Elliptical ultrasonic-assisted spinning forming device and method

Abstract

This invention discloses an elliptical ultrasonic-assisted spinning forming apparatus and method. The apparatus includes a workpiece fixture that drives the workpiece to rotate around its centerline. A spinning wheel is freely rotatable and mounted on a tool holder, which is mounted on a feed drive mechanism. The feed drive mechanism, in conjunction with the rotation of the workpiece fixture, allows the spinning wheel to roll over various parts of the workpiece's side surface. A first amplitude transformer is connected at one end to the tool holder and at the other end to a first transducer. A second amplitude transformer forms an angle with the extension direction of the first amplitude transformer, with one end connected to the tool holder and the other end connected to a second transducer. An ultrasonic generator is connected to the first and second transducers to drive the tool holder and the spinning wheel via the first and second amplitude transformers, performing ultrasonic vibration in directions perpendicular and parallel to the workpiece's centerline. The method utilizes this apparatus. By appropriately setting the ultrasonic phase and amplitude, the workpiece surface can be impacted both perpendicularly and tangentially, improving the quality of the spun workpiece.

Description

Technical Field

[0001] This invention relates to the field of workpiece plastic forming technology, and in particular to an elliptical ultrasonic-assisted spinning forming apparatus and method. Background Technology

[0002] Spin forming is a plastic forming process used to manufacture hollow rotating parts. It uses a workpiece fixture to drive the workpiece blank to rotate, and uses a spinning roller to roll the surface of the workpiece blank, gradually pressing the workpiece blank into the required shape. It has the advantages of flexible forming, high material utilization, and suitability for mass production.

[0003] The surface quality of currently spun workpieces still needs to be improved, and the problem of how to provide a spun forming device to produce workpieces with higher surface quality needs to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide an elliptical ultrasonic-assisted spinning forming apparatus and method. The technical problem to be solved is how to provide a spinning forming apparatus that produces workpieces with higher surface quality through spinning.

[0005] To achieve the above objectives, the solution of the present invention is as follows:

[0006] An elliptical ultrasound-assisted spinning forming apparatus, comprising:

[0007] Workpiece clamps: used to clamp and fix workpieces, and can rotate to drive the workpiece to rotate around its center line;

[0008] Spinning roller: Located beside the workpiece fixture, it is freely rotatable and mounted on the tool holder;

[0009] Tool Post and Feed Drive Mechanism: The tool post is mounted on the feed drive mechanism, which can drive the tool post to move parallel and perpendicular to the workpiece centerline, and cooperate with the workpiece fixture to rotate so that the spinning wheel presses various parts of the workpiece side.

[0010] Ultrasonic vibration assembly: includes a first amplitude transformer and a second amplitude transformer, which are set at an angle to each other and are connected to a knife holder at one end. It also includes a first transducer and a second transducer, with the first transducer connected to the other end of the first amplitude transformer and the second transducer connected to the other end of the second amplitude transformer. An ultrasonic generator is connected to both the first and second transducers.

[0011] The ultrasonic generator is used to drive the spinning wheel to perform ultrasonic vibration perpendicular to the center line of the workpiece and ultrasonic vibration parallel to the center line of the workpiece, with a phase difference and / or amplitude difference between them. A real-time feedback control system is used to acquire local curvature data of the workpiece surface and dynamically adjust the phase difference so that the spinning wheel performs periodic vibration in a circular or elliptical or straight trajectory in a set direction.

[0012] Furthermore, the axis of rotation of the spinning wheel is parallel to the center line of the workpiece; the first amplitude rod is perpendicular to the center line of the workpiece, and the second amplitude rod is parallel to the center line of the workpiece; it also includes a frame, and the tool drive mechanism includes a first lead screw slide assembly and a second lead screw slide assembly; the first lead screw slide assembly includes a first lead screw rotatably mounted on the frame and parallel to the center line of the workpiece, and a first slide slidably mounted on the frame and threadedly connected to the first lead screw; the second lead screw slide assembly includes a second lead screw rotatably mounted on the first slide and perpendicular to the center line of the workpiece, and a second slide slidably mounted on the first slide and threadedly connected to the second lead screw; the tool holder is mounted on the second slide.

