Multi-focal dot-ring laser spot generation system and laser welding method

Abstract

The present invention provides a multifocal point-ring light spot generation system and a laser welding method, and belongs to the field of laser processing technology. The system comprises a ring light source, a first collimating lens, a ring-shaped beam generation module, and a first reflector sequentially spaced apart along a first linear direction, and a point light source, a second collimating lens, a first focusing lens, a multi-curvature hollow reflector, and a second focusing lens sequentially spaced apart along a second linear direction. A through hole is installed at the center of the multi-curvature hollow reflector and the second focusing lens to allow a beam emitted from the point light source to pass through, and the specular curvature of the multi-curvature hollow reflector is adjustable. This can solve technical challenges such as high processing costs and reduced deep welding stability caused by structural limitations of conventional point-ring laser devices.

Description

Technology Field

[0001] The present invention belongs to the field of laser processing technology and, in particular, relates to a multifocal point-ring light spot generation system and a laser welding method. Background Technology

[0002] With the advancement of laser welding, the laser welding market has already become highly competitive, and the demand for welding technology in manufacturing is steadily increasing. Traditional welding methods (e.g., arc welding and ultrasonic welding) have certain limitations, such as excessively high temperatures during the welding process, significant deformation, and unstable weld quality. Particles generated by spatter adhere to the molten pool and the workpiece surface, easily causing changes in surface roughness and potentially damaging the base material; at the same time, they contaminate the clean internal environment of the gun head, affecting the service life of the optical lens.

[0003] In the relevant technology, a point-ring laser device can effectively solve the aforementioned problems, wherein a single laser device emits two laser beams simultaneously—one as a central beam and the other as an outer ring beam—and forms focusing points of the central point and outer ring beams through a complex optical path system. During welding, the central point beam forms a molten pool while the outer ring laser rapidly heats and melts the edges, preventing spatter.

[0004] However, conventional point-ring laser devices, such as the AMB product from IPG and the ABP series from Raker, have complex and expensive point-ring laser head systems in the outer optical path, resulting in high laser welding processing costs. Furthermore, the structure of the aforementioned point-ring laser head is limited by model specifications, causing both the outer ring spot and the point spot to be focused on the same focal plane. Consequently, since the spot shape is fixed, when performing laser welding with multiple penetration depths on thick workpieces, the outer ring spot experiences a reduction in the heat-affected zone due to energy attenuation and insufficient penetration when the point spot penetrates to different depths. This leads to inconsistencies in the melt width of the weld at different workpiece thicknesses, causing a problem where the stability of deep welding is compromised. The problem to be solved

[0005] Embodiments of the present invention provide a multifocal point-ring light spot generation system and a laser welding method, which can solve technical challenges such as high processing costs and reduced deep welding stability caused by structural limitations of conventional point-ring laser devices. The technical solution is as follows. means of solving the problem

[0006] In a first aspect, an embodiment of the present invention provides a multifocal point-ring light spot generation system, which comprises the following:

[0007] The first optical path component includes a ring light source, a first collimating lens, a ring-shaped beam generating module, and a first reflector, which are sequentially spaced apart along a first straight direction.

[0008] The second optical path component includes a point light source, a second collimating lens, a first focusing lens, a multi-curvature hollow reflector, and a second focusing lens, which are sequentially spaced apart along a second linear direction, and through holes are installed at the centers of the multi-curvature hollow reflector and the second focusing lens to allow a beam emitted from the point light source to pass through, and the surface curvature of the multi-curvature hollow reflector is adjustable.

[0009] The beam emitted from the above ring light source passes through the first collimation lens and the ring-shaped beam generation module, is sequentially reflected by the first reflector and the multi-curvature hollow reflector, and is focused through the second focusing lens to form a ring light spot.

[0010] The beam emitted from the above point light source passes through the second collimating lens, the first focusing lens, the multi-curvature hollow reflector, and the through hole at the center of the second focusing lens, and is then focused to form a point light spot located inside the ring light spot.

[0011] Optionally, a plurality of the first optical path components are installed, and a plurality of the multi-curvature hollow reflectors corresponding one-to-one with the plurality of first optical path components are installed in the second optical path components, and the plurality of multi-curvature hollow reflectors are spaced apart along the second linear direction.

