High-precision forming device and forming process for double-curved surface component

Abstract

The application relates to a high-precision forming device and forming process of a hyperboloid component, and belongs to the technical field of metal stamping forming equipment. The device comprises a base rigid frame, an array of adjustable curved surface modules, a pressure sensing execution unit, a vibration module, a first forming seat installed at the bottom of the pressure sensing execution unit, a second forming seat installed at the top of the pressure sensing execution unit, and the array of adjustable curved surface modules is installed on the first forming seat and the second forming seat respectively, the array of adjustable curved surface modules processes workpieces through the pressure sensing execution unit, the curved surface module has a supporting column and a vibration rod assembly, the vibration rod assembly is slidingly installed in the supporting column, and the vibration rod assembly is in transmission connection with the vibration module to impact the workpieces so as to eliminate stress. The device is used for solving the technical problems of significant cumulative error, difficult springback control and low mold versatility in the process of repeated loading of shape force, segmented mold pressing and welding splicing for processing.

Description

Technical Field

[0001] This invention belongs to the technical field of metal stamping and forming equipment, and specifically relates to a high-precision forming device and forming process for hyperboloid components. Background Technology

[0002] The vacuum chamber of a fusion reactor is the core pressure-bearing component in a tokamak nuclear fusion device that contains plasma. Its inner wall directly faces the high-temperature plasma, thus placing higher demands on the structural strength, dimensional accuracy, and surface quality of the components. Among these, the hyperboloid profile accuracy of the vacuum chamber directly determines the plasma confinement performance and the operational stability of the device. If the profile deviation exceeds the standard, it may lead to plasma rupture and damage to the device.

[0003] Currently, the mainstream manufacturing process for hyperboloid components in fusion reactor vacuum chambers is segmented molding and welding. This process involves manufacturing multiple single-curvature molds, molding the blanks separately, and then welding the components together as a whole.

[0004] Existing technologies derive the springback radius of material processing by establishing a mechanical model for cold forming and studying the mechanical properties of special sheet materials; fitting the surface of the hyperbolic sheet material and mathematically characterizing it; determining the springback amount of the hyperbolic forming mold shape through finite element numerical simulation; processing and manufacturing the outer plate of the curved plate mold; performing heat treatment to finish the insufficient curvature of the outer plate; assembling and spot welding the base plate according to the numbering and partitioning of the base plate on a special mold installation and storage rack; reconstructing the hyperbolic surface shape after each bending using optical surface scanning measurement technology; and manufacturing a template box for real-time measurement and control of the shape accuracy of the sheet material forming.

[0005] The existing processing method for hyperboloid forming equipment establishes a target 3D digital model based on the desired shape; decomposes it into multiple rectangular elements; under the constraint of Gaussian curvature, the minimum energy loading trajectory of strain for each element is solved according to the principle of minimum energy, thereby obtaining the target loading position of the indenter and the designed layout position of the support system; the indenter is driven to apply forming force at the corresponding target loading position, and the support system is arranged at the corresponding designed layout position; after applying the forming force, the real-time shape of the formed workpiece is detected, the point cloud data of the real-time shape is obtained, and the actual 3D digital model is constructed; the difference between the actual 3D digital model and the target 3D digital model is compared, and if the difference exceeds the tolerance range, the indenter is driven again to apply the forming force.

[0006] The existing technology has at least the following problems in its use: During use, repeated loading of forming force and segmented molding and welding splicing processes present technical problems such as significant cumulative error, difficulty in controlling springback, and low mold versatility. Summary of the Invention

[0007] This invention provides a high-precision forming device and forming process for hyperboloid components, which solves the technical problems of significant cumulative error, difficult springback control, and low mold versatility in the prior art during repeated loading of forming force and segmented molding and welding splicing processes.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution: A high-precision forming device for hyperboloid components includes a base rigid frame, an adjustable hyperboloid module array, a pressure sensing and actuation unit, and a vibration module. The base rigid frame includes: a first forming seat installed at the bottom of the pressure sensing and actuation unit; and a second forming seat installed at the top of the pressure sensing and actuation unit. The hyperboloid module array is respectively installed on the first forming seat and the second forming seat, and the hyperboloid module array processes the workpiece through the pressure sensing and actuation unit. Each hyperboloid module has a support column and a vibration rod assembly. The vibration rod assembly is slidably installed in the support column and is transmitted to the vibration module to impact the workpiece to eliminate stress.

[0009] Furthermore, the support column has an inner cylinder and an outer cylinder, with an installation gap between the inner cylinder and the outer cylinder. The inner cylinder has a through sliding hole in the middle, and multiple spaced movable grooves are formed on the inner wall of the sliding hole. The vibration rod assembly is slidably installed in the installation gap. A limiting plate is provided between the inner cylinder and the outer cylinder. A replaceable curved support block is detachably installed in the sliding hole, and the curved support block has a forming block and a drive rod. Multiple limiting blocks are provided on the side wall of the drive rod. The drive rod slides into the sliding hole, and the limiting blocks engage with the movable grooves to achieve sliding installation.

