Ultrathin-walled tube ball spinning die assisted by ultrasonic vibration

Abstract

The invention belongs to the technical field of die design, and particularly relates to an ultrasonic vibration-assisted ultra-thin-walled tube ball spinning die, an ultrasonic vibration mechanism is fixed to a supporting piece, the output end of the ultrasonic vibration mechanism drives a vibration transmission frame to vibrate, and a second slope on a second protrusion at the top end of the vibration transmission frame abuts against a first slope on a first protrusion at the bottom end of a female die; the vibration energy is transmitted to the female die; the female die floats in the barrel in a fine adjustment mode through the first gap and the second gap and is self-adaptively centered on the ultra-thin-wall pipe blank, meanwhile, a plurality of balls circumferentially arranged in a first through hole and a first step hole in the female die conduct spinning machining on the pipe blank under the assistance of vibration, materials are effectively softened, and plastic flowing is promoted; ultrasonic vibration directly acts on a deformation area, the forming quality of the ultra-thin wall pipe is improved, and uneven wall thickness and surface defects are reduced. The clearance floating structure ensures the self-adaptive centering of the female die and controls the thinning amount; the whole structure is compact, the vibration transmission path is efficient, the device is suitable for vertical driller refitting, and machining precision and yield are improved.

Description

Technical Field

[0001] This invention belongs to the field of mold design technology, and in particular relates to an ultrasonic vibration-assisted ultra-thin wall tube ball spinning mold. Background Technology

[0002] Ultra-thin-walled tubes are widely used in aerospace, precision instruments, and medical devices due to their advantages such as lightweight and high structural efficiency. Ball spinning, as a key process for plastic forming of such tubes, applies pressure to the tube blank using balls, causing localized plastic deformation, thereby achieving the purpose of thinning, sizing, or shaping.

[0003] However, traditional ball spinning process has many problems in the processing of ultra-thin wall tubes: First, the forming quality is poor. Due to the large deformation resistance and poor fluidity of ultra-thin wall tube materials, defects such as uneven wall thickness distribution, increased surface roughness, orange peel texture, and even microcracks are prone to occur during the spinning process, which seriously affect the service performance of the product. Secondly, controlling the thinning amount is difficult. Under severe shear deformation, the wall thickness in some areas is reduced excessively, making it difficult to meet the high-precision dimensional tolerance requirements, resulting in a low yield.

[0004] To address this, an ultrasonic vibration-assisted ultrathin-walled tube ball spinning die is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide an ultrasonic vibration-assisted ultrathin-walled tube ball spinning die to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following solution: An ultrasonic vibration-assisted ultrathin-walled tube ball spinning die includes: a cylindrical body, a support member fixedly disposed at the top end of the cylindrical body, an ultrasonic vibration mechanism fixedly disposed on the support member, a transmission frame fixedly disposed at the output end of the ultrasonic vibration mechanism, the transmission frame extending into the cylindrical body, a female mold disposed within the cylindrical body, the female mold and the transmission frame being disposed vertically correspondingly, a first gap being left between the female mold and the inner wall of the cylindrical body, a first through hole coaxially opened on the female mold for the ultrathin-walled tube to pass through, a first stepped hole circumferentially opened at the top end of the inner wall of the first through hole, and a plurality of balls circumferentially disposed within the first stepped hole; The top of the vibration transmission frame is fixed with two second protrusions, which are symmetrically arranged at the center. The top of the second protrusions is provided with a second slope, and the two second slopes are arranged opposite to each other. The bottom end of the female mold is fixed with two first protrusions, the two first protrusions are correspondingly arranged with two second protrusions, and the bottom end of the first protrusion is provided with a first slope, the two first slopes are respectively corresponding to and abutting with the two second slopes; A limiting groove is provided inside the cylinder, the first protrusion extends into the limiting groove, and a second gap is left between the first protrusion and the inner wall of the limiting groove.

[0007] Preferably, a first mounting groove is provided on the side wall of the cylinder, and a second mounting groove is provided on each of the two side walls opposite to the first mounting groove. The second mounting groove is located below the first mounting groove, and the opposite sides of the vibration transmission frame are respectively located in the two second mounting grooves. The second protrusion is located in the first mounting groove.

[0008] Preferably, the vibration transmission frame is provided with a second through hole for the ultra-thin wall tube to pass through. The second through hole is coaxially arranged with the cylinder body, and the two second protrusions are symmetrically arranged along the axis of the second through hole.

