W-shaped metal seal ring partition multi-pulse electromagnetic bulging device and method

Abstract

A W-shaped metal sealing ring partition multi-pulse electromagnetic bulging device and method belong to the field of high-energy rate forming technology of aviation thin-walled components. In view of the problems of weak eddy current induction of low-conductivity metal, insufficient conventional electromagnetic bulging driving force, uneven deformation of W-shaped cross section, excessive wall thickness thinning and poor die fitting precision, the device is provided with an axial partition type independent driving coil, a ring driving piece, a time-sharing multi-path pulse power supply and a W-shaped forming die; each partition coil is discharged by an independent pulse circuit time sequence controllable discharge, and the electromagnetic force amplitude and loading time sequence of different forming sections are accurately controlled. The forming method uses high-conductivity material as the driving piece, and gradually bulges by partition multi-pulse, disperses the deformation amount by preforming in each partition, and corrects the cross section profile by pulse shaping in the whole domain. The present application effectively improves the utilization rate of electromagnetic driving force of low-conductivity material, suppresses local necking and uneven wall thickness, improves the profile forming consistency and size precision of W-shaped sealing ring, and is suitable for precise batch manufacturing of sealing ring of aviation engine.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic plastic forming technology, specifically relating to an electromagnetic bulging device for a low-conductivity high-temperature alloy W-shaped sealing ring and its partitioned multi-pulse forming method. Background Technology

[0002] W-shaped metal sealing rings are core thin-walled sealing components in the gas passages of aero-engines. They are primarily made of high-temperature alloys and other low-conductivity, high-strength, heat- and corrosion-resistant metallic materials. They maintain structural stability and sealing reliability under extreme engine conditions of high temperature, high pressure, and high-frequency vibration, playing a decisive role in the overall performance, operational safety, and service life of the aero-engine system. The W-shaped sealing ring cross-section exhibits multiple curvatures and non-uniform deformation characteristics. The deformation and forming resistance differ significantly in the crest, trough, and transition regions, placing extremely high demands on the precision control of the forming process.

[0003] Electromagnetic bulging is a high-energy-rate, high-speed plastic forming process that relies on pulsed electromagnetic force to drive the instantaneous plastic deformation of metal materials. It has outstanding advantages such as high forming accuracy, no friction scratches on the workpiece surface, high forming efficiency, and good overall integrity, and has now become an important processing method for the precision forming of thin-walled ring components in aerospace applications. However, when applying electromagnetic bulging to high-temperature alloy W-shaped sealing rings, two interrelated core technical challenges remain to be effectively addressed.

[0004] The first challenge is the insufficient electromagnetic bulging driving force for high-temperature alloys with low conductivity. The driving force for electromagnetic bulging originates from the interaction between the induced eddy currents in the workpiece itself and the pulsed magnetic field. The conductivity of high-temperature alloys is only about 1 / 40 to 1 / 50 that of copper, resulting in weak eddy current induction intensity and low electromagnetic energy coupling efficiency. When directly using coil drive, the forming driving force is severely insufficient and cannot meet the plastic forming requirements of complex W-shaped cross-sections.

[0005] To address the driving force issue of low-conductivity materials, a conventional approach in this field is to add a high-conductivity driving plate between the blank and the coil. The strong induced eddy currents in the driving plate generate electromagnetic force, which then drives the blank to deform. For example, US Patent 7954357 discloses a multi-layer driving plate structure for electromagnetic sheet metal forming, where an elastomer layer presses the sheet metal tightly against the mold surface. However, existing driving plate-assisted electromagnetic forming technologies are all developed for flat parts or simple round tubes. Their forming mode is uniform loading—a single set of coils applies a uniform electromagnetic force to the entire driving plate, causing the driving plate to deform uniformly and thus shaping the entire blank. This uniform forming mode cannot meet the non-uniform forming requirements of W-shaped sealing rings where the deformation varies significantly between the peak, trough, and transition regions: if uniform loading is used, the peak region with large deformation may not be fully formed, while the transition region with small deformation may be over-deformed. To date, there are no reports in the prior art of using driving plates and independent zoned coils in synergy for differentiated forming of complex annular cross-section components.