[0012] Optionally, a dynamic change module is installed inside at least one of the plurality of first optical path components, the dynamic change module is positioned between the first reflector and the multi-curvature hollow reflector installed in the corresponding first optical path component, and the dynamic change module includes two wedge-shaped prisms that are coaxially arranged along the beam direction emitted from the ring light source and rotatable in the axial direction, and the refractive surfaces of the two wedge-shaped prisms are arranged to face each other.

[0013] Optionally, a plurality of the first optical path components are spaced apart along the first straight direction.

[0014] Optionally, a conical lens installed along the first straight direction is installed inside the annular beam generating module.

[0015] Optionally, the conical lenses include a negative conical lens and a positive conical lens, which are spaced apart coaxially along the direction of the beam emitted from the ring light source and whose conical surfaces face each other.

[0016] Optionally, a biaxial galvanometer is installed between the second collimating lens and the first focusing lens.

[0017] Optionally, the collimation degree of the first collimation lens and the second collimation lens can be adjusted.

[0018] In a second aspect, an embodiment of the present invention provides a laser welding method realized based on a multifocal point-ring light spot generation system according to the first aspect described above, which comprises the following:

[0019] A beam is emitted through the above-mentioned ring light source, passes through the first collimating lens and the ring-shaped beam generating module, is sequentially reflected by the first reflector and the multi-curvature hollow reflector, and is focused on the surface of a workpiece through the second focusing lens to form a ring light spot.

[0020] A beam is emitted through the above point light source, and after passing through the second collimating lens, the first focusing lens, the multi-curvature hollow reflector, and the through hole at the center of the second focusing lens, it is focused on the surface of the workpiece to form a point light spot located inside the ring light spot.

[0021] By adjusting the surface curvature of the above-mentioned multi-curvature hollow reflector, a ring light spot is formed outside the focal plane of the above-mentioned point light spot, and at the same time, a ring light spot is formed on a focal plane different from the above-mentioned point light spot.

[0022] Optionally, the laser welding method may additionally include the following: installing a plurality of sets of the first optical path components, and installing a plurality of the multi-curvature hollow reflectors in the second optical path components that correspond one-to-one with a plurality of the first optical path components.

[0023] A plurality of sets of the first light path components are focused on the workpiece to form a ring light spot by adjusting the focal plane, thereby forming a plurality of ring light spots outside the point light spot, or forming a plurality of ring light spots on a focal plane different from the point light spot. Effects of the invention

[0024] The beneficial effects brought about by the technical solution provided by the embodiments of the present invention include at least the following.

[0025] By employing the multi-focal point-ring spot generation system provided by the embodiment of the present invention, positional control on the optical path is achieved regarding the focal plane of the ring spot formed by focusing through the cooperative operation of the first optical path component and the second optical path component during the laser welding process. This enables multi-focal relay with the point spot and allows welding to proceed at different focal planes. Simultaneously, heating and melting of the molten pool boundary on the point spot focal plane are ensured to suppress spatter, and when processing workpieces of different thicknesses, the melting width of the weld is consistently controlled at different penetration depths. Since the overall optical path structure is simply configured, technical problems such as high processing costs and reduced stability of deep welding caused by the structural limitations of conventional point-ring laser devices are effectively resolved. Brief explanation of the drawing

[0026] To more clearly explain the technical solution according to the embodiments of the present invention, the drawings necessary for describing the embodiments are briefly introduced below. It is evident that the drawings mentioned in the following description represent only some embodiments of the present invention, and a person skilled in the art can obtain other drawings based on these drawings without any separate creative effort. FIG. 1 is a schematic diagram of the structure of a multifocal point-ring light spot generation system provided by an embodiment of the present invention. FIG. 2 is a schematic diagram of the structure of another multifocal point-ring light spot generation system provided by an embodiment of the present invention. FIG. 3 is a schematic diagram of the structure of a dynamic change module provided by an embodiment of the present invention. FIG. 4 is a schematic diagram of the optical path of a biaxial galvanometer inside a module provided by an embodiment of the present invention. FIG. 5 is a flowchart of a laser welding method provided by an embodiment of the present invention. FIG. 6 is a schematic diagram of workpiece processing provided by an embodiment of the present invention. Specific details for implementing the invention

[0027] In order to clarify the purpose, technical solution, and advantages of the present invention, the method of implementing the present invention will be described in more detail below in conjunction with the drawings.