[0010] Furthermore, the vibration rod assembly includes: a drive mounting ring; a support column mounted on the drive mounting ring, one end of the support column being fixed to the drive mounting ring, and the other end of the support column being provided with a fixing block, the support column being slidably mounted in the mounting gap; a first mounting end cap having a fixing groove, the fixing block being engaged in the fixing groove, the first mounting end cap having a stepped surface; and a second mounting end cap being threadedly connected to the first mounting end cap.

[0011] Furthermore, the multiple molding blocks are closely arranged, and each molding block has a molding surface. The first molding seat and the second molding seat both have corresponding molding surfaces. The second mounting end cap transmits vibration to the molding blocks under the drive of the vibration module. The multiple molding blocks are independently controlled to form regional vibration or single-point vibration, which is used to cope with different types of concentrated stress after bending of workpieces of different shapes.

[0012] Furthermore, the curved surface module array consists of 120-150 independent curved surface modules. Each curved surface module is connected to the rigid frame of the base through a high-precision electrically controlled lead screw to achieve position adjustment. The forming surfaces of the first forming seat and the second forming seat form a mold.

[0013] Furthermore, the pressure sensing and execution unit includes a piezoelectric ceramic pressure sensor and a miniature hydraulic cylinder. The piezoelectric ceramic pressure sensor is used to collect the contact pressure value between the module and the workpiece in real time. The miniature hydraulic cylinder, in conjunction with a PID algorithm, dynamically adjusts the pressure applied to each area, thereby making the workpiece fit against the curved surface of the mold.

[0014] A high-precision forming process for hyperboloid components includes the following steps: Step 1: Establishing a material cold-forming constitutive model based on finite element simulation software, inputting the target hyperboloid parameters and material properties of the component, calculating the material springback compensation amount in reverse, generating pre-deformed mold surface data, and reconstructing the mold based on the surface data; Step 2: Cutting the workpiece, hoisting it onto the reconstructed mold, completing the pre-positioning of the blank using a suction cup, applying pressure to the workpiece for initial forming, and using pressure sensors to provide real-time feedback of the contact pressure value. The mold dynamically adjusts the applied pressure according to the contact pressure value to determine the fit between the workpiece and the mold; Step 3: Activating a vibration module to apply vibration to the workpiece, reducing the residual stress to a preset value N1; Step 4: Using an online laser profilometer to scan the contour of the formed part, comparing the measured data with the model, generating a deviation compensation command and feeding it back to the mold, and the mold performs local fine-tuning corrections to the workpiece.

[0015] Furthermore, the step of reconstructing the mold based on surface data in step one includes: determining the elastic modulus and yield strength of the material in the range of 20-800℃ through a high-temperature tensile test; determining the thermophysical parameters corresponding to the thermal expansion coefficient of the material through differential scanning calorimetry; establishing a constitutive model containing the thermophysical properties and mechanical properties of the material in finite element simulation software; inputting the target hyperboloid parameters of the component and the forming pressure process parameters; performing numerical simulation of the forming process; analyzing the material springback law; calculating the material springback compensation amount in reverse according to the numerical simulation results; generating pre-deformed mold surface data; wherein the deviation between the pre-deformed mold surface and the theoretical compensation surface is ≤0.03mm.

[0016] Furthermore, in step three, the step of activating the vibration module to apply vibration to the workpiece and reduce the residual stress to a preset value N1 also includes: setting the vibration frequency preset value P1, the amplitude preset value P2, and the vibration duration T of the vibration module; activating the vibration module to apply vibration and monitoring the stress change inside the component in real time through the stress wave detection device; and stopping the vibration module when the stress wave detection device detects that the residual stress inside the component has dropped below the preset value N1.

[0017] Furthermore, the step of locally fine-tuning and correcting the workpiece using the mold in step four also includes: starting a precision online laser profilometer to perform a full contour scan of the molded part and generating point cloud data; comparing the scanned point cloud data with the theoretical contour model, analyzing the contour deviation of each region, and determining whether there are regions where the deviation exceeds the preset contour value N3; if there are regions where the deviation exceeds the preset contour value N3, the central control system automatically calculates the adjustment amount of the corresponding mold module, the control module performs local fine-tuning, and then repeats steps two to four for that region until the deviation meets the requirements.

[0018] This invention provides a high-precision forming device and forming process for hyperboloid components, with the following advantages: it enables integrated forming of components, eliminating the segmented welding and subsequent machining steps of traditional processes, shortening the production cycle, and reducing the production cycle of single components, making it suitable for mass production; it improves the contour accuracy of hyperboloid components and reduces local deviations, making it suitable for production with more stringent precision requirements; it reuses molds to meet the forming needs of components of various specifications by reconfiguring the same set of mold systems; and it reduces post-processing steps and improves the surface quality of workpieces by actively controlling residual stress through a vibration module. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart illustrating a high-precision forming process for hyperboloid components provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a high-precision forming device for hyperboloid components provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a high-precision forming device for hyperboloid components provided in an embodiment of the present invention in step S100. Figure 4 An exploded view of a high-precision forming device for hyperboloid components provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a high-precision forming device for hyperboloid components provided in an embodiment of the present invention in step S200. Figure 6 This is a schematic diagram of the structure of a high-precision forming device for hyperboloid components provided in an embodiment of the present invention, showing steps S300 and S400. Figure 7 An exploded view of the curved surface module provided in an embodiment of the present invention; Figure 8 This is an exploded view of the vibration rod assembly provided in an embodiment of the present invention; Figure 9 This is a cross-sectional view of a support column provided in an embodiment of the present invention.

