Rib plate electric auxiliary forming tool and process for current partition customization

Abstract

The invention discloses a rib plate electric auxiliary forming tool for current partition customization. The rib plate electric auxiliary forming tool comprises integrated clamping electrode assemblies arranged on the two sides of a wall plate correspondingly and edge pressing electrode assemblies arranged on the two sides of the wall plate correspondingly. Each integrated clamping electrode assembly comprises a wall plate electrode clamp which is clamped on the edge of the wall plate and a transverse rib electrode clamp which is clamped at the end part of the transverse rib and is insulated from the wall plate electrode clamp; the wall plate electrode clamp or the transverse rib electrode clamp in at least one integrated clamping electrode assembly is independently electrified or the wall plate electrode clamp and the transverse rib electrode clamp are simultaneously electrified; the edge pressing electrode assembly comprises an edge pressing block placed on the edge of the top face of the wall plate and longitudinal bar electrode clamps clamped at the ends of the longitudinal bars and insulated from the edge pressing block, and at least one of the edge pressing block and the longitudinal bar electrode clamps is powered on. According to the invention, plate-rib separation integrated clamping and plate-rib double-region separation / synchronous current introduction are realized through the clamp, active control of current distribution, trend and action range is realized, and energy field'partition customization 'and overall near-uniform forming of complex components are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal extrusion assisted forming, and particularly relates to an electro-assisted forming tooling and process for ribbed plate parts with customized current zoning. Background Art

[0002] At present, the forming and manufacturing of aluminum alloy integral panels in the aerospace field mostly adopt mature process methods such as chemical milling grid composite bending, roll bending, stretch bending or shot peening; with the continuous development of high-end equipment manufacturing technology, process methods such as creep age forming, electromagnetic incremental forming, and multi-stage integral progressive aging composite forming have also been applied to the forming and manufacturing of aluminum alloy integral panels, especially large integral ribbed panels of high-strength aluminum alloy. However, since most high-temperature titanium alloys are non-age hardening alloys, with relatively high processing temperatures, narrow processing windows, and large springback after deformation, using conventional cold deformation or warm deformation methods to form their grid rib integral panel parts requires a relatively high equipment tonnage, and forming defects such as cracking at the root of the rib and instability deformation at the upper end of the rib are likely to occur during the forming process, and it is difficult to ensure the final forming dimensional accuracy.

[0003] On the one hand, electro-pulse assisted forming can utilize the electroplastic effect to significantly reduce the forming load and improve the bending forming limit of materials, effectively avoiding the problem of cracking at the root of the rib during the forming process; on the other hand, it can quickly provide thermal deformation conditions by using the Joule heat rise generated by the self-resistance of the material to make up for the heat loss during the deformation process. Compared with resistance furnace heating, it is expected to significantly improve the heating speed, reduce energy consumption and tooling costs. Using electro-pulse assisted forming technology is expected to form high-temperature titanium alloy panels with higher structural strength. However, in the current process of electro-assisted forming of titanium alloy panels, the current loading mainly uses conductive electrodes to apply uniform current to the rib / plate, and the current spatial distribution is only concentrated on the total rib / plate. The current conduction methods and current parameters of different ribs are the same, and the current distribution cannot be actively regulated. However, during the forming process of multi-curvature panels, due to the uneven geometric distribution of the components and the intermittent local loading of the die and the panel, the deformation of different regions is uneven. The single current parameter results in the same electro-thermal history in different deformation regions, which cannot meet the precise matching of electro-thermal-force parameters in the local loading region, further increasing the difficulty of deformation coordination in each deformation region and easily leading to cracking at the root of the rib and instability of the rib in the transition region. Therefore, by customizing the current loading method and current process parameters in different deformation regions to match the deformation characteristics of the local loading region of the panel is an effective way to achieve high-precision forming of multi-curvature panels. Summary of the Invention

[0004] To solve the deficiencies existing in the prior art, the present invention provides an electro-assisted forming tooling and process for ribbed plate parts with customized current zoning. While the electrodes realize the integrated clamping of the plate and rib by separation through a fixture, the current is separated / simultaneously introduced into the double regions of the plate and rib through circuit design, realizing the active control of current distribution, direction and action scope, and achieving the "zoning customization" of the energy field and the overall near-uniform forming of complex components.