[0013] Furthermore, the workpiece fixture is rotatably mounted on the machine frame; the tool holder is mounted on the second slide table via a height adjustment mechanism, which can drive the tool holder to make linear displacement along the sliding direction perpendicular to the first slide table and the second slide table.

[0014] Furthermore, the outer ring of the spinning wheel that contacts the workpiece has a circular cross-section; it also includes a controller connected to an ultrasonic generator for real-time control of ultrasonic vibration during the spinning process, so that the spinning wheel makes vibration contact with the workpiece in a direction tangential to the pre-formed surface of the workpiece.

[0015] An ultrasonic-assisted spinning forming method utilizes an elliptical ultrasonic-assisted spinning forming device as described above. This method employs a real-time feedback control system to acquire local curvature data of the workpiece surface. Based on the workpiece surface contour, the ultrasonic generator is adjusted in real-time to drive the vibration of the first and second amplitude transformers. In the first stage, the spinning wheel impacts the workpiece surface tangentially. This tangential impact achieves two effects simultaneously: firstly, it performs preliminary surface modification; secondly, it generates shear stress, compressing the material along the tangential direction, effectively promoting the flow of surface metal towards the forming direction, thereby significantly improving the subsequent forming performance of the material. In the second stage, the impact direction of the spinning wheel is adjusted so that it impacts along the normal direction of the workpiece. This normal impact serves as a finishing process, performing secondary spinning modification on the surface treated in the first stage. The energy of the impact in this stage is concentrated on the workpiece surface, having a relatively small impact on the macroscopic flowability and overall deformation of the material. The main purpose is to refine and shape the workpiece after the previous processing, improving surface quality and performance, thereby reducing roughness and increasing smoothness.

[0016] After completing the first stage of spinning along the tangential direction of the workpiece, the spatial orientation of the spinning wheel is adjusted a second time to change its contact angle with the workpiece from tangential to normal. Then, the workpiece surface is rolled a second time using the contact surface with a larger radius of curvature on the spinning wheel. This normal rolling process aims to eliminate the micro-ripples and residual stress generated by the first tangential spinning, thereby significantly improving the surface quality of the workpiece and reducing its roughness.

[0017] The beneficial effects of the present invention after adopting the above scheme are as follows: the workpiece fixture drives the workpiece to rotate around the workpiece centerline, the spinning wheel is freely rotatably mounted on the tool holder, the tool holder is mounted on the tool feed drive mechanism, the tool feed drive mechanism cooperates with the rotation of the workpiece fixture to enable the spinning wheel to roll onto various parts of the side of the workpiece, one end of the first amplitude rod is connected to the tool holder, and the other end is connected to the first transducer, the second amplitude rod is arranged at an angle with the first amplitude rod, one end is connected to the tool holder, and the other end is connected to the second transducer, the ultrasonic generator is connected to the first transducer and the second transducer, so as to drive the tool holder to drive the spinning wheel through the first amplitude rod and the second amplitude rod to perform ultrasonic vibration in the directions perpendicular to and parallel to the workpiece centerline, and then, during the spinning process along the workpiece surface, by reasonably setting the phase and amplitude of the ultrasonic generator to drive the spinning wheel to generate vibration in two directions, it is possible to achieve impact on the workpiece surface in the perpendicular direction and the tangential direction along the workpiece surface respectively, thereby effectively improving the surface quality of the spun workpiece. Attached Figure Description

[0018] Figure 1 This is a perspective view of the present invention;

[0019] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0020] Figure 3 This is a perspective view of the invention from another angle;

[0021] Figure 4 for Figure 3 A magnified view of a section at point B in the middle;

[0022] Figure 5 A cross-sectional view of the preferred spinning wheel;

[0023] Figure 6 This is a schematic diagram showing the position of the workpiece's centerline.

[0024] Figure 7 A schematic diagram of a preferred elliptical vibration trajectory of a spinning wheel;

[0025] Figure 8 This is a schematic diagram of the equivalent vibration in the first stage;

[0026] Figure 9 Schematic diagram of actual phase angle and theoretical phase angle;

[0027] Figure 10 This is a schematic diagram of the equivalent vibration in the second stage.