[0028] FIG. 1 is a schematic diagram of the structure of a multifocal point-ring light spot generation system provided by an embodiment of the present invention. FIG. 2 is a schematic diagram of the structure of another multifocal point-ring light spot generation system provided by an embodiment of the present invention. FIG. 3 is a schematic diagram of the structure of a dynamic change module provided by an embodiment of the present invention. FIG. 4 is a schematic diagram of the optical path of a biaxial galvanometer within a module provided by an embodiment of the present invention. As shown in FIG. 1 to 4, an embodiment of the present invention provides a multifocal point-ring light spot generation system, which includes a first optical path component (1) and a second optical path component.

[0029] Among these, the first optical path component (1) includes a ring light source (11), a first collimating lens (12), a ring-shaped beam generating module (13), and a first reflector (14) sequentially spaced apart along a first straight direction.

[0030] The second optical path component (2) includes a point light source (21), a second collimating lens (22), a first focusing lens (23), a multi-curvature hollow reflector (24), and a second focusing lens (25) that are sequentially spaced apart along the second linear direction. A through hole is installed at the center of the multi-curvature hollow reflector (24) and the second focusing lens (25) to allow a beam emitted from the point light source (21) to pass through, and the curvature of the mirror surface of the multi-curvature hollow reflector (24) is adjustable.

[0031] A beam emitted from a ring light source (11) passes through a first collimating lens (12) and a ring-shaped beam generating module (13), is sequentially reflected by a first reflector (14) and a multi-curvature hollow reflector (24), and is focused through a second focusing lens (25) to form a ring light spot. A beam emitted from a point light source (21) passes through a through hole at the center of a second collimating lens (22), a first focusing lens (23), a multi-curvature hollow reflector (24), and a second focusing lens (25), and is focused to form a point light spot located inside the ring light spot.

[0032] In an embodiment of the present invention, when laser welding of a workpiece is performed, the first optical path component (1) and the second optical path component (2) operate in cooperation. A beam emitted by a point light source (21) passes through a second collimating lens (22) to form parallel light, is focused through a first focusing lens (23), passes sequentially through a multi-curvature hollow reflector (24) and a through hole at the center of the second focusing lens (25), and is focused on the surface of the workpiece to form a light spot. At the same time, a beam emitted by a ring light source (11) passes through a first collimating lens (12) to form parallel light, and then passes through a ring-shaped beam generating module (13) to form a ring-shaped beam. Specifically, the ring-shaped beam generating module (13) may adopt the form of a fiber optic circulator, a DOE (Diffractive Optical Element), or a conical lens. Fiber optic circulators convert the basic mode into a ring mode using a fiber optic grating or a conical coupler, but the ring diameter is fixed by fiber optic parameters and cannot be dynamically adjusted. A Gaussian beam can generate a ring beam through diffraction of a DOE phase plate, and while the ring diameter can be dynamically adjusted, an expensive spatial light modulator is required for real-time adjustment. Parallel light can form a ring beam by generating a Bessel beam through a conical lens; this method allows for continuous adjustment of the ring diameter, has a long non-diffraction distance, and simultaneously offers ultra-high power compatibility. Considering cost and ease of setup comprehensively, an embodiment of the present invention adopts a method in which collimated parallel light is combined with a conical lens (131) installed inside a ring beam generation module (13) to generate a ring beam. Subsequently, the reflection is sequentially passed through the outer lens portion of the through hole of the first reflector (14) and the multi-curvature hollow reflector (24), and finally focused through the outer lens portion of the through hole of the second focusing lens (25) to form a ring light spot on the outer edge of the point light spot of the workpiece.During welding, the central point light spot forms a molten pool, while the outer ring light spot rapidly heats and melts the edges to prevent spatter.

