A lightweight alloy hollow panel and its forming device and method

Abstract

A lightweight alloy hollow plate and its forming device and method, a lightweight alloy hollow plate forming device, comprising an upper left pressing member, an upper right pressing member, a left support member, a right support member, a middle support member and a bottom support member. The left support member and the right support member are respectively provided at both ends of the upper side of the bottom support member. The middle support member is located in the middle of the upper side of the bottom support member. There is a gap between the two ends of the middle support member and the left support member and the right support member respectively. The upper left pressing member is located on the upper side of the left support member and the middle support member. The upper right pressing member is located on the upper side of the right support member and the middle support member. A welding coil is installed below the gap between the middle support member and the left support member and / or the right support member. The welding coil is electrically connected to a second discharge circuit to form a loop. One end of the upper plate member and the lower plate member are respectively electrically connected to a first discharge circuit, and the other ends are connected through a conductive structure to form a loop to realize the convenient manufacture of the lightweight alloy hollow plate.

Description

Technical Field

[0001] The present invention belongs to the field of metal forming manufacturing, and particularly relates to a lightweight alloy hollow panel and a forming device and method thereof, mainly used for the manufacturing process of lightweight alloy hollow panels. Background Art

[0002] The hollow structure is the best means to achieve structural lightweighting. At present, it has become a general trend that some parts in the fields of aerospace, automotive industry, etc. adopt aluminum alloy hollow structures. The existing manufacturing of lightweight alloy hollow structures basically uses the superplastic forming / diffusion bonding (SPF / DB) process. This process has strict requirements for the forming environment (high temperature, high pressure environment), long forming time (hour level), and poor airtightness of the device.

[0003] At present, the manufacturing process of hollow panels has obvious defects. For example, in patent CN201710546411.4, a method for improving the forming quality of SPF / DB three-layer structures realizes the forming of the hollow structure of alloy panels. However, it needs to be completed at a very low strain rate at a high temperature for an extremely long time, and the die design is extremely complex, which has become a bottleneck restricting its production and manufacturing.

[0004] At present, there are also some problems in the process of using electromagnetic forming to manufacture hollow panels. For example, in patent CN201911302452.4, a rapid forming method and forming device for hollow metal panels can realize the rapid forming of hollow panels. However, due to the required background magnetic field for forming, the requirements for current parameters are too high, the energy is large, and the energy utilization rate is not high. And the fixed coil makes the forming flexibility not high, and it is difficult to adapt to the forming of workpieces of various materials and sizes. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to solve the problems existing in the above background art, and provide a forming device for lightweight alloy hollow panels to realize the forming and connection of lightweight alloys.

[0006] Another technical problem to be solved by the present invention is: to provide a method using the above-mentioned forming device for lightweight alloy hollow panels to realize the manufacturing of lightweight alloy hollow panels.

[0007] Another technical problem to be solved by the present invention is: to provide a rapidly formed lightweight alloy hollow panel.

[0008] In order to achieve the above technical features, the object of the present invention is achieved as follows: A forming device for a lightweight alloy hollow plate member includes an upper left pressing member, an upper right pressing member, a left supporting member, a right supporting member, a middle supporting member, and a bottom supporting member. The left supporting member and the right supporting member are respectively provided at both ends of the upper side of the bottom supporting member. The middle supporting member is located in the middle of the upper side of the bottom supporting member. There is a gap between both ends of the middle supporting member and the left supporting member and the right supporting member respectively. The upper left pressing member is located above the left supporting member and the middle supporting member. The upper right pressing member is located above the right supporting member and the middle supporting member. A welding coil is installed below the gap between the middle supporting member and the left supporting member and / or the right supporting member. The welding coil is electrically connected to a second discharge circuit to form a loop. During use, the lower plate member to be processed is placed on the bottom supporting member. The left supporting member, the right supporting member, and the middle supporting member are respectively located above the upper plate member. The upper plate member to be processed is placed above the left supporting member, the right supporting member, and the middle supporting member. The upper left pressing member and the upper right pressing member are respectively located above the upper plate member. One ends of the upper plate member and the lower plate member are respectively electrically connected to a first discharge circuit, and the other ends are connected through a conductive structure to form a loop.

