Hollow member multi-field synergy air inflation forming method and device

Abstract

The application discloses a hollow member multi-energy field coordinated air expansion forming method and device. The method comprises the following steps: applying current loading to a blank; introducing gas into the internal closed cavity of the blank; collecting current loading state information during the hot air expansion forming process of the blank, and setting and / or adjusting the gas pressure loading parameter according to the current loading state information, so that the gas pressure loading path dynamically changes with the change of the current loading state. The application introduces the current loading state into the gas pressure loading control process, adjusts the gas pressure loading parameter according to the change of the current loading state, and thus improves the material state adjustment capability, forming stability and process adaptability in the hot air expansion forming process.

Description

Technical Field

[0001] This invention relates to the field of metal plastic forming technology, specifically to a method and apparatus for multi-energy field synergistic gas expansion forming of hollow components. Background Technology

[0002] Tubular blanks and hollow thin-walled components are widely used in aerospace, automotive, rail transportation, and high-end equipment industries due to their high lightweight properties and great potential for integrated manufacturing. As the service requirements and lightweight demands of components continue to increase, the forming and manufacturing difficulties of complex cross-sections, irregular curved surfaces, and high-precision hollow components continue to rise. Hot gas forming is an advanced plastic forming method for tubular blanks or hollow thin-walled components. It typically involves heating the blank to a suitable temperature and placing it in a mold cavity, then introducing a pressure medium into the blank cavity. Under the combined action of high temperature and internal pressure, the blank undergoes plastic expansion deformation and gradually conforms to the mold surface, thereby achieving the integral forming of complex hollow components.

[0003] Existing hot gas expansion forming processes mostly employ external heating methods such as furnace heating and induction heating to raise the temperature of the billet. After the material reaches a predetermined temperature, internal gas pressure is applied to complete the expansion and forming process. In this type of process, the heating and forming processes are often separated to some extent. Heat loss is prone to occur during the heating, transfer, and forming processes of the billet. At the same time, due to different heating conditions and stress states in different areas, uneven temperature distribution is likely to occur, which in turn affects the consistency of material flow, wall thickness distribution, and forming stability.

[0004] With the development of electric-assisted forming technology, publicly available technologies have introduced schemes that incorporate current loading into pneumatic forming or hot pneumatic forming processes. These schemes typically utilize the Joule heating effect generated when current passes through the blank to achieve rapid heating, or use the current to improve the forming conditions of the material in a hot state, thereby shortening the heating time, improving heat utilization efficiency, and enhancing the material's forming ability to a certain extent. Compared with traditional external heating methods, current loading has the advantages of faster response, adjustable heat input, and ease of integration with the forming process.

[0005] However, in existing technologies, electric current is mainly used as a heating method or auxiliary heat source, and its coordination with the gas pressure loading process is still insufficient. Existing solutions often employ fixed or sequential current and gas pressure loading modes, with the gas pressure loading path typically set independently, failing to dynamically match and adaptively adjust according to the actual changes in the current state during the forming process. Because the material temperature field, flow stress, and microstructure evolution caused by the current have time-varying characteristics, a fixed gas pressure loading curve is difficult to coordinate with them, easily leading to defects such as uneven local bulging, excessive wall thinning, or cracking. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a multi-energy field coordinated gas expansion forming method and device for hollow components. This solves the technical problem in the prior art that the current and gas pressure loading paths cannot be dynamically matched, making it difficult to adapt to the time-varying evolution law of material properties under the action of current, which in turn easily leads to forming defects.

[0007] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for multi-energy field coordinated gas expansion forming of hollow components, comprising: Apply current to the billet; Gas is introduced into the enclosed cavity inside the billet; During the hot gas expansion forming process of the billet, current loading status information is collected, and the gas pressure loading parameters are set and / or adjusted according to the current loading status information so that the gas pressure loading path changes dynamically with the change of current loading status.

[0008] In some embodiments, the pneumatic loading parameters include one or more of pressure level, loading rate, and holding time.