[0021] In the figure: 10-Base rigid frame; 101-First forming seat; 102-Second forming seat; 211-Forming block; 212-Drive rod; 213-Limiting block; 221-Inner cylinder; 222-Outer cylinder; 223-Installation gap; 224-Sliding hole; 225-Modular groove; 226-Limiting plate; 231-Drive mounting ring; 232-Support column; 233-Fixing block; 234-First mounting end cap; 235-Fixing groove; 236-Second mounting end cap; 30-Pressure sensing actuator; 50-Central control system; 60-Workpiece. Detailed Implementation

[0022] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0023] Example: like Figures 2 to 9 As shown, a high-precision forming device for hyperboloid components includes a base rigid frame 10, an adjustable hyperboloid module array, a pressure sensing and actuation unit 30, and a vibration module. The base rigid frame 10 includes: a first forming seat 101, installed at the bottom of the pressure sensing and actuation unit 30; and a second forming seat 102, installed at the top of the pressure sensing and actuation unit 30. The adjustable hyperboloid module array is respectively installed on the first forming seat 101 and the second forming seat 102. The adjustable hyperboloid module array processes the workpiece 60 through the pressure sensing and actuation unit 30. The hyperboloid module has a support column and a vibration rod assembly. The vibration rod assembly is slidably installed in the support column and is connected to the vibration module to achieve impact on the workpiece 60 to eliminate stress.

[0024] In this embodiment, the first forming seat 101 and the second forming seat 102 are respectively disposed above and below, and are used to form two forming curved surfaces to form and stamp the workpiece 60. The vibration module drives the vibration rod assembly to impact the formed workpiece 60 to offset the stress generated during the stamping process. The vibration point is on each corresponding curved surface module. Each forming block can be independently controlled, and regional vibration or single-point vibration can be realized, which is convenient for directional stress relief processing of the stress concentration position obtained by simulation, so as to adapt to the forming scenarios of various curved surface components with different shapes.

[0025] Furthermore, the support column has an inner cylinder 221 and an outer cylinder 222, with an installation gap 223 between the inner cylinder 221 and the outer cylinder 222. A through sliding hole 224 is provided in the middle of the inner cylinder 221, and multiple spaced movable grooves 225 are provided on the inner wall of the sliding hole 224. The vibration rod assembly is slidably installed in the installation gap 223. A limiting plate 226 is provided between the inner cylinder 221 and the outer cylinder 222. A replaceable curved support block is detachably installed in the sliding hole 224, and the curved support block has a forming block 211 and a drive rod 212. Multiple limiting blocks 213 are provided on the side wall of the drive rod 212. The drive rod 212 slides into the sliding hole 224, and the limiting blocks 213 engage with the movable grooves 225 to achieve sliding installation.

[0026] In this embodiment, the inner cylinder 221 and the outer cylinder 222 are concentrically distributed. The sliding hole 224 of the inner cylinder 221 can also be used to install pressure sensors to cooperate with the curved support blocks for disassembly and installation. Through the contact drive rod 212, the transmitted pressure is converted into detection parameters. The replaceable curved support blocks are independently set curved blocks after design calculation. Multiple curved support blocks are used to fit tightly together to form the entire molding surface. The multiple curved support blocks can be glued or snap-fitted together to prevent displacement on the corresponding first molding seat 101 and second molding seat 102 distributed on the upper and lower surfaces, which would cause defects on the curved surface and affect the molding quality. The engagement of the limiting block 213 and the movable groove 225 of the rod 212 prevents the drive rod 212 from rotating around the axis. The multiple straight grooves distributed along the axis of the movable groove 225 are used to adjust the distribution position of the limiting block 213 at different heights on the drive rod 212, thereby limiting the movement stroke and indirectly limiting the energy storage stroke of the vibrating rod. This is used to actively adapt to the stress relief function of workpieces 60 of different thicknesses during the design process. Correspondingly, a larger vibration stroke is allowed for thick-walled workpieces 60 to achieve effective vibration and impact, while a smaller stroke is limited for thin-walled workpieces 60 to prevent excessive damage to the structure from vibration and impact.

