CN-121988877-A - Cylindrical workpiece laser welding method and device based on acousto-optic deflection dynamic beam splitting and coordinated rotation

CN121988877ACN 121988877 ACN121988877 ACN 121988877ACN-121988877-A

Abstract

The invention belongs to the technical field of laser welding, and discloses a cylindrical workpiece laser welding method and device based on acousto-optic deflection dynamic beam splitting collaborative rotation, which can control the distance between corresponding emergent lights by changing the horizontal positions of two acousto-optic deflection modules, the array light spots formed by the focusing light spots of the four beams of light are diamond-shaped with different sizes, the directions of two beams of positive first-order diffracted light I 01 and I 11 emitted can be controlled by changing the included angle of the beam splitting directions of the two acousto-optic deflection modules, and the autorotation cylindrical workpiece cooperates with the diamond-shaped array light spots to form a circular or ring-shaped welding seam, so that the operation is simple and reliable. And in the welding process, four-point simultaneous welding can be guaranteed to be efficiently completed, and the machining efficiency and the adjustable machining size are improved while the balance and consistency of the welding of the devices are guaranteed. Furthermore, the laser welding of cylindrical workpieces with different sizes is realized by dynamically changing the beam splitting output and the distance of the four beams of emergent light by utilizing the injection power and the frequency of the ultrasonic field.

Inventors

ZHU GUANGZHI
TONG HUI
YE HANLI
Huang zunnan
ZHANG BOYU

Assignees

华中科技大学

Dates

Publication Date: 20260508
Application Date: 20260316

Claims (10)

1. The cylindrical workpiece laser welding device based on the acousto-optic deflection dynamic beam splitting collaborative rotation is characterized by comprising a first acousto-optic deflection module, a second acousto-optic deflection module, two ultrasonic field generation modules, a focusing module and a control module which are the same, wherein the beam splitting direction of the first acousto-optic deflection module is parallel to an X axis, the included angle between the beam splitting direction of the second acousto-optic deflection module and a Y axis is beta, the included angle is more than or equal to 0 degree and less than or equal to 90 degrees, the Z axis is the propagation direction of incident light, and the X axis, the Y axis and the Z axis are perpendicular to each other; The two ultrasonic field generating modules are respectively used for generating a first ultrasonic field acting on the first acousto-optic deflection module and a second ultrasonic field acting on the second acousto-optic deflection module, wherein the direction of the first ultrasonic field is along the X-axis direction, and the included angle between the direction of the second ultrasonic field and the Y-axis is beta; The method comprises the steps of enabling incident light to vertically enter a first acousto-optic deflection module, generating Bragg diffraction under the action of a first ultrasonic field to generate zero-order diffraction light I 0 which is not deflected and positive-order diffraction light I 1 which is deflected along the direction of the first ultrasonic field and the plane direction of the incident light, enabling zero-order diffraction light I 0 and positive-order diffraction light I 1 to enter a second acousto-optic deflection module, generating Bragg diffraction under the action of a second ultrasonic field to generate zero-order diffraction light I 00 and I 10 which are not deflected, and generating positive-order diffraction light I 01 and I 11 which are deflected along the direction of the second ultrasonic field and the plane direction of the incident light, focusing each beam of diffraction light I 00 、I 01 、I 10 and I 11 on a cylindrical workpiece to be welded through a focusing module to form corresponding focusing light spots, and forming an array of the focusing light spots; The control module is used for adjusting the horizontal positions of the two acousto-optic deflection modules to control the distance between each beam of diffracted light I 00 、I 01 、I 10 and I 11 so that the array light spots are diamond-shaped with different sizes, and is also used for adjusting the included angle beta between the beam splitting direction of the second acousto-optic deflection module and the Y axis, and forming a circular welding seam or a circular ring-shaped welding seam on the cylindrical workpiece under the cooperation of the diamond array light spots and the autorotation cylindrical workpiece so as to realize the laser welding of the cylindrical workpiece.
2. The laser welding device for cylindrical workpieces according to claim 1, wherein when an included angle beta = 0 ° between the beam splitting direction of the second acoustic deflection module and the Y axis, the diamond array light spots are square array light spots, and a circular weld seam is formed on the cylindrical workpiece under the cooperation of the square array light spots and the autorotation cylindrical workpiece; and when the included angle between the beam splitting direction of the second optical deflection module and the Y axis is 0 degrees < beta <90 degrees, forming a circular ring-shaped welding seam on the cylindrical workpiece under the cooperation of the diamond array light spots and the autorotation cylindrical workpiece.
3. The laser welding apparatus according to claim 1 or 2, wherein the control module is further configured to adjust the injection frequency of the two ultrasonic field generating modules to change the bragg diffraction angle of the corresponding acousto-optic deflection module, thereby dynamically changing the spacing between the diffracted light beams I 00 、I 01 、I 10 and I 11 .
4. A cylindrical workpiece laser welding apparatus according to claim 3, wherein a spacing between each of the diffracted beams I 00 、I 01 、I 10 and I 11 The Bragg diffraction angles with the two acousto-optic deflection modules satisfy the following conditions: Wherein, the Is the bragg diffraction angle of the first acousto-optic deflection module, Is the Bragg diffraction angle of the second optical deflection module, Is the horizontal distance of the two acousto-optic deflection modules, Is the distance between the second sound deflection module and the focusing module.
5. The laser welding apparatus for cylindrical workpieces according to claim 3, wherein the control module is further configured to adjust the injected rf power of the two ultrasonic field generating modules to change the diffraction efficiency of the corresponding acousto-optic deflection module, thereby dynamically changing the energy of each of the diffracted light beams I 00 、I 01 、I 10 and I 11 .
6. The laser welding apparatus for cylindrical workpieces according to claim 1 or 2, further comprising a polarization state adjustment module provided before the second optical deflection module, wherein the polarization state adjustment module is configured to adjust polarization directions of the zero-order diffracted light I 0 and the positive-order diffracted light I 1 so that polarization states of the zero-order diffracted light I 0 and the positive-order diffracted light I 1 are identical to polarization states of incident light.
7. The laser welding apparatus according to claim 6, further comprising a mirror for changing a propagation direction of each of the diffracted lights I 00 、I 01 、I 10 and I 11 so that each of the diffracted lights I 00 、I 01 、I 10 and I 11 is focused onto the cylindrical workpiece to be welded via the focusing module to form a corresponding focused spot.
8. The laser welding device for cylindrical workpieces according to claim 1, wherein when the cylindrical workpiece is a cylindrical battery, the welding of the circular pole or the circular pole is realized under the cooperation of the diamond array light spots and the autorotation cylindrical battery.
9. The cylindrical workpiece laser welding apparatus according to claim 1, wherein the ultrasonic field generation module comprises a radio frequency drive power supply, a piezoelectric transduction unit, and an acousto-optic interaction medium; the piezoelectric transduction unit is a layer of metal sheet attached to the surface of the acousto-optic interaction medium, and electrode layers at two ends of the piezoelectric layer in the piezoelectric transduction unit are connected with the radio frequency driving power supply; when the ultrasonic energy-adjustable ultrasonic field is operated, the radio frequency signal with adjustable energy is applied to drive the radio frequency driving power supply to work, the conversion from electricity to mechanical movement is realized at the position of the piezoelectric transduction unit, and when the mechanical movement acts on the acousto-optic interaction medium, the ultrasonic field with adjustable energy and body grating property is formed.
10. A cylindrical workpiece laser welding method based on acousto-optic deflection dynamic beam splitting and cooperative rotation is characterized by comprising the step of realizing cylindrical workpiece laser welding by adopting the cylindrical workpiece laser welding device according to any one of claims 1-9.

