阅读说明：本技术 一种焊接设备及其应用与焊接方法 (Welding equipment and application and welding method thereof ) 是由 薛亚飞 罗子艺 韩善果 蔡得涛 郑世达 房卫萍 于 2021-08-13 设计创作，主要内容包括：本发明公开了一种焊接设备及其应用与焊接方法,属于激光焊接技术领域。该焊接设备包括光束整形系统及长焦会聚透镜和短焦会聚透镜；长焦会聚透镜间隔设置于光束整形系统的一侧以对从光束整形系统发出的贝塞尔光束进行第一次聚焦压缩,短焦会聚透镜间隔设置于长焦会聚透镜的背离光束整形系统的一侧以对贝塞尔光束第二次聚焦压缩后对待焊接材料进行焊接。上述焊接设备可用于对待焊接材料进行焊接,与高斯光束相比,上述设备形成的直径小、焦深长、能量密度高的贝塞尔聚焦光束能够使焊接过程中接头界面受热均匀,降低激光焊接对于对焦精度的要求,提高焊接工艺适应性和焊接质量。同时,贝塞尔光束增长的焦深有利于具有较大接触间隙材料的搭接焊。(The invention discloses welding equipment and application and a welding method thereof, and belongs to the technical field of laser welding. The welding equipment comprises a beam shaping system, a long-focus converging lens and a short-focus converging lens; the long-focus converging lenses are arranged on one side of the beam shaping system at intervals to perform primary focusing compression on the Bezier beams emitted from the beam shaping system, and the short-focus converging lenses are arranged on one side of the long-focus converging lenses, which is far away from the beam shaping system, at intervals to perform secondary focusing compression on the Bezier beams and then weld materials to be welded. Compared with a Gaussian beam, the Bessel focused beam formed by the welding equipment and having small diameter, long focal depth and high energy density can enable a joint interface to be heated uniformly in the welding process, reduce the requirement of laser welding on focusing precision and improve the adaptability of the welding process and the welding quality. Meanwhile, the increased focal depth of the bessel beam is beneficial to lap welding of materials with larger contact gaps.)

1. A welding apparatus comprising a beam processing device, said beam processing device comprising a beam shaping system and a 4f imaging system;

the 4f imaging system comprises a long-focus convergent lens and a short-focus convergent lens;

the long-focus converging lens is arranged on one side of the beam shaping system at intervals to perform first focusing compression on the Bezier beam emitted from the beam shaping system, and the short-focus converging lens is arranged on one side of the long-focus converging lens, which is far away from the beam shaping system, at intervals to perform second focusing compression on the Bezier beam emitted from the long-focus converging lens and weld materials to be welded.

2. The welding apparatus of claim 1, wherein the beam shaping system comprises a cone lens, a spatial light modulator, or a diffractive optical element;

preferably, the axicon is a conical lens;

preferably, the base angle of the conical lens is 0.5 to 6 °, more preferably 1 to 5 °.

3. The welding apparatus of claim 1, wherein the focal length of the tele converging lens is f1, the focal length of the prefocusing lens is f2, and the demagnification of the tele converging lens and the prefocusing lens is between 10 and 50, f1/f 2.

4. The welding apparatus of claim 1, wherein the distance between the beam shaping system and the tele converging lens is 20-200mm, the distance between the tele converging lens and the short converging lens is 50-450mm, and the distance between the short converging lens and the material to be welded is 4-20 mm.

5. The welding apparatus of claim 1, further comprising a beam generating device comprising a laser disposed on a side of the beam shaping system remote from the 4f imaging system such that a gaussian beam emitted by the laser is shaped into a bessel beam by the beam shaping system;

preferably, the laser comprises a nanosecond laser, a picosecond laser, or a femtosecond laser;

preferably, the wavelength range of the laser is 200-2500 nm.

6. The welding apparatus according to any one of claims 1 to 5, further comprising moving means for controlling the beam processing means to move to cause the short focus converging lens to focus the compressed Bessel beam in a scanning motion on the surface of the material to be welded;

preferably, the moving means comprises a moving table or a robotic arm.