[0005] To solve the above technical problems, a technical solution adopted by the present invention is as follows: An electro-assisted forming tooling for a ribbed plate part with customized current zoning is used to assist in the stamping and bending forming of an integral panel with grid ribs. The integral panel with grid ribs is integrally composed of a panel and a plurality of transverse ribs and a plurality of longitudinal ribs that crisscross above the panel, and includes an integrated clamping electrode assembly respectively arranged on the left and right sides of the panel, and a blank-holder electrode assembly respectively arranged on the front and back sides of the panel; Each integrated clamping electrode assembly includes a panel electrode clamp clamped on the edge of the panel, a transverse rib electrode clamp clamped on the end of the transverse rib and insulated from the panel electrode clamp. The panel electrode clamp and the transverse rib electrode clamp on the same side are connected to the same-sex electrode terminal, and the panel electrode clamp and the transverse rib electrode clamp on the other same side are connected to an opposite-sex electrode terminal through a transverse rib switch assembly. The transverse rib switch assembly controls the independent energization of the panel electrode clamp or the transverse rib electrode clamp in at least one integrated clamping electrode assembly or the simultaneous energization of the panel electrode clamp and the transverse rib electrode clamp; The blank-holder electrode assembly includes a blank-holder block placed on the top edge of the panel, a longitudinal rib electrode clamp clamped on the end of the longitudinal rib and insulated from the blank-holder block. The blank-holder block and the longitudinal rib electrode clamp on the same side are connected to the same-sex electrode terminal, and the blank-holder block and the longitudinal rib electrode clamp on the other same side are connected to an opposite-sex electrode terminal through a longitudinal rib switch assembly. The longitudinal rib switch assembly enables at least one of the blank-holder block and each longitudinal rib electrode clamp to be energized.

[0006] Further, the panel electrode clamp includes a connecting block, a fixed chuck fixedly arranged on one side of the top of the connecting block, and a movable chuck rotatably arranged at the bottom of the connecting block and located below the fixed chuck. A fixed insulating handle is fixedly arranged on the other side of the top of the connecting block, and a movable insulating handle fixedly connected to the end of the movable chuck is arranged below the fixed insulating handle. At least one first return spring is connected between the movable insulating handle and the fixed insulating handle.

[0007] Further, the transverse rib electrode clamp includes cylinders fixedly arranged on both sides of the top surface of the fixed chuck, the two cylinders are arranged oppositely, and the output shaft end of each cylinder is fixedly connected with a vertically arranged transverse rib chuck.

[0008] Further, a first insulating layer is arranged between the cylinder and the fixed chuck, and a second insulating layer is arranged between the output shaft end of the cylinder and the transverse rib chuck.

[0009] Further, tooth groove structures are arranged on the opposite surfaces of the fixed chuck and the movable chuck, and on the opposite side surfaces of the two transverse rib chucks.

[0010] Further, the transverse rib switch assembly includes multiple first single-pole single-throw switches that are correspondingly arranged and connected in parallel with the integrated clamping electrode assembly. A single-pole triple-throw switch is connected in series on each first single-pole single-throw switch. The three contacts of the single-pole triple-throw switch are respectively correspondingly connected to the wall panel electrode clamp, or to the transverse rib electrode clamp, or to both the wall panel electrode clamp and the transverse rib electrode clamp simultaneously.

[0011] Further, a plurality of notches correspondingly arranged with the ends of the longitudinal ribs are formed in the blank holder. The longitudinal rib electrode clamp includes two second return springs respectively fixedly connected to the inner walls on both sides of the notch, and guide blocks respectively fixedly arranged on both sides of the bottom surface of the notch. One end of each second return spring away from the side wall of the notch is connected with a vertically arranged longitudinal rib chuck.

[0012] Further, a third insulating layer is arranged between the second return spring and the blank holder and / or the longitudinal rib chuck, and the guide block is made of insulating material.

[0013] Further, the longitudinal rib switch assembly includes multiple second single-pole single-throw switches that are correspondingly arranged and connected in parallel with the blank holder and the longitudinal rib electrode clamp. Each second single-pole single-throw switch is respectively correspondingly connected to the blank holder and each longitudinal rib chuck.