[0006] The second challenge is the precise control of non-uniform deformation in the complex W-shaped cross-section. The W-shaped sealing ring cross-section includes crest, trough, and transition regions, each with different radii of curvature and significantly different required deformation amounts. The traditional integrated forming mode of synchronous pulse discharge of the entire coil uses uniform electromagnetic loading, which cannot implement differentiated energy matching for different curvature sections. This easily leads to local stress concentration in the component, causing quality problems such as excessive wall thickness reduction, poor cross-sectional profile fit, and insufficient forming consistency.

[0007] For the partitioned electromagnetic forming of complex cross-section components, Chinese patent CN109848280A discloses a partitioned electromagnetic forming method and apparatus for bellows, which achieves partitioned forming by setting radially expanding coils that can move axially inside the pipe. The partitioning method of this scheme is a moving partition along the axial direction of the pipe. The coil itself is a single general-purpose coil, rather than a dedicated partitioning coil fixedly arranged for different curvature sections of the W-shaped cross-section. It cannot achieve independent sequential loading of the crests, troughs and transition zones within the same annular cross-section. Moreover, this scheme adopts a process route that combines thermoforming and electromagnetic forming, which requires an additional heating system. The heat-affected zone is difficult to control, making it unsuitable for aerospace sealing rings with strict requirements for dimensional accuracy and microstructure.

[0008] Chinese patent CN122231145A discloses an electromagnetic forming device and method for corrugated pipes. It employs an integrated coil assembly for "edge pressing-forming-edge pressing" in conjunction with an upper and lower spliced ​​corrugated pipe mold. Three electromagnetic forming machines are powered separately, and multi-wave progressive forming is achieved by moving the support rod, coils, and pipe as a whole. This scheme has a fixed three-coil function of "edge pressing-forming-edge pressing," designed for single-segment corrugations with consistent geometric parameters, rather than addressing the different deformation amounts in different curvature sections of a W-shaped cross-section. Furthermore, multi-wave forming relies on overall movement and segment-by-segment processing, forming only one segment per clamping, making it impossible to complete the differentiated forming of all sections of a complex W-shaped cross-section in a single clamping operation.

[0009] Chinese patent CN106944528A discloses a flexible electromagnetic force loading electromagnetic forming device and method for metal pipe fittings. The method divides the drive coil into a main coil, an auxiliary coil, and a flexible coil module. By using different winding cross-sectional areas of the sub-coils and positive, negative, and short-circuit connection methods, the radial and axial electromagnetic forces are controlled under a series power supply from the same capacitor. The radial force is homogenized by "reducing the current density in the middle and increasing the current density at the ends" to eliminate end effects. However, this scheme relies on the physical structure of the coil for force field control. Once the winding is complete, it cannot be dynamically adjusted, and the series power supply from the same capacitor lacks the ability to perform time-sharing multi-channel independent pulse loading. Its technical goal is to achieve uniform compensation of the radial force, rather than differentiated loading of the W-shaped sealing ring based on the deformation differences in each section. Furthermore, it does not use a forming mold, making it a free electromagnetic forming method, which cannot achieve precise mold-fitting forming of complex W-shaped cross-sections.

[0010] Chinese patent CN112387844A discloses an electromagnetic step-by-step forming method and apparatus based on three coils. This method improves the uniformity of tube deformation through the step-by-step coordination of a background magnetic field excitation coil, a main forming coil, and a secondary shaping coil. This scheme targets conventional circular tubes, with the three coils functionally divided into background magnetic field excitation, main forming, and secondary shaping. It does not rely on differentiated, step-by-step loading based on different deformation sections of a W-shaped cross-section. Furthermore, the coils are positioned outside the tube, relying on attractive force to drive the tube's formation; this is an external coil attraction-type electromagnetic forming, which is completely different from the internal coil bulging method of this invention in terms of force direction and deformation mode.