[0033] Furthermore, by dynamically controlling the mirror surface curvature of the multi-curvature hollow reflector (24), the phase of the reflected or transmitted light wave is modulated by converting driving signals such as electricity, magnetism, and atmospheric pressure into precise micro-displacements of the mirror surface, and axial focus adjustment of the ring light spot can be realized by applying global uniform pressure. When the curvature increases, the divergence of the beam is strengthened, and the focus after passing through the second focus lens (25) is closer to the second focus lens (25). When the curvature decreases, the concentration of the beam is strengthened, and the focus after passing through the focus lens is further away from the second focus lens (25). When the ring light spot and the point light spot are located on the same focus plane, the focus plane of the ring light spot is moved downward by adjusting the mirror surface curvature of the multi-curvature hollow reflector (24) to decrease, thereby forming a pre-melting zone of the ring light spot at a deeper position in the weld of the workpiece and improving the heat-affected area. Meanwhile, at the focal plane where the point light is located, the ring-shaped beam can still heat and melt the boundary of the molten pool formed by the point light from the outer edge, thereby preventing spatter and oxidation.

[0034] By employing the multi-focal point-ring light spot generation system provided by the embodiment of the present invention, position control on the light path is achieved for the focal plane of the ring light spot formed by focusing through the cooperative operation of the first light path component (1) and the second light path component (2) during the laser welding process. This enables multi-focal relay with the point light spot and allows welding to proceed at different focal planes. At the same time, heating and melting of the molten pool boundary on the point light spot focal plane are ensured to suppress spatter, and when processing workpieces of different thicknesses, the melting width of the weld is consistently controlled at different penetration depth positions. The overall light path structure is simply configured, effectively solving the technical problems of high processing costs and reduced stability of deep welding caused by the structural limitations of conventional point-ring laser devices.

[0035] Optionally, a plurality of first optical path components (1) are installed, and a plurality of multi-curvature hollow reflectors (24) corresponding one-to-one with a plurality of first optical path components (1) are installed in the second optical path component (2), and the plurality of multi-curvature hollow reflectors (24) are spaced apart along a second straight direction. For example, in an embodiment of the present invention, two first optical path components (1) are installed, spaced apart along a first straight direction, that is, the direction of light emission of a ring light source (11), and both components are installed on the side of the second optical path component (2) where the point light source (21) is located. Through this same side arrangement, it is easy for the multi-curvature hollow reflectors (24) of the second optical path component (2) to be positioned in the same direction on the optical path of the point light source (21), and the overall space occupied by the system can be reduced by maximizing the extended length on the optical path of the second optical path component (2). The ring-shaped light beam reflected by the first reflector (14) from the two second light path components (2) can be directed toward the east, reflected by the correspondingly set multi-curvature hollow reflector (24), and focused through the second focusing lens (25) to form a ring-shaped light spot. By setting two sets of first light path components (2), two independent ring-shaped light spots can be formed on the surface of the workpiece to be welded, and / or multiple ring-shaped light spots can be formed on a focal plane different from the point light spot. Additionally, depending on the processing specifications of the actual workpiece, the two first light path components (1) can be operated selectively or simultaneously. For example, when the two first light path components (1) are operated simultaneously, two ring-shaped light spots of different diameters can be formed outside the point light spot. For example, the diameter of one inner ring spot located outside the point spot can be 2 to 3 times the diameter of the point spot and can be used to form a melt pool boundary, and the diameter of a second outer ring spot located outside the inner ring spot is 1 times the diameter of the inner ring spot.It can be 5 to 2 times, and this can be used to suppress spatter and oxidation. Meanwhile, as another feasible method, the specular curvature of the multi-curvature hollow reflector (24) provided in the second optical path component (2) is actively adjusted to control the focal planes of the two ring-shaped light spots, thereby forming a combination of a point light spot and a multi-focal ring-shaped light spot and realizing concentric coupling of a composite multi-focal beam. Simultaneous welding at different focal planes is realized, further enhancing the ability to control the melt width of the weld. For example, the point light spot is focused on the surface of the workpiece or slightly below the surface of the workpiece during operation. An inner ring light spot located outside the point light spot may have a focal plane that is slightly deeper than the focal plane where the point light spot is located, thereby forming a preheating zone at the bottom. The focal plane of an outer ring light spot located outside the inner ring light spot is deeper than that of the inner ring light spot, and this is controlled as a pre-melting zone or heat-affected zone.