7. Use of a welding device according to any of the claims 1-6 for welding of materials to be welded.

8. A method of welding, comprising the steps of: the welding device according to any one of claims 1 to 6, wherein the Bezier beam obtained after shaping by the beam shaping system is subjected to first focusing compression by the long-focus converging lens and second focusing compression by the short-focus converging lens in sequence, and then the Bezier beam obtained after the second focusing compression is subjected to welding on a material to be welded.

9. The welding method according to claim 8, wherein the bessel beam after the second focusing compression is subjected to butt welding or lap welding on a material to be welded;

preferably, the material to be welded comprises a metal or non-metal material;

preferably, the metal comprises a titanium alloy, stainless steel, aluminum alloy, copper alloy, or carbon steel;

preferably, the non-metallic material comprises ceramic, glass or plastic.

10. The welding method of claim 8, wherein the welding modality comprises laser welding, laser-arc hybrid welding, or laser-plasma arc hybrid welding.

Technical Field

The invention relates to the technical field of laser welding, in particular to welding equipment and an application and welding method thereof.

Background

Generally, the depth of focus of a focused gaussian laser beam in a laser welding process is small, and the center of the laser focus needs to be accurately controlled at a specific position of an interface of a material to be welded, so that the adaptability of the welding process is seriously influenced. Moreover, the gradient of the axial intensity distribution of the focused Gaussian beam is large, so that the interface is heated unevenly in the welding process easily, particularly for the lap welding of materials with large contact gaps, the uneven heating of the interface is more obvious, the defect that air holes are easily formed in welding seams can be easily caused, and the final welding quality is influenced because some welding seams can not be fused.

In view of this, the invention is particularly proposed.

Disclosure of Invention

The invention aims to provide welding equipment which is simple in structure, can form a Bessel focused beam with small diameter, long focal depth and high energy density, enables a joint interface to be heated uniformly in a welding process, reduces the requirement of laser welding on focusing precision, and improves welding process adaptability and welding quality.

The invention also aims to provide an application of the welding device.

The invention also aims to provide a welding method for welding by adopting the welding equipment.

The invention can be realized as follows:

in a first aspect, the present invention provides a welding apparatus comprising a beam processing device including a beam shaping system and a 4f imaging system.

The 4f imaging system includes a tele converging lens and a short converging lens.

The long-focus converging lens is arranged on one side of the beam shaping system at intervals to perform first focusing compression on the Bezier beam emitted from the beam shaping system, and the short-focus converging lens is arranged on one side of the long-focus converging lens, which is far away from the beam shaping system, at intervals to perform second focusing compression on the Bezier beam emitted from the long-focus converging lens and weld materials to be welded.

In alternative embodiments, the beam shaping system comprises a cone lens, a spatial light modulator, or a diffractive optical element.

In an alternative embodiment, the axicon is a conical lens.

In an alternative embodiment, the base angle of the conical lens is 0.5-6 °, preferably 1-5 °.

In an alternative embodiment, the focal length of the tele converging lens is f1, the focal length of the tele converging lens is f2, and the demagnification of the tele converging lens and the tele converging lens is between 10 and 50, f1/f 2.

In an alternative embodiment, the distance between the beam shaping system and the tele converging lens is 20-200mm, the distance between the tele converging lens and the short converging lens is 50-450mm, and the distance between the short converging lens and the material to be welded is 4-20 mm.

In an alternative embodiment, the welding apparatus further comprises a beam generating device comprising a laser disposed on a side of the beam shaping system remote from the 4f imaging system such that a gaussian beam emitted by the laser is shaped into a bessel beam by the beam shaping system.

In alternative embodiments, the laser comprises a nanosecond laser, a picosecond laser, or a femtosecond laser.

In an alternative embodiment, the wavelength range of the laser is 200-.

In an alternative embodiment, the welding apparatus further comprises moving means for controlling the movement of the beam processing means to cause the short focus converging lens to focus the compressed bessel beam in a scanning motion on the surface of the material to be welded.

In an alternative embodiment, the moving means comprises a moving table or a robotic arm.

In a second aspect, the invention provides the use of a welding apparatus as in any one of the preceding embodiments, for example for welding materials to be welded.

In a third aspect, the present invention provides a welding method comprising the steps of: with the welding equipment according to any one of the preceding embodiments, the bessel beam shaped by the beam shaping system is subjected to first focusing compression by the long-focus converging lens and second focusing compression by the short-focus converging lens in sequence, and then the bessel beam subjected to second focusing compression is welded to the material to be welded.