[0014] There is also provided a current-zone customized ribbed plate electro-assisted forming process, which is applied to the current-zone customized ribbed plate electro-assisted forming tooling as described above, and includes the following steps: S1. Workpiece assembly: The grid rib wall panel to be stamped and formed is accurately placed on the bending die arranged on the lower bolster of the hydraulic press, and the bending punch is aligned with the bending die. S2. Electrode clamping: The two blank holding electrode assemblies are respectively placed on the front and rear ends of the top surface of the wall panel, so that the blank holder contacts and presses the two ends of the wall panel. Each longitudinal rib electrode clamp correspondingly clamps the end of the longitudinal rib; the wall panel electrode clamp of the integrated clamping electrode assembly correspondingly clamps the left and right edges of the wall panel, and the air cylinder is started to drive the transverse rib electrode clamp to move and correspondingly clamp the end of the transverse rib. S3. Process parameter setting: According to the optimal forming process parameters of the grid rib wall panel to be formed and its non-uniform deformation law, the working modes of the transverse rib switch assembly and the longitudinal rib switch assembly are adjusted, and the separated / synchronized energization state of the multi-plate rib double region is set. S4. Energization heating: According to the preset energization sequence, a forming operation current with a preset power and current magnitude is passed through some electrode clamps by a pulse power generator, and it lasts for a preset time length to locally heat the sheet material to the preset forming temperature. S5. Stamping and forming: According to the set energization application methods of the sheet ribs in different regions, the bending punch and the bending die are controlled to cooperate to complete the forming process of the energized region of the sheet material. S6. Repeat Steps 4 and 5 to perform sectional energized bending for different ribbed plate areas. Wait until the plane grid ribbed wall plate is formed into the designed geometric shape, then turn off the pulsed current generator, unload the blank-holding electrode assembly and the integrated clamping electrode assembly, and remove the grid ribbed wall plate that has completed the bending forming.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention combines a pneumatically driven transverse rib electrode clamp and a manually operated wall plate electrode clamp to form an integrated clamping electrode assembly, effectively realizing the integrated clamping of the grid ribbed wall plate's ribs and wall plate. Through the insulating layer, the two electrode clamps are insulated from each other, and at the same time, the sectional energization effect of the transverse ribs and the wall plate is achieved; by arranging a longitudinal rib electrode clamp inside the blank-holder block to form an integrated blank-holding electrode assembly, combined with the design of a tensioned internal chuck structure, it plays a role in blank-holding control during the bending forming process, achieving the sectional energization effect of the longitudinal ribs and the wall plate; the integrated chuck design simplifies the assembly process, improves production efficiency, realizes the integrated design of overall clamping fixation-sectional / overall conductive heating from the structure, optimizes the process flow, and realizes safe, efficient, and high-precision current direction control and electric-assisted forming. 2. Through a reasonable design of the current sectional circuit and combined with the design of the chuck separation electrode structure tooling, the present invention can realize the separation / synchronous current input in multiple ribbed plate double regions, thereby realizing the "spatial domain" control of actively controlling the current distribution, direction, and action domain, realizing the "sectional customization" of the energy field, actively constructing an uneven current / load mapping relationship, effectively coordinating the deformation behaviors of different deformation regions, and realizing the overall near-uniform forming of complex components. Description of the Drawings

[0016] Figure 1 Stereoscopic structure schematic diagram of the overall grid ribbed wall plate part for bending forming by using the current sectional customization ribbed plate part electric-assisted forming tooling of the present invention; Figure 2 Overall structure schematic diagram of the current sectional customization ribbed plate part electric-assisted forming tooling of the present invention in the working state; Figure 3 One of the stereoscopic structure schematic diagrams of the integrated clamping electrode assembly; Figure 4 Another stereoscopic structure schematic diagram of the integrated clamping electrode assembly; Figure 5 Schematic diagram of the transverse rib wall plate current sectional circuit structure; Figure 6 One of the stereoscopic structure schematic diagrams of the blank-holding electrode assembly; Figure 7 Another stereoscopic structure schematic diagram of the blank-holding electrode assembly; Figure 8It is a schematic diagram of the current partition circuit structure of the longitudinal bar wall panel.

[0017] In the figure: 1. Integrated clamping electrode assembly; 11. Wall panel electrode clamp; 111. Connecting block; 112. Fixed chuck; 113. Movable chuck; 114. Fixed insulating handle; 115. Movable insulating handle; 116. First return spring; 12. Horizontal bar electrode clamp; 121. Cylinder; 122. Horizontal bar chuck; 123. Pusher plate; 124. First insulating layer; 125. Second insulating layer; 2. Edge pressing electrode assembly; 21. Edge pressing block; 22. Longitudinal bar electrode clamp; 221. Second return spring; 222. Guide block; 223. Longitudinal bar chuck; 224. Connecting plate; 225. Third insulating layer; 100. Wall panel; 200. Horizontal bar; 300. Longitudinal bar. Specific embodiments

[0018] The following elaborates on the preferred embodiments of the present invention in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined.

[0019] It should be noted that when a component is referred to as "installed on" another component, it can be directly on the other component or there can also be an intermediate component. When a component is considered to be "set on" another component, it can be directly set on the other component or there may be an intermediate component at the same time. When a component is considered to be "fixed to" another component, it can be directly fixed to the other component or there may be an intermediate component at the same time.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0021] The present invention provides an electro-assisted forming tooling and process for customized current partitioning of ribbed plate parts, which is used for Figure 1 the stamping and bending forming of the auxiliary grid rib integral wall panel part as shown. This grid rib integral wall panel part is integrally composed of a wall panel 100 and a number of horizontal ribs 200 and a number of longitudinal ribs 300 that crisscross above the wall panel. In this embodiment, the grid rib integral wall panel is made of titanium alloy. The number of horizontal ribs 200 is 3, which are sequentially marked as T1, T2, and T3. The number of longitudinal ribs 300 is also 3, which are sequentially marked as L1, L2, and L3. The following will detail the specific structure and working principle of the electro-assisted tooling for ribbed plate parts with this grid rib integral wall panel as the processing object.