[0011] In summary, existing technologies have developed along separate technical routes for drive plate solutions addressing insufficient driving force for low-conductivity materials and partitioned coil solutions addressing non-uniform deformation of complex cross-sections: drive plate solutions are only suitable for overall uniform forming modes and cannot adapt to non-uniform differentiated forming requirements; existing partitioned electromagnetic forming solutions (CN109848280A, CN122231145A, CN106944528A, etc.) either employ movable uniform partitioning, fixed-function integrated coils, or rely on passive control of the coil's physical structure with the goal of uniform compensation, none of which utilize drive plate auxiliary structures, nor have they proposed a solution combining fixed partitioned independent loading and multi-pulse progressive forming to address the significant differences in deformation in the peak, trough, and transition regions of the W-shaped sealing ring. Those skilled in the art lack the technical motivation and inspiration to combine high-conductivity annular drive plates, axially layered fixed partitioned coils, time-division multiple independent pulse power supplies, and a two-stage multi-pulse process of "gradual pre-forming + full-domain shaping" for application to low-conductivity high-temperature alloy W-shaped sealing rings. Therefore, the existing technology lacks a dedicated electromagnetic bulging device and forming process for adapting to W-shaped sealing rings of low-conductivity high-temperature alloys, making it difficult to meet the mass production requirements of high precision, high uniformity, and high reliability for high-end sealing components of aero-engines. Summary of the Invention

[0012] To address the shortcomings of existing technologies, this invention provides a W-shaped metal sealing ring partitioned multi-pulse electromagnetic bulging device and method.

[0013] This invention is achieved through the following technical solutions.

[0014] The present invention discloses a W-shaped metal sealing ring partitioned multi-pulse electromagnetic bulging device, comprising a forming mold, a partitioned electromagnetic drive assembly, a time-division multi-channel pulse power supply, a ring drive plate, and a control system.

[0015] The forming mold has a forming cavity inside that is adapted to a W-shaped metal sealing ring structure, which is used for molding the blank to be processed.

[0016] The partitioned electromagnetic drive assembly includes multiple sets of independent drive coils, which are arranged sequentially in layers along the axial direction of the workpiece. Each drive coil is independently positioned corresponding to different deformation and forming sections of the W-shaped sealing ring. Preferably, the drive coils are wound on a hollow epoxy skeleton, with the outer wall of the coils covered by a high-strength, high-temperature resistant insulating protective layer. A non-closed steel liner is inlaid on the hollow epoxy skeleton. The non-closed steel liner is formed by two semi-circular ring components joined together, with a gap between the two semi-circular ring components and they are not connected to each other, forming a non-closed ring structure. This non-closed structure can prevent the steel liner from forming a closed eddy current loop under the action of a pulsed magnetic field, thereby reducing eddy current losses and additional heat generation. At the same time, the steel liner provides radial structural support for the coils and magnet assembly, constraining the structural deformation of the coil assembly during electromagnetic bulging, and ensuring the stability of the magnetic field distribution and forming accuracy. The multiple sets of drive coils are arranged sequentially in layers along the axial direction of the workpiece, with the main working areas of each drive coil interconnected, covering the entire forming area of ​​the workpiece.

[0017] The time-division multi-channel pulse power supply is electrically connected to multiple sets of independent drive coils, each power supply circuit is independently controllable, and the pulse current amplitude, discharge sequence, and discharge count of each set of drive coils can be adjusted individually. Preferably, the time-division multi-channel pulse power supply is equipped with multiple independent energy storage and discharge circuits, and the energy storage voltage and discharge delay parameters of each energy storage and discharge circuit are independently adjustable; the single-channel pulse discharge voltage adjustment range is 0-50kV, and the pulse delay adjustment range is 0-100μs, which can realize time-division, graded, and differentiated pulse discharge of different coils.

