flanging technology has solved the wrinkling and cracking problems encountered in actual forming to a certain extent, but in the face of workpieces with complex geometric shapes and the diversity of materials, traditional processes still have great limitations. In addition, although technologies such as dynamic forming have improved the forming quality of sheet metal, the increase in equipment and process complexity in actual industrial environments has limited the promotion and application of these technologies.

[0005] References: [1]. Li Jianwei et al. Research on wrinkling problem in aluminum alloy plate flanging process[J]. Forging Technology, 2020, 55(6): 48-52.

[0006] [2]. Wang Wei et al. Research on optimization of sheet metal flanging process based on dynamic forming[J]. Mechanical Engineering Materials, 2019, 47(3): 73-78. Summary of the invention

[0007] The technical problem of the present invention is that in the traditional plate flanging process, due to structural position, high-speed deformation and other reasons, the plate will produce buckling due to uneven distribution of electromagnetic force during the flanging process, and the plate flanging will be uneven.

[0008] The purpose of the present invention is to address the above-mentioned problems and to provide a plate flanging forming method based on a convex magnetic collector, wherein a convex magnetic collector is added between the driving coil and the flanging plate, and the protrusion of the convex magnetic collector is in close contact with the middle part of the flanging area of ​​the plate. The convex magnetic collector is used to improve the magnetic field distribution in the flanging area of ​​the plate, thereby improving the flatness of the flanging area of ​​the plate after forming.

[0009] In order to achieve the above object, the technical solution provided by the present invention is: The plate flanging forming method based on a convex magnetic collector comprises the following steps: Step 1: Determine the parameters of the drive coil according to the sheet forming specifications, select the corresponding wire material and wire diameter, and wind it into the drive coil through a winding machine; Step 2: According to the parameters of the driving coil and the sheet forming specifications obtained in step 1, determine the material and size parameters of the convex magnetic collector; Step 3: According to the parameters obtained in step 2, a convex magnetic collector is manufactured; Step 4: After annealing pretreatment of the sheet to be formed, the middle part of the sheet to be formed is fixed by a mold; Step 5: Arrange a convex magnetic collector in the opposite direction of the flanged area of ​​the plate to be formed, with the protrusion of the convex magnetic collector aligned with the middle of the flanged area of ​​the plate to be formed. Step 6: Arrange a driving coil at the bottom of the convex magnetic collector, and connect the driving coil to a pulse power supply via a switch; Step 7: Control the switch to supply power to the driving coil and control the discharge time of the pulse power supply to flanging the sheet to be formed; Step 8: Determine whether the flanging forming effect of the plate meets the flanging forming specifications of the plate. If it meets the flanging forming specifications, end; otherwise, execute step 7 to flanging the plate again until the plate forming specifications are met.

[0010] Preferably, in step 1, a plate flanging simulation model including a driving coil and a plate is constructed using finite element software, a pulse current is applied to the driving coil in the plate flanging simulation model, the flanging effect of the plate is simulated, and compared with the plate flanging forming effect, the parameters of the driving coil are adjusted to perform plate flanging simulation until the plate forming specifications are reached, and the parameters of the driving coil are obtained.

[0011] Preferably, in step 2, a convex magnet collector is added to the plate flanging simulation model, and the plate flanging simulation model is used again to perform plate flanging simulation, and the width and height of the protrusion of the convex magnet collector are repeatedly adjusted to achieve the best flatness and uniformity of the plate flanging area after the plate flanging is formed, thereby obtaining the optimal size parameters of the convex magnet collector.

[0012] Taking a circular plate with a radius of 50 mm as an example, in a preferred solution, the height of the protrusion of the convex magnetic collector is 0.8-1.2 mm, and the width is 5-7 mm.

[0013] Preferably, the distance between the convex magnetic collector and the plate to be formed is 0.2-0.4 mm.

[0014] Preferably, the distance between the convex magnetic collector and the driving coil is 0.4-0.8 mm.

[0015] Preferably, in step 6, the pulse power supply is a capacitor power supply, the capacitance of the capacitor power supply is 320 μF, and the voltage of the capacitor power supply is 4.5 kV.

[0016] The plate flanging device of the plate flanging forming method based on a convex magnetic collector comprises a convex magnetic collector, a driving coil, a pulse power supply and a pressing die; the driving coil is connected to the pulse power supply via a switch; the pressing die is used to fix the non-flanging area of ​​the plate to be formed.