[0036] Optionally, a dynamic change module (3) is installed in at least one of a plurality of first optical path components (1), and the dynamic change module (3) is positioned between the first reflector (14) and the multi-curvature hollow reflector (24) installed in the corresponding first optical path component (1), and the dynamic change module (3) includes two wedge-shaped prisms (31) that are coaxially arranged along the beam direction emitted from the ring light source (11) and rotatable in the axial direction, and the refractive surfaces of the two wedge-shaped prisms (31) are arranged to face each other. For example, in an embodiment of the present invention, a dynamic change module (3) is additionally installed in the first optical path component (1), which installs two wedge-shaped prisms and installs a corresponding motor and rotor to control the rotation of the two wedge-shaped prisms (31). When two wedge-shaped prisms (31) rotate in the same direction and at the same speed, their refraction vectors are combined into a single fixed deflection angle, thereby causing the light spot focused by the optical ring beam to move circularly on the focal plane. By controlling the initial phase angle difference of the two wedge-shaped prisms through relative rotation, the centrifugal position of the circular motion can be fixed, and by realizing the parallel movement of the centrifugal, the movement of the light spot after focusing can be realized. Meanwhile, during the rotation adjustment process, the modulus length of the combined refraction angle can be adjusted by changing the rotation speed ratio or the relative angle of the two wedge-shaped prisms (31), thereby realizing dynamic magnification / reduction adjustment of the radius of the ring-shaped light spot. This improves upon the defect in that the point light spot and the ring light spot generated by the conventional point-ring laser device are only capable of synchronized vibration, and independent vibration and light spot shape adjustment are impossible.

[0037] Optionally, the conical lenses (131) include a negative conical lens (131a) and a positive conical lens (131b) that are spaced apart coaxially along the direction of the beam emitted from the ring light source (11) and have conical surfaces facing each other. Referring to FIG. 2 for exemplary description, in an embodiment of the present invention, a positive-negative conical lens composed of a negative conical lens (131a) and a positive conical lens (131b) may be integrated to form a ring beam generating module (13). When collimated parallel light passes through the ring beam generating module (13), the light first passes through the negative conical lens (131a) to form a ring light spot that diverges, and then passes through the positive conical lens (131b) to integrate the ring beam that diverges into the parallel light, thereby realizing control of the ring width diameter of the ring light. This forms a ring-shaped light spot of the required size by combining the reflection of the multi-curvature hollow reflector (24) and the focusing of the second focusing lens (25), and can further adjust the final size of the ring-shaped light spot by changing the vertex angle, spacing, and size of the passing beam of the negative conical lens (131a) and the positive conical lens (131b) to improve processing suitability.

[0038] Optionally, a biaxial galvanometer (4) is installed between the second collimating lens (22) and the first focusing lens (23). For example, by installing a biaxial galvanometer (4) between the second collimating lens (22) and the first focusing lens (23) in the second optical path component, any deflection within the two-dimensional plane of the beam is realized through the cooperative vibration of two high-speed galvanometers, and by controlling the deflection angle and direction of the beam using mechanical vibration, precise control of the laser beam emitted from the point light source (21) is achieved, thereby achieving dynamic movement control of the focusing point of the point light spot.

[0039] Optionally, the collimation degree of the first collimation lens (12) and the second collimation lens (22) can be adjusted. For example, in relation to beam size adjustment of the ring light source (11) and the point light source (21) in an embodiment of the present invention, the first collimation lens (12) and the second collimation lens (22) may select collimation at the same focal length or collimation at different focal lengths, and at the same time, the output may also be selected in combination according to craft requirements. Such adjustment enables disassembly and replacement of external operations through a modular design of the corresponding positions of the first optical path component (1) and the second optical path component (2), thereby precisely controlling the focus and various parameters of the finally formed light spot and further improving the flexibility and suitability of the system.

[0040] For example, in an embodiment of the present invention, the multi-curvature hollow mirror (24) is entirely composed of a water-cooled metal mirror, and the mirror body contains a multi-channel waterway to enable cooling water circulation, thereby ensuring the overall temperature of the mirror surface during processing and accommodating a higher output beam reflection.

[0041] FIG. 5 is a flowchart of a laser welding method provided by an embodiment of the present invention. As shown in FIG. 5, an embodiment of the present invention further provides a laser welding method realized based on the multifocal point-ring light spot generation system of FIGS. 1 to 4, and the method comprises the following steps.