[0018] The annular drive plate is coaxially disposed between multiple sets of independent drive coils and a low-conductivity metal annular blank, and is used to receive the pulse electromagnetic force of each zone coil during electromagnetic bulging and transmit the radial bulging driving force to the low-conductivity metal annular blank.

[0019] The control system is connected to a time-division multiplex pulse power supply signal and is used to precisely match and adjust the electromagnetic loading parameters of each drive coil according to the deformation requirements of different sections of the sealing ring, so as to realize zoned differentiated electromagnetic expansion drive.

[0020] The annular drive plate is made of a highly conductive material, such as copper.

[0021] The W-shaped metal sealing ring partitioned multi-pulse forming method based on the above-mentioned device, as described in this invention, includes the following steps:

[0022] S1. Blank placement and positioning: Place the high conductivity material ring drive plate inside the low conductivity high temperature alloy ring blank. The diameter of the drive plate is slightly larger than the diameter of the coil. Complete the coaxial and precise positioning and fixing of the drive plate and the high temperature alloy ring blank. Close the mold and lock the forming mold to make the blank and the forming cavity precisely aligned.

[0023] S2. Forming parameter calibration: Based on the deformation and forming resistance differences of each structural section of the W-shaped sealing ring, the discharge voltage, pulse number, and timing interval parameters of each group of drive coils are calibrated through the control system to establish a zoned differentiated electromagnetic loading strategy.

[0024] S3. Separate and timed preforming: The control system drives the time-division multi-channel pulse power supply according to the preset time sequence, controls each group of drive coils to discharge pulses independently in sequence, applies electromagnetic expansion force to different forming sections of the blank step by step, and adopts a small deformation amount multiple pulse progressive forming method to disperse the deformation amount of a single forming and avoid the defects of stress concentration and uneven deformation in the forming of low conductivity materials.

[0025] S4. Full-area synchronous shaping and correction: After the pre-forming process is completed, the control system controls all drive coils to output small-amplitude shaping pulses synchronously to perform full-area fine shaping of the overall outline of the blank, correct local deformation deviations, make the blank completely fit into the forming cavity, and ensure the consistency of the sealing ring cross-sectional dimensions.

[0026] S5. Cooling, demolding, and part removal: After forming, keep the mold closed and allow it to cool naturally to stabilize the forming state and reduce springback fluctuations. After the workpiece cools down to room temperature, open the forming mold and remove the formed W-shaped metal sealing ring to complete the precision forming process.

[0027] Preferably, the low conductivity metal blank is an aerospace high-temperature alloy blank, and the partitioned step-by-step preforming is carried out in sequence according to the segment order of deformation from small to large, so as to gradually release the forming stress of the blank and avoid excessive local deformation.

[0028] Preferably, in the step-by-step preforming process of the partition, the number of pulse discharges in a single forming section is set to 3 to 6 times, the deformation amount of a single pulse forming is controlled to be 15% to 40% of the total deformation amount in that section, and the cumulative deformation amount reaches 100% of the total deformation amount in that section, so as to achieve progressive uniform forming.

[0029] Preferably, the pulse discharge voltage of the full-domain shaping correction is 30% to 50% of the pre-forming pulse voltage. Under the premise of ensuring the workpiece contour accuracy and fit, it effectively suppresses excessive thinning of the workpiece wall thickness and improves the structural strength and dimensional stability of the finished product.

[0030] The basic concept of this invention is to use a high conductivity driving sheet as an electromagnetic force transmission medium, and to implement zoned sequential loading on each deformation section of the W-shaped sealing ring by multiple sets of independent driving coils arranged along the axial direction of the blank, and to adopt a two-stage multi-pulse progressive forming strategy of "gradual pre-forming + full-domain shaping" to achieve precise mold forming of low conductivity high temperature alloy materials.