[0017] Compared with the prior art, the beneficial effects of the present invention include: 1) The present invention increases the electromagnetic field in the middle of the flanging area by adding a convex magnetic collector between the driving coil and the flanging plate, and using the protrusion of the convex magnetic collector to reduce the distance between the magnetic collector and the middle of the flanging area of ​​the plate, thereby effectively improving the magnetic field distribution in the flanging area of ​​the plate, making the electromagnetic force more uniform, thereby effectively avoiding the flanging buckling phenomenon caused by uneven electromagnetic force due to the end effect during the flanging process of the plate. Through this optimization, the flanging forming area of ​​the plate is smoother, and the surface and dimensional accuracy of the formed plate are improved, which is conducive to improving the quality of assembly and welding in subsequent processes.

[0018] 2) The present invention can adapt to the flanging requirements of panels with different forming specifications by adjusting the size and geometric parameters of the magnetic collector without replacing the drive coil, thus avoiding the trouble of frequent coil replacement and greatly improving the flexibility and production efficiency of panel flanging processing. At the same time, this flexibility makes the system more widely applicable, especially suitable for production lines with variable panel sizes.

[0019] 3) The convex magnetic collector of the present invention not only has a relatively simple manufacturing process and lower cost, but also can reduce the requirements of the plate flanging process for the drive coil to a certain extent, reducing the overall manufacturing cost of the plate flanging device. In addition, the convex magnetic collector can improve the eddy current distribution of the drive coil, reduce the electromagnetic force of the drive coil, bear part of the electromagnetic force impact, significantly extend the service life of the drive coil, reduce equipment maintenance and replacement costs, make the electromagnetic flanging process more economical, and can be better applied to large-scale production.

[0020] 4) Due to the flexibility of configuring the convex magnetic collector, the present invention can meet the processing requirements of various plates, reduce the downtime and equipment adjustment time caused by plate changes, and significantly shorten the flanging processing cycle. At the same time, by improving the uniformity of electromagnetic force distribution, the plate flanging process can be formed in place at one time, reducing rework and correction operations, further improving the overall production efficiency, and facilitating the rapid production of large-scale, high-precision plate flanging. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 The present invention is a schematic diagram of the process of a plate flanging forming method based on a convex magnetic concentrator according to an embodiment of the present invention.

[0023] Figure 2 It is a schematic diagram of a plate flanging forming device based on a convex magnetic collector according to an embodiment of the present invention.

[0024] Figure 3 Schematic diagram of a plate flanging forming circuit based on a convex magnetic concentrator according to an embodiment of the present invention.

[0025] Figure 4 Schematic diagram of a convex magnetic collector device according to an embodiment of the present invention.

[0026] Figure 5 Schematic diagram of the simulation results of conventional electromagnetic flanging of a plate according to an embodiment of the present invention.

[0027] Figure 6 It is a schematic diagram of the simulation results of plate flanging based on a convex magnetic concentrator according to an embodiment of the present invention.

[0028] Explanation of the reference numerals: driving coil 1 , convex magnetic collector 2 , protrusion 201 , plate 3 , flange area 301 , mold 4 . DETAILED DESCRIPTION

[0029] In an embodiment, a convex magnetic collector is introduced between the driving coil and the forming plate to strengthen the electromagnetic force in the middle of the plate flanging area, reduce the electromagnetic force at the end of the plate flanging area, improve the buckling phenomenon of the plate during flanging, and finally make the plate flanging to an ideal angle.

[0030] like Figure 1 As shown, the plate flanging forming method based on the convex magnetic collector includes the following steps: Step 1: Determine the parameters of the drive coil according to the sheet forming specifications, select the corresponding wire material and wire diameter, and wind it into the drive coil through a winding machine; The finite element software COMSOL Multiphysics is used to build a plate flanging simulation model including a driving coil and a plate. A pulse current is applied to the driving coil in the plate flanging simulation model to simulate the flanging effect of the plate. Compared with the plate flanging forming effect, the parameters of the driving coil are adjusted to perform plate flanging simulation until the plate forming specifications are met and the parameters of the driving coil are obtained.