[0022] See the appendixFigure 2 , an electro-assisted forming tooling for a ribbed plate with customized current zoning, comprising an integrated clamping electrode assembly 1 respectively arranged on the left and right sides of the wall plate 100, and a blank-holding electrode assembly 2 respectively arranged on the front and back sides of the wall plate 100.

[0023] As Figure 3 and Figure 4 shown, each integrated clamping electrode assembly 1 includes a wall plate electrode clamp 11 clamped on the edge of the wall plate 100, and a transverse rib electrode clamp 12 clamped on the end of the transverse rib 200 and insulated from the wall plate electrode clamp 11. The wall plate electrode clamp 11 and the transverse rib electrode clamp 12 on the same side are connected to the same-sex electrode terminal (such as the positive electrode) of a pulse power generator (not shown in the figure), and the wall plate electrode clamp 11 and the transverse rib electrode clamp 12 on the other same side are connected to the opposite-sex electrode terminal (such as the negative electrode) of the pulse power generator through a transverse rib switch assembly. The transverse rib switch assembly controls the wall plate electrode clamp 11 or the transverse rib electrode clamp 12 in at least one integrated clamping electrode assembly 1 to be energized alone or the wall plate electrode clamp 11 and the transverse rib electrode clamp 12 to be energized simultaneously.

[0024] Specifically, the wall plate electrode clamp 11 includes a connecting block 111, a fixed chuck 112 fixedly arranged on one side of the top of the connecting block 111, and a movable chuck 113 rotatably arranged at the bottom of the connecting block 111 and located below the fixed chuck 112. Among them, the fixed chuck 112 is integrally formed with the connecting block 111 or fixedly assembled by means of screw connection, etc. A through hole is provided at the bottom end of the connecting block 111, and the connecting end of the movable chuck 113 is inserted into the through hole. A shaft rod horizontally placed in the through hole is inserted into the connecting end of the movable chuck 113, so that the movable chuck 113 can swing up and down around the shaft rod. After the movable chuck 113 swings downward, the two chucks are in an open state, so that the edge of the wall plate 100 can enter between the two chucks; after the movable chuck 113 swings upward, it can cooperate with the fixed chuck 112 to respectively clamp the upper and lower surfaces of the wall plate 100 to realize the clamping function. Both chucks are made of conductive metal material (such as copper), and are connected to the pulse current output electrodes of an external pulse power generator through cables. The wall plate electrode clamps 11 on both sides of the wall plate 100 are respectively connected to output electrodes with different electricities, and the wall plate 100 can be connected to the current circuit. In order to improve the clamping surface of the two chucks and at the same time meet the need of accommodating the end of the transverse rib 200 in the middle, in this embodiment, both chucks are set as a comb-like structure similar to a "Y" shape, so that there is a vacant notch between the end clamping parts; in order to improve the anti-slip effect after the clamping surfaces of the two chucks are clamped with the upper and lower surfaces of the wall plate, so as to avoid loosening or position deviation of the wall plate electrode clamp 11 and affecting the conductive effect, tooth groove structures are provided on the opposite surfaces of the fixed chuck 112 and the movable chuck 113 (specifically, the two clamping positions at the bottom end of the bottom surface of the fixed chuck 112 and the two clamping positions at the top end of the top surface of the movable chuck 113), so that the clamping surface is a non-planar surface such as a wavy surface or a grid surface.

[0025] A fixed insulating handle 114 is fixedly provided on the other side of the top of the connection block 111, and a movable insulating handle 115 fixedly connected to the end of the movable clamp 113 is provided below the fixed insulating handle 114. Both the fixed insulating handle 114 and the movable insulating handle 115 are made of insulating materials, so that a person can safely hold the two insulating handles to clamp the wall plate electrode clamp 11 on the edge of the wall plate 100. The end of the fixed insulating handle 114 is fixedly assembled on the connection block 111 by plugging, bonding or screw connection, while the end of the movable insulating handle 115 is fixedly connected to one end of the movable clamp 113 located in the through hole by plugging, bonding, screw connection, etc. In this way, by operating the opening and closing operation between the movable insulating handle 115 and the fixed insulating handle 114, the opening and closing operation between the movable clamp 113 and the fixed clamp 112 can be correspondingly realized. Three first reset springs 116 are connected between the movable insulating handle 115 and the fixed insulating handle 114. After the personnel hold the two handles tightly so that the movable clamp 113 cooperates with the fixed clamp 112 to clamp the upper and lower surfaces of the wall panel 100 respectively, and then releases the handles, the first return spring 116 can automatically open the two handles, so that the two clamps are in a tensioned clamping state.