[0031] Compared with the prior art, the present invention has the following beneficial technical effects:

[0032] 1) This invention achieves active, independently time-controllable, and precise electromagnetic loading of each deformation section of a low-conductivity W-shaped sealing ring. Compared to the axially moving partitioning mechanism used in existing partitioned electromagnetic forming technologies (such as CN109848280A), this invention uses fixed partitioned coils arranged sequentially in layers along the axial direction of the blank. This eliminates the need for axially moving components, resulting in a more compact structure. Furthermore, it allows for independent pulse energy matching for different curvature characteristics of peaks, troughs, and transition zones within the same annular cross-section. Compared to existing technologies that rely on passive force field adjustment based on coil physical structure (such as changes in winding cross-sectional area and switching between series and parallel connections) (such as CN106944528A), this invention uses a time-division multiplex pulse power supply to actively and independently control the discharge timing and voltage amplitude of each coil. This provides greater adjustment freedom, superior control precision, and the ability to dynamically optimize the loading strategy based on the real-time deformation state of different sections. Simultaneously, this invention eliminates the need for complex coil physical structure adjustments, achieving flexible force field control through a time-division multiplex pulse power supply. This simplifies the device structure and reduces manufacturing costs and assembly difficulty.

[0033] 2) This invention utilizes a high-conductivity annular driving plate in conjunction with partitioned independent coils. Electromagnetic force is first applied to the driving plate, which then radially drives the low-conductivity annular blank to expand synchronously. This solves the problems of weak eddy current induction and insufficient forming driving force inherent in low-conductivity materials. Furthermore, by applying differentiated loading to the driving plate through partitioned coils, it overcomes the limitation of traditional driving plate-assisted forming, which only allows for uniform overall deformation. It is important to note that this integration is not a simple superposition of driving plate technology and partitioned coil technology: under the non-uniform pulsed magnetic field of the partitioned coils, the eddy current distribution, electromagnetic force distribution, and deformation mode of the driving plate will undergo fundamental changes. Problems such as partitioned deformation coordination, electromagnetic compatibility, and stress reconstruction, which are not present in traditional driving plate solutions, require technical expertise to overcome and resolve. The forming effect is unpredictable.

[0034] 3) The present invention adopts a partitioned timing and graded progressive pulse forming method, which can accurately match the forming load according to the deformation requirements of different areas of the W-shaped cross section, avoiding problems such as excessive local stretching, uneven wall thickness, wrinkling and cracking caused by traditional single-pulse overall forming, and effectively ensuring the contour of the sealing ring and the sealing fit accuracy.

[0035] 4) This invention can homogenize the internal stress of components, reduce residual stress concentration, and improve the dimensional stability and fatigue resistance of the sealing ring, making it suitable for the demanding operating conditions of aerospace. Furthermore, the solution features adjustable parameters, wide adaptability, high formability and integration, facilitating mass industrial production and possessing significant engineering application and promotional value. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the operation of the device of the present invention;

[0037] Figure 2 This is an exploded view of the components of the device of the present invention;

[0038] Figure 3 This is an exploded view of the magnet assembly of the device of the present invention;

[0039] Figure 4 This is a schematic diagram of the overall device of the present invention;

[0040] Figure 5 This is a schematic diagram of the forming process of the present invention.

[0041] In the diagram: 1. Upper mold base 2. Socket head bolt 3. Fixing sleeve 4. Lower mold base 5. Epoxy skeleton 6. Upper epoxy mold base 7. Lower epoxy mold base 8. Socket head bolt 9. Steel liner 10. Drive plate 11. Blank 12. Die 13. Coil 1 14. Coil 2 15. Coil 3. Detailed Implementation

[0042] 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.

[0043] Example 1

[0044] This embodiment provides a W-shaped metal sealing ring partitioned multi-pulse electromagnetic bulging device and its forming method.

[0045] Device structure:

[0046] like Figure 1 , Figure 2 , Figure 3 As shown, the device of the present invention mainly consists of an upper mold base 1, a lower mold base 4, a fixing sleeve 3, an epoxy skeleton 5, an upper epoxy mold base 6, a lower epoxy mold base 7, a concave mold 12, a driving plate 10, a steel liner 9, and three sets of independent driving coils (coil one 13, coil two 14, and coil three 15).