In an alternative embodiment, the bessel beam after the second focusing compression is used for butt welding or lap welding the materials to be welded.

In an alternative embodiment, the material to be welded comprises a metallic or non-metallic material.

In alternative embodiments, the metal comprises a titanium alloy, stainless steel, aluminum alloy, copper alloy, or carbon steel.

In alternative embodiments, the non-metallic material comprises ceramic, glass, or plastic.

In alternative embodiments, the welding modality includes laser welding, laser-arc hybrid welding, or laser-plasma arc hybrid welding.

The beneficial effect of this application includes:

this application is through setting gradually the light beam plastic system, long burnt convergent lens and short burnt convergent lens, the light beam plastic system can be the Bessel light beam with the gaussian beam plastic, the Bessel light beam after the plastic loops through the long burnt convergent lens and the short burnt convergent lens system of two different focuses and carries out the focus compression of light beam, the diameter of formation is little, the focal depth is long, the Bessel light beam that energy density is high and then treat welding material and carry out laser welding, thereby can improve welding process joint interface inhomogeneous of being heated, reduce the focusing accuracy requirement among the laser welding process, welding process adaptability and welding quality are improved. Meanwhile, the increased focal depth of the Bessel beam is utilized, and splicing welding of materials with larger contact gaps is facilitated.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic view of a welding apparatus provided herein for performing a first weld;

FIG. 2 is a schematic view of a welding apparatus provided herein for performing a second weld;

fig. 3 is a schematic view of beam shaping performed by the beam shaping system of the welding apparatus provided by the present application as a cone lens.

Icon: 1-gaussian beam; 2-a beam shaping system; 3-an initial bessel beam; 4-a tele converging lens; 5-short focus converging lens; 6-focused Bessel beam; 7-butt welding the sample; 8-lap welding a sample; 9-conical lens.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The following describes the welding device and its application and welding method provided by the present application.

The present application provides a welding apparatus, which is shown in fig. 1 to 3, and includes a beam processing device, which includes a beam shaping system 2 and a 4f imaging system.

The 4f imaging system includes a telephoto converging lens 4 and a short-focus converging lens 5.

The beam shaping system 2 is specifically a gaussian beam 1 shaping system to shape the gaussian beam 1 into a bessel beam.

In alternative embodiments, the beam shaping system 2 may comprise, for example, a cone lens, a spatial light modulator, or a diffractive optical element.

Wherein the axicon lens can be an axicon lens 9. The base angle of the conical lens 9 may be 0.5-6 °, such as 0.5 °, 1 °, 1.5 °, 2 °, 2.5 °, 3 °, 3.5 °, 4 °, 4.5 °, 5 °, 5.5 °, or 6 °, etc., preferably 1-5 °. The preferred base angle range described above is advantageous for bringing the focal depth and spot size of the bessel beam to the appropriate range.

In the present application, the long-focus converging lens 4 is disposed at an interval on one side of the beam shaping system 2 (i.e., the light exit side of the beam shaping system 2) to perform the first focusing compression on the initial bessel beam 3 emitted from the beam shaping system 2, and the short-focus converging lens 5 is disposed at an interval on one side of the long-focus converging lens 4 away from the beam shaping system 2 (i.e., the light exit side of the long-focus converging lens 4) to perform the second focusing compression on the bessel beam emitted from the long-focus converging lens 4 to obtain the focused bessel beam 6 and to weld the material to be welded.

In an alternative embodiment, the focal length of the tele converging lens 4 is f1, the focal length of the short converging lens 5 is f2, and the beam reduction magnification f1/f2 of the tele converging lens 4 and the short converging lens 5 is 10-50, that is, f1 is 10-50 times (e.g., 10 times, 15 times, 20 times, 25 times, 30 times, 35 times, 40 times, 45 times, or 50 times, etc.) of f 2.

In alternative embodiments, the distance between the beam shaping system 2 and the tele converging lens 4 may be 20-200m (e.g., 20m, 50m, 80m, 100m, 150m, or 200m, etc.). The distance between the tele converging lens 4 and the short converging lens 5 may be 50-450mm (e.g. 50mm, 100mm, 150mm, 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, etc.). The distance between the short focus converging lens 5 and the material to be welded may be 4-20mm (e.g. 4mm, 5mm, 10mm, 15mm or 20mm etc.).