[0009] Preferably, a fourth stepped hole is provided circumferentially at the top of the inner wall of the cylinder, the fourth stepped hole is coaxially arranged with the cylinder, the bottom surface of the female mold is in contact with the bottom wall of the fourth stepped hole, and the first gap is left between the female mold and the side wall of the fourth stepped hole.

[0010] Preferably, the limiting groove is formed on the bottom wall of the fourth step hole.

[0011] Preferably, a third step is provided circumferentially at the top of the outer wall of the cylinder, and the support member is fixedly installed on the third step by screws.

[0012] Preferably, the ultrasonic vibration mechanism includes an amplitude transformer, the large end of which is coaxially fixed to a flange, the flange being fixedly mounted on the support member by a plurality of bolts and nuts, the output end of the amplitude transformer being fixedly connected to the vibration transmission frame, and the large end of the amplitude transformer being connected to a transducer, the transducer being connected to an ultrasonic generator via a wire.

[0013] Preferably, the inclination angle of the first slope is 30° to 45°.

[0014] Preferably, the widths of both the first gap and the second gap are 0.2-0.8 mm.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: In this invention, the ultrasonic vibration mechanism is fixed on the support member, and its output end drives the vibration transmission frame to vibrate. The second slope on the second protrusion at the top of the vibration transmission frame abuts against the first slope on the first protrusion at the bottom of the female mold, transmitting the vibration energy to the female mold. The female mold floats slightly within the cylinder through the first gap and the second gap, adaptively centering the ultra-thin-walled tube blank. At the same time, multiple balls arranged circumferentially in the first through hole and the first stepped hole on the female mold perform spinning processing on the tube blank under the assistance of vibration, effectively softening the material and promoting plastic flow.

[0016] This invention significantly improves the forming quality of ultra-thin-walled tubes by directly applying ultrasonic vibration to the deformation zone, reducing uneven wall thickness and surface defects; the gap floating structure ensures self-alignment of the female mold and precise control of the thinning amount; the overall structure is compact and the vibration transmission path is efficient, making it suitable for retrofitting vertical drilling machines to improve processing accuracy and yield. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the cylinder in this invention; Figure 3 This is a schematic diagram of the overall shape of the female mold in this invention; Figure 4 This is a schematic diagram of the internal structure of the female mold in this invention; Figure 5 This is a schematic diagram of the vibration transmission frame in this invention; The components include: 1. Support; 2. Ball bearing; 3. Female mold; 4. Vibration transmission frame; 5. Amplitude rod; 6. Cylinder; 7. Transducer; 8. Ultrasonic generator; 9. Bolt; 10. Nut; 301. First step hole; 302. First through hole; 303. First ramp; 304. First protrusion; 401. Second protrusion; 402. Second through hole; 403. Second ramp; 601. First mounting groove; 602. Second mounting groove; 603. Third step; 604. Fourth step hole; 605. Restriction groove. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Reference Figures 1 to 5This invention discloses an ultrasonic vibration-assisted ultrathin-walled tube ball spinning mold, comprising: a cylinder 6, a support member 1 fixedly disposed at the top end of the cylinder 6, an ultrasonic vibration mechanism fixedly disposed on the support member 1, a transmission frame 4 fixedly disposed at the output end of the ultrasonic vibration mechanism, the transmission frame 4 extending into the cylinder 6, a female mold 3 disposed inside the cylinder 6, the female mold 3 and the transmission frame 4 being disposed vertically correspondingly, a first gap being left between the female mold 3 and the inner wall of the cylinder 6, a first through hole 302 coaxially opened on the female mold 3 for the ultrathin-walled tube to pass through, a first stepped hole 301 circumferentially opened at the top end of the inner wall of the first through hole 302, and a plurality of balls 2 circumferentially disposed inside the first stepped hole 301; Two second protrusions 401 are fixed to the top of the vibration transmission frame 4. The two second protrusions 401 are symmetrically arranged in the center. The top of the second protrusions 401 is provided with a second slope 403. The two second slopes 403 are arranged opposite to each other. Two first protrusions 304 are fixed to the bottom end of the female mold 3. The two first protrusions 304 are correspondingly arranged with two second protrusions 401. A first slope 303 is opened at the bottom end of the first protrusion 304. The two first slopes 303 and the two second slopes 403 are respectively corresponding and abutting. A limiting groove 605 is provided inside the cylinder 6, and a first protrusion 304 extends into the limiting groove 605. A second gap is left between the first protrusion 304 and the inner wall of the limiting groove 605.