[0031] Step 2: According to the parameters of the driving coil and the sheet forming specifications obtained in step 1, determine the material and size parameters of the convex magnetic collector; Add a convex magnetism collector to the plate flanging simulation model, and use the plate flanging simulation model again to simulate the plate flanging. Load the drive coil with pulse current to generate electromagnetic force in the plate. Analyze the final forming effect, adjust the model parameters, compare the uniformity of the final forming effect of the plate, and obtain the optimal geometric size parameters of the convex magnetism collector and the spacing between the convex magnetism collector, the drive coil, and the plate.

[0032] Step 3: According to the parameters obtained in step 2, a convex magnetic collector is manufactured; Step 4: After annealing pretreatment of the sheet to be formed, the middle part of the sheet to be formed is fixed by a mold; Step 5: Arrange a convex magnetic collector in the opposite direction of the flanged area of ​​the plate to be formed, with the protrusion of the convex magnetic collector aligned with the middle of the flanged area of ​​the plate to be formed. Step 6: Arrange a driving coil at the bottom of the convex magnetic collector, and connect the driving coil to a pulse power supply via a switch; Step 7: Control the switch to supply power to the driving coil and control the discharge time of the pulse power supply to flanging the sheet to be formed; Step 8: Determine whether the flanging forming effect of the plate meets the flanging forming specifications of the plate. If it meets the flanging forming specifications, end; otherwise, execute step 7 to flanging the plate again until the plate forming specifications are met.

[0033] During the flanging process of the plate, the electromagnetic force F exerted on the plate satisfies the following formula:

[0034] In the formula, is the induced eddy current density in the plate, is the magnetic flux density around the plate. The direction of the electromagnetic force F satisfies Lenz's law.

[0035] like Figure 2 As shown, the plate flanging device of the embodiment includes a driving coil 1, a convex magnetic collector 2, a plate to be flanging 3, a mold 4 and a pulse power supply. The driving coil 1 is used to provide an electromagnetic field and generate an induced eddy current in the plate to be flanging; the convex magnetic collector 2 is used to improve the electromagnetic field distribution in the plate flanging area 301; the protrusion 201 is used to strengthen the magnetic field strength in the middle of the plate flanging area, such as Figure 4 As shown; the plate 3 to be flanging is selected according to the actual situation; the mold 4 is used to control the range of the plate flanging area 301, and the material can be selected according to the actual situation.

[0036] like Figure 3 As shown, the drive coil 1 is connected to the pulse power supply via an air switch. In the embodiment, the pulse power supply is a capacitor, the capacitance of the capacitor is 320μF, and the voltage of the capacitor is 4.5kV. The discharge circuit of the capacitor is composed of a diode, a freewheeling circuit resistor, a line inductor and a line resistor. First, the capacitor is charged by an external charging system, and the switch is closed after the capacitor is fully charged. The electrical energy stored in the capacitor is loaded onto the drive coil through the discharge circuit.

[0037] In the traditional electromagnetic flanging process, the reason why the flanging buckling phenomenon occurs in the plate is different from that of the pipe. Since the part of the plate closer to the mold is subject to stronger constraints, the end of the flanging part of the plate will be lifted. To improve this phenomenon, the present invention uses a convex magnetism collector to strengthen the electromagnetic force in the middle of the flanging area of ​​the plate, thereby improving the electromagnetic force distribution in the flanging area of ​​the plate. The metal plate is made of AA5083-O aluminum alloy material, the number of turns of the driving coil is 2×5, and the cross-sectional area of ​​each turn of the coil is 2mm×4mm. The outer diameter of the plate to be formed is 100mm, and the inner diameter of the driving coil is 64mm. After the convex magnetism collector is introduced, the inner diameter of the plate and the driving coil remains unchanged. The inner diameter of the convex magnetism collector is 60mm and the outer diameter is 90mm. The axes of the plate to be flanging, the driving coil and the convex magnetism collector are collinear.

[0038] The capacitor is charged by an external charging system. After the capacitor is charged, the air switch is closed to load the energy stored in the capacitor to the driving coil. In a short period of time, the driving coil will generate a strong pulse magnetic field and generate induced eddy currents in the plate. The bulge in the middle of the convex magnetic collector can reduce the distance between the magnetic collector and the middle of the plate flange area, increase the magnetic flux density in the middle of the plate flange area, and improve the electromagnetic force in the plate flange area by adjusting the magnetic flux density distribution in the plate flange area, thereby effectively solving the plate flange buckling phenomenon.