The beam-shrinking multiplying power of the long-focus converging lens 4 and the short-focus converging lens 5, the distance between the beam shaping system 2, the long-focus converging lens 4 and the short-focus converging lens 5 and the base angle of the conical lens are matched with each other to regulate the focal depth and the spot size of the Bessel beam, so that a focusing spot and a focal depth meeting the laser welding requirement are formed.

Further, the welding device further comprises a light beam generating device, wherein the light beam generating device comprises a laser, and the laser is arranged on the side, far away from the 4f imaging system, of the light beam shaping system 2 (namely, the light inlet side of the light beam shaping system 2) so that the Gaussian light beam 1 emitted by the laser is shaped into an initial Bessel light beam 3 through the light beam shaping system 2.

The laser may include, for example, a nanosecond laser, a picosecond laser, or a femtosecond laser, which may be referred to.

The wavelength range of the laser may be 200 and 2500 nm.

Further, the welding equipment also comprises a moving device which is used for controlling the light beam processing device to move so as to enable the short-focus converging lens 5 to focus the compressed focused Bessel light beam 6 to perform scanning motion on the surface of the material to be welded.

By reference, the moving means may comprise a moving table or a robot arm.

When the moving device is a moving stage, the whole beam processing device can be positioned on the surface of the moving stage and keeps consistent with the moving state of the moving stage, so that the moving of the beam processing device is realized through the moving of the moving stage, and the short-focus converging lens 5 focuses the compressed focused Bessel beam 6 to perform scanning motion. The principles of the robot arm can be referred to the mobile station and will not be described in detail herein.

Furthermore, the application also provides the application of the welding device, for example, the welding device can be used for welding materials to be welded.

Correspondingly, the application also provides a welding method, which comprises the following steps: by adopting the welding equipment, the initial Bessel beam 3 obtained after being shaped by the beam shaping system 2 is sequentially subjected to first focusing compression by the long-focus converging lens 4 and second focusing compression by the short-focus converging lens 5, and then the Bessel beam (focused Bessel beam 6) subjected to the second focusing compression is welded on a material to be welded.

In an alternative embodiment, the focused bessel beam 6 after the secondary focusing compression is subjected to butt welding or lap welding on the material to be welded.

The materials to be welded may include metal or nonmetal materials, and specifically, the materials to be butted or overlapped may be metal material-metal material, metal material-nonmetal material, or nonmetal material-nonmetal material.

The metal may include, for example, a titanium alloy, stainless steel, aluminum alloy, copper alloy, carbon steel, or the like. Non-metallic materials may include, for example, ceramics, glass, or plastics, among others.

In particular, the welding forms used may include, for example, laser welding, laser-arc hybrid welding, laser-plasma arc hybrid welding, or the like.

In the method, the heating unevenness of the joint interface in the welding process can be improved, the focusing precision requirement in the laser welding process is reduced, and the welding process adaptability and the welding quality are improved. Meanwhile, the increased focal depth of the Bessel beam is utilized, and splicing welding of materials with larger contact gaps is facilitated.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

Referring to fig. 1 and fig. 3, the present embodiment provides a welding apparatus, which includes a light beam generating device, a light beam processing device, and a moving device.

The beam generating means comprise a nanosecond laser and the beam processing means comprise a beam shaping system 2 and a 4f imaging system.

The beam shaping system 2 is a conical lens 9, and the base angle of the conical lens 9 is 1 deg..

The 4f imaging system includes a telephoto converging lens 4 and a short-focus converging lens 5.

The laser is arranged at intervals on the light inlet side of the conical lens 9 so that the Gaussian beam 1 emitted by the laser is shaped into an initial Bessel beam 3 through the conical lens 9. The wavelength of the laser is 1064 nm.

The long-focus converging lens 4 is arranged on the light-emitting side of the conical lens 9 at intervals to perform first focusing compression on the initial Bessel light beam 3 emitted by the conical lens 9.