[0021] The ultrasonic vibration mechanism and the spinning die are integrated into the frame consisting of the cylinder 6 and the support 1 to form a modular unit that can be directly adapted to the spindle of a vertical drilling machine, achieving low-cost equipment modification.

[0022] The ultrasonic vibration is directly transmitted from the vibration transmission frame 4 to the female mold 3 and the ball bearings 2 that are in contact with the tube blank, resulting in minimal energy loss and precise application.

[0023] During operation, the high-frequency vibration generated by the ultrasonic vibration mechanism is transmitted through the vibration transmission frame 4. The second protrusion 401 at the top of the vibration transmission frame 4 abuts against the inclined surface of the first slope 303 on the first protrusion 304 at the bottom of the female mold 3 via the second ramp 403, efficiently transmitting the vibration energy to the female mold 3. The female mold 3 obtains radial floating space within the cylinder 6 through the first gap, while the first protrusion 304 achieves circumferential fine adjustment within the limiting groove 605 through the second gap, enabling the female mold 3 to self-align under stress. Multiple ball bearings 2 circumferentially arranged within the first through hole 302 of the female mold 3 perform spinning processing on the ultra-thin-walled tube blank under the assistance of ultrasonic vibration. The vibration effectively softens the material, reduces deformation resistance, and promotes uniform material flow. By directly vibrating the deformation zone, it significantly improves the uniformity of wall thickness distribution and reduces surface defects. At the same time, the floating gap design ensures precise control of the thinning amount.

[0024] In a further optimized design, a first mounting groove 601 is provided on the side wall of the cylinder 6, and a second mounting groove 602 is provided on each of the two opposite side walls of the first mounting groove 601. The second mounting groove 602 is located below the first mounting groove 601, and the opposite sides of the vibration transmission frame 4 are respectively located in the two second mounting grooves 602. The second protrusion 401 is located in the first mounting groove 601.

[0025] The two second protrusions 401 are arranged sequentially along the direction of vibration propagation.

[0026] The vibration transmission frame 4 is embedded in the second mounting groove 602 of the cylinder 6 on both sides, and the second protrusion 401 is located in the first mounting groove 601 to achieve precise positioning, ensure that the vibration transmission frame 4 remains stable during vibration transmission, avoids deflection, and ensures that vibration energy is efficiently transmitted to the female mold 3 along the designed path.

[0027] The scheme is further optimized by providing a second through hole 402 on the vibration transmission frame 4 for the ultra-thin wall tube to pass through. The second through hole 402 is coaxially arranged with the cylinder 6, and the two second protrusions 401 are symmetrically arranged along the axis of the second through hole 402.

[0028] The second through hole 402 on the vibration transmission frame 4 is coaxially arranged with the cylinder 6, providing a smooth passage for the ultra-thin-walled tube. The second protrusion 401 is symmetrically arranged along the axis of the second through hole 402 to ensure that the vibration excitation force acts symmetrically on the female mold 3, avoiding the generation of eccentric force that affects the forming accuracy.

[0029] In a further optimized design, a fourth step hole 604 is provided circumferentially at the top of the inner wall of the cylinder 6. The fourth step hole 604 is coaxially arranged with the cylinder 6. The bottom surface of the female mold 3 contacts the bottom wall of the fourth step hole 604, and a first gap is left between the female mold 3 and the side wall of the fourth step hole 604.

[0030] The bottom surface of the female mold 3 contacts the bottom wall of the fourth step hole 604, achieving axial positioning. The first gap between the outer edge of the female mold 3 and the side wall of the fourth step hole 604 provides radial floating space, allowing the female mold 3 to adaptively fine-tune during spinning, automatically centering the tube blank axis and improving forming accuracy.

[0031] The design was further optimized so that the limiting groove 605 was opened on the bottom wall of the fourth step hole 604.

[0032] The limiting groove 605 is formed on the bottom wall of the fourth step hole 604, and the first protrusion 304 extends into it to form a circumferential constraint. It integrates the anti-rotation function in a limited space and together with the fourth step hole 604, it forms a complete positioning system, which simplifies the mold structure and improves reliability.

[0033] The design is further optimized by providing a third step 603 circumferentially opened at the top of the outer wall of the cylinder 6, and the support member 1 is fixedly installed on the third step 603 by screws.