[0042] S1, a beam is emitted through a ring light source (11), passes through a first collimation lens (12) and a ring-shaped beam generating module (13), is sequentially reflected by a first reflector (14) and a multi-curvature hollow reflector (24), and is focused on the surface of a workpiece through a second focusing lens (25) to form a ring light spot.

[0043] S2, a beam is emitted through a point light source (21), and after passing through a through hole at the center of a second collimating lens (22), a first focusing lens (23), a multi-curvature hollow reflector (24), and a second focusing lens (25), it is focused on the surface of a workpiece to form a point light spot located inside a ring light spot.

[0044] S3, by adjusting the mirror surface curvature of the multi-curvature hollow reflector (24), a ring light spot is formed outside the focal plane of the point light spot, and at the same time, a ring light spot is formed on a focal plane different from the point light spot.

[0045] By employing the multi-focal point-ring light spot generation system provided by an embodiment of the present invention and executing the laser welding method, position control on the light path is achieved for the focal plane of the ring light spot formed by focusing through the cooperative operation of the first light path component (1) and the second light path component (2) during the laser welding process. This enables multi-focal relay with the point light spot and allows welding to proceed at different focal planes. At the same time, heating and melting of the molten pool boundary on the point light spot focal plane are ensured to suppress spatter, and when processing workpieces of different thicknesses, the melting width of the weld is consistently controlled at different penetration depth positions. The overall light path structure is simply configured, effectively solving the technical problems of high processing costs and reduced stability of deep welding caused by the structural limitations of conventional point-ring laser devices.

[0046] S4, a plurality of sets of first optical path components (1) are installed, and a plurality of multi-curvature hollow reflectors (24) corresponding one-to-one with a plurality of first optical path components (1) are installed in the second optical path components (2).

[0047] S5, a plurality of sets of first light path components (1) are focused on a workpiece to form a ring light spot, and the focus plane is adjusted to form a plurality of ring light spots outside the point light spot, or a plurality of ring light spots are formed on a focus plane different from the point light spot.

[0048] Furthermore, by installing multiple sets of first light path components (1) and actively adjusting the mirror surface curvature of the multi-curvature hollow reflector (24) provided in the second light path component (2) to adjust the focal planes of the two ring-shaped light spots respectively, a combination of a point light spot and a multi-focal ring-shaped light spot is formed, and concentric coupling of a composite multi-focal beam is realized. Simultaneous welding at different focal planes is realized, thereby further improving the ability to control the melt width of the weld. For example, the point light spot is focused on the surface of the workpiece or slightly below the surface of the workpiece during operation. An inner ring light spot located outside the point light spot may have a focal plane that is slightly deeper than the focal plane where the point light spot is located, thereby forming a preheating area at the bottom. The focal plane of an outer ring light spot located outside the inner ring light spot is deeper than that of the inner ring light spot, and this is controlled as a pre-melting area or a heat-affected area.

[0049] Specifically, through a number of processing experiments performed by the applicant, a distance threshold control parameter between the focal planes of the ring light spot and the point light spot formed by two first light path components (1) for workpieces of different thicknesses to be welded was derived, and by setting the spacing between the point light spot focal planes according to the threshold range, an optimal welding effect can be obtained.

[0050] At this time, in accordance with the description above, the depth of focus of the point light spot on the workpiece processing surface is set to Z1, the depth of focus of the inner ring light spot to Z2, and the depth of focus of the outer ring light spot to Z3. Axial spacing ΔZ of the ring-point light spot. ₁ =|Z ₂ -Z ₁ |,ΔZ ₂ =|Z ₃ -Z ₁ | satisfies the following threshold rule.

[0051] For thin plates with a thickness of less than 1 mm, ΔZ₁ 0.1-0.3mm (realization of fine preheating of the inner ring), ΔZ ₂ 0.3-0.5mm (realization of auxiliary protection for the outer ring).

[0052] For medium-thick plates with a thickness range of 1~3mm, ΔZ ₁ 0.3-0.8mm (realization of significant preheating of the inner ring), ΔZ ₂ 0.8-1.5mm (realization of expanded heat-affected zone of the outer ring).

[0053] For thick plates / high-reflection materials exceeding 3mm in thickness, ΔZ ₁ 0.5-2mm (deep preheating of the inner ring and realization of anti-reflection), ΔZ ₂ 1.5-3mm (realization of spatter suppression of the outer ring).