The short-focus converging lens 5 is arranged at an interval on one side of the long-focus converging lens 4 (away from the conical lens 9) (namely, the light-emitting side of the long-focus converging lens 4) so as to perform secondary focusing compression on the Bezier light beam converged and emitted from the long-focus converging lens 4, and obtain a focused Bezier light beam 6.

Wherein the distance between the beam shaping system 2 and the tele converging lens 4 is 40 mm. The distance between the telephoto-converging lens 4 and the telephoto-converging lens 5 is 176 mm. The distance between the short focus converging lens 5 and the material to be welded is 16 mm. The reduction magnification f1/f2 of the telephoto condenser lens 4 and the telephoto condenser lens 5 is 10.

The moving device is a moving platform, the laser, the conical lens 9, the long-focus converging lens 4 and the short-focus converging lens 5 are integrally arranged on the surface of the moving platform and are consistent with the moving state of the moving platform, so that the light beam processing device moves through the movement of the moving platform, and the short-focus converging lens 5 focuses and compresses the focused Bessel light beam 6 to perform scanning motion.

Example 2

Referring to fig. 2 and 3, the present embodiment provides a welding apparatus, which includes a light beam generating device, a light beam processing device, and a moving device.

The beam generating means comprises a picosecond laser and the beam processing means comprises a beam shaping system 2 and a 4f imaging system.

The beam shaping system 2 is a conical lens 9, and the base angle of the conical lens 9 is 2 degrees.

The 4f imaging system includes a telephoto converging lens 4 and a short-focus converging lens 5.

The laser is arranged at intervals on the light inlet side of the conical lens 9 so that the Gaussian beam 1 emitted by the laser is shaped into an initial Bessel beam 3 through the conical lens 9. The wavelength of the laser is 1035 nm.

The long-focus converging lens 4 is arranged on the light-emitting side of the conical lens 9 at intervals to perform first focusing compression on the initial Bessel light beam 3 emitted by the conical lens 9.

The short-focus converging lens 5 is arranged at an interval on one side of the long-focus converging lens 4 (away from the conical lens 9) (namely, the light-emitting side of the long-focus converging lens 4) so as to perform secondary focusing and compression on the Bezier light beam converged and emitted from the long-focus converging lens 4 to obtain a focused Bezier light beam 6.

Wherein the distance between the beam shaping system 2 and the tele converging lens 4 is 50 mm. The distance between the telephoto-converging lens 4 and the telephoto-converging lens 5 is 186 mm. The distance between the short focus converging lens 5 and the material to be welded is 6 mm. The reduction magnification f1/f2 of the telephoto condenser lens 4 and the telephoto condenser lens 5 is 30.

The moving device is a moving platform, the laser, the conical lens 9, the long-focus converging lens 4 and the short-focus converging lens 5 are integrally arranged on the surface of the moving platform and are consistent with the moving state of the moving platform, so that the light beam processing device moves through the movement of the moving platform, and the short-focus converging lens 5 focuses and compresses the focused Bessel light beam 6 to perform scanning motion.

Example 3

Referring to fig. 1 and fig. 3, the present embodiment provides a welding apparatus, which includes a light beam generating device, a light beam processing device, and a moving device.

The beam generating means comprises a femtosecond laser and the beam processing means comprises a beam shaping system 2 and a 4f imaging system.

The beam shaping system 2 is a conical lens 9, and the base angle of the conical lens 9 is 2.5 degrees.

The 4f imaging system includes a telephoto converging lens 4 and a short-focus converging lens 5.

The laser is arranged at intervals on the light inlet side of the conical lens 9 so that the Gaussian beam 1 emitted by the laser is shaped into an initial Bessel beam 3 through the conical lens 9. The wavelength of the laser is 1030 nm.

The long-focus converging lens 4 is arranged on the light-emitting side of the conical lens 9 at intervals to perform first focusing compression on the initial Bessel light beam 3 emitted by the conical lens 9.

The short-focus converging lens 5 is arranged at an interval on one side of the long-focus converging lens 4 (away from the conical lens 9) (namely, the light-emitting side of the long-focus converging lens 4) so as to perform secondary focusing and compression on the Bezier light beam converged and emitted from the long-focus converging lens 4 to obtain a focused Bezier light beam 6.