[0034] The support component 1 is fixed to the third step 603 on the outer wall of the cylinder 6 by screws, forming a stable installation reference. The step mating structure ensures that the support component 1 and the cylinder 6 are precisely aligned, providing a rigid support foundation for the ultrasonic vibration mechanism and reducing vibration energy loss.

[0035] The scheme is further optimized. The ultrasonic vibration mechanism includes an amplitude transformer 5. The large end of the amplitude transformer 5 is coaxially fixed to a flange. The flange is fixedly installed on the support 1 by multiple bolts 9 and nuts 10. The output end of the amplitude transformer 5 is fixedly connected to the vibration transmission frame 4. The large end of the amplitude transformer 5 is connected to a transducer 7. The transducer 7 is connected to the ultrasonic generator 8 through a wire.

[0036] Support 1 is rigidly connected to cylinder 6 by bolts, and the amplitude rod 5 is fixed at the node by flange, which effectively isolates the impact of vibration on the main unit and ensures the stability of the processing.

[0037] The ultrasonic generator 8 provides an electrical signal to the transducer 7 via a wire. The transducer 7 converts the electrical energy into mechanical vibration, which is then amplified by the amplitude transformer 5. The amplitude transformer 5 is fixed to the support member 1 by a flange, bolts 9, and nuts 10. Its output end is fixed to the vibration transmission frame 4, forming a complete vibration transmission chain to ensure efficient energy conversion and transmission.

[0038] The scheme was further optimized so that the inclination angle of the first slope 303 was between 30° and 45°.

[0039] The inclination angle of the first ramp 303 is limited to 30° to 45° to achieve vibration component conversion. If the inclination angle is too small, the axial component force will be insufficient; if it is too large, the radial component force loss will increase. This range balances the vibration transmission efficiency and the force conversion effect.

[0040] The design was further optimized so that the widths of the first and second gaps are both 0.2–0.8 mm.

[0041] The widths of the first and second gaps are set at 0.5mm, which ensures the adaptive floating of the female mold 3 while maintaining the overall structural stability.

[0042] The ultrasonic generator 8 provides a high-frequency electrical signal to the transducer 7 via a wire. The transducer 7 converts the electrical energy into mechanical vibration of the same frequency. The vibration energy is transmitted to the amplitude transformer 5, which amplifies the amplitude and outputs it. The amplitude transformer 5 is fixedly mounted on the support member 1 by the flange at the large end, bolts 9, and nuts 10. The support member 1 is fixedly mounted on the third step 603 at the top of the outer wall of the cylinder 6 by screws, forming a stable mounting base.

[0043] The amplified vibration is transmitted to the vibration transmission frame 4 through the output end of the amplitude transformer 5. The vibration transmission frame 4 is located in the second mounting groove 602 on both sides of the side wall of the cylinder 6, and its two second protrusions 401 at the top are located in the first mounting groove 601. The second slope 403 at the top of the second protrusion 401 abuts against the inclined surface of the first slope 303 on the first protrusion 304 at the bottom of the female mold 3. The inclination angle of the first slope 303 is 30° to 45°. This inclined surface structure converts the radial vibration component transmitted by the amplitude transformer 5 into an axial vibration component.

[0044] Vibrational energy is transmitted to the female mold 3 through the ramp contact pair. The bottom surface of the female mold 3 contacts the bottom wall of the fourth stepped hole 604 at the top of the inner wall of the cylinder 6, achieving axial positioning. A first gap of approximately 0.5 mm is left between the outer edge of the female mold 3 and the side wall of the fourth stepped hole 604. At the same time, the first protrusion 304 at the bottom end of the female mold 3 extends into the limiting groove 605 on the bottom wall of the fourth stepped hole 604, and a second gap of approximately 0.5 mm is left between the first protrusion 304 and the inner wall of the limiting groove 605. This gap design allows the female mold 3 to have a slight floating margin in the radial and circumferential directions.

[0045] Under the assistance of ultrasonic vibration, multiple ball bearings 2 arranged circumferentially in the first stepped hole 301 within the first through hole 302 of the female mold 3 spin-form the ultra-thin-walled tube blank passing through the second through hole 402 of the vibration transmission frame 4. The ultrasonic vibration effectively softens the material, reduces deformation resistance, and promotes uniform material flow. At the same time, the floating structure of the female mold 3 allows it to automatically adjust its axial position under stress, ensuring alignment with the theoretical axis of the tube blank.