[0027] Furthermore, the vibrating rod assembly includes: a drive mounting ring 231; a support column 232, mounted on the drive mounting ring 231, with one end of the support column 232 fixed to the drive mounting ring 231 and a fixing block 233 provided at the other end of the support column 232, and the support column 232 slidably mounted in the mounting gap 223; a first mounting end cover 234, having a fixing groove 235, with the fixing block 233 snapped into the fixing groove 235, and the first mounting end cover 234 having a stepped surface; and a second mounting end cover 236, threadedly connected to the first mounting end cover 234.

[0028] In this embodiment, the support column 232 is a structural column with an arc-shaped cross-section. A convex fixing block 233 is provided on the top of the support column 232. The fixing block 233 has a stepped surface that is consistent with the first mounting end cover 234. The first mounting end cover 234 has a fixing groove 235 that is consistent with the fixing block 233. During the gradual engagement of the internal thread of the second mounting end cover 236 and the external threads on the first mounting end cover 234 and the fixing block 233, the second mounting end cover 236 fixes the first mounting end cover 234 and the fixing block 233.

[0029] Furthermore, multiple molding blocks 211 are arranged closely together, and each molding block 211 has a molding surface. The first molding seat 101 and the second molding seat 102 both have corresponding molding surfaces, and the molding surfaces of the first molding seat 101 and the second molding seat 102 constitute a mold.

[0030] The present invention will be further described in detail below with reference to specific embodiments, such as Figures 1 to 9 As shown, this embodiment takes the manufacturing of the inner and outer shell components of a fusion reactor vacuum chamber as an example. The component material of workpiece 60 is 316L stainless steel, and the target hyperboloid parameters are: principal radius of curvature R1=4.2m, secondary radius of curvature R2=6.5m, wall thickness 20mm, and unfolded size 3000mm×2000mm.

[0031] One type of high-precision forming process for hyperboloid components, referring to... Figure 1 As shown, a high-precision forming process for hyperboloid components includes steps S100 to S400, wherein: Step S100: Establish a material cold forming constitutive model based on finite element simulation software, input the target hyperboloid parameters and material properties of the component, calculate the material springback compensation amount in reverse, generate pre-deformed mold surface data, and reconstruct the mold based on the surface data. Step S200: Cut the workpiece 60 and hoist it onto the reconstructed mold. The blank is pre-positioned by a suction cup. The mold applies pressure to the workpiece 60 for initial shaping. The contact pressure value is fed back in real time by setting up pressure sensors. The mold dynamically adjusts the applied pressure according to the contact pressure value to determine the fit between the workpiece 60 and the mold. Step S300: Start the vibration module to apply vibration to the workpiece 60, so that the residual stress is reduced to the preset value N1; In step S400, an online laser profilometer is used to scan the contour of the molded part, the measured data is compared with the model, a deviation compensation command is generated and fed back to the mold, and the mold performs local fine-tuning correction on the workpiece 60.

[0032] Furthermore, a constitutive model for cold forming of the material is established based on finite element simulation software. The target hyperboloid parameters and material properties of the component are input, and the material springback compensation is calculated in reverse. Pre-deformed mold surface data is generated, and the mold is reconstructed based on the surface data. This step also includes: determining the elastic modulus and yield strength of the material in the range of 20-800℃ through high-temperature tensile testing; determining the thermophysical parameters corresponding to the coefficient of thermal expansion of the material through differential scanning calorimetry; establishing a constitutive model in the finite element simulation software that includes the material's thermophysical properties and mechanical properties; inputting the target hyperboloid parameters and forming pressure process parameters of the component; performing numerical simulation of the forming process; and analyzing the material springback law. Based on the numerical simulation results, the material springback compensation is calculated in reverse, and pre-deformed mold surface data is generated. The deviation between the pre-deformed mold surface and the theoretical compensation surface is ≤0.03mm.