[0009] The conductive structure is a conductive block installed between the upper right pressing member and the bottom supporting member.

[0010] A groove is provided on one side of the conductive block. The groove can clamp and fix the ends of the upper plate member and the lower plate member and the right supporting member located between the upper plate member and the lower plate member.

[0011] Concave platforms are respectively provided on the sides of the upper right pressing member and the bottom supporting member connected to the conductive block. The upper and lower ends of the conductive block are respectively abutted and limited by the concave platforms on both sides.

[0012] Installation hole positions are provided on the bottom supporting member below the gap between the middle supporting member and the left supporting member and / or the right supporting member, and the welding coil is installed in the installation hole positions.

[0013] The first discharge circuit includes a first capacitor bank and a first switch. The first capacitor bank is connected in series with the first switch. The first capacitor bank has a freewheeling circuit with adjustable circuit parameters.

[0014] The second discharge circuit includes a second capacitor bank and a second switch. The second capacitor bank is connected in series with the second switch. The second capacitor bank has a freewheeling circuit with adjustable circuit parameters; the welding coil is connected in series or in parallel with the second discharge circuit.

[0015] A method using the above-mentioned forming device for a lightweight alloy hollow plate member includes the following steps:

[0016] S1. Anneal and pre-treat and surface polish the upper plate member and the lower plate member, place them at the corresponding positions of the device, and electrically connect the upper plate member and the lower plate member to the first discharge circuit;

[0017] S2: Place the two welding coils inside the mounting hole positions of the bottom support member respectively, and connect the welding coils in series or in parallel with the second discharge circuit.

[0018] S3: Apply a crimping force to the upper left pressing member and the upper right pressing member by using a crimping device to fix the whole forming device.

[0019] S4: Charge the capacitor banks of the first discharge circuit and the second discharge circuit through a charging system, and store electrical energy in the capacitor banks. First, close the first discharge circuit to allow a pulsed current to flow through the upper plate member and the lower plate member, generating a pulsed magnetic field around the plate members, thereby generating an electromagnetic force to cause the upper plate member to deform upward at the part located between the upper left pressing member and the upper right pressing member.

[0020] S5: After the deformation of the upper plate member is completed, close the second discharge circuit to allow a pulsed current to flow through the welding coils, thereby generating a pulsed strong magnetic field, and further generating an induced eddy current in the lower plate member. Under the combined action of the magnetic field and the eddy current, the lower plate member is subjected to the Lorentz force and is constrained by the left support member, the right support member, and the middle support member, and the lower plate member at the intervals between the left support member and the middle support member and between the right support member and the middle support member collides with the upper plate member to achieve welding.

[0021] In S3, the pressure of the crimping device is set to 1 - 1.5 Mpa.

[0022] A lightweight alloy hollow plate member is prepared by using the method of the lightweight alloy hollow plate member forming device described above.

[0023] The present invention has the following beneficial effects:

[0024] 1. The present invention uses electromagnetic forming to realize the forming of the upper plate member in the manufacturing of hollow plate members. The forming environment requirements are low (room temperature, general atmospheric pressure environment is sufficient), the forming speed is fast (millisecond level), the airtightness requirement for the mold is not high, and the electromagnetic force can be flexibly adjusted according to the shape of the required hollow plate member through circuit parameters and other means for the force field, etc.

[0025] 2. The present invention realizes the integral forming of hollow plate members. After the upper plate member is formed, a pulsed current is passed through the welding coils to realize the welding of the upper and lower plate members. The process is simple and easy to operate, and both the forming and welding times are in the millisecond level. The welding quality can also be improved through circuit parameter adjustment.