[0009] In some embodiments, the hot gas expansion forming process of the billet includes an initial stage, an intermediate stage, and a later stage; In the initial stage, current is applied at a first current loading level, and the air pressure loading rate is controlled or maintained at the first air pressure level. During the intermediate stage, the air pressure loading rate and pressure level are adjusted according to the changes in the current loading state; In the later stage, the current loading is switched to a preset current state, and the air pressure is loaded at the second air pressure level. Wherein, the second air pressure level is greater than the first air pressure level, and the preset current state includes one of the following: load amplitude reduction state, intermittent on / off state, and current value hold state.

[0010] In some embodiments, setting and / or adjusting the pneumatic loading parameters based on the current loading state information includes: When the current loading value is greater than the first set threshold, adjust the air pressure loading rate; When the current load amplitude decreases to the set range, enters intermittent switching, or undergoes phase switching, the air pressure load level is adjusted accordingly.

[0011] In some embodiments, the hot gas expansion forming process of the billet further includes the following steps: Different current loading conditions are set in different areas of the billet to create spatial differences in the current loading state in different areas of the billet.

[0012] In some embodiments, the current loading conditions include current loading intensity, loading duration, or loading sequence; The spatial differences in the current loading state are achieved through partitioned electrode arrangement, local conductive path design, or partitioned contact structure setting.

[0013] In some embodiments, the hot gas expansion forming process of the billet further includes the following steps: Collect state signals to characterize the current state of the billet during the forming process; The current loading parameters and / or air pressure loading parameters are corrected based on the state signal to adapt the air pressure loading process to the current state changes of the billet.

[0014] In some embodiments, the status signal includes one or more of a temperature signal, a pressure signal, and a resistance change signal.

[0015] In some embodiments, the current loading employs one or more of direct current, pulsed current, or periodically changing current.

[0016] Secondly, the present invention also provides a hollow component multi-energy field coordinated air expansion forming apparatus for performing the hollow component multi-energy field coordinated air expansion forming method as described in any one of the above claims, the hollow component multi-energy field coordinated air expansion forming apparatus comprising: A current loading unit is used to apply current to the billet; A pneumatic loading unit is used to input gas pressure into the billet; and The control unit, connected to the current loading unit and the air pressure loading unit, is used to acquire current loading status information and set and adjust air pressure loading parameters according to the current loading status information.

[0017] Compared with existing technologies, the multi-energy field collaborative gas expansion forming method and apparatus for hollow components provided by this invention introduces current loading during the hot gas expansion forming process, and sets and / or adjusts the gas pressure loading parameters according to the current loading state, so that the gas pressure loading path changes synchronously and dynamically with the change of the current loading state. This allows the billet to obtain a material state that adapts to its deformation requirements at different forming stages, thereby achieving regulation of the material state and deformation behavior during the hot gas expansion forming process. This solves the problem that the current and gas pressure loading paths cannot be dynamically matched in existing technologies, and can adapt to the time-varying evolution law of material properties under the action of current. It effectively avoids forming defects such as uneven local expansion, excessive wall thickness reduction or cracking, improves forming quality and stability, and enhances the process adaptability of complex hollow components. Attached Figure Description

[0018] Figure 1 This is a flowchart of the multi-energy field coordinated gas expansion forming method for hollow components provided in the embodiments of the present invention; Figure 2 This is a structural diagram of the hollow component multi-energy field synergistic air expansion forming device provided in the embodiment of the present invention.

[0019] Figure descriptions: 200, Hollow component multi-energy field collaborative air expansion forming device; 201, Current loading unit; 202, Air pressure loading unit; 203, Control unit; 204, Billet. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0021] To address the technical problem that the current and air pressure loading paths cannot be dynamically matched, making it difficult to adapt to the time-varying evolution of material properties under current, and thus easily leading to forming defects, this invention provides a multi-energy field collaborative air expansion forming method and apparatus for hollow components. By introducing the current loading state into the air pressure loading control process, the air pressure loading parameters are adjusted according to the changes in the current loading state, thereby improving the material state adjustment capability, forming stability and process adaptability in the hot air expansion forming process.

[0022] Please see Figure 1 , Figure 1 This is a schematic diagram of a multi-energy field coordinated air expansion forming method for hollow components according to an embodiment of the present invention. In a first aspect, embodiments of this application provide a multi-energy field coordinated air expansion forming method for hollow components, comprising: S110: Apply current to the billet; S120: Gas is introduced into the closed internal cavity of the billet; S130: During the hot gas expansion forming process of the billet, current loading status information is collected, and the gas pressure loading parameters are set and / or adjusted according to the current loading status information so that the gas pressure loading path changes dynamically with the change of current loading status.