[0026] The transverse rib electrode clamp 12 includes a cylinder 121 fixedly arranged on both sides of the top surface of the fixed chuck 112, and the two cylinders 121 are arranged opposite to each other, and the output shaft end of each cylinder 121 is fixedly connected to a vertically arranged transverse rib clamp 122. Specifically, the two cylinders 121 are respectively fixedly connected to the top surface of the fixed chuck 122 by screws, and are respectively located on both sides of the vacant slot of the fixed chuck 122. The output shaft end of the cylinder 121 is fixedly connected to a push plate 123, and the two sides of the push plate 123 are fixedly connected to the ends of the guide rods on both sides of the cylinder body of the cylinder 122, and the transverse rib clamp 122 is fixedly connected to the side of the push plate 123 by bonding or screw connection, so that the cylinders 121 on both sides can push the two transverse rib clamps 122 to move closer to or away from each other. In the process of the wall plate electrode clamp 11 clamping the wall plate 100, the end of the transverse rib 122 is located in the empty slot of the fixed clamp 112, so that the end of the transverse rib 122 is located between the two transverse rib clamps 122 on both sides. After the wall plate electrode clamp 11 completes the clamping of the wall plate 100, the cylinders 121 on both sides are started to drive the two transverse rib clamps 122 on both sides to approach the side of the transverse rib 200 and clamp the end of the transverse rib 200. Both transverse rib clamps 122 are made of conductive metal materials (such as copper), and are connected to the pulse current output electrodes of the external pulse power generator through cables. The transverse rib clamps 122 at both ends of the same transverse rib 200 are respectively connected to output electrodes of different electrical properties, so that the corresponding transverse rib 200 can be connected to the current circuit.

[0027] Preferably, a first insulating layer 124 is provided between the cylinder 122 and the fixed chuck 112, and a second insulating layer 125 is provided between the output shaft end of the cylinder 121 (specifically, the push plate 123) and the cross rib chuck 122. By providing the first insulating layer 124 and the second insulating layer 125, it can effectively ensure that the cross rib electrode clamp 12 and the wall plate electrode clamp 11 are in an insulated state from each other, facilitating the separate control of the two current loops. In this embodiment, both the first insulating layer 124 and the second insulating layer 125 are rectangular plates made of epoxy resin material, which can ensure the insulation effect and meet the hardness requirements of the connection. Similarly, to enhance the reliability of the clamping of the opposite sides of the two cross rib chucks 122 and the side surface of the end of the cross rib 200, tooth groove structures similar to the foregoing are provided on the opposite sides of the two cross rib chucks 122. Further preferably, to make the output thrusts of the six cylinders 121 in the three integrated clamping electrode assemblies 1 on one side the same and the telescoping of the output shafts synchronous, the air paths of the six cylinders 121 are arranged in series in sequence. In this way, through the same air supply path, the synchronous and equal-force output movement of the six cylinders 121 can be achieved.

[0028] The cross rib switch assembly includes multiple first single-pole single-throw switches that are correspondingly and parallely arranged with the integrated clamping electrode assembly 1. A single-pole triple-throw switch is connected in series on each first single-pole single-throw switch. The three contacts of the single-pole triple-throw switch are respectively connected to the wall plate electrode clamp 11, or to the cross rib electrode 12 clamp, or to both the wall plate electrode clamp 11 and the cross rib electrode clamp 12 at the same time. In this embodiment, the number of cross ribs 200 is 3, and correspondingly, the number of integrated clamping electrode assemblies 1 provided on one side is also three. Therefore, as Figure 5As shown, the first single-pole single-throw switch is set to three parallel paths, respectively marked as S1, S2, and S3. Each first single-pole single-throw switch is connected in series with a single-pole triple-throw switch, respectively marked as S10, S20, and S30. The three contacts of S10 are respectively marked as K101, K102, and K103. The contact K101 is connected to the cable of the transverse rib electrode clamp 12 in the first integrated clamping electrode assembly 1, the contact K103 is connected to the cable of the wall panel electrode clamp 11 in the integrated clamping electrode assembly 1, and the contact K102 is simultaneously connected to the cables of both the transverse rib electrode clamp 12 and the wall panel electrode clamp 11 in the integrated clamping electrode assembly 1, and a diode protection circuit is introduced into the corresponding two cables to ensure the unidirectionality of the current. When S1 is closed and S10 is at the contact K101 position, only the end of the first transverse rib 200 (T1) is energized; when S1 is closed and S10 is at the contact K103 position, only the end of the wall panel 100 at the bottom of the first transverse rib 200 is energized; when S1 is closed and S10 is at the contact K102 position, only the end of the first transverse rib 200 and the end of the wall panel 100 at its bottom are energized. The three contacts of S20 are respectively marked as K201, K202, and K203, and the three contacts of S30 are respectively marked as K301, K302, and K303. The connection methods of S20 with the electrode plates in the second integrated clamping electrode assembly 1 and S30 with the electrode plates in the third integrated clamping electrode assembly 1 are similar and will not be elaborated.