Wherein the distance between the beam shaping system 2 and the tele converging lens 4 is 35 mm. The distance between the telephoto-converging lens 4 and the telephoto-converging lens 5 is 168 mm. The distance between the short focus converging lens 5 and the material to be welded is 8 mm. The reduction magnification f1/f2 of the telephoto condenser lens 4 and the telephoto condenser lens 5 is 20.

The moving device is a moving platform, the laser, the conical lens 9, the long-focus converging lens 4 and the short-focus converging lens 5 are integrally arranged on the surface of the moving platform and are consistent with the moving state of the moving platform, so that the light beam processing device moves through the movement of the moving platform, and the short-focus converging lens 5 focuses and compresses the focused Bessel light beam 6 to perform scanning motion.

Example 4

This example differs from example 1 in that: the base angle of the conical lens 9 is 0.5 °.

Example 5

This example differs from example 1 in that: the base angle of the conical lens 9 is 6 °.

Example 6

This example differs from example 1 in that: the beam shaping system 2 is a spatial light modulator.

Example 7

This example differs from example 1 in that: the beam shaping system 2 is a diffractive optical element.

Example 8

This example differs from example 1 in that: the wavelength of the laser is 200 nm.

Example 9

This example differs from example 1 in that: the moving device is a mechanical arm.

Example 10

The present embodiment provides a welding method, which specifically uses the welding apparatus provided in embodiment 1 to weld materials to be welded.

Specifically, a collimated gaussian beam 1 emitted by a laser enters a conical lens 9 and is shaped into an initial bessel beam 3, the beam is sequentially subjected to first focusing compression by a long-focus converging lens 4 and second focusing compression by a short-focus converging lens 5, and a focused bessel beam 6 subjected to second focusing compression is subjected to butt welding on a material to be welded (i.e. a butt welding sample 7).

Wherein, the material to be welded is stainless steel-stainless steel with the thickness of 2mm, and the welding form is laser welding.

The specific welding process parameters are as follows: the laser power is 2kW, the pulse width is 500ns, the welding speed is 2m/min, and the defocusing amount is 0 mm.

Example 11

The present embodiment provides a welding method, which specifically uses the welding device provided in embodiment 2 to weld materials to be welded.

Specifically, a collimated gaussian beam 1 emitted by a laser enters a conical lens 9 and is shaped into an initial bessel beam 3, the beam is sequentially subjected to first focusing compression by a long-focus converging lens 4 and second focusing compression by a short-focus converging lens 5, and a focused bessel beam 6 subjected to the second focusing compression is subjected to lap welding on a material to be welded (namely a lap welding sample 8).

Wherein, the material to be welded is silicate glass-silicate glass, and the welding form is laser welding.

The specific welding process parameters are as follows: the laser power was 45W, the frequency was 110kHz, the pulse width was 20ps, and the dot spacing was 0.03 mm.

Example 12

This embodiment provides a welding method, which specifically uses the welding apparatus provided in embodiment 3 to weld materials to be welded.

Specifically, a collimated gaussian beam 1 emitted by a laser enters a conical lens 9 and is shaped into an initial bessel beam 3, the beam is sequentially subjected to first focusing compression by a long-focus converging lens 4 and second focusing compression by a short-focus converging lens 5, and a focused bessel beam 6 subjected to the second focusing compression is subjected to lap welding on a material to be welded (namely a lap welding sample 8).

Wherein, the material to be welded is quartz glass-quartz glass, the surface roughness of the quartz glass is better than 150nm, and the welding mode is laser welding.

The specific welding process parameters are as follows: the pulse width is 300fs, the pulse energy is 8uJ, the frequency is 750kHz, and the number of radiation pulses of a single welding spot is 2500.

In summary, the collimated gaussian beam emitted by the laser is shaped into the initial bessel beam by the beam shaping system, the shaped initial bessel beam sequentially passes through the 4f system formed by the two focusing lenses with different focal lengths to be focused and compressed, and the focused bessel beam with small diameter, long focal depth and high energy density formed after focusing and compression is adopted for laser welding, so that the non-uniformity of heating of a joint interface in the welding process can be improved, the focusing precision requirement in the laser welding process is reduced, and the welding process adaptability and the welding quality are improved. Meanwhile, the increased focal depth of the focused Bessel beam is utilized, and the splicing welding of materials with larger contact gaps is facilitated.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.