[0023] Based on the above-mentioned multi-energy field synergistic gas expansion forming method for hollow components, this solution also provides a more specific implementation step, which specifically includes: Step 1: Provide the blank. The blank is a metal tube or sheet, preferably an aluminum alloy, magnesium alloy, titanium alloy, or high-strength steel. The blank to be formed is placed in the cavity of the forming mold, which includes an upper mold and a lower mold. After the upper and lower molds are closed, a cavity matching the shape of the target component is formed. Both ends of the blank are sealed by a sealing structure, creating a closed cavity inside the blank to meet the subsequent pneumatic loading conditions.

[0024] Step 2: Apply current loading to the billet. Electrodes are placed at both ends or in a predetermined area of ​​the billet, forming a conductive contact with the billet. This allows current to flow through the billet body, forming a conductive loop and thus applying current loading. The electrodes can be one or more of end-clamping electrodes, partial contact electrodes, or zoned electrodes to adapt to different billet structures and the loading requirements of the forming area. Current application is not merely for heating the billet, but for establishing an adjustable current loading state. This current loading state alters the temperature and flow stress state of the billet and serves as a basis for adjusting the pneumatic loading parameters, allowing the pneumatic loading path to change with the current loading state, thereby achieving coordinated adjustment between current loading and pneumatic loading.

[0025] Preferably, end-clamping electrodes are used as the main current application method, allowing the current to pass through the blank body along the length direction or the main conductive direction, thereby achieving overall current loading. This method has a relatively simple structure, is easy to coordinate with blank clamping and end sealing structures, and is beneficial for simultaneously meeting conductivity and sealing requirements during hot gas expansion forming. The current loading can employ one or more of direct current, pulsed current, or periodically changing current. Preferably, pulsed current or periodically changing current is used, causing the current loading state to change in stages during the forming process. Current loading parameters include one or more of current amplitude, loading period, duty cycle, and duration, and can be set according to the blank material, thickness, structural form, and forming stage.

[0026] Preferably, the thermal state of the billet can be established by current loading, or by a combination of current loading and external heating. Using current loading as the main heating method allows the billet to gradually enter a suitable thermal deformation state during the forming process, thereby reducing reliance on traditional furnace heating methods.

[0027] Furthermore, in this embodiment, the current loading is combined with the sealing structure. Specifically, the sealing structure not only seals the internal cavity of the billet, but also serves as the electrode mounting base, realizing the integrated design of sealing and conductivity. This allows the billet to form a stable conductive circuit while maintaining internal sealing, thereby maintaining the continuity of air pressure loading and the stability of current loading.

[0028] Step 3: Introduce gas into the enclosed cavity inside the billet. Applying gas pressure into the enclosed cavity causes the billet to expand and deform under the pressure. The gas is preferably an inert gas. The gas pressure loading system includes a gas input interface, pressure regulating components, and connecting pipes, used to provide the necessary gas pressure driving force for hot gas expansion forming inside the billet.

[0029] Step 4: During the hot gas expansion forming process of the billet, collect current loading status information, and set and / or adjust the gas pressure loading parameters based on the current loading status information so that the gas pressure loading path changes dynamically with the change of current loading status. The gas pressure loading parameters include one or more of the following: pressure level, loading rate, and holding time.

[0030] Specifically, during the forming process, current loading is used not only to change the temperature and flow stress state of the billet, but also as a basis for adjusting the pneumatic loading parameters. The control system collects real-time information on the amplitude, frequency, and duty cycle of the current loading. Based on the current loading state, the control system sets and adjusts one or more of the following: pneumatic loading rate, pressure level, and holding time, transforming the pneumatic loading path from a fixed path to an adjustable path that changes with the current loading state. Preferably, in the control system, a first set threshold is set as a higher threshold for the current loading value based on actual conditions. When the current loading value is greater than the first set threshold, it indicates that the current loading is high. When the current loading is high or in the current action stage, the pneumatic loading rate is controlled to ensure that the billet enters the bulging process in a more suitable material state. When the current loading amplitude weakens, is intermittently switched, or the stage changes, the pneumatic loading level is adjusted accordingly to ensure that the bulging process adapts to the current material state of the billet. In this way, the current loading state no longer only corresponds to the heat input process, but also participates in the adjustment of the hot gas expansion forming path.