[0039] This embodiment is simulated by COMSOL Multiphysics multi-physics software, and the simulation results of the traditional plate flanging method are as follows: Figure 5 As shown, the simulation results of the plate flanging method based on the convex magnetic collector of the present invention are as follows Figure 6 As shown, Figure 5 and Figure 6 The size and direction of the arrows represent the size and direction of the electromagnetic force. Figure 5 and Figure 6 It can be seen that the buckling phenomenon in the process of plate flanging of the method of the present invention is significantly improved, the electromagnetic force is more evenly distributed in the process of plate flanging, and the plate flanging area obtained by the method of the present invention is smoother.

Claims

1. A plate flanging forming method based on a convex magnetic collector, characterized in that: The convex magnetism collector is in the shape of a ring with a gap, a protrusion is arranged on the top of the convex magnetism collector, and the cross section of the convex magnetism collector is in the shape of a convex letter. The protrusion of the convex magnetism collector is closely attached to the middle of the flanged area of ​​the plate to be formed. Under the action of the electromagnetic field of the driving coil, the convex magnetism collector improves the magnetic field distribution in the flanged area of ​​the plate, improves the flatness of the flanged area of ​​the plate after forming, and realizes uniform flanged edge of the plate. The plate flanging forming method comprises the following steps: Step 1: Determine the parameters of the drive coil according to the sheet forming specifications, select the corresponding wire material and wire diameter, and wind it into the drive coil through a winding machine; Step 2: According to the parameters of the driving coil and the sheet forming specifications obtained in step 1, determine the material and size parameters of the convex magnetic collector; Step 3: According to the parameters obtained in step 2, a convex magnetic collector is manufactured; Step 4: After annealing pretreatment of the sheet to be formed, the middle part of the sheet to be formed is fixed by a mold; Step 5: Arrange a convex magnetic collector in the opposite direction of the flanged area of ​​the plate to be formed, with the protrusion of the convex magnetic collector aligned with the middle of the flanged area of ​​the plate to be formed. Step 6: Arrange a driving coil at the bottom of the convex magnetic collector, and connect the driving coil to a pulse power supply via a switch; Step 7: Control the switch to supply power to the driving coil and control the discharge time of the pulse power supply to flanging the sheet to be formed; Step 8: Determine whether the flanging forming effect of the plate meets the flanging forming specifications of the plate. If it meets the flanging forming specifications, end; otherwise, execute step 7 to flanging the plate again until the plate forming specifications are met.

2. The plate flanging forming method according to claim 1, characterized in that: In the step 1, a plate flanging simulation model including a driving coil and a plate is constructed using finite element software, a pulse current is applied to the driving coil in the plate flanging simulation model, the flanging effect of the plate is simulated, and compared with the plate flanging forming effect, the parameters of the driving coil are adjusted to perform plate flanging simulation until the plate forming specifications are reached, and the parameters of the driving coil are obtained.

3. The plate flanging forming method according to claim 2, characterized in that: In the step 2, a convex magnet collector is added to the plate flanging simulation model, and the plate flanging simulation model is used again to perform plate flanging simulation, and the width and height of the protrusion of the convex magnet collector are repeatedly adjusted to achieve the best flatness and uniformity of the plate flanging area after the plate flanging is formed, thereby obtaining the optimal size parameters of the convex magnet collector.

4. The plate flanging forming method according to claim 1, characterized in that: The height of the protrusion of the convex magnetic collector is 0.8-1.2 mm.

5. The plate flanging forming method according to claim 1, characterized in that: The width of the protrusion of the convex magnetic collector is 5-7 mm.

6. The plate flanging forming method according to claim 1, characterized in that: The distance between the convex magnetic collector and the plate to be formed is 0.2-0.4 mm.

7. The plate flanging forming method according to claim 1, characterized in that: The distance between the convex magnetic collector and the driving coil is 0.4-0.8mm.

8. The plate flanging forming method according to claim 1, characterized in that: In step 6, the pulse power supply is a capacitor power supply, and the capacitance of the capacitor power supply is 320 , the voltage of the capacitor power supply is 4.5kV.

9. The plate flanging device of the plate flanging forming method according to any one of claims 1 to 8, characterized in that: The plate flanging device comprises a convex magnetic collector, a driving coil, a pulse power supply and a pressing die; the driving coil is connected to the pulse power supply via a switch; the pressing die is used to fix the non-flanging area of ​​the plate to be formed.

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