[0047] The epoxy skeleton 5, upper epoxy mold base 6, lower epoxy mold base 7, steel liner 9, coil one 13, coil two 14, and coil three 15 form a magnet assembly via hexagon socket head cap screws 8, which is coaxially assembled with upper mold base 1 and lower mold base 4. The drive plate 10 is placed inside the center of the blank 11. Upper mold base 1, lower mold base 4, and fixing sleeve 3 are connected via hexagon socket head cap screws 2. Coil one 13, coil two 14, and coil three 15 are three sets of independent drive coils, arranged sequentially in layers along the axial direction of the blank, corresponding to the three different deformation forming sections: the peak area, trough area, and transition area of ​​the W-shaped sealing ring. Each coil is powered by an independent discharge circuit, and the discharge parameters can be independently controlled. The main working areas of each drive coil are interconnected, covering the entire forming area of ​​the blank.

[0048] The drive coil is wound on a hollow epoxy skeleton, and the outer wall of the coil is covered with a high-strength, high-temperature resistant insulating protective layer. A steel liner 9 is inlaid on the hollow epoxy skeleton. The steel liner 9 is a non-closed steel liner, which is formed by two semi-circular ring components joined together. There is a gap between the two semi-circular ring components and they are not connected to each other, forming a non-closed ring structure. This non-closed structure can prevent the steel liner from forming a closed eddy current loop under the action of the pulsed magnetic field, thereby reducing eddy current loss and additional heat generation. At the same time, the steel liner provides radial structural support for the coil and magnet assembly, constrains the structural deformation of the coil assembly during the electromagnetic expansion process, and ensures the stability of the magnetic field distribution and the forming accuracy. The drive plate 10 is made of a high conductivity material (such as copper) into a ring structure and is placed inside the low conductivity high-temperature alloy blank 11. It is used to receive the pulsed electromagnetic force of the partitioned coil and transmit the radial expansion driving force to the blank.

[0049] The time-sharing multi-channel pulse power supply is equipped with three independent energy storage and discharge circuits, each electrically connected to coil one, coil two, and coil three respectively. The energy storage voltage of each circuit is independently adjustable within the range of 0–50kV, and the pulse delay is independently adjustable within the range of 0–100μs, enabling time-sharing, graded, and differentiated pulse discharge for different coils. The control system is connected to the time-sharing multi-channel pulse power supply signal and is used to precisely match and adjust the electromagnetic loading parameters of each drive coil according to the deformation requirements of different sections of the sealing ring.

[0050] Forming method:

[0051] S1. Placing and positioning the blank: Place the high conductivity annular drive plate 10 of copper inside the high temperature alloy annular blank 11. The diameter of the drive plate 10 is slightly larger than the diameter of the coil to complete the coaxial and precise positioning and fixing of the blank. Close the mold and lock the forming mold to make the blank and the forming cavity of the die 12 precisely aligned.

[0052] S2. Forming Parameter Calibration: Based on the differences in deformation and forming resistance in the peak, trough, and transition regions of the W-shaped sealing ring, the discharge voltage, pulse count, and timing interval parameters of the three sets of drive coils are calibrated using the control system. In this embodiment, the peak region has the largest deformation, so it is set to a higher discharge voltage (35kV) and 3 pulses; the trough region has a moderate deformation, so it is set to a medium discharge voltage (28kV) and 3 pulses; the transition region has the smallest deformation, so it is set to a lower discharge voltage (20kV) and 3 pulses. The pulse timing interval for each region is set to 50μs.

[0053] S3. Segmented and Time-Based Pre-forming: The control system drives a time-division multi-channel pulse power supply according to a preset timing sequence, controlling each group of drive coils to discharge pulses independently in sequence. Discharge is performed sequentially according to the order of increasing deformation—first the transition zone, then the trough zone, and finally the peak zone—gradually releasing the forming stress of the blank. The deformation amount of a single pulse forming is controlled to be 30%–40% of the total deformation in that section, achieving progressive and uniform forming.