[0033] In this embodiment, 316L stainless steel was selected as the material. High-temperature tensile tests revealed its elastic modulus at 20°C to be GPa and its yield strength to be 580 MPa; at 800°C, its elastic modulus to be 110 GPa and its yield strength to be 220 MPa. Differential scanning calorimetry determined its coefficient of thermal expansion in the temperature range of 20°C to 600°C to be 13.5 × 10⁻⁶. -6 / ℃. The finite element simulation software used is ABAQUS. The molding temperature is set to room temperature and the molding pressure range is 35-MPa. The material springback compensation is 0.85mm after numerical simulation analysis. Based on this, the surface data of the pre-deformed mold is generated and imported into the central control system 50. Based on the independent control characteristics of each curved surface module, single-point vibration or regional fixed-point vibration can be initiated in a targeted manner according to the actual stress distribution of the workpiece after bending and forming, precisely applying high-frequency vibration impact to the concentrated stress areas of the workpiece. During the forming process, by preset vibration frequency, amplitude and duration parameters, and in conjunction with a stress wave detection device, the changes in residual stress inside the component are monitored in real time, and the fixed-point vibration operation state is dynamically adjusted to accurately reduce the residual stress of the workpiece to the preset standard value; Simultaneously, by combining the online scanning correction mechanism of the laser profilometer, the forming deviation area is repeatedly stamped, vibrated at fixed points, and stress calibrated to completely eliminate the concentrated residual stress generated during the bending and stamping process of the workpiece, thus avoiding quality defects such as springback, deformation, and cracking of the component and significantly improving the forming accuracy of the hyperboloid component. The mold uses 127 independently adjustable curved surface modules. After the system controls each module to move to the target position via an electrically controlled lead screw, a laser interferometer is used to detect the positioning accuracy of the modules. The positional deviation of all modules is ≤0.05mm. The actual deviation between the pre-deformed mold surface and the theoretical compensation surface is 0.028mm, which meets the requirement of deviation ≤0.03mm. The high-temperature tensile test is conducted at five temperature points: 20℃, 200℃, 400℃, 600℃, and 800℃. Three sets of parallel samples are set at each temperature point, and the average value is taken as the final mechanical parameter to ensure data reliability. Differential scanning calorimetry is performed using a TAQ2000 differential scanning calorimeter with a heating rate of 10℃ / min and a test range of 20-800℃. The thermal expansion coefficient of the material is accurately obtained, providing data support for thermal deformation compensation. The finite element simulation software used is ABAQUS, with solid elements C3D8R used for mesh generation. The mesh size is controlled at 5mm×5mm×3mm. Boundary constraints are set to fix the bottom of the mold and allow the billet to move freely around the edges. The forming pressure is applied according to the actual process curve. The entire forming process is simulated through the explicit dynamic analysis module, with a simulation step size of 1e-5s to ensure the capture of details of material plastic deformation. Numerical simulation allows for direct observation of the stress-strain distribution of the material during the forming process and precise analysis of the springback differences in different regions. The springback in the edge region is typically 30%~50% higher than that in the center region. The springback compensation obtained by reverse calculation is more accurate than traditional empirical values. The surface data of the pre-deformed mold is imported into the central control system 50 in IGES format. The control system communicates with the adjustable surface module array using the EtherCAT bus protocol, with a control response time ≤1ms. A KEYENCELS-9000 series laser interferometer with a measurement resolution of 0.01μm is used to detect the position of the top surface of the module point by point, ensuring that the surface accuracy after mold reconstruction meets the requirements and laying the foundation for subsequent forming accuracy.

[0034] Further, the workpiece 60 is cut and hoisted onto the reconstructed mold. The blank is pre-positioned using suction cups. The mold applies pressure to the workpiece 60 for initial shaping. Pressure sensors provide real-time feedback of the contact pressure value. The mold dynamically adjusts the applied pressure based on the contact pressure value to determine the fit between the workpiece 60 and the mold. This step also includes: cutting the blank to a preset size and performing surface treatment to remove the oxide layer and surface oil; hoisting the pre-treated blank onto the reconstructed mold and pre-positioning the blank using evenly distributed vacuum suction cups; activating the pressure system and applying the corresponding pressure according to the pressure curves corresponding to the edge and center areas. Pressure sensors provide real-time feedback of contact pressure data. The system dynamically adjusts the applied pressure for each area using a PID algorithm. Fit is determined when the difference between the contact pressure and the applied pressure reaches the preset pressure range N2.

[0035] In this embodiment, a 316L stainless steel sheet is cut into 3200mm × 2200mm blanks. First, the surface oxide scale is removed by mechanical grinding, and then the surface oil is wiped off with anhydrous alcohol to complete the pretreatment. Sixteen vacuum suction cups are evenly arranged on the mold. After the pretreated blank is hoisted onto the mold surface, the vacuum system is activated to complete the pre-positioning, ensuring that the blank does not shift. The pressure system is applied according to a pressure curve of 60MPa at the edge area and 35MPa at the center area. Each adjustable curved surface module has a built-in piezoelectric ceramic pressure sensor with a measurement range of 0-100MPa and a resolution of 0.1MPa, acquiring contact pressure data in real time at a frequency of 100Hz. The miniature hydraulic cylinder is configured to dynamically adjust the applied pressure in each area based on PID control logic. The central control system 50 dynamically adjusts the output pressure of the miniature hydraulic cylinder through a PID algorithm. The control system uses a PID algorithm with a proportional coefficient Kp=2.5, an integral time Ti=0.8s, and a derivative time Td=0.2s to calculate the difference between the contact pressure data and the preset pressure, and dynamically adjusts the output pressure of the miniature hydraulic cylinder in each area. It outputs a precise control signal to regulate the pressure output of the miniature hydraulic cylinder. The preset pressure range N2 is set to ±0.5MPa. When the difference between the contact pressure and the set pressure is stable within ±0.5MPa, it is determined that the blank and the mold surface are completely in contact. At this time, the pressure adjustment response time is ≤0.3s.

[0036] Furthermore, the vibration module is activated to apply vibration to the workpiece 60, reducing the residual stress to a preset value N1. This step also includes: setting the vibration frequency preset value P1, the amplitude preset value P2, and the vibration duration T of the vibration module; activating the vibration module to apply vibration, and monitoring the stress change inside the component in real time through the stress wave detection device; when the stress wave detection device detects that the residual stress inside the component has dropped below the preset value N1, the vibration module is stopped.