[0031] In one embodiment, staged control can be used to achieve hot gas expansion forming. The hot gas expansion forming process of the billet includes an initial stage, an intermediate stage, and a later stage. In each stage, the gas pressure loading parameters are adjusted according to the current loading state, so that the gas pressure loading path changes with the current loading state, thereby forming a coordination relationship between current loading and gas pressure loading in different forming stages.

[0032] Specifically, in the initial stage, the billet is subjected to a high initial current loading level, while the gas pressure loading rate is controlled or a low initial gas pressure level is maintained, allowing the billet to gradually enter a suitable hot deformation state. The high-current DC loading method is used to rapidly heat the billet, quickly changing its temperature and flow stress state, while effectively suppressing grain coarsening. In the initial stage, the main function of current loading is to establish a material state suitable for the subsequent bulging process, while gas pressure loading is coordinated with this material state to prevent the billet from deforming too quickly before reaching a suitable state.

[0033] In the intermediate stage, as the current loading state changes, the air pressure loading rate and pressure level are adjusted accordingly to ensure stable plastic deformation of the billet under overall air pressure. During this stage, the current loading state not only affects the material state changes but also serves as the basis for adjusting the air pressure loading parameters, ensuring the bulging process is coordinated with the material state changes. For example, when the current loading is high or in the current-driven stage, the air pressure loading rate is controlled to ensure the billet enters the bulging process in a more suitable material state; when the current loading amplitude decreases, is intermittently switched, or the stage changes, the air pressure loading level is adjusted accordingly to ensure the bulging process adapts to the current material state of the billet.

[0034] In the later stages, when the billet is close to the target shape, the current loading switches to a preset current state, which includes one of three states: reduced loading amplitude, intermittent on / off state, or current value maintenance state. This allows for reducing, intermittent, or maintaining the current loading. Simultaneously, the air pressure loading level is increased to a second air pressure level, which is higher than the first air pressure level, to promote further conformation of the billet to the mold cavity and complete the shaping process. During this stage, the current loading and air pressure loading maintain a coordinated relationship, ensuring that the subsequent shaping process adapts to the current material state of the billet. Among them, the reduced loading amplitude state refers to the current loading amplitude being reduced compared to the set loading amplitude, so that the billet temperature is kept within a suitable range or decreases slowly, avoiding excessive thinning in some areas due to excessive temperature; the intermittent on-off state refers to the current being periodically switched on and off according to a preset time interval. At this time, the preset current state is the pulse current, which is used for temperature compensation and control, achieving precise temperature control, and can be used to control the temperature only in specific areas as needed. This method maintains the temperature and plasticity required for billet deformation, while avoiding excessive energy consumption or material performance degradation caused by continuous high current; the current value hold state refers to maintaining the current loading parameters unchanged, adapting to the shaping requirements when the billet deformation rate is low, and maintaining the stability of the material state.

[0035] It should be noted that the synergistic adjustment mechanism in this invention runs through the entire hot gas expansion forming process and can be combined with staged control and spatial distribution adjustment. That is to say, the coordination relationship between current and gas pressure is reflected not only in different forming stages, but also in the local adjustment of different areas of the billet, so that this invention can not only achieve overall process adjustment, but also further adjust the local deformation behavior.

[0036] In one embodiment, thermal expansion forming can be achieved by spatial distribution adjustment. Specifically, by setting electrodes in different regions of the billet, or by adjusting the conductive contact method, conductive path, and conductive path distribution in different regions, different current loading conditions are set in different regions of the billet, so that different regions of the billet form spatial differences in current loading states, thereby creating different temperature states and flow stress states in different regions of the billet.