[0028] Labeling Explanation: 1-Workpiece Fixture, 2-Workpiece, 3-Spinning Roller, 4-Tool Post, 5-Tool Feed Drive Mechanism, 6-Workpiece Centerline, 7-First Amplitude Variable Rod, 8-First Transducer, 9-Second Amplitude Variable Rod, 10-Second Transducer, 11-Ultrasonic Generator, 12-Frame, 13-First Lead Screw Slide Assembly, 14-Second Lead Screw Slide Assembly, 15-First Lead Screw, 16-First Slide, 17-Second Lead Screw, 18-Second Slide, 19-Height Adjustment Mechanism, 21-First Handwheel, 22-Second Handwheel, 23-Vibration Trajectory, 24-Workpiece Surface, 25-Tangent Point, 26-Equivalent Spinning Roller, 27-Normal Direction. Detailed Implementation

[0029] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Embodiments of the invention will now be described in full with reference to the accompanying drawings. It should be noted that the invention may be implemented in various forms and is not limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0031] This invention provides an elliptical ultrasound-assisted spinning forming device, such as... Figure 1-10As shown, it includes: a workpiece clamp 1, a spinning wheel 3, a tool holder 4, a feed drive mechanism 5, a first amplitude transformer 7, a first transducer 8, a second amplitude transformer 9, a second transducer 10, and an ultrasonic generator 11; the workpiece clamp 1 is used to clamp and fix the workpiece 2, that is, it can clamp and fix the workpiece 2 or release it, and is rotatably set, preferably electrically rotatable (with a main shaft connected to a motor), so as to drive the workpiece 2 to rotate around the workpiece centerline 6; the spinning wheel 3 is located beside the workpiece 2 on the workpiece clamp 1 and is freely rotatably mounted on the tool holder 4; the tool holder 4 is mounted on the feed drive mechanism 5; the feed drive mechanism 5 is used to... The drive tool holder 4 moves at least parallel and perpendicular to the workpiece centerline 6 to coordinate with the rotation of the workpiece clamp 1, allowing the spinning roller 3 to roll onto various parts of the side of the workpiece 2. Movement perpendicular to the workpiece centerline 6 causes the spinning roller 3 to move radially closer to or further away from the workpiece, adapting to diameter changes at different axial positions. Movement parallel to the workpiece centerline 6 causes the spinning roller 3 to displace axially along the workpiece. A first amplitude transformer 7 (a conventional ultrasonic amplitude transformer used to amplify the amplitude or velocity of mechanical vibrations and focus ultrasonic energy onto a small area) is connected at one end to the tool holder 4. Transducer 8 (a conventional ultrasonic transducer, whose function is to convert input electrical power into mechanical power (i.e., ultrasound) and then transmit it) is connected to the other end of the first amplitude transformer 7; the second amplitude transformer 9 (a conventional ultrasonic amplitude transformer, used to amplify the amplitude or velocity of mechanical vibration and focus ultrasonic energy into a small area) is arranged at an angle to the first amplitude transformer 7, with one end connected to the tool holder 4; the second transducer 10 (a conventional ultrasonic transducer, whose function is to convert input electrical power into mechanical power (i.e., ultrasound) and then transmit it) is connected to the other end of the second amplitude transformer 9. The ultrasonic generator 11 (a device that converts mains power into high-frequency AC power to drive the transducer) is connected to the first transducer 8 and the second transducer 10. It is used to drive the tool holder 4 and the spinning wheel 3 via the first amplitude transformer 7 and the second amplitude transformer 9 to perform ultrasonic vibration in directions perpendicular to and parallel to the workpiece centerline 6. In a more specific embodiment, the first amplitude transformer 7 is perpendicular to the workpiece centerline 6, while the second amplitude transformer 9 is parallel to the workpiece centerline 6. Of course, this specific embodiment is not the limitation. The angle settings of the two can achieve the above-mentioned ultrasonic impact effect.

