Electromagnetic forming device and method for part drawing process
By using electromagnetic forming equipment and methods, the stress state in the deep drawing process of parts was optimized, the problem of cracking caused by uneven material wall thickness was solved, and high-precision forming and small fillet forming of parts were achieved.
Patent Information
- Application Number
- CN202510790894.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-13
- Publication Date
- 2025-11-11
AI Technical Summary
In traditional deep drawing processes, uneven material wall thickness distribution often leads to tensile cracking defects occurring at the points of greatest wall thickness variation. The root cause of workpiece breakage is damage caused by excessive tensile stress on the sidewalls of the deep-drawn part.
An electromagnetic forming device is used, which provides electromagnetic force to drive the high-speed movement of the punch through radial side push coils and axial drawing coils. Combined with upper and lower induction coils, the circumferential compressive stress in the flange area is reduced. Small fillet forming is achieved by using expansion coils, and the stress state is optimized to reduce the tensile stress value.
It improved the forming height and manufacturing precision of parts, suppressed material wrinkling defects, achieved the forming of small rounded corners, and improved the forming performance of parts.
Smart Images
Figure CN120920596A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of materials processing and forming technology, and in particular relates to an electromagnetic forming apparatus and method for deep drawing processes of parts. Background Technology
[0002] In traditional deep drawing processes, the workpiece wall thickness is unevenly distributed, and tensile cracking defects often occur at the points of greatest wall thickness variation. The root cause of workpiece fracture is excessive tensile stress on the load-bearing areas of the drawn part's sidewalls, leading to damage. Summary of the Invention
[0003] Purpose of the invention: In traditional deep drawing processes, due to uneven material wall thickness distribution, tensile cracking defects often occur at the points of greatest wall thickness variation. The root cause of workpiece breakage is excessive tensile stress on the load-bearing area of the side wall of the deep-drawn part, leading to failure. To increase the drawing depth, it is necessary to change the stress state of the load-bearing area of the side wall and reduce the tensile stress value, which requires reducing the drawing resistance at the flange location. In a first aspect, this application provides an electromagnetic forming apparatus for a deep drawing process of parts, the apparatus comprising: punch; A concave die, which matches the convex die; Radial thrust coils are used to provide radial thrust to the sheet metal; An axial drawing coil is used to provide axial thrust to the punch, which extrudes the sheet metal. The lower and upper induction coils are used to reduce the circumferential compressive stress in the flange area of the sheet metal; The radial push coil, the axial drawing coil, the lower induction coil, and the upper induction coil are connected in series.
[0004] Preferably, the device further includes: An expansion coil is disposed at the rounded corner of the punch, and the expansion coil can achieve the forming of parts with small rounded corner radii.
[0005] Preferably, the device further includes: A drive plate is disposed between the axial drawing coil and the punch.
[0006] Preferably, the drive plate is connected to the punch, and the drive plate is made of copper.
[0007] Preferably, the device further includes: A pressure ring is used to press the sheet metal onto the die.
[0008] Preferably, the lower induction coil is installed on the pressure ring, the radial push coil is installed on the pressure ring, and the installation position of the radial push coil corresponds to the end of the sheet material.
[0009] Preferably, the upper induction coil is mounted on the concave mold, and the mounting position of the upper induction coil corresponds to the mounting position of the lower induction coil.
[0010] Secondly, this application also provides an electromagnetic forming method for a deep drawing process of parts, the method comprising: S1: The sheet metal is clamped by a pressure ring and a die and placed on the upper part of the punch; S2: The axial drawing coil and the radial side push coil discharge simultaneously, the punch moves upward at high speed and draws the sheet metal, and the material flow in the flange area is increased under the action of radial side push. S3: Use lower and upper induction coils to reduce circumferential compressive stress in the flange area of the sheet metal; S4: Based on the deformation results of the sheet metal in S2, adjust the position of the radial side push coil to be close to the outer edge of the sheet metal after deformation in the previous step, thereby increasing the magnitude of the radial side push electromagnetic force. Then, energize the axial drawing coil to perform the second step of drawing and forming of the sheet metal.
[0011] Preferably, the method further includes: S5: Energize the expanding coil to form parts with small fillet radii.