[0029] S1, S2, and S3 constitute the total control valves of the single-board rib circuit. The three-way control switches independently control the on / off of the corresponding circuits. Through the combination of different circuit on / off states, the single-board rib, double-board rib, and multi-board rib separate power-on control modes can be realized, and further the double-region separation / synchronization power-on of the transverse rib and multi-board rib can be achieved.

[0030] As Figure 6 and Figure 7 shown, the edge pressing electrode assembly 2 includes an edge pressing block 21 placed on the top edge of the wall panel 100, and a longitudinal rib electrode clamp 22 clamped at the end of the longitudinal rib 300 and insulated from the edge pressing block 21. The edge pressing block 21 and the longitudinal rib electrode clamp on the same side are connected to the same-sex electrode terminal (such as the positive electrode) of the pulse power generator, and the edge pressing block 21 and the longitudinal rib electrode clamp 22 on the other same side are connected to the opposite-sex electrode terminal (such as the negative electrode) of the pulse power generator through the longitudinal rib switch assembly. The longitudinal rib switch assembly enables at least one of the edge pressing block 21 and each longitudinal rib electrode clamp 22 to be energized.

[0031] Specifically, the edge pressing block 21 is a cube structure made of a conductive metal material (such as copper). Its length matches the width of the front and rear ends of the bottom wall 100. Three notches corresponding to the ends of the longitudinal bars 300 are provided inside it, and through holes are provided in the middle of the bottom walls of the notches. During assembly, the edge pressing block 21 is directly placed on the top edge of the front and rear ends of the bottom wall 100, and the ends of the three longitudinal bars 300 pass through the through holes and stand in the three notches. The top end of the edge pressing block 21 is connected to the pulse current output electrode of an external pulse power generator through a cable, and the corresponding longitudinal bar 300 can be connected to the current circuit.

[0032] The longitudinal bar electrode clamp 22 includes two second return springs 221 respectively fixedly connected to the inner walls on both sides of the notch, and guide blocks 222 respectively fixedly arranged on both sides of the bottom surface of the notch. One vertically arranged longitudinal bar chuck 223 is connected to one end of each second return spring 221 away from the notch side wall. A guide chute is provided at the top of the guide block 222, and a guide slider slidably connected to the guide chute is fixedly arranged at the bottom end of the longitudinal bar chuck 223. Specifically, the guide block 222 is fixed to the bottom surface of the notch by any one of the assembly methods such as plugging, bonding, and screw connection. The guide chute is perpendicular to the side surface of the longitudinal bar 300. Through the sliding cooperation between the guide slider and the guide chute, the longitudinal bar chuck 223 can move horizontally, so as to approach or move away from the side surface of the end of the longitudinal bar 300. The second return spring 221 is horizontally arranged, and connecting plates 224 are respectively fixedly connected to both ends thereof. The connecting plates 224 are respectively fixedly connected to the side wall of the notch and the side surface of the longitudinal bar chuck 223 by screws. After the edge pressing block 21 is placed on the top surface of the wall panel 100 according to the preset position, the ends of the three longitudinal bars 300 respectively stand in the middle of the notch and between the two longitudinal bar chucks 223. Under the tension thrust of the second return spring 221, the longitudinal bar chucks 223 on both sides clamp the side walls on both sides of the end of the longitudinal bar 300.

[0033] Both of the two longitudinal bar chucks 223 are made of a conductive metal material (such as copper) and are connected to the pulse current output electrodes of an external pulse power generator through cables. The longitudinal bar chucks 223 at both ends of the same longitudinal bar 300 are respectively connected to output electrodes with different electricities, and the corresponding longitudinal bar 300 can be connected to the current circuit.

[0034] Preferably, a third insulating layer 225 is provided between the connecting plates 224 at both ends of the second return spring 211 and the blank holding block 21 and / or the longitudinal bar electrode clamp, and the guide block 222 is also made of an insulating material. By providing the third insulating layer 225 and making the guide block 222 of an insulating material, it can effectively ensure that the longitudinal bar chuck 223 and the blank holding block 21 are in an insulated state from each other, facilitating the separate control of the two current loops. In this embodiment, both the third insulating layer 225 and the guide block 222 are rectangular plates made of epoxy resin material, which can ensure the insulating effect while meeting the hardness requirements of the connection. Similarly, to enhance the reliability of the clamping between the two longitudinal bar chucks 223 and the side surface of the end of the transverse bar 200, similar tooth groove structures are also provided on the opposite side surfaces of the two longitudinal bar chucks 223.