[0032] In operation, the present invention first clamps the workpiece 2 to be processed onto the workpiece fixture 1, ensuring that its centerline is aligned with the axis of rotation. The elliptical ultrasonic vibration parameters (i.e., the parameters of the ultrasonic generator 11) are then set. The main control parameters of the elliptical ultrasonic vibration include frequency, amplitude, and phase angle (the phase difference angle between the vibrations of the first amplitude transformer 7 and the second amplitude transformer 9). Typically, the ultrasonic frequency is between 20kHz and 40kHz. Then, two sine functions with an initial phase difference are output, and the sinusoidal AC signal is continuously adjusted according to the material processing conditions and requirements to regulate the processing. Parameters such as the spinning gap, spinning wheel feed ratio, and spindle speed (the workpiece fixture 1 is mounted on the spindle) are determined based on the workpiece. These parameters ensure the production... The precision and surface quality of the workpiece are important factors. Depending on the process requirements, single or multiple spinning operations can be performed. The multi-pass spinning process parameters and the spinning wheel 3 can be selected according to requirements. After the parameters are set, processing can begin. The workpiece fixture 1 drives the workpiece 2 to rotate around the workpiece centerline 6, and then the tool drive mechanism 5 drives the tool holder 4 to move. The spinning wheel 3, following the movement of the tool holder 4, presses against the surface of the workpiece 2. Simultaneously, the ultrasonic generator 11 is activated, causing the tool holder 4 to vibrate perpendicularly to the workpiece centerline 6 through the first transducer 8 and the first amplitude transformer 7 (vibrating according to the previously set parameters). This, in turn, causes the spinning wheel 3 to vibrate perpendicularly to the workpiece centerline 6 on the workpiece surface 24, which is then transmitted through the second transducer 10 and the second amplitude transformer. 9. The tool holder 4 vibrates parallel to the workpiece centerline 6 (vibrating according to the previously set parameters), which in turn causes the spinning roller 3 to vibrate parallel to the workpiece centerline 6 on the workpiece surface 24. By adjusting the phase and amplitude of the vibrations perpendicular to and parallel to the workpiece centerline 6 driven by the ultrasonic generator 11 (according to the previously set parameters), the spinning roller 3 can be made to impact the workpiece 2 surface with a composite motion trajectory in two directions, such as an ellipse. This achieves the formation of normal and tangential impact components on the surface of the workpiece 2. The normal component can play the role of ultrasonic impact, and the tangential component can improve the fluidity of the material. On the one hand, it reduces the deformation and springback of the workpiece 2. On the other hand, the lateral extrusion force of the spinning roller 3 makes the material of the workpiece 2 more tangentially formed. The process is smoother and more uniform, reducing the possibility of deformation and springback of workpiece 2 after forming. It also reduces spinning force and friction, enhancing the lateral fluidity of the workpiece and improving its precision. Due to reduced friction, the workpiece surface is less damaged during processing, thus improving surface finish. The normal component acts as an ultrasonic impactor, while the tangential component improves material fluidity and surface quality. Simultaneously, the frequency of ultrasonic vibration reduces friction between the spinning wheel 3 and workpiece 2, extending the lifespan of the spinning wheel. The reduced processing force and friction enhance the lateral fluidity of the workpiece blank, improving its precision. This is achieved using a flange spinning wheel (…). Figure 5The special edge structure (as shown) allows it to be used in machining processes with a wide range of angles. Simultaneously, the frequency of ultrasonic vibration reduces friction between the tool and the material, extending tool life. This method can be applied to various materials, including metals and plastics. Once the workpiece reaches the desired shape and size, the feed is stopped, and the forming process is complete. Measuring tools (such as vernier calipers and micrometers) are used to check the dimensional accuracy of the workpiece to ensure it meets design requirements. Depending on the workpiece requirements, heat treatment (such as annealing or quenching) may be necessary to release residual stress.