[0037] In this embodiment, spatial distribution adjustment is achieved by setting partitioned electrodes in different regions of the billet. For target components with complex geometries, the billet is divided into main deformation regions, transition regions, and constraint regions. Different current loading conditions can be set for the main deformation regions, transition regions, and constraint regions of the billet according to the deformation requirements of different parts of the target component. This allows different regions to obtain different current loading intensities, durations, or sequences during the forming process. For example, a first set of electrodes is set in the main deformation region, applying a higher current loading intensity and a longer loading duration; a second set of electrodes is set in the transition region, applying a medium current loading intensity; and a third set of electrodes is set in the constraint region, applying a lower current loading intensity or even no current. In this way, the main deformation region enters a suitable deformation state earlier, while other regions maintain a material state adapted to their function, thereby allowing the billet to form a deformation response corresponding to the local forming requirements under overall pneumatic loading.

[0038] The spatial difference in current loading state is achieved through partitioned electrode arrangement, local conductive path design, or partitioned contact structure setting, so as to form a material state distribution on the blank that matches the forming requirements of different areas, thereby improving the adaptability of the hot gas expansion forming process to the local forming requirements of complex components.

[0039] It should be noted that the spatial distribution adjustment method in this invention is not a separate measure independent of pneumatic loading, but rather an important component of the current-pneumatic synergistic adjustment mechanism. The current loading state in different regions not only affects the material state of that region, but also serves as one of the foundations for pneumatic loading adjustment. In other words, different pneumatic loading adjustment logics can be set for different current loading states in different regions, ensuring that the expansion deformation in each region is adapted to the current material state of that region. For example, for major deformation regions that enter a high deformation capacity state early, pneumatic loading at a corresponding pressure level can be pre-matched to promote the priority completion of deformation in that region; for constrained regions with smaller deformation requirements, when the current loading level is low and the material flow capacity is weak, a lower pneumatic loading effect is maintained to avoid excessive deformation in that region. Through this method, the spatial distribution differences in current loading are transformed into differentiated adjustment of pneumatic loading, achieving synergistic matching of current and pneumatic pressure at the spatial level, further improving the accuracy and forming quality of complex components in thermal pneumatic expansion forming.

[0040] In one embodiment, hot air expansion forming can be achieved using a state signal adjustment method. The control system can not only control the current loading parameters and air pressure loading parameters according to a preset program, but also further adjust them based on the state signals. Specifically, this includes the following steps: acquiring state signals characterizing the current state of the billet during the forming process; and correcting the current loading parameters and / or air pressure loading parameters based on the state signals to adapt the air pressure loading process to changes in the current state of the billet. For example, the control system compares the acquired state signals with preset target values. When the billet temperature is lower than the target temperature, the control system increases the current loading amplitude or extends the current loading time to supplement heat input; simultaneously, it correspondingly reduces the air pressure loading rate to prevent deformation of the billet due to insufficient temperature. When the billet resistance change signal indicates a significant change in the billet cross-section, the control system correspondingly increases the air pressure loading level to promote further fitting of the billet into the mold cavity.

[0041] In this embodiment, the state signal includes one or more of temperature signal, pressure signal, and resistance change signal. Specifically, the temperature signal is acquired by a thermocouple mounted on the surface of the mold or billet, and is used to characterize the current thermal state of the billet; the pressure signal is acquired by a pressure sensor mounted in the air pressure pipeline, and is used to characterize the air pressure loading state; the resistance change signal is calculated by measuring the voltage and current across the billet, and is used to characterize the electrical conductivity or material state change of the billet during the forming process.

[0042] Furthermore, the status signal adjustment can be used to adjust the parameter matching relationships in different forming stages. In the initial stage, if the status signal indicates that the billet temperature rise rate is lower than expected, the control system can increase the current loading amplitude or extend the duration of the initial stage, and correspondingly delay the start time of the pneumatic loading to ensure that the billet reaches a suitable material state before entering the bulging stage. In the intermediate stage, if the status signal indicates that the billet temperature is too high, the control system can reduce the current loading amplitude or increase the interval time of the pulse current, while reducing the pneumatic loading rate to avoid local necking or cracking of the billet due to overheating.

[0043] It should be noted that, in this embodiment, the state signal adjustment is not an additional control method that exists independently of the current-pressure coordinated adjustment mechanism, but rather is used to supplement and improve this coordinated adjustment mechanism. That is, based on adjusting the pressure loading parameters according to the current loading state, the control system further combines the state signal to correct the pressure loading rate, pressure level, holding time, or current loading parameters, so that the pressure loading process can better adapt to the current state changes of the billet.