[0037] In this embodiment, the preset value N1 is set to ≤50MPa, the preset vibration frequency P1 is selected as 150Hz, and the vibration frequency of the vibration module is continuously adjustable within the range of 150-200Hz; the preset amplitude P2 is selected as 0.1mm, the amplitude adjustment range of the vibration module is 0.08-0.12mm, and the amplitude adjustment accuracy is ±0.01mm; the initial vibration duration T is set to 20min. The vibration module uses an electromagnetic vibrator, which is installed at the bottom of the rigid frame 10 of the mold base. After startup, the stress change inside the component is monitored in real time by a stress wave detection device. The stress wave detection device uses an X-ray stress meter. The initial stress value is 110MPa. After 18 minutes of vibration, the stress drops to 48MPa, reaching below the preset value N1. The control system automatically stops the vibration module. The actual vibration duration is 18 minutes. The vibration parameters are set based on the material's natural frequency characteristics. Modal analysis determines the natural frequency range of the 316L stainless steel hyperboloid component to be 140-180Hz, and 150Hz is selected as the preset vibration frequency. The amplitude is set to 0.1mm to ensure stress relief without causing secondary deformation of the component. The electromagnetic vibrator is mounted on a vibration mounting base at the bottom of the rigid frame 10 of the mold base. The mounting base uses rubber damping pads to isolate the vibration and prevent it from being transmitted to other equipment. The excitation force is adjusted in real time by the control system and dynamically optimized based on stress monitoring data to ensure optimal vibration performance. The kinetic energy is precisely applied to the workpiece 60; the stress wave detection device can be an X-ray stress meter, which can realize non-contact real-time monitoring. The detection points are evenly distributed on the surface of the component in a 50mm×50mm grid, with a total of 120 detection points, which fully cover the key areas of the component; the detection data is wirelessly transmitted to the central control system 50, and the system draws a stress distribution cloud map in real time, which intuitively shows the trend of residual stress change; the vibration stops when the residual stress at all detection points drops below 50MPa. Compared with the traditional heat treatment stress relief method, which requires heating to 0-800℃ and holding for 2-4 hours.

[0038] Furthermore, an online laser profilometer is used to scan the contour of the molded part. The measured data is compared with the model to generate a deviation compensation command, which is then fed back to the mold. The mold performs local fine-tuning correction on the workpiece 60. This step also includes: starting the precision online laser profilometer to perform a full contour scan of the molded part and generating point cloud data; comparing the scanned point cloud data with the theoretical contour model to analyze the contour deviation in each region and determine whether there are regions where the deviation exceeds the preset contour value N3; if there are regions where the deviation exceeds the preset contour value N3, the central control system 50 automatically calculates the adjustment amount of the corresponding mold module, the control module performs local fine-tuning, and then the region is pressed and molded again until the deviation meets the requirements.

[0039] In this embodiment, the preset contour value N3 can be specifically set to 0.3 mm / m. After scanning is started, the instrument performs a full-coverage scan of the molded part, generating high-density point cloud data. After comparing it with the theoretical contour model, it is found that the deviation of a certain area on the edge of the component is 0.32 mm / m, which exceeds the preset value N3. The central control system 50 automatically calculates the adjustment amounts of the corresponding three adjustable curved surface modules as 0.02 mm, 0.03 mm, and 0.025 mm, respectively. The central control system 50 converts the deviation data of the laser scan into the precise adjustment amount of the mold module through the built-in data processing algorithm, controls the electric control screw to drive the corresponding module to perform displacement adjustment. After precise fine adjustment, the area is subjected to secondary pressure molding at a pressure of 55 MPa on the edge area. After scanning again, the deviation of the area is reduced to 0.22 mm / m, the overall contour accuracy of the component is 0.28 mm / m, and the maximum local deviation is 0.25 mm. After meeting the accuracy requirements, the processing ends.

[0040] Furthermore, the adaptive mold system includes a base rigid frame 10, an adjustable curved surface module array, a pressure sensing and actuation unit 30, a vibration module, and a central control system 50. The central control system 50 is electrically connected to the adjustable curved surface module array, the pressure sensing and actuation unit 30, the vibration module, the online laser profilometer, and the stress wave detection device, respectively, to receive feedback data and output control commands, thereby realizing mold reconstruction, pressure adjustment, vibration control, and local fine-tuning functions.

[0041] In this embodiment, the base rigid frame 10 is made of high-strength alloy steel and is formed by CNC milling to provide stable support for each functional unit. The central control system 50 adopts a PLC controller with a built-in dedicated data processing module. This data processing module can quickly process feedback data from devices such as laser profilometers and pressure sensors, and communicate with each unit via industrial Ethernet.

[0042] Furthermore, the adjustable curved surface module array consists of 120-150 independent curved surface modules. Each curved surface module is connected to the base rigid frame 10 through a high-precision electric control screw to achieve position adjustment. There are multiple molds, and each mold is installed in a one-to-one correspondence with a curved surface module.