[0054] S4. Full-area synchronous shaping and correction: After the pre-forming process is completed, the control system controls all drive coils to output small-amplitude shaping pulses synchronously. The shaping pulse discharge voltage is 40% of the pre-forming pulse voltage. The overall contour of the blank is finely shaped throughout the entire area to correct local deformation deviations and make the blank completely fit the forming cavity of the die 12.

[0055] S5. Cooling, Demolding, and Part Removal: After forming, keep the mold closed and allow it to cool naturally for 30 minutes to stabilize the forming state and reduce springback fluctuations. After the workpiece has cooled to room temperature, open the forming mold and remove the formed W-shaped metal sealing ring to complete the precision forming process. The drive piece is a sacrificial disposable piece.

[0056] Forming effect:

[0057] The high-temperature alloy W-shaped sealing ring is formed using the method described in this embodiment. The resulting workpiece has significantly improved wall thickness uniformity, good cross-sectional profile fits well with the mold cavity, and has no local necking or cracking defects. The dimensional accuracy meets the requirements for use of sealing rings in aero-engines.

[0058] Example 2

[0059] The difference between this embodiment and Embodiment 1 is that the number of pulse discharges in a single forming section is set to 6, and the deformation amount of a single pulse forming is controlled at 15% to 18% of the total deformation amount in that section. The pulse discharge voltage for full-domain shaping correction is 30% of the pre-forming pulse voltage. This embodiment is suitable for forming ultra-thin-walled W-shaped sealing rings with thinner walls (≤0.5mm) and higher requirements for deformation uniformity.

[0060] Example 3

[0061] The difference between this embodiment and Embodiment 1 is that the number of drive coils is set to four or six groups to accommodate more complex W-shaped cross-section partitioning requirements. For W-shaped sealing rings with more cross-sectional peaks and troughs, the number of partitioning coils can be increased accordingly to ensure that each deformation characteristic segment has an independent coil for control.

[0062] Industrial applicability

[0063] The W-shaped metal sealing ring partitioned multi-pulse electromagnetic bulging device and method provided by this invention can be widely used in the precision mass production of high-temperature alloy W-shaped sealing rings for aero-engines. It can also be extended to the electromagnetic forming process of other low-conductivity, difficult-to-deform metal ring thin-walled components, and has good industrial practical value and application prospects.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A W-shaped metal sealing ring partitioned multi-pulse electromagnetic expansion device, characterized in that, The system includes a forming mold, a partitioned electromagnetic drive assembly, a time-division multi-channel pulse power supply, a ring drive plate, and a control system. The forming mold has a forming cavity adapted to a W-shaped metal sealing ring structure for molding the workpiece. The partitioned electromagnetic drive assembly includes multiple sets of independent drive coils, which are arranged in layers along the axial direction of the workpiece, and each drive coil is independently arranged corresponding to different deformation and forming sections of the W-shaped sealing ring. The time-division multi-channel pulse power supply is electrically connected to the multiple sets of independent drive coils one-to-one, and each power supply circuit is independently controllable, allowing for individual adjustment of the pulse current amplitude, discharge sequence, and discharge count of each set of drive coils. The annular drive plate is coaxially arranged between multiple independent drive coils and a low-conductivity metal annular blank. It is used to receive the pulsed electromagnetic force of each zone coil during electromagnetic bulging and to transmit the radial bulging driving force to the low-conductivity metal annular blank. The control system is connected to a time-division multiplex pulse power supply signal and is used to accurately match and adjust the electromagnetic loading parameters of each drive coil according to the deformation requirements of different sections of the sealing ring, so as to realize zone-differentiated electromagnetic bulging drive.