[0026] 3. The present invention improves the economy of the electromagnetic forming device for hollow plate members. In the existing electromagnetic forming of hollow plate members, the winding process of the forming coil is very cumbersome, the energy of the forming power supply is large, and the service life of the forming coil is short. The present invention does not require a coil in the forming stage and requires less energy. The welding coil in the welding stage is simple and easy to manufacture, greatly improving the economy of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic three-dimensional structure diagram of the forming device of the present invention.

[0028] Figure 2 This is a circuit diagram of the rapid forming method for lightweight alloy hollow plate parts of the present invention.

[0029] Figure 3 This is a schematic diagram of current loading in the rapid forming method for lightweight alloy hollow plate parts of the present invention.

[0030] Figure 4 This is a configuration diagram of current and magnetic field during the forming process of the upper plate part.

[0031] Figure 5 This is a configuration diagram of current and magnetic field during the welding process of the lower plate part.

[0032] Figure 6 This is a schematic diagram of electromagnetic force simulation during the forming process of the upper plate part.

[0033] Figure 7 This is a schematic diagram of electromagnetic force simulation during the welding process of the lower plate part.

[0034] Figure 8 This is a schematic diagram of the simulation results of the rapid forming of lightweight alloy hollow plate parts of the present invention.

[0035] In the figure: upper left pressing part 1, upper right pressing part 2, upper plate part 3, left support part 4, right support part 5, conductive block 6, middle support part 7, lower plate part 8, welding coil 9, bottom support part 10, first discharge circuit 12, first capacitor bank 13, first switch 14, second discharge circuit 15, second capacitor bank 16, second switch 17. DETAILED DESCRIPTION OF THE INVENTION

[0036] The following further describes the embodiments of the present invention with reference to the accompanying drawings.

[0037] Embodiment 1:

[0038] Refer to Figure 1-8, A forming device for a lightweight alloy hollow plate member, comprising an upper left pressing member 1, an upper right pressing member 2, a left support member 4, a right support member 5, a middle support member 7 and a bottom support member 10. At both ends of the upper side of the bottom support member 10, the left support member 4 and the right support member 5 are respectively provided. The middle support member 7 is located in the middle of the upper side of the bottom support member 10. There is a gap between the two ends of the middle support member 7 and the left support member 4 and the right support member 5 respectively. The upper left pressing member 1 is located above the left support member 4 and the middle support member 7, and the upper right pressing member 2 is located above the right support member 5 and the middle support member 7. A welding coil 9 is installed below the gap between the middle support member 7 and the left support member 4 and / or the right support member 5. The welding coil 9 is electrically connected to a second discharge circuit 15 to form a loop. During use, the lower plate member 8 to be processed is placed on the bottom support member 10, and the left support member 4, the right support member 5 and the middle support member 7 are respectively located above the upper plate member 3. The upper plate member 3 to be processed is placed above the left support member 4, the right support member 5 and the middle support member 7. The upper left pressing member 1 and the upper right pressing member 2 are respectively located above the upper plate member 3. One end of the upper plate member 3 and the lower plate member 8 is electrically connected to a first discharge circuit 12 respectively, and the other end is connected through a conductive structure to form a loop.

[0039] The upper left pressing member 1 and the upper right pressing member 2 realize the overall edge pressing of the device, and the left support member 4, the right support member 5 and the middle support member 7 realize the edge pressing during welding. The first discharge circuit 12 passes current into the upper plate member 3 and the lower plate member 8. The upper plate member 3 and the lower plate member 8 are connected through a conductive structure to generate a Lorentz force, driving the upper plate member 3 to deform. At the same time, the lower plate member 8 is fixed by the bottom support member 10 so that it does not deform. After the deformation of the upper plate member 3 is completed, a pulsed current is passed into the welding coil 9 by the second discharge circuit 15, so that the lower plate member 8 is subjected to the Lorentz force and collides with the upper plate member 3 at high speed under the restraint of the left support member 4, the right support member 5 and the middle support member 7 to realize welding.