[0043] In this embodiment, the adjustable curved surface module array uses 127 independent modules, which is within the range of 120-150. The forming contact surface of each module is made of high-strength alloy material and the surface is precision ground. The splicing gap between modules is ≤0.1mm. The bottom of each module is connected to the rigid frame 10 of the base through a high-precision electric control screw. The adjustment accuracy of the high-precision electric control screw is ±0.05mm. With the servo motor drive, it can realize the X, Y, and Z directions. Correspondingly, the X, Y, and Z directions can be defined as vertically distributed along the height of the device and two design directions distributed along the length and width of the device, respectively. The specific reference direction setting is independently adjusted according to the actual design and process. The module and the mold are positioned by positioning pins, and the installation deviation requirement is ≤0.03mm. The entire array supports continuous forming of hyperboloids with curvature radii of 0.5m-8m, which is suitable for the processing needs of this embodiment and various specifications of components.

[0044] Furthermore, the pressure sensing and execution unit 30 includes a piezoelectric ceramic pressure sensor and a miniature hydraulic cylinder. The piezoelectric ceramic pressure sensor is used to collect the contact pressure value between the module and the workpiece 60 in real time. The miniature hydraulic cylinder, in conjunction with a PID algorithm, dynamically adjusts the pressure applied to each area, thereby making the workpiece 60 fit against the curved surface of the mold.

[0045] In this embodiment, a piezoelectric ceramic pressure sensor is integrated into the inner side of the contact surface of each adjustable curved surface module. The pressure measurement resolution is 0.1MPa, which can accurately capture minute changes in contact pressure. The micro hydraulic cylinder has a cylinder diameter of 10mm, a stroke range of 0-50mm, and a working pressure range of 0-80MPa. The micro hydraulic cylinder receives the PID adjustment signal from the central control system 50 and realizes dynamic adjustment of the output pressure through the pressure transmission of the hydraulic oil circuit. With the help of the PID algorithm, dynamic closed-loop control of the pressure is realized, with a pressure adjustment accuracy of ±0.2MPa. This ensures that the pressure in each area is adjusted as needed, so that the blank and the mold surface fit tightly together, reducing gaps and overpressure damage.

[0046] In summary, this invention patent accurately obtains material parameters through high-temperature tensile testing and differential scanning calorimetry, and combines this with ABAQUS finite element simulation to achieve springback pre-compensation, ensuring mold reconstruction accuracy. Through zoned pressure loading and PID dynamic adjustment, it achieves tight fit between the billet and the mold. Through precise frequency and amplitude control and real-time stress monitoring by the electromagnetic vibration module, it effectively reduces residual stress in the components. Through closed-loop control of laser profilometer scanning and local mold fine-tuning, it ensures component contour accuracy. Through a modularly designed adaptive mold system, it achieves compatible processing of components of various specifications, realizing integrated high-precision molding of hyperboloid components for fusion reactor vacuum chambers. This shortens the production cycle, achieves a contour accuracy of 0.28 mm / m, residual stress ≤48 MPa, increases mold reuse rate, and improves production efficiency.

Claims

1. A high-precision forming device for hyperboloid components, comprising a rigid base frame (10), an adjustable curved surface module array, a pressure sensing and actuation unit (30), and a vibration module, characterized in that, The base rigid frame (10) includes: The first molding base (101) is installed at the bottom of the pressure sensing and actuation unit (30); The second molding seat (102) is installed on top of the pressure sensing and actuation unit (30); The curved surface module array is respectively installed on the first forming seat (101) and the second forming seat (102), and the curved surface module array processes the workpiece (60) through the pressure sensing execution unit (30); The curved surface module has a support column and a vibration rod assembly. The vibration rod assembly is slidably installed in the support column and is connected to the vibration module to impact the workpiece (60) to eliminate stress.

2. The high-precision forming device for hyperboloid components according to claim 1, characterized in that, The support column has an inner cylinder (221) and an outer cylinder (222). An installation gap (223) is provided between the inner cylinder (221) and the outer cylinder (222). A through sliding hole (224) is provided in the middle of the inner cylinder (221). Multiple spaced movable grooves (225) are provided on the inner wall of the sliding hole (224). The vibration rod assembly is slidably installed in the installation gap (223). A limit plate (226) is provided between the inner cylinder (221) and the outer cylinder (222). A replaceable curved support block is detachably installed in the sliding hole (224). The curved support block has a forming block (211) and a drive rod (212). Multiple limit blocks (213) are provided on the side wall of the drive rod (212). The drive rod (212) slides into the sliding hole (224), and the limit block (213) engages with the movable groove (225) to achieve sliding installation.