[0035] The longitudinal bar switch assembly includes a plurality of second single-pole single-throw switches that are correspondingly arranged in parallel with the blank holding block 21 and the longitudinal bar electrode clamp 22. Each second single-pole single-throw switch is respectively connected to the blank holding block 21 and each longitudinal bar chuck 223. In this embodiment, the number of longitudinal bars 300 is 3. Correspondingly, the number of longitudinal bar electrode clamps 22 arranged on one side is also three, and the number of blank holding blocks 21 is 1. Therefore, as Figure 8 shown, the second single-pole single-throw switches are arranged in 4 parallel paths, respectively marked as S1, S2, S3, and S4. Among them, the output ends of S1, S2, and S3 are respectively connected to the cables of the three longitudinal bar electrode clamps 22. Through different on / off combinations of these three second single-pole single-throw switches, multi-bar simultaneous / separate energization can be achieved; the output end of S4 is connected to the cable of the blank holding block 21, enabling separate current control of the wall panel 100. This circuit design can achieve separate / synchronous energization of the double regions of the longitudinal bars and the multi-panel bars.

[0036] The present invention also provides a current-zone customized ribbed panel electro-assisted forming process, which is applied to the current-zone customized ribbed panel electro-assisted forming tooling as described above, and includes the following steps: S1. Workpiece assembly: The grid rib wall panel to be stamped and formed is accurately placed on the bending die provided on the lower bolster of the hydraulic press, and the bending punch is aligned with the bending die. S2. Electrode clamping: The two blank holding electrode assemblies 2 are respectively placed on the front and rear ends of the top surface of the wall panel 100, so that the blank holding block 21 contacts and presses the two ends of the wall panel 100. Each longitudinal bar electrode clamp 22 correspondingly clamps the end of the longitudinal bar 300; the wall panel electrode clamp 11 of the integrated clamping electrode assembly 1 correspondingly clamps the left and right edges of the wall panel 100, and the air cylinder 121 is started to drive the two transverse bar chucks 122 of the transverse bar electrode clamp 12 to move relatively and correspondingly clamp the end of the transverse bar 200. S3. Process parameter setting: According to the optimal forming process parameters of the grid rib panel to be formed and its non-uniform deformation law, adjust the working modes of the transverse rib switch assembly and the longitudinal rib switch assembly 22, and set the separation / synchronous power-on state of the multi-plate rib double region; S4. Power-on heating: According to the preset power-on sequence, pass the forming operation current with a preset power and current magnitude through the pulse power generator to some electrode clamps, and continue for a preset duration to locally heat the sheet metal to the preset forming temperature; S5. Stamping forming: According to the set power-on application methods for different regional sheet ribs, control the cooperation of the bending punch and the bending die to complete the forming process of the power-on region of the sheet metal; S6. Repeat steps 4 and 5, perform sectional power-on bending for different sheet rib regions. After the flat grid rib panel is formed into the designed geometric shape, turn off the pulse current generator, unload the blank-holder electrode assembly 2 and the integral clamping electrode assembly 1, and remove the grid rib panel that has completed the bending forming.

[0037] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity in description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0038] The above is only the embodiment of the present invention, and thus does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. An electro-assisted forming tooling for ribbed parts with customized current zoning, characterized in that: It includes an integrated clamping electrode assembly respectively arranged on the left and right sides of the wall panel, and a hemming electrode assembly respectively arranged on the front and back sides of the wall panel; Each integrated clamping electrode assembly includes a wall panel electrode clamp clamped on the edge of the wall panel, a cross rib electrode clamp clamped on the end of the cross rib and insulated from the wall panel electrode clamp. The wall panel electrode clamp and the cross rib electrode clamp on the same side are connected to the same-sex electrode terminal. The wall panel electrode clamp and the cross rib electrode clamp on the other same side are connected to the opposite-sex electrode terminal through a cross rib switch assembly. The cross rib switch assembly controls the wall panel electrode clamp or the cross rib electrode clamp in at least one integrated clamping electrode assembly to be energized separately or the wall panel electrode clamp and the cross rib electrode clamp to be energized simultaneously; The hemming electrode assembly includes a hemming block placed on the top edge of the wall panel, a longitudinal rib electrode clamp clamped on the end of the longitudinal rib and insulated from the hemming block. The hemming block and the longitudinal rib electrode clamp on the same side are connected to the same-sex electrode terminal. The hemming block and the longitudinal rib electrode clamp on the other same side are connected to the opposite-sex electrode terminal through a longitudinal rib switch assembly. The longitudinal rib switch assembly enables at least one of the hemming block and each longitudinal rib electrode clamp to be energized.