[0033] Regarding phase difference angle control: First, the curvature of the workpiece surface needs to be sensed using sensors or measurement systems (such as laser scanning or contact measurement). Curvature can be obtained from the normal direction on the surface or by calculating local curvature. Local curvature: The degree of curvature can be determined by fitting a local area of ​​the workpiece surface and calculating the curvature of that area. Curvature is usually represented using the second derivative or obtained by fitting an ellipse to the surface. Normal direction: The normal direction is calculated based on the curvature. The normal direction is the directional reference for the ultrasonic vibration path because the ultrasonic vibration direction is closely related to the normal direction of the workpiece surface. Then, the phase difference is dynamically adjusted. Preferably, this work is performed in real time based on changes in the curvature of the workpiece surface. When the curvature of the workpiece surface changes, a real-time feedback control system uses sensors to acquire local curvature data of the workpiece surface, and adjusts the phase difference in real time through the feedback control system. Based on different curvature regions, the vibration trajectory is automatically optimized. Assuming that the normal direction and the curvature k at this point are known, and assuming that the principal axis direction of the vibration trajectory needs to be aligned with the normal direction, the phase difference is adjusted to achieve this goal. The adjustment formula for the phase difference can be obtained by calculating the angle between the vibration direction and the normal direction:

[0034] ;

[0035] in, and Here is the parametric equation for an elliptical locus. The function representing the displacement of the spinning wheel along the x-axis (horizontal direction) as a function of time t. The function representing the displacement of the spinning wheel in the y-axis direction (vertical direction) as a function of time t;

[0036] In order for the principal axis of the ellipse to be aligned with the normal direction 27, the following must also be satisfied:

[0037] ;

[0038] in, It is the component of the normal unit vector n at the contact point between the workpiece surface and the spinning wheel in the x-direction of the tool (spinning wheel) coordinate system. It is the component of the normal unit vector n at the contact point between the workpiece surface and the spinning wheel in the y-direction of the tool (spinning wheel) coordinate system;

[0039] By adjusting the phase difference, we can align the principal axis of the trajectory with the normal direction of the workpiece surface, thus adapting the vibration path to the surface curvature. Based on this relationship, the phase difference can be approximated by the following function:

[0040] ;

[0041] .

[0042] To ensure the effectiveness of the tangential impact, it is preferable that the spinning wheel 3 rotates around an axis, and the axis of rotation of the spinning wheel 3 is parallel to the center line 6 of the workpiece.

[0043] The tool feed drive mechanism 5 can be any existing two-axis drive mechanism capable of achieving the above functions. Specifically, in this embodiment, it includes a frame 12, a first lead screw slide assembly 13, and a second lead screw slide assembly 14. The first lead screw slide assembly 13 includes a first lead screw 15 and a first slide 16. The first lead screw 15 is rotatably mounted on the frame 12, and the first slide 16 is slidably mounted on the frame 12. The first lead screw 15 extends in a direction parallel to the workpiece centerline 6, and the first slide 16 is threadedly connected to the first lead screw 15 so that when the first lead screw 15 rotates, it drives the first slide 16 to move in a direction parallel to the workpiece centerline 6. The second lead screw slide assembly 14 includes a second lead screw 17 and a second slide 18. The second lead screw 17... The first slide 15 is rotatably mounted on the first slide 16, and the second slide 18 is slidably mounted on the first slide 16 to move with the first slide 16. The second lead screw 17 extends in a direction perpendicular to the workpiece centerline 6. The second slide 18 is threadedly connected to the second lead screw 17 so that when the second lead screw 17 rotates, it can drive the second slide 18 to move in a direction perpendicular to the workpiece centerline 6. The tool holder 4 is mounted on the second slide 18. The rotation of the first lead screw 15 and the second lead screw 17 can be manually driven or electrically driven. Specifically, in this embodiment, the end of the first lead screw 15 is provided with a first handwheel 21, and the end of the second lead screw 17 is provided with a second handwheel 22. The tool holder 4 is manually driven to move by the first handwheel 21 and the second handwheel 22.

[0044] In order to flexibly adjust the position of the spinning roller 3 so as to adjust the impact direction by adjusting the position of the spinning roller 3, for example, so that the ultrasonic vibration perpendicular to the workpiece centerline 6 acts on the workpiece 2 to generate an impact perpendicular to the surface of the workpiece 2, or an impact inclined to the surface of the workpiece 2, etc., in a preferred embodiment, the tool holder 4 is mounted on the second slide 18 by a height adjustment mechanism 19. The height adjustment mechanism 19 can drive the tool holder 4 to make linear displacement along the sliding direction perpendicular to the first slide 16 and the second slide 18.