[0054] In addition, regarding the influence of the workpiece material to be welded, for materials with high thermal conductivity (e.g., aluminum), it is necessary to set the axial spacing between the dot-ring light spot to be smaller, while for materials with low thermal conductivity (e.g., titanium), the spacing can be appropriately increased.

[0055] Furthermore, as one of the possible implementation methods, a multi-curvature hollow reflector (24) installed corresponding to the first reflector (14) of the first optical path component (1) and the first optical path reflector (14) of the second optical path component (2) can be configured to achieve synchronized position adjustment along the second linear direction (i.e., longitudinal direction) through an external driving structure, for example, a motor driving method, thereby enabling adjustment of the width of the ring-shaped beam reflected on the outer lens surface of the incident side through hole of the second focusing lens (25), and finally, the focus plane of the ring light spot focused at the workpiece location to be adjusted in real time.

[0056] Accordingly, the first focusing lens (23) in the second light path component (2) can also be configured to be positioned along the second straight direction by motor driving, thereby allowing the focus plane of the point light point focused on the workpiece position to be adjusted in real time.

[0057] FIG. 6 is a schematic diagram of workpiece processing provided by an embodiment of the present invention. Referring further to FIG. 6, when welding a workpiece with a gradually changing thickness using the multi-focal point-ring light spot generation system, the first section (51) of the rod-shaped workpiece (5) has a relatively thin thickness, and after welding a certain distance in the horizontal direction, the second section (53) has a relatively thick thickness after passing through the transition section (52). At the start of processing, a point light spot and an inner ring light spot and an outer ring light spot located outside the point light spot are respectively formed on the workpiece through two sets of first light path components (1) and one set of second light path components (2), and the focal plane where the inner ring light spot and the outer ring light spot are located gradually deepens with respect to the point light spot, and the focal plane spacing of the three light spots is maintained equally to realize a uniform distribution in the thickness direction of the first section (51). Welding is performed along the horizontal direction so that the light spot moves to the transition section (52), and at the same time, the first focusing lens (23), two sets of first light path reflectors (14), and multi-curvature hollow reflectors (24) are controlled to rise at a set speed, and stop moving after reaching the second section (53). Simultaneously with welding of the second section (53), the focal planes of the point light spot, inner ring light spot, and outer ring light spot are realized to maintain a uniform distribution along the thickness direction, thereby realizing real-time control of the pre-melting zone or heat-affected zone and ensuring the stability of deep welding.

[0058] Unless otherwise defined, technical or scientific terms used in this specification have the ordinary meanings understood by those skilled in the art to which the present invention pertains. Terms such as "first," "second," and similar terms used in the patent application specification and claims of the present invention do not indicate any order, quantity, or importance, but are used merely to distinguish different components. Likewise, terms such as "one" or "1," etc., do not indicate a quantitative limitation but indicate the existence of at least one. Terms such as "include," etc., mean that the element or object presented before such term comprehensively encompasses the elements or objects listed afterward and their corresponding ones, and do not exclude the existence of other elements or objects. Terms such as "connection" or "interconnection," etc., are not limited merely to physical or mechanical connections but may include direct or indirect electrical connections. Terms such as "up," "down," "left," "right," etc., are used solely to indicate relative positional relationships, and if the absolute position of the subject being described changes, said relative positional relationships may change accordingly.

[0059] The above description is merely an optional embodiment of the present invention and is not intended to limit the present invention; any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. Explanation of the symbols

[0060] 1: First optical path component 2: Second Optical Path Component 3: Dynamic Change Module 4: Biaxial galvanometer 5: Rod-shaped workpiece 11: Ring light source 12: First collimating lens 13: Ring-shaped beam generation module 14: First mirror 21: Point light source 22: Second collimating lens 23: First focusing lens 24: Multi-curvature hollow mirror 25: Second focal lens 31: Wedge prism 51: Paragraph 1 52: Transitional spur 53: Paragraph 2 131: Conical lens 131a: Negative cone lens 131b: Positive cone lens