2. The electro-assisted forming tooling for the ribbed plate part customized by current zoning according to claim 1, characterized in that: The wall panel electrode clamp includes a connecting block, a fixed chuck fixedly arranged on one side of the top of the connecting block, and a movable chuck rotatably arranged at the bottom of the connecting block and located below the fixed chuck. A fixed insulating handle is fixedly arranged on the other side of the top of the connecting block. An active insulating handle fixedly connected to the end of the movable chuck is arranged below the fixed insulating handle. At least one first return spring is connected between the active insulating handle and the fixed insulating handle.

3. The electro-assisted forming tooling for the ribbed plate part customized by current zoning according to claim 2, characterized in that: The cross rib electrode clamp includes cylinders fixedly arranged on both sides of the top surface of the fixed chuck. The two cylinders are arranged oppositely, and a vertically arranged cross rib chuck is fixedly connected to the output shaft end of each cylinder.

4. The electro-assisted forming tooling for the ribbed plate part customized by current zoning according to claim 3, characterized in that: A first insulating layer is arranged between the cylinder and the fixed chuck, and a second insulating layer is arranged between the output shaft end of the cylinder and the cross rib chuck.

5. The electro-assisted forming tooling for the ribbed plate part customized by current zoning according to claim 3, characterized in that: Tooth groove structures are arranged on the opposite surfaces of the fixed chuck and the movable chuck and on the opposite side surfaces of the two cross rib chucks.

6. The electro-assisted forming tooling for the ribbed plate part customized by current zoning according to any one of claims 1 to 5, characterized in that: The cross rib switch assembly includes multiple first single-pole single-throw switches arranged in parallel corresponding to the integrated clamping electrode assembly. A single-pole triple-throw switch is connected in series on each first single-pole single-throw switch. The three contacts of the single-pole triple-throw switch are respectively connected to the wall panel electrode clamp or the cross rib electrode clamp or both the wall panel electrode clamp and the cross rib electrode clamp simultaneously.

7. The electro-assisted forming tooling for the ribbed plate part customized by current zoning according to claim 1, characterized in that: Several notches corresponding to the ends of the longitudinal ribs are formed in the hemming block. The longitudinal rib electrode clamp includes two second return springs respectively fixedly connected to the inner walls on both sides of the notch, and guide blocks respectively fixedly arranged on both sides of the bottom surface of the notch. A vertically arranged longitudinal rib chuck is connected to one end of each second return spring away from the notch side wall.

8. The electro-assisted forming tooling for the ribbed plate part customized by current zoning according to claim 7, characterized in that: A third insulating layer is arranged between the second return spring and the hemming block and / or the longitudinal rib chuck, and the guide block is made of insulating material.

9. The electro-assisted forming tooling for the ribbed plate part customized by current zoning according to claim 1 or 7 or 8, characterized in that: The longitudinal rib switch assembly includes multiple second single-pole single-throw switches arranged in parallel corresponding to the hemming block and the longitudinal rib electrode clamp. Each second single-pole single-throw switch is respectively connected to the hemming block and each longitudinal rib chuck.

10. A current-zone-customized electric-assisted forming process for stiffener plates, which is applied to the current-zone-customized electric-assisted forming tooling for stiffener plates as described in any one of claims 1 to 9, and is characterized in that, It includes the following steps: S1. Workpiece assembly: The grid rib panel to be stamped and formed is accurately placed on the bending die set on the lower bolster of the hydraulic press, and the bending punch is aligned with the bending die. S2. Electrode clamping: The two blank-holding electrode assemblies are respectively placed on the front and rear ends of the top surface of the panel, so that the blank-holding blocks contact and hold the edges of both ends of the panel. Each longitudinal rib electrode clamp correspondingly clamps the end of the longitudinal rib; the panel electrode clamp of the integrated clamping electrode assembly correspondingly clamps the left and right edges of the panel, and the cylinder is started to drive the transverse rib electrode clamp to move and correspondingly clamp the end of the transverse rib. S3. Process parameter setting: According to the optimal forming process parameters of the grid rib panel to be formed and its non-uniform deformation law, the working modes of the transverse rib switch assembly and the longitudinal rib switch assembly are adjusted, and the separation / synchronization energization state of the multi-panel rib double region is set. S4. Energization heating: According to the preset energization sequence, a forming operation current with a preset power and current magnitude is passed through some electrode clamps by the pulse power generator for a preset duration, so that the sheet metal is locally heated to the preset forming temperature. S5. Stamping and forming: According to the set energization application method for different regional panel ribs, the bending punch and the bending die are controlled to cooperate to complete the forming process of the energized area of the sheet metal. S6. Repeat Step 4 and Step 5, perform sectional voltage application and bending for different panel rib areas. Wait until the planar grid rib panel is formed into the preset geometric shape, turn off the pulse current generator, unload the blank-holding electrode assembly and the integrated clamping electrode assembly, and remove the grid rib panel after bending and forming.

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