[0045] In a more specific embodiment, the workpiece fixture 1 is rotatably mounted on the frame 12 with the rotating shaft extending laterally. The tool post 4, driven by the tool drive mechanism 5, performs horizontal and vertical displacement (three-axis spatial displacement) in two directions. It can be modified from an existing horizontal lathe. It only requires replacing the original lathe tool and corresponding mounting structure with the tool post 4 in this application, and then installing the workpiece fixture 1 on the spindle of the lathe. It has the advantage of low cost.

[0046] The outer ring of the spinning wheel 3 has a circular cross-section at the contact point with the workpiece 2, which facilitates the machining of irregular rotating bodies. This spinning wheel 3 not only satisfies the longitudinal machining angle but also the transverse machining angle, specifically equivalent to... Figure 8 As shown, during processing, a tangent point 25 is formed with the workpiece surface, and the tangent in the direction perpendicular to the workpiece surface can be equivalent to an equivalent spinning wheel 26.

[0047] The ultrasonic generator 11 drives the spinning wheel 3 to perform ultrasonic vibration perpendicular to the workpiece centerline 6 and ultrasonic vibration parallel to the workpiece centerline 6, with a phase difference and / or amplitude difference between them, so that the vibration trajectory 23 of the spinning wheel 3 is circular or elliptical. Of course, the phase and amplitude can be set as needed, for example, according to the contour shape of different positions on the surface of the workpiece 2, so as to adjust in real time during the processing and ensure the consistency of the processing effect at each position.

[0048] Preferably, a controller is also included. The controller is connected to the ultrasonic generator 11. During the process of the spinning roller 3 rolling the surface of the workpiece 2, the ultrasonic generator 11 drives the vibration of the spinning roller 3 in real time, so that the spinning roller 3 can vibrate and contact the surface of the workpiece 2 along a direction tangential to the surface of the workpiece 24. Of course, the vibration trajectory can also be adjusted according to the required processing effect. The controller can be an existing programmable controller or a controller built into the ultrasonic generator 11. As long as it can be preset so that the spinning roller 3 makes corresponding vibration adjustments when processing different positions, and maintains the processing consistency at each position on the surface of the workpiece 2, it is acceptable.

[0049] An ultrasonic-assisted spinning forming method uses an elliptical ultrasonic-assisted spinning forming device as described above. The method adjusts the vibration of the ultrasonic generator 11 driving the first amplitude rod 7 and the second amplitude rod 9 in real time according to the surface contour shape of the workpiece 2, so that the spinning wheel 3 can simultaneously impact the surface of the workpiece 2 in two directions: perpendicular to the workpiece 2 and tangential to the workpiece 2.

[0050] An explanation of the principle behind elliptical ultrasonic vibration:

[0051] The basic principle behind the elliptical motion generated by two orthogonal amplitude rods is to synthesize an elliptical trajectory by precisely controlling the amplitude and phase difference of their vibration components in two orthogonal directions. The difference in vibration amplitude determines the major and minor axes of the ellipse, while the phase difference controls the rotation and shape of the ellipse.

[0052] The tool trajectory in elliptical vibration ultrasonic machining is an ellipse, and its motion equation can be expressed by parametric equations:

[0053] ; ;

[0054] ;

[0055] Combining the two formulas, the trajectory parametric equation is as follows:

[0056] ;

[0057] When the phase difference angle is equal to 90°, the specific trajectory curve of the ellipse is a straight line. By controlling the amplitude ratio of the X-axis and Y-axis, a straight line can be used to achieve vertical ultrasonic impact of any normal phase.

[0058] ;

[0059] This indicates that the trajectory is a straight line passing through the origin.

[0060] When faced with complex irregular curved surfaces, this technology can accurately locate any point on the surface. By adjusting the amplitude ratio and thus precisely controlling the impact direction, it can achieve impact modification along the normal direction at this point, greatly expanding the application range of impact modification technology on complex shaped workpieces.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the design of this case. All equivalent changes made based on the key design features of this case shall fall within the protection scope of this case.