[0012] The beneficial effects of this application are as follows: (1) Electromagnetic force is used to drive the rigid punch to move at high speed, and radial electromagnetic force is used to improve the forming height of the part; (2) The material in the flange area can flow significantly under the action of radial electromagnetic force. The use of upper and lower induction coils to reduce the circumferential compressive stress of the material in the flange area can suppress the wrinkling defects of the material during subsequent deformation. (3) By setting an expansion coil at the fillet of the punch, the lower fillet of the part can be formed. In the end, while increasing the forming height of the part, the manufacturing accuracy of the part is improved and small fillet deformation is achieved. Attached Figure Description
[0013] Figure 1 A schematic diagram of the electromagnetic-assisted forming device for large fillet deep-drawing parts provided in this application embodiment; Figure 2 A schematic diagram of the electromagnetic-assisted forming method for large-corner deep-drawn parts provided in this application embodiment. Figure 1 ; Figure 3 A schematic diagram of the electromagnetic-assisted forming method for large-corner deep-drawn parts provided in this application embodiment. Figure 2 ; Figure 4 is a schematic diagram of the electromagnetic-assisted forming method for large-corner deep-drawn parts provided in the embodiments of this application. Figure 3 ; Figure 5 This is a schematic diagram of the electromagnetic-assisted forming device for small-rounded corner deep-drawing parts provided in the embodiments of this application; Figure 6 A schematic diagram of the electromagnetic-assisted forming method for small-corner deep-drawn parts provided in this application embodiment. Figure 1 ; Figure 7 A schematic diagram of the electromagnetic-assisted forming method for small-corner deep-drawn parts provided in this application embodiment. Figure 2 ; Figure 8 A schematic diagram of the electromagnetic-assisted forming method for small-corner deep-drawn parts provided in this application embodiment. Figure 3 ; Figure 9 A schematic diagram of the electromagnetic-assisted forming method for small-corner deep-drawn parts provided in this application embodiment. Figure 4 ; Figure 10 This is a schematic diagram of the electromagnetic assisted forming device for difficult-to-form sheet metal in a cryogenic environment, provided in an embodiment of this application. Figure 11 A schematic diagram of an electromagnetically assisted forming method for difficult-to-form sheet metal under cryogenic conditions, provided in an embodiment of this application. Figure 1 ; Figure 12 A schematic diagram of an electromagnetically assisted forming method for difficult-to-form sheet metal under cryogenic conditions, provided in an embodiment of this application. Figure 2 ; Figure 13 This is a schematic diagram of the electromagnetic hydraulic forming apparatus provided in the embodiments of this application; Figure 14 A schematic diagram of the electromagnetic hydraulic forming method provided in the embodiments of this application. Figure 1 ; Figure 15 is a schematic diagram of the electromagnetic hydraulic forming method provided in the embodiments of this application. Figure 2 ; The components are: 1. Axial drawing coil skeleton; 2. Axial drawing coil; 3. High conductivity drive plate; 4. Punch; 5. Lower induction coil; 6. Pressure ring; 7. Radial side push coil; 8. Die; 9. Upper induction coil; 10. Sheet metal; 11. Bulging coil; 12. Liquid nitrogen; 13. Water. Detailed Implementation
[0014] It should be noted that in order to increase the drawing depth of the material, the stress state of the force transmission zone of the side wall needs to be changed and the tensile stress value needs to be reduced. This requires reducing the drawing resistance of the flange. There are two ways to reduce the drawing resistance of the flange: (1) reduce the flange blank holder force, but this will cause the part to wrinkle; (2) apply radial lateral thrust to the flange edge.
[0015] The present application will be described in further detail below with reference to the accompanying drawings.
[0016] Example 1: like Figure 1 , Figure 2 , Figure 3 , Figure 4 This invention relates to the structure and one application method of the present invention. By utilizing the combined action of a radial push coil and upper and lower induction coils, the drawing height of the part is increased. The specific steps are as follows: S1: The sheet metal 10 is clamped by the pressure ring 6 and the die 8 and placed on the upper part of the punch 4; S2: The axial drawing coil 2 and the radial side push coil 7 discharge simultaneously, the punch 4 moves upward at high speed and draws the sheet metal, and the material flow in the flange area is increased under the action of radial side push. S3: The lower induction coil 5 and the upper induction coil 9 are used to reduce the circumferential compressive stress in the flange area of the sheet metal; S4: Based on the deformation results of the sheet metal in S2, adjust the radial lateral push coil structure. The new lateral push coil is close to the outer edge of the sheet metal after the previous deformation, thereby increasing the magnitude of the radial lateral push electromagnetic force. Then, energize the axial drawing coil to perform the second-step drawing forming of the sheet metal.
[0017] Example 2: Figures 5 to 9 This invention relates to the structure and a usage scheme of the present invention. The combined action of radial side-pushing coils and upper and lower induction coils increases the drawing height of the part; the use of local rounded corner coils achieves the forming of small rounded corner areas, improving the local forming limit of the material. The specific steps are as follows: S1: The sheet metal 10 is clamped by the pressure ring 6 and the die 8 and placed on the upper part of the punch 4; S2: The axial drawing coil 2 and the radial side push coil 7 discharge simultaneously, the punch 4 moves upward at high speed and draws the sheet metal, and the material flow in the flange area is increased under the action of radial side push. S3: The lower induction coil 5 and the upper induction coil 9 are used to reduce the circumferential compressive stress in the flange area of the sheet metal; S4: Based on the deformation results of the sheet metal in S3, adjust the radial side-pushing coil structure. The new side-pushing coil is close to the outer edge of the sheet metal after the previous deformation, thereby increasing the magnitude of the radial side-pushing electromagnetic force. The axial drawing coil 2 and the newly manufactured radial side-pushing coil discharge simultaneously, further increasing the drawing height of the part and realizing the second-step drawing forming of the sheet metal; S5: Energize the expansion coil 11 to form parts with small fillet radii.