Claims

Claim 1 In a multifocal point-ring light spot generation system, a first optical path component (1) comprises a ring light source (11), a first collimating lens (12), a ring-shaped beam generation module (13), and a first reflector (14) sequentially spaced apart along a first straight direction, and a second optical path component (2) comprises a point light source (21), a second collimating lens (22), a first focusing lens (23), a multi-curvature hollow reflector (24), and a second focusing lens (25) sequentially spaced apart along a second straight direction, wherein a through hole is installed at the center of the multi-curvature hollow reflector (24) and the second focusing lens (25) to allow a beam emitted from the point light source (21) to pass through, and the specular curvature of the multi-curvature hollow reflector (24) is adjustable, and the beam emitted from the ring light source (11) passes through the first collimating lens (12) and the ring-shaped beam generation module (13) and then the first A multi-focal point-ring light spot generation system characterized by being sequentially reflected by a reflector (14) and a multi-curvature hollow reflector (24), and focused through a second focusing lens (25) to form a ring light spot, and a beam emitted from the point light source (21) passing through a through hole at the center of the second collimating lens (22), the first focusing lens (23), the multi-curvature hollow reflector (24), and the second focusing lens (25), and then focused to form a point light spot located inside the ring light spot; wherein a plurality of the first light path components (1) are installed, and a plurality of the multi-curvature hollow reflectors (24) corresponding one-to-one with the plurality of first light path components (1) are installed in the second light path components (2), and the plurality of multi-curvature hollow reflectors (24) are spaced apart along the second straight direction. Claim 2 A multifocal point-ring light spot generating system according to claim 1, wherein a dynamic change module (3) is installed inside at least one of the plurality of first light path components (1), the dynamic change module (3) is positioned between the first reflector (14) and the multi-curvature hollow reflector (24) installed in the first light path component (1) corresponding thereto, and the dynamic change module (3) includes two wedge-shaped prisms (31) that are coaxially arranged along the beam direction emitted from the ring light source (11) and rotatable in the axial direction, and the refractive surfaces of the two wedge-shaped prisms (31) are arranged to face each other. Claim 3 A multifocal point-ring light spot generation system according to claim 1, characterized in that a plurality of the first light path components (1) are spaced apart along the first straight direction. Claim 4 A multifocal point-ring light spot generation system according to claim 1, characterized in that a conical lens (131) installed along the first straight direction is installed inside the ring-shaped beam generation module (13). Claim 5 A multifocal point-ring light spot generating system according to claim 4, wherein the conical lenses (131) are spaced apart coaxially along the beam direction emitted from the ring light source (11) and include a negative conical lens (131a) and a positive conical lens (131b) with conical surfaces facing each other. Claim 6 A multifocal point-ring light spot generating system characterized in that, in any one of claims 1 to 5, a biaxial galvanometer (4) is installed between the second collimating lens (22) and the first focusing lens (23). Claim 7 A multifocal point-ring light spot generating system characterized in that, in any one of claims 1 to 5, the collimation degree of the first collimation lens (12) and the second collimation lens (22) is adjustable. Claim 8 A laser welding method is realized based on a multifocal point-ring light spot generation system according to any one of claims 1 to 5, wherein a beam is emitted through the ring light source (11), passes through the first collimating lens (12) and the ring-shaped beam generation module (13), is sequentially reflected by the first reflector (14) and the multi-curvature hollow reflector (24), and is focused on the surface of a workpiece through the second focusing lens (25) to form a ring light spot, and a beam is emitted through the point light source (21), passes through the second collimating lens (22), the first focusing lens (23), the multi-curvature hollow reflector (24), and the through hole at the center of the second focusing lens (25), and is focused on the surface of the workpiece to form a point light spot located inside the ring light spot, and the mirror surface curvature of the multi-curvature hollow reflector (24) is adjusted to form a ring light spot outside the focal plane of the point light spot, and at the same time, the point A laser welding method characterized by forming a light spot on a focal plane different from the light spot. Claim 9 A laser welding method according to claim 8, wherein a plurality of sets of the first light path components (1) are installed, a plurality of multi-curvature hollow reflectors (24) corresponding one-to-one with a plurality of the first light path components (1) are installed in the second light path components (2), and a focal plane is adjusted such that the plurality of sets of the first light path components (1) are focused on the workpiece to form a ring light spot, thereby forming a plurality of ring light spots outside the point light spot, or forming a plurality of ring light spots on a focal plane different from the point light spot. Claim 10 delete

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