2. The W-shaped metal sealing ring partitioned multi-pulse electromagnetic expansion device according to claim 1, characterized in that, The drive coil is wound on a hollow epoxy skeleton, and the outer wall of the coil is covered with a high-strength, high-temperature resistant insulating protective layer. A non-closed steel liner is inlaid on the hollow epoxy skeleton. The non-closed steel liner is formed by two semi-circular ring components joined together, with a gap between the two semi-circular ring components and they are not connected to each other, forming a non-closed ring structure.

3. The W-shaped metal sealing ring partitioned multi-pulse electromagnetic expansion device according to claim 1, characterized in that, The time-division multi-channel pulse power supply is equipped with multiple independent energy storage and discharge circuits. The energy storage voltage and discharge delay parameters of each energy storage and discharge circuit are independently adjustable. The single-channel pulse discharge voltage adjustment range is 0 to 50kV, and the pulse delay adjustment range is 0 to 100μs, which can realize time-division, graded, and differentiated pulse discharge of different coils.

4. The W-shaped metal sealing ring partitioned multi-pulse electromagnetic bulging device according to claim 1, characterized in that, The annular drive plate is made of a highly conductive material.

5. A W-shaped metal sealing ring partitioned multi-pulse forming method based on the device according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Blank placement and positioning: Place the high conductivity material ring drive plate inside the low conductivity high temperature alloy ring blank. The diameter of the drive plate is slightly larger than the diameter of the coil. Complete the coaxial and precise positioning and fixing of the drive plate and the high temperature alloy ring blank. Close the mold and lock the forming mold to make the blank and the forming cavity precisely aligned. S2. Forming parameter calibration: Based on the deformation and forming resistance differences of each structural section of the W-shaped sealing ring, the discharge voltage, pulse number, and timing interval parameters of each group of drive coils are calibrated through the control system to establish a zoned differentiated electromagnetic loading strategy. S3. Separate and timed preforming: The control system drives the time-division multi-channel pulse power supply according to the preset time sequence, controls each group of drive coils to discharge pulses independently in sequence, applies electromagnetic expansion force to different forming sections of the blank step by step, and adopts a small deformation amount multiple pulse progressive forming method to disperse the deformation amount of a single forming and avoid the defects of stress concentration and uneven deformation in the forming of low conductivity materials. S4. Full-area synchronous shaping and correction: After the pre-forming process is completed, the control system controls all drive coils to output small-amplitude shaping pulses synchronously to perform full-area fine shaping of the overall outline of the blank, correct local deformation deviations, make the blank completely fit into the forming cavity, and ensure the consistency of the sealing ring cross-sectional dimensions. S5. Cooling, demolding, and part removal: After forming, keep the mold closed and allow it to cool naturally to stabilize the forming state and reduce springback fluctuations. After the workpiece cools down to room temperature, open the forming mold and remove the formed W-shaped metal sealing ring to complete the precision forming process.

6. The W-shaped metal sealing ring partitioned multi-pulse forming method according to claim 5, characterized in that, The low conductivity metal blank is an aerospace high temperature alloy blank. The partitioned step-by-step preforming is carried out in sequence according to the segment order of deformation from small to large, so as to gradually release the forming stress of the blank and avoid excessive local deformation.

7. The W-shaped metal sealing ring partitioned multi-pulse forming method according to claim 6, characterized in that, During the step-by-step preforming process of the partition, the number of pulse discharges in a single forming section is set to 3 to 6 times, and the deformation amount of a single pulse forming is controlled to be 15% to 40% of the total deformation amount in that section. The cumulative deformation amount reaches 100% of the total deformation amount in that section, thereby achieving progressive and uniform forming.

8. The W-shaped metal sealing ring partitioned multi-pulse forming method according to claim 5, characterized in that, The pulse discharge voltage of the full-domain shaping correction is 30% to 50% of the pre-forming pulse voltage. Under the premise of ensuring the workpiece contour accuracy and fit, it effectively suppresses excessive thinning of the workpiece wall thickness and improves the structural strength and dimensional stability of the finished product.

Images