[0044] Step 5: Once the blank gradually conforms to the mold cavity and reaches the target shape under the combined action of current and air pressure loading, stop the current and air pressure loading to complete the forming process. Then, remove the sealing structure and take out the formed part for cooling or subsequent processing.

[0045] Secondly, this application also provides a hollow component multi-energy field coordinated gas expansion forming apparatus 200, used to perform the hollow component multi-energy field coordinated gas expansion forming method as described above. The hollow component multi-energy field coordinated gas expansion forming apparatus 200 includes a current loading unit 201, a gas pressure loading unit 202, and a control unit 203. The current loading unit 201 is used to apply current to the blank 204; the gas pressure loading unit 202 is used to input gas pressure into the blank 204; the control unit 203 is connected to the current loading unit 201 and the gas pressure loading unit 202, and is used to acquire current loading status information and set and adjust the gas pressure loading parameters according to the current loading status information.

[0046] Specifically, the current loading unit 201 includes a power supply, electrodes, wires, and a current regulating component. The power supply can be a DC power supply, an AC power supply, or a pulse power supply, capable of outputting currents of different amplitudes, frequencies, and duty cycles according to process requirements. The electrodes are electrically connected to corresponding parts of the billet 204. The current regulating component is connected to the power supply and the electrodes, and is used to adjust the current output parameters according to the instructions of the control unit 203, thereby adjusting the current loading state. The pneumatic loading unit 202 includes a gas source, a gas delivery pipeline, a pressure regulating component, and a pressure detection component. The gas source is connected to the closed cavity inside the billet 204 via the gas delivery pipeline. The pressure regulating component is connected to the gas source and is used to adjust the gas pressure input into the billet 204 according to the instructions of the control unit 203. At the same time, it can also detect the current gas pressure value in real time and feed it back to the control unit 203, realizing closed-loop regulation of the pneumatic loading parameters.

[0047] Furthermore, the control unit 203 is connected to the current adjustment component of the current loading unit 201, the pressure adjustment component of the air pressure loading unit 202, and the pressure detection component, respectively. It can collect the current loading status information in real time, output adjustment commands according to the preset collaborative adjustment logic, and complete the dynamic adjustment of the air pressure loading parameters. At the same time, it can receive the collected status signal of the billet 204 and further correct the current loading parameters and air pressure loading parameters to ensure that the entire forming process proceeds stably according to the preset collaborative matching relationship.

[0048] In this embodiment, the hollow component multi-energy field coordinated air expansion forming device 200 also includes a blank 204 clamping device and a sealing structure. The blank 204 clamping device is used to clamp and position the blank 204, and cooperates with the sealing structure to achieve clamping and sealing of the two ends or edges of the blank 204, providing an installation basis for current loading and air pressure loading. In addition to sealing the internal cavity of the blank 204, the sealing structure also integrates the electrodes of the current loading unit 201, enabling the electrodes to form a stable conductive contact with the blank 204. This establishes a stable conductive circuit while completing the sealing, avoiding air leakage or unstable contact at the conductive parts, and ensuring the continuous and stable operation of air pressure loading and current loading.

[0049] In one embodiment, when the billet 204 is a tubular billet 204, the billet 204 clamping device includes clamping seats respectively disposed at both ends of the tubular billet 204, and a sealing structure disposed between the clamping seats and the ends of the tubular billet 204. The positive electrode and negative electrode of the current loading unit 201 are respectively integrated and installed on the two clamping seats. The electrodes are electrically connected to the ends of the tubular billet 204. One of the clamping seats is provided with a gas channel extending along the axial direction. One end of the gas channel is connected to a gas source, and the other end is connected to the internal cavity of the tubular billet 204, thereby realizing the integration of clamping, sealing, conductivity and gas intake functions.

[0050] In another embodiment, for a billet 204 that requires zoned current loading, the current loading unit 201 is provided with multiple sets of independently controlled zoned electrodes. Each set of zoned electrodes is connected to a different current regulation branch. The control unit 203 can independently adjust the current loading parameters of each zone, thereby forming differentiated current loading states in different areas of the billet 204 to match the local deformation requirements of different areas.