[0040] It should be noted that the upper left pressing member 1, the upper right pressing member 2, the left support member 4, the right support member 5, the middle support member 7 and the bottom support member 10 are all insulators.

[0041] See Figure 1 , The conductive structure is a conductive block 6 installed between the upper right pressing member 2 and the bottom support member 10. The setting of the conductive block 6 enables the upper plate member 3 and the lower plate member 8 to be connected to form a loop. When the conductive block 6 is not provided, a loop can be formed through cable connection. Of course, the right support member 5 can also be replaced with a conductive material. The conductive block 6 is preferably made of copper.

[0042] Furthermore, a groove is provided on one side of the conductive block 6, and the groove can clamp and fix the ends of the upper plate member 3 and the lower plate member 8 and the right support member 5 located between the upper plate member 3 and the lower plate member 8. The structure is simple and the fixation is stable.

[0043] Furthermore, on one side of the upper right pressing member 2 and the bottom support member 10 connected to the conductive block 6, there are respectively concave platforms. The upper and lower ends of the conductive block 6 are respectively abutted and limited with the concave platforms on both sides, and the structure is more stable.

[0044] See Figure 1 、 2 , on the bottom support member 10, there is an installation hole position below the intervals between the middle support member 7, the left support member 4 and the right support member 5, and the welding coil 9 is installed in the installation hole position, and the installation is simple. The welding coils 9 can be installed in the installation hole positions below the intervals on both sides, or one side can be selected for installation according to the forming requirements.

[0045] See Figure 2 , the first discharge circuit 12 includes a first capacitor bank 13 and a first switch 14. The first capacitor bank 13 is connected in series with the first switch 14, and the first capacitor bank 13 is provided with a freewheeling circuit for adjusting circuit parameters. By adjusting the circuit parameters of the first capacitor bank 13 with the freewheeling circuit, the deformation of the upper plate member 3 is regulated.

[0046] The second discharge circuit 15 includes a second capacitor bank 16 and a second switch 17. The second capacitor bank 16 is connected in series with the second switch 17, and the second capacitor bank 16 is provided with a freewheeling circuit for adjusting circuit parameters; the welding coil 9 is connected in series or in parallel with the second discharge circuit 15. By adjusting the circuit parameters of the second capacitor bank 16 with the freewheeling circuit, the deformation speed and collision angle of the lower plate member 8 are regulated, so as to achieve reliable welding.

[0047] Embodiment 2:

[0048] A method using the above-mentioned lightweight alloy hollow plate forming device includes the following steps:

[0049] S1. Anneal and pre-treat and surface polish the upper plate member 3 and the lower plate member 8, place them at the corresponding positions of the device, and electrically connect the upper plate member 3 and the lower plate member 8 to the first discharge circuit 12. See Figure 1 、 2 .

[0050] S2: Place the two welding coils 9 respectively inside the installation hole positions of the bottom support member 10, and connect the welding coils 9 in series or in parallel with the second discharge circuit 15. See Figure 2 .

[0051] S3: Apply a blank holding force on the upper left pressing member 1 and the upper right pressing member 2 by using a blank holding device to fix the whole forming device.

[0052] S4: Charge the capacitor banks of the first discharge circuit 12 and the second discharge circuit 15 through the charging system, and store electrical energy in the capacitor banks. First, close the first switch 14 of the first discharge circuit 12, so that a pulsed high current as shown from 0 to t1 in Figure 3 flows through the upper plate member 3 and the lower plate member 8, generating a strong pulsed magnetic field around the plate members. The configuration diagram of the current and the magnetic field is as shown in Figure 4 , thus generating a strong electromagnetic force as shown in Figure 6 , causing the upper plate member 3 to deform upward at the part between the upper left pressing member 1 and the upper right pressing member 2.