3. The high-precision forming device for hyperboloid components according to claim 2, characterized in that, The vibrating bar assembly includes: Drive mounting ring (231); A support column (232) is installed on the drive mounting ring (231). One end of the support column (232) is fixed on the drive mounting ring (231), and a fixing block (233) is provided at the other end of the support column (232). The support column (232) is slidably installed in the mounting gap (223). The first mounting end cap (234) has a fixing groove (235), and the fixing block (233) is engaged in the fixing groove (235). The first mounting end cap (234) has a stepped surface. The second mounting end cap (236) is threadedly connected to the first mounting end cap (234).

4. The high-precision forming device for hyperboloid components according to claim 3, characterized in that, The multiple forming blocks (211) are arranged closely together, and the multiple forming blocks (211) have forming surfaces. The first forming seat (101) and the second forming seat (102) both have corresponding forming surfaces. The second mounting end cap (236) transmits vibration to the forming blocks (211) under the drive of the vibration module. The multiple forming blocks (211) are independently controlled by the vibration module to form regional vibration or single-point vibration, which is used to cope with different types of concentrated stress after bending of workpieces of different shapes.

5. The high-precision forming device for hyperboloid components according to claim 4, characterized in that, The curved surface module array consists of 120-150 independent curved surface modules. Each curved surface module is connected to the base rigid frame (10) through a high-precision electric control screw to achieve position adjustment. The forming surfaces of the first forming seat (101) and the second forming seat (102) form a mold.

6. The high-precision forming device for hyperboloid components according to claim 5, characterized in that, The pressure sensing and execution unit (30) includes a piezoelectric ceramic pressure sensor and a miniature hydraulic cylinder. The piezoelectric ceramic pressure sensor is used to collect the contact pressure value between the module and the workpiece (60) in real time. The miniature hydraulic cylinder is configured to dynamically adjust the pressure applied to each area according to PID control logic, so that the workpiece (60) fits against the mold surface.

7. A high-precision forming process for hyperboloid components, based on the high-precision forming apparatus for hyperboloid components according to any one of claims 1-6, characterized in that, The process includes the following steps: Step 1: Establish a constitutive model of the material for cold forming based on finite element simulation software, input the target hyperboloid parameters and material properties of the component, calculate the material springback compensation amount in reverse, generate the surface data of the pre-deformed mold, and reconstruct the mold based on the surface data; Step 2: Cut the workpiece (60), hoist it onto the reconstructed mold, and use a suction cup to pre-position the blank. The mold applies pressure to the workpiece (60) for initial shaping. Pressure sensors are installed to provide real-time feedback of the contact pressure value. The mold dynamically adjusts the applied pressure according to the contact pressure value to determine the fit between the workpiece (60) and the mold. Step 3: Start the vibration module to apply vibration to the workpiece (60) to reduce the residual stress to the preset value N1; Step 4: Use an online laser profilometer to scan the contour of the molded part, compare the measured data with the model, generate a deviation compensation command and feed it back to the mold, and the mold performs local fine-tuning correction on the workpiece (60).

8. The high-precision forming process for hyperboloid components according to claim 7, characterized in that, The constitutive model for cold forming of the material is established based on finite element simulation software. The target hyperboloid parameters and material properties of the component are input, and the material springback compensation is calculated in reverse to generate pre-deformed mold surface data. The step of reconstructing the mold based on the surface data in step one includes: The elastic modulus and yield strength of the material in the range of 20-800℃ were determined by high temperature tensile test, and the thermophysical parameters corresponding to the coefficient of thermal expansion of the material were determined by differential scanning calorimetry. A constitutive model incorporating the thermophysical properties and mechanical properties of the material is established in finite element simulation software. The parameters of the target hyperboloid of the component and the forming pressure process parameters are input to perform numerical simulation of the forming process and analyze the material springback law. The material springback compensation amount is calculated in reverse based on the numerical simulation results, and the pre-deformed mold surface data is generated. The deviation between the pre-deformed mold surface and the theoretical compensation surface is ≤0.03mm.

9. The high-precision forming process for hyperboloid components according to claim 7, characterized in that, In step three, the step of activating the vibration module to apply vibration to the workpiece (60) and reduce the residual stress to the preset value N1 further includes: Set the vibration frequency preset value P1, the amplitude preset value P2, and the vibration duration T of the vibration module; The vibration module is activated to apply vibration. Based on the stress distribution of workpieces of different shapes, different modules are selected for accurate control and vibration application. The stress wave detection device monitors the stress changes inside the component in real time. When the stress wave detection device detects that the residual stress inside the component has dropped below the preset value N1, the vibration module stops operating.

10. The high-precision forming process for hyperboloid components according to claim 7, characterized in that, The step of making local fine-tuning corrections to the workpiece (60) using the mold in step four also includes: The precision online laser profilometer is activated to perform a full contour scan of the molded part and generate point cloud data. The point cloud data obtained by scanning is compared with the theoretical contour model to analyze the contour deviation of each region and determine whether there are regions where the deviation exceeds the preset contour value N3. If there is a region where the deviation exceeds the preset value N3 of the contour, the central control system (50) automatically calculates the adjustment amount of the corresponding mold module, the control module makes local fine adjustments, and then repeats steps two to four for the region until the deviation meets the requirements.

Images