[0018] Example 3: Figures 10 to 12This invention relates to the structure and a usage scheme of the present invention. By utilizing the combined action of radial side-pushing coils and upper and lower induction coils, the drawing height of the part is increased. Simultaneously, a liquid nitrogen cooling device 12 is added to refine the grains of the material at low temperatures, thereby improving the sheet metal forming performance. The specific steps are as follows: S1: The sheet metal 10 is clamped by the pressure ring 6 and the die 8 and placed on the upper part of the punch 4; S2: Turn on the liquid nitrogen cooling device 12 switch to introduce liquid nitrogen into the die to cool the sheet metal; S3: The axial drawing coil 2 and the radial side push coil 7 discharge simultaneously, the punch 4 moves upward at high speed and draws the sheet metal, and the material flow in the flange area is increased under the action of the radial side push. S4: The lower induction coil 5 and the upper induction coil 9 are used to reduce the circumferential compressive stress in the flange area of the sheet metal; S5: Then energize the axial drawing coil to perform the second drawing process on the sheet metal.
[0019] Example 4: Figures 13 to 15 This invention relates to the structure and a usage scheme of the present invention. By utilizing the combined action of a radial side-pushing coil and upper and lower induction coils, the drawing height of the part is increased. Simultaneously, the electromagnetic force is transmitted using liquid 13. This scheme facilitates uniform thickness distribution of the sheet metal and improves the forming accuracy of the part. The specific steps are as follows: S1: The sheet metal 10 is clamped by the pressure ring 6 and the die 8 and placed on the upper part of the punch 4; S2: The axial drawing coil 2 and the radial side thrust coil 7 discharge simultaneously, which increases the material flow in the flange area under the action of radial side thrust. S3: The lower induction coil 5 and the upper induction coil 9 are used to reduce the circumferential compressive stress in the flange area of the sheet metal; S4: Then energize the axial drawing coil, and the liquid 13 moves upward at high speed to draw the sheet metal.
Claims
1. An electromagnetic forming apparatus for deep drawing processes of parts, characterized in that, The device includes: punch; A concave die, which matches the convex die; Radial thrust coils are used to provide radial thrust to the sheet metal; An axial drawing coil is used to provide axial thrust to the punch, which extrudes the sheet metal. The lower and upper induction coils are used to reduce the circumferential compressive stress in the flange area of the sheet metal; The radial push coil, the axial drawing coil, the lower induction coil, and the upper induction coil are connected in series.
2. The apparatus as claimed in claim 1, characterized in that, The device further includes: An expansion coil is disposed at the rounded corner of the punch, and the expansion coil can achieve the forming of parts with small rounded corner radii.
3. The apparatus as described in claim 1, characterized in that, The device further includes: A drive plate is disposed between the axial drawing coil and the punch.
4. The apparatus as described in claim 3, characterized in that, The drive plate is connected to the punch, and the drive plate is made of copper.
5. The apparatus as claimed in claim 1, characterized in that, The device further includes: A pressure ring is used to press the sheet metal onto the die.
6. The apparatus as claimed in claim 5, characterized in that, The lower induction coil is installed on the pressure ring, and the radial push coil is installed on the pressure ring. The installation position of the radial push coil corresponds to the end of the sheet material.
7. The apparatus as claimed in claim 6, characterized in that, The upper induction coil is installed on the concave mold, and the installation position of the upper induction coil corresponds to the installation position of the lower induction coil.
8. An electromagnetic forming method for deep drawing processes of parts, characterized in that, The method includes: S1: The sheet metal is clamped by a pressure ring and a die and placed on the upper part of the punch; S2: The axial drawing coil and the radial side push coil discharge simultaneously, the punch moves upward at high speed and draws the sheet metal, and the material flow in the flange area is increased under the action of radial side push. S3: Use lower and upper induction coils to reduce circumferential compressive stress in the flange area of the sheet metal; S4: Based on the deformation results of the sheet metal in S2, adjust the position of the radial side push coil to be close to the outer edge of the sheet metal after deformation in the previous step, thereby increasing the magnitude of the radial side push electromagnetic force. Then, energize the axial drawing coil to perform the second step of drawing and forming of the sheet metal.
9. The method according to claim 8, characterized in that, The method further includes: S5: Energize the expanding coil to form parts with small fillet radii.