[0053] S5: After the deformation of the upper plate member 3 is completed, close the second switch 17 of the second discharge circuit 15, and pass a pulsed current as shown from 0 to t2 in Figure 3 through the welding coil 9, thereby generating a pulsed strong magnetic field, and then generating an induced eddy current in the lower plate member 8. The configuration diagram of the eddy current and the magnetic field is as shown in Figure 5 . Under the combined action of the magnetic field and the eddy current, the lower plate member 8 is subjected to a Lorentz force as shown in Figure 7 . Constrained by the left support member 4, the right support member 5, and the middle support member 7, the lower plate member 8 at the intervals between the left support member 4 and the middle support member 7, and the right support member 5 and the middle support member 7 collides with the upper plate member 3 at high speed to achieve welding. Finally, the forming effect of the hollow plate member is as shown in Figure 8 .

[0054] In S3, the pressure of the blank holding device is set to 1 - 1.5 Mpa.

[0055] During the forming process of the hollow plate member, the magnitude and direction of the electromagnetic force satisfy:

[0056] F = J × B

[0057] where F is the Lorentz force, J is the current density on the workpiece, and B is the magnetic flux density.

[0058] In this embodiment, the multi - physical field software Ls - dyna is used for numerical analysis, and the simulation results are as shown in Figure 6 ~8. Through numerical simulation analysis, it is proved that this scheme is feasible and can achieve the forming of lightweight alloy hollow plate members.

[0059] The present invention brings great convenience to the manufacturing of lightweight alloy hollow plate members. The existing manufacturing of lightweight alloy hollow structures basically adopts the superplastic forming / diffusion bonding (SPF / DB) process. This process has strict requirements for the forming environment (high - temperature, high - pressure environment), a long forming time (hour - level), and poor airtightness of the device. The present invention has low requirements for the forming environment (room temperature, general atmospheric pressure environment is sufficient), a short forming time (millisecond - level), and low requirements for the airtightness of the device and the mold.

[0060] Example 3:

[0061] A lightweight alloy hollow panel is prepared by using the method of the forming device for the lightweight alloy hollow panel described above.

[0062] The present invention brings great convenience to the manufacture of lightweight alloy hollow panels. The existing manufacture of lightweight alloy hollow structures basically adopts the superplastic forming / diffusion bonding (SPF / DB) process. This process has strict requirements for the forming environment (high temperature, high pressure environment), long forming time (hour level), and poor airtightness of the device. The present invention has low requirements for the forming environment (room temperature, general atmospheric pressure environment is sufficient), short forming time (millisecond level), and low requirements for the airtightness of the device and the mold.

Claims

1. A forming device for a lightweight alloy hollow panel, characterized in that: It includes an upper left pressing member (1), an upper right pressing member (2), a left supporting member (4), a right supporting member (5), a middle supporting member (7) and a bottom supporting member (10). At both ends of the upper side of the bottom supporting member (10), the left supporting member (4) and the right supporting member (5) are respectively provided. The middle supporting member (7) is located in the middle of the upper side of the bottom supporting member (10). There is a gap between both ends of the middle supporting member (7) and the left supporting member (4) and the right supporting member (5) respectively. The upper left pressing member (1) is located on the upper sides of the left supporting member (4) and the middle supporting member (7). The upper right pressing member (2) is located on the upper sides of the right supporting member (5) and the middle supporting member (7). A welding coil (9) is installed below the gap between the middle supporting member (7) and the left supporting member (4) and / or the right supporting member (5). The welding coil (9) is electrically connected to a second discharge circuit (15) to form a loop. During use, a lower plate member (8) for processing is placed on the bottom supporting member (10). The left supporting member (4), the right supporting member (5) and the middle supporting member (7) are respectively located on the upper side of an upper plate member (3). The upper plate member (3) for processing is placed on the upper sides of the left supporting member (4), the right supporting member (5) and the middle supporting member (7). The upper left pressing member (1) and the upper right pressing member (2) are respectively located on the upper side of the upper plate member (3). One ends of the upper plate member (3) and the lower plate member (8) are respectively electrically connected to a first discharge circuit (12), and the other ends are connected through a conductive structure to form a loop.