Description

Cylindrical workpiece laser welding method and device based on acousto-optic deflection dynamic beam splitting and coordinated rotation Technical Field The invention belongs to the technical field of laser welding, and particularly relates to a cylindrical workpiece laser welding method and device based on acousto-optic deflection dynamic beam splitting and cooperative rotation. Background The new energy batteries occupy a vital role in energy development and intelligent revolution, not only provide key technical support for electric automobiles, renewable energy storage and the like, but also play an irreplaceable role in promoting global transformation to low-carbon economy. Cylindrical batteries are an important choice for high performance, high safety routes, as an important member of the new energy battery family, with their excellent thermal management capabilities, high safety and high standardization potential. The laser synchronous welding process based on the array light spots is a core technology for realizing reliable high-quality welding of circular welding seams. The array facula circular weld joint generating technology is an efficient and precise welding technology which forms a circular weld joint through beam shaping or beam splitting to form multiple facula which act on a workpiece in parallel, realizes multi-region synchronous heating and melting, and forms the circular weld joint through the autorotation of a cylindrical battery, and has the core advantages of improving efficiency, stabilizing a molten pool and inhibiting defects, and is widely applied to the fields of power batteries, automobile electronics, semiconductors and the like. The dynamic beam splitting technology is a technical difficulty for meeting the welding requirements of cylindrical batteries with different sizes. In the precision machining field, aiming at laser welding, the time synchronization, the space synchronization and the energy coordination can be realized by splitting a plurality of laser beams obtained, the multi-point welding can be efficiently finished, the thermal deformation and the stress concentration are controlled, and the relative balance of the devices is ensured. However, the current commonly used diffraction laser beam splitter is sensitive to laser wavelength, and meanwhile, the processing cost is extremely high due to the fact that electron beam lithography is relied on, and the beam splitting mode is fixed and cannot meet the processing requirements of workpieces with different sizes. The traditional beam splitter is used for fixing the welding spot position during welding, and cannot adapt to workpiece position deviation, curved surface structure or dynamic thermal deformation (such as thermal expansion error + -0.5 mm during welding of an automobile battery tray). Therefore, a simple laser beam splitting mode with good comprehensive performance, capable of adjusting energy and beam spacing in real time and electrically controlling is sought, so that high-quality welding of circular or annular welding seams of cylindrical workpieces with different sizes is realized, balance and consistency in welding of devices are ensured, and meanwhile, machining efficiency and adjustable machining size are improved, so that the laser beam splitting mode is particularly important in a laser welding machining system. Disclosure of Invention Aiming at the defects or improvement demands of the prior art, the invention provides a cylindrical workpiece laser welding method and device based on acousto-optic deflection dynamic beam splitting and cooperative rotation, which aim to realize high-quality welding of circular or annular welding seams of cylindrical workpieces with different sizes, ensure balance and consistency in welding devices and simultaneously improve processing efficiency and adjustable processing size. The invention provides a cylindrical workpiece laser welding device based on the cooperative rotation of an acousto-optic deflection dynamic beam splitting, which comprises a first acousto-optic deflection module, a second acousto-optic deflection module, two ultrasonic field generation modules, a focusing module and a control module, wherein the two same acousto-optic deflection modules are sequentially marked as the first acousto-optic deflection module and the second acousto-optic deflection module, the beam splitting direction of the first acousto-optic deflection module is parallel to an X axis, the included angle between the beam splitting direction of the second acousto-optic deflection module and a Y axis is beta, beta is less than or equal to 0 DEG and less than 90 DEG, the Z axis is the propagation direction of incident light, and the X axis, the Y axis and the Z axis are perpendicular to each other; the two ultrasonic field generating modules are respectively used for generating a first ultrasonic field acting on the first acousto-optic deflection module and a second ultrasonic field a