[0046] Throughout the entire process, ultrasonic vibration acts directly on the spinning deformation zone, significantly improving material flowability. Combined with the adaptive floating function of the female mold 3, it effectively controls the wall thickness reduction, improving forming accuracy and surface quality.

[0047] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0048] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An ultrasonic vibration-assisted ultrathin-walled tube ball spinning die, characterized in that, include: A cylindrical body (6) is provided with a support member (1) fixedly installed at the top end of the cylindrical body (6). An ultrasonic vibration mechanism is fixedly installed on the support member (1). A transmission frame (4) is fixedly installed at the output end of the ultrasonic vibration mechanism. The transmission frame (4) extends into the cylindrical body (6). A female mold (3) is provided inside the cylindrical body (6). The female mold (3) and the transmission frame (4) are arranged vertically and vertically. A first gap is left between the female mold (3) and the inner wall of the cylindrical body (6). A first through hole (302) for the ultra-thin wall tube to pass through is coaxially opened on the female mold (3). A first stepped hole (301) is circumferentially opened at the top end of the inner wall of the first through hole (302). A plurality of balls (2) are circumferentially arranged in the first stepped hole (301). The top of the vibration transmission frame (4) is fixed with two second protrusions (401), the two second protrusions (401) are symmetrically arranged in the center, and the top of the second protrusions (401) is provided with a second slope (403), and the two second slopes (403) are arranged opposite to each other; The bottom end of the female mold (3) is fixed with two first protrusions (304), the two first protrusions (304) are correspondingly arranged with the two second protrusions (401), the bottom end of the first protrusion (304) is provided with a first slope (303), the two first slopes (303) are respectively corresponding to and abutting with the two second slopes (403); The cylinder (6) is provided with a limiting groove (605), the first protrusion (304) extends into the limiting groove (605), and a second gap is left between the first protrusion (304) and the inner wall of the limiting groove (605).

2. The ultrasonic vibration-assisted ultrathin-walled tube ball spinning die according to claim 1, characterized in that: The cylinder (6) has a first mounting groove (601) on its side wall. The two opposite sides of the first mounting groove (601) have a second mounting groove (602). The second mounting groove (602) is located at the lower part of the first mounting groove (601). The two opposite sides of the vibration transmission frame (4) are located in the two second mounting grooves (602) respectively. The second protrusion (401) is located in the first mounting groove (601).

3. The ultrasonic vibration-assisted ultrathin-walled tube ball spinning die according to claim 1, characterized in that: The vibration transmission frame (4) is provided with a second through hole (402) for the ultra-thin wall tube to pass through. The second through hole (402) is coaxially arranged with the cylinder (6), and the two second protrusions (401) are symmetrically arranged along the axis of the second through hole (402).

4. The ultrasonic vibration-assisted ultra-thin-walled tube ball spinning die according to claim 1, characterized in that: The inner wall of the cylinder (6) is provided with a fourth step hole (604) circumferentially. The fourth step hole (604) is coaxially arranged with the cylinder (6). The bottom surface of the female mold (3) is in contact with the bottom wall of the fourth step hole (604). The first gap is left between the female mold (3) and the side wall of the fourth step hole (604).

5. The ultrasonic vibration-assisted ultrathin-walled tube ball spinning die according to claim 4, characterized in that: The limiting groove (605) is formed on the bottom wall of the fourth step hole (604).

6. The ultrasonic vibration-assisted ultrathin-walled tube ball spinning die according to claim 4, characterized in that: The top of the outer wall of the cylinder (6) is provided with a third step (603) and the support (1) is fixedly installed on the third step (603) by screws.

7. The ultrasonic vibration-assisted ultrathin-walled tube ball spinning die according to claim 4, characterized in that: The ultrasonic vibration mechanism includes an amplitude transformer (5), the large end of which is coaxially fixed with a flange. The flange is fixedly installed on the support member (1) by multiple bolts (9) and nuts (10). The output end of the amplitude transformer (5) is fixedly connected to the vibration transmission frame (4). The large end of the amplitude transformer (5) is connected to a transducer (7). The transducer (7) is connected to the ultrasonic generator (8) by a wire.

8. The ultrasonic vibration-assisted ultrathin-walled tube ball spinning die according to claim 4, characterized in that: The inclination angle of the first slope (303) is 30° to 45°.

9. The ultrasonic vibration-assisted ultrathin-walled tube ball spinning die according to claim 4, characterized in that: The widths of both the first gap and the second gap are 0.2–0.8 mm.

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