Claims

1. An elliptical ultrasonic-assisted spinning forming device, characterized in that, include: Workpiece clamp (1): Used to clamp and fix workpiece (2), and can rotate to drive workpiece (2) to rotate around workpiece centerline (6); Spinning wheel (3): Located on the side of the workpiece fixture (1), it is freely rotatable and mounted on the tool holder (4); Tool holder (4) and tool drive mechanism (5): The tool holder (4) is mounted on the tool drive mechanism (5). The tool drive mechanism (5) can drive the tool holder (4) to move in parallel and perpendicular directions along the workpiece centerline (6). In conjunction with the rotation of the workpiece fixture (1), the spinning wheel (3) rolls the workpiece (2) on all sides. Ultrasonic vibration assembly: includes a first amplitude transformer (7) and a second amplitude transformer (9), the first amplitude transformer (7) and the second amplitude transformer (9) are set at an angle, and one end of each is connected to a knife holder (4). It also includes a first transducer (8) and a second transducer (10), the first transducer (8) is connected to the other end of the first amplitude transformer (7), the second transducer (10) is connected to the other end of the second amplitude transformer (9), and the first transducer (8) and the second transducer (10) are connected to an ultrasonic generator (11). The ultrasonic generator (11) is used to drive the spinning wheel (3) to perform ultrasonic vibration perpendicular to the workpiece centerline (6) and ultrasonic vibration parallel to the workpiece centerline (6), with a phase difference and / or amplitude difference between them. The real-time feedback control system is used to obtain local curvature data of the workpiece surface and dynamically adjust the phase difference so that the spinning wheel (3) can perform periodic vibration in a circular or elliptical or straight trajectory in a set direction. According to the surface contour of the workpiece (2), the ultrasonic generator (11) is adjusted in real time to drive the first amplitude rod (7) and the second amplitude rod (9) to vibrate. In the first stage, the spinning wheel (3) impacts the surface of the workpiece (2) along the tangential direction. This tangential impact achieves two effects at the same time: first, it performs preliminary modification on the surface of the workpiece; second, it generates a shear stress, squeezes the material along the tangential direction, promotes the flow of the surface metal towards the forming direction, thereby improving the subsequent forming performance of the material. In the second stage, the impact direction of the spinning wheel (3) is adjusted so that it impacts the normal direction of the workpiece (2). The normal impact in this stage is used as a finishing method to perform secondary spinning modification on the surface treated in the first stage. The energy of the impact in this stage is concentrated on the surface of the workpiece, and has little impact on the macroscopic fluidity and overall deformation of the material. This is to refine and straighten the workpiece after the previous processing, improve the surface quality and performance, thereby reducing roughness and improving smoothness.

2. The elliptical ultrasonic-assisted spinning forming device according to claim 1, characterized in that: The rotating shaft of the spinning wheel (3) is parallel to the workpiece centerline (6); the first amplitude rod (7) is perpendicular to the workpiece centerline (6), and the second amplitude rod is parallel to the workpiece centerline (6); it also includes a frame (12), and the tool drive mechanism (5) includes a first lead screw slide assembly (13) and a second lead screw slide assembly (14); the first lead screw slide assembly (13) includes a first lead screw (15) rotatably mounted on the frame (12) and parallel to the workpiece centerline (6), and a first slide (16) slidably mounted on the frame (12) and threadedly connected to the first lead screw (15); the second lead screw slide assembly (14) includes a second lead screw (17) rotatably mounted on the first slide (16) and perpendicular to the workpiece centerline (6), and a second slide (18) slidably mounted on the first slide (16) and threadedly connected to the second lead screw (17); the tool holder (4) is mounted on the second slide (18).

3. The elliptical ultrasonic-assisted spinning forming device according to claim 2, characterized in that: The workpiece fixture (1) is rotatably mounted on the frame (12); the tool holder (4) is mounted on the second slide (18) through a height adjustment mechanism (19), which can drive the tool holder (4) to make linear displacement along the sliding direction perpendicular to the first slide (16) and the second slide (18).

4. The elliptical ultrasonic-assisted spinning forming device according to claim 1, characterized in that: The outer ring of the spinning wheel (3) that contacts the workpiece (2) has a circular cross section; it also includes a controller connected to an ultrasonic generator (11) for controlling ultrasonic vibration in real time during the spinning process, so that the spinning wheel (3) vibrates in contact with the workpiece (2) in a direction tangential to the pre-formed surface of the workpiece (2).

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