2. The forming device for a lightweight alloy hollow panel according to claim 1, characterized in that: The conductive structure is a conductive block (6) installed between the upper right pressing member (2) and the bottom supporting member (10).

3. A forming device for a lightweight alloy hollow panel according to claim 2, characterized in that: One side of the conductive block (6) is provided with a groove, and the groove can clamp and fix the ends of the upper plate member (3) and the lower plate member (8) and the right supporting member (5) located between the upper plate member (3) and the lower plate member (8).

4. The forming device for a lightweight alloy hollow panel according to claim 3, characterized in that: On the sides of the upper right pressing member (2) and the bottom supporting member (10) connected to the conductive block (6), bosses are respectively provided. The upper and lower ends of the conductive block (6) are respectively abutted and limited with the bosses on both sides.

5. A forming device for a lightweight alloy hollow panel according to claim 1, characterized in that: On the bottom supporting member (10), installation holes are provided below the gap between the middle supporting member (7) and the left supporting member (4) and / or the right supporting member (5), and the welding coil (9) is installed in the installation holes.

6. The forming device for a lightweight alloy hollow panel according to claim 1, wherein: The first discharge circuit (12) includes a first capacitor bank (13) and a first switch (14). The first capacitor bank (13) is connected in series with the first switch (14), and the first capacitor bank (13) is provided with a freewheeling circuit for adjusting circuit parameters.

7. A forming device for a lightweight alloy hollow panel according to claim 1, characterized in that: The second discharge circuit (15) includes a second capacitor bank (16) and a second switch (17). The second capacitor bank (16) is connected in series with the second switch (17), and the second capacitor bank (16) is provided with a freewheeling circuit for adjusting circuit parameters; the welding coil (9) is connected in series or in parallel with the second discharge circuit (15).

8. A method using the forming device for a lightweight alloy hollow panel member according to any one of claims 1-7, characterized in that, It includes the following steps: S1. Anneal and preprocess and surface polish the upper plate member (3) and the lower plate member (8), place them at the corresponding positions of the device, and electrically connect the upper plate member (3) and the lower plate member (8) to the first discharge circuit (12); S2: Place the two welding coils (9) respectively inside the mounting hole positions of the bottom support (10), and connect the welding coils (9) in series or in parallel with the second discharge circuit (15); S3: Apply a hemming force to the upper left pressing part (1) and the upper right pressing part (2) by using a hemming device to fix the whole forming device; S4: Charge the capacitor banks of the first discharge circuit (12) and the second discharge circuit (15) through a charging system, and store electrical energy in the capacitor banks; First, close the first discharge circuit (12) to allow a pulsed current to flow through the upper plate (3) and the lower plate (8), generating a pulsed magnetic field around the plates, thereby generating an electromagnetic force that causes the upper plate (3) to deform upward at the part between the upper left pressing part (1) and the upper right pressing part (2); S5: After the deformation of the upper plate (3) is completed, close the second discharge circuit (15) to allow a pulsed current to flow through the welding coils (9), thereby generating a pulsed strong magnetic field, and then inducing eddy currents in the lower plate (8). Under the combined action of the magnetic field and the eddy currents, the lower plate (8) is subjected to the Lorentz force and is constrained by the left support (4), the right support (5) and the middle support (7), and the lower plate (8) at the intervals between the left support (4) and the middle support (7), and the right support (5) and the middle support (7) collides with the upper plate (3) to achieve welding.

9. The method of a forming device for a lightweight alloy hollow panel according to claim 8, characterized in that: In S3, the pressure of the hemming device is set to 1 - 1.5 Mpa.

10. A lightweight alloy hollow panel, characterized in that, Prepared by using the method of a lightweight alloy hollow plate forming device described in claim 8.

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