[0051] This invention uses the current loading state as the basis for adjusting the pneumatic loading, transforming the pneumatic loading path from a fixed path to an adjustable path that changes with the current loading state. Through staged control, current loading and pneumatic loading are coordinated at different forming stages. Simultaneously, the combination of conductive and sealing structures provides the foundation for this coordinated adjustment and allows for further adjustment of the process based on state signals. Based on this technical solution, this invention is not a simple superposition of energization and hot gas expansion forming, but rather a forming method and apparatus centered on current-gas pressure coordinated adjustment, focusing on the adjustment of material state and pneumatic drive path during hot gas expansion forming. By introducing adjustable current loading during hot gas expansion forming and coordinating the adjustment of current loading and pneumatic loading parameters, the billet 204 achieves a temperature and flow stress state adapted to deformation requirements at different forming stages, thereby realizing the adjustment of the hot gas expansion forming process and improving the adjustability, stability, and process adaptability of the forming process.

[0052] In the description of this application, it should be noted that the terms "upper" and "lower," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0053] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0054] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for multi-energy field coordinated gas expansion forming of hollow components, characterized in that, include: Apply current to the billet; Gas is introduced into the enclosed cavity inside the billet; During the hot gas expansion forming process of the billet, current loading status information is collected, and the gas pressure loading parameters are set and / or adjusted according to the current loading status information so that the gas pressure loading path changes dynamically with the change of current loading status.

2. The method for multi-energy field synergistic gas expansion forming of hollow components according to claim 1, characterized in that, The pneumatic loading parameters include one or more of the following: pressure level, loading rate, and holding time.

3. The method for multi-energy field synergistic gas expansion forming of hollow components according to claim 1 or 2, characterized in that, The hot gas expansion forming process of the billet includes an initial stage, an intermediate stage, and a later stage. In the initial stage, current is applied at a first current loading level, and the air pressure loading rate is controlled or maintained at the first air pressure level. During the intermediate stage, the air pressure loading rate and pressure level are adjusted according to the changes in the current loading state; In the later stage, the current loading is switched to a preset current state, and the air pressure is loaded at the second air pressure level. Wherein, the second air pressure level is greater than the first air pressure level, and the preset current state includes one of the following: load amplitude reduction state, intermittent on / off state, and current value hold state.

4. The method for multi-energy field coordinated gas expansion forming of hollow components according to claim 3, characterized in that, Based on the current loading status information, the air pressure loading parameters are set and / or adjusted, including: When the current loading value is greater than the first set threshold, adjust the air pressure loading rate; When the current load amplitude decreases to the set range, enters intermittent switching, or undergoes phase switching, the air pressure load level is adjusted accordingly.

5. The method for multi-energy field synergistic gas expansion forming of hollow components according to claim 1, characterized in that, The hot gas expansion forming process of the billet also includes the following steps: Different current loading conditions are set in different areas of the billet to create spatial differences in the current loading state in different areas of the billet.

6. The method for multi-energy field synergistic gas expansion forming of hollow components according to claim 5, characterized in that, The current loading conditions include current loading intensity, loading duration, or loading sequence; The spatial differences in the current loading state are achieved through partitioned electrode arrangement, local conductive path design, or partitioned contact structure setting.

7. The method for multi-energy field synergistic gas expansion forming of hollow components according to claim 1, characterized in that, The hot gas expansion forming process of the billet also includes the following steps: Collect state signals to characterize the current state of the billet during the forming process; The current loading parameters and / or air pressure loading parameters are corrected based on the state signal to adapt the air pressure loading process to the current state changes of the billet.

8. The method for multi-energy field synergistic gas expansion forming of hollow components according to claim 7, characterized in that, The status signal includes one or more of the following: temperature signal, pressure signal, and resistance change signal.

9. The method for multi-energy field coordinated gas expansion forming of hollow components according to claim 1, characterized in that, The current loading uses one or more of the following: direct current, pulse current, or periodically changing current.

10. A multi-energy field synergistic air expansion forming device for hollow components, characterized in that, For performing the hollow component multi-energy field coordinated air expansion forming method as described in any one of claims 1-9, the hollow component multi-energy field coordinated air expansion forming apparatus comprises: A current loading unit is used to apply current to the billet; A pneumatic loading unit is used to input gas pressure into the billet; and The control unit, connected to the current loading unit and the air pressure loading unit, is used to acquire current loading status information and set and adjust air pressure loading parameters according to the current loading status information.

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