Composite laser and laser processing system

Abstract

This application provides a composite laser and a laser processing system, comprising a laser, a collimator, a second beam splitter, a first beam splitter, and a focusing lens. A first reflective film is provided on the periphery of the first beam splitter near the second beam splitter, and a second reflective film is provided on the periphery of the second beam splitter near the first beam splitter. The first and second beam splitters of the laser are used to split the collimated parallel laser beam output from the collimator. A portion of the beam passes through the through-hole of the second beam splitter and is reflected and amplified into a ring beam, while the other portion of the beam is focused into a central beam. This central beam is used for laser processing of the workpiece, and the ring beam is used for auxiliary heating of the workpiece. This results in a low-cost composite laser and laser processing system, and can alleviate problems such as workpiece curling, spatter, bubbles, and cracks during laser processing.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and more specifically, to a composite laser and a laser processing system. Background Technology

[0002] In recent years, with the continuous development of laser processing technology, laser processing has been increasingly widely used in the field of industrial processing. At the same time, higher requirements are constantly being put forward for laser processing technology.

[0003] Traditional laser processing typically uses a Gaussian laser beam distribution. When the laser beam is Gaussian, the temperature at the processing center becomes too high, which can cause splashing during processing and damage the electronic components around the workpiece. At the same time, due to the large temperature difference between the processing center and the surrounding area, a temperature gradient is formed, resulting in uneven heating of the workpiece, which can easily lead to various problems such as deformation, bubbles, and cracks.

[0004] To address these issues, laser manufacturers typically require an additional ring-shaped light-assisted processing system to complement the existing laser. This system creates a ring-shaped heating field around the original processing location to reduce the temperature gradient and mitigate problems such as splashing, bubbles, and cracks.

[0005] Currently, there are two common types of ring-beam assisted processing systems. One type directly uses a separate ring laser to form a ring-shaped spot for auxiliary processing. The other type is a laser processing system with a ring fiber, developed by IPG. Specifically, the laser's fiber structure includes a central fiber and a ring fiber. The laser controls the central fiber and the ring fiber to form a central beam and a ring beam, respectively. The central beam performs laser processing, while the ring beam provides auxiliary processing. Both of these common laser processing systems are relatively complex and have high production costs.

[0006] Therefore, it is necessary to invent a composite laser that is simple in structure, low in cost, and easy to operate, which can also alleviate problems such as workpiece curling, splashing, bubbles, and cracks that occur during laser processing. Summary of the Invention

[0007] The purpose of this application is to provide a composite laser and a laser processing system to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this application provides the following technical solution: A composite laser, comprising, in sequence, a laser, a collimator, a second beam splitter, a first beam splitter, and a focusing lens. A first reflective film is provided on the periphery of the first beam splitter near the second beam splitter, and a second reflective film is provided on the periphery of the second beam splitter near the first beam splitter. Both the first and second beam splitters have through holes. A collimator is provided in the output optical path of the laser to adjust the laser emitted by the laser into collimated parallel light. A second beam splitter and a first beam splitter are sequentially arranged in the output optical path of the collimator. The first and second beam splitters are used to split the collimated parallel laser beam output by the collimator. A portion of the beam passes through the through hole of the second beam splitter, reaches the first reflective film of the first beam splitter, and is first reflected and expanded onto the second reflective film of the second beam splitter, where it is further reflected and expanded into a ring beam. Another portion of the beam passes through the through holes of the first and second beam splitters, reaches the focusing lens, and is focused into a central beam. The central beam is used for laser processing of the workpiece, while the ring beam is used for auxiliary heating of the workpiece.

[0009] The ingenious design of the composite laser in this application lies in the fact that the through-hole of the second beam splitter is larger than that of the first beam splitter. This ensures that when the collimated parallel light passes through the collimator and then through the second beam splitter, it can pass entirely through the second beam splitter without being affected by the second reflective film. Upon reaching the first beam splitter, a portion of the beam can be reflected by the first reflective film to the second reflective film. Simultaneously, the first reflective film of the first beam splitter is tilted from the inside out, away from the second reflective film. This ensures that the beam expanded from the first reflective film reaches the second reflective film and forms a beam-expanding effect, and is then reflected again by the second reflective film in a beam-expanding manner.

[0010] This application also provides a laser processing system including the aforementioned composite laser, a workpiece, and a moving stage for moving the annular beam, the central beam, and the workpiece relative to each other on at least two different axes.

[0011] In alternative solutions, the composite laser and laser processing system described in this application can be used in a variety of laser processing applications such as laser cutting, laser welding, laser engraving, laser cleaning, and laser additive manufacturing.

[0012] Through the above structural design, the composite laser and laser processing system of this application can expand the ring beam and separate it from the central beam, forming two separate beams. Furthermore, the ring beam forms an auxiliary heating field, reducing the temperature gradient between the laser processing location and its surroundings. This results in a composite laser and laser processing system that is both cost-effective and reduces problems such as workpiece curling, spatter, bubbles, and cracks during laser processing. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 A first structural schematic diagram of the composite laser provided in this application;

[0015] Figure 2 A schematic diagram of the second structure of the composite laser provided in this application;

[0016] Figure 3 A schematic diagram of the first structure of the first beam splitter of the composite laser provided in this application;

[0017] Figure 4 A schematic diagram of the second structure of the first beam splitter of the composite laser provided in this application;

[0018] Figure 5 A schematic diagram of the third structure of the composite laser provided in this application;

[0019] Figure 6 This is a first structural schematic diagram of the laser processing system provided in this application.

[0020] Reference numerals: 1. Laser, 2. Collimator, 3. First beam splitter, 4. Second beam splitter, 5. Focusing lens, 6. Workpiece, 7. First reflecting mirror, 8. Second reflecting mirror, 9. Dimming mirror, 31. First reflecting film, 41. Second reflecting film, 91. Dimming aperture, 92. Third reflecting film, L. Collimated parallel beam, L1. Ring beam, L2. Central beam. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present application and are not intended to limit the scope of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are within the scope of protection of the present application.

[0022] Please see Figure 1 , Figure 1The first structural schematic diagram of the composite laser provided in this application is shown. The composite laser includes, in sequence, a laser 1, a collimator 2, a second beam splitter 4, a first beam splitter 3, and a focusing lens 5. The first beam splitter 3 has a first reflective film 31 on its periphery near the second beam splitter 4, and the second beam splitter 4 has a second reflective film 41 on its periphery near the first beam splitter 3. Both the first beam splitter 3 and the second beam splitter 4 have through holes (regional structures where the first reflective film 31 or the second reflective film 41 is not provided). A collimator 2 is provided in the output optical path of the laser 1. The collimator 2 is used to adjust the laser emitted by the laser 1 into a collimated parallel beam L. A second beam splitter 4 and a first beam splitter 3 are arranged sequentially in the output optical path of the collimator 2. The first beam splitter 3 and the second beam splitter 4 are used to split the collimated parallel laser beam output by the collimator 2. A part of the beam passes through the through hole of the second beam splitter 4 and reaches the first reflective film 31 of the first beam splitter 3. It is then reflected and expanded onto the second reflective film 41 of the second beam splitter 4. It is then reflected and expanded into a ring beam L1 by the second reflective film 41. The other part of the beam passes through the through hole of the second beam splitter 4 and the first beam splitter 3 and reaches the focusing lens 5. It is then focused into a central beam L2.

[0023] The through-hole of the second beam splitter 4 in this application is larger than the through-hole of the first beam splitter 3, so as to ensure that when the collimated parallel light L passes through the collimator 2 through the second beam splitter 4, it can pass entirely through the second beam splitter 4 without being reflected by the second reflective film 41. When it reaches the first beam splitter 3, part of the beam can be reflected by the first reflective film 31 to the second reflective film 41.

[0024] Meanwhile, the first reflective film 31 of the first beam splitter 3 of this application is tilted from the inside out to the side away from the second reflective film 41. This ensures that the beam expanded from the first reflective film 31 reaches the second reflective film to form a beam expansion effect, and can be reflected again by the second reflective film 41 in a beam expansion manner.

[0025] Of course, the size of the second beam splitter 4 and the second reflective film 41 is usually larger than the size of the corresponding first beam splitter 3 and the first reflective film 31, so that the beam expanded from the first reflective film 31 can be reflected again by the second reflective film 41 as much as possible.

[0026] The central beam L2 obtained from the aforementioned composite laser is used for laser processing, while the annular beam L1 is used for auxiliary heating. Specifically, the annular beam L1 forms an annular auxiliary heating field around the processing point of the central beam L2. Laser processing here can cause the workpiece 6 to reach a molten state, while auxiliary heating cannot, but it can still modify the material of the workpiece 6 to some extent. (It should be noted that "annular" here is not limited to a circular ring; it could also be an elliptical ring, or other shapes that are approximately circular, elliptical, or circular / elliptical.) This reduces the temperature gradient, mitigating problems such as splashing, bubbles, and cracks.

[0027] Please see Figure 2 , Figure 2 The diagram shows a second structural schematic of the composite laser provided in this application, which is a preferred embodiment of this application. The focal point f2 of the central beam L2 of the composite laser acts on the workpiece 6 to use the strongest processing energy, while the focal point f1 of the ring beam L1 does not act on the workpiece 6.

[0028] In an optional embodiment, at least one of the first beam splitter 3 and the second beam splitter 4 can be moved back and forth in the optical path transmission direction. By moving the first beam splitter 3 and / or the second beam splitter 4 back and forth in the optical path transmission direction, the position of the focal point f1 and the spot size of the ring beam L1 can be adjusted, thereby controlling the energy of the ring beam L1 acting on the workpiece 6 and the temperature of the generated suitable heating field.

[0029] When the workpiece 6 is a thin layer of metal material, the focal point f1 is located between the focusing lens 5 and the workpiece 6, which will produce a better processing effect; when the workpiece 6 is a thick layer of metal material, f1 is located on the side of the workpiece 6 away from the focusing lens 5, which will also produce a better processing effect.

[0030] Please see Figure 3 , Figure 3 This is a schematic diagram of the first structure of the first beam splitter of the composite laser provided in this application. The first beam splitter 3 of this application has a through hole in the center and is a lens structure with a reflective film that is thicker on the inside and thinner on the outside. The thickness gradually decreases from the inside to the outside, and the curvature is designed to decrease from R1 to R2 and then to R3 from the inside to the outside (the illustration is only to show that the curvature decreases from the inside to the outside, and does not mean that the curvature is the same at the same distance from the center. That is, multiple R1, multiple R2, or multiple R3 at the same distance from the center may also be different). This is to facilitate the first reflective film 31 of the first beam splitter 3 to tilt from the inside to the outside towards the side away from the second reflective film 41. This ensures that the beam expanded from the first reflective film 31 reaches the second reflective film to form a beam expansion effect, thereby expanding the ring beam L1 and separating it from the central beam L2.

[0031] Please refer to the following for further information. Figure 3and Figure 4 , Figure 4 This is a schematic diagram (cross-sectional view) of the second structure of the first beam splitter of the composite laser provided in this application. In this embodiment, the first beam splitter 3 exhibits a change in thickness and curvature as it rotates from the center towards a fixed direction. For example, in the Y direction shown in the diagram, when rotating clockwise, the structure of the first beam splitter 3 changes from thin (h1) to thick (h2), and then from thick (h2) to thin (h1), resulting in a change in curvature from R6 to R5, then to R4, and finally from R4 to R6. This structural design is intended to influence the diffusion angle of the first reflective film 31 during reflection, changing it from θ1 to θ2, and then from θ1 to θ2 (θ1 > θ2), thereby controlling the position and shape of the spot of the ring beam L1 acting on the workpiece 6. Specifically, the first beam splitter 3 can rotate around the collimated parallel light L output direction as the rotation axis. During the rotation, the center of the spot of the ring beam L1 acting on the workpiece 6 can deviate from the center of the spot of the central beam L2 acting on the workpiece 6. In practical applications, the center of the spot of the ring beam L1 acting on the workpiece 6 can be closer to the workpiece position on the pre-processing direction side than the center of the spot of the central beam L2 acting on the workpiece 6. Moreover, more and more laser processing is non-linear processing, that is, more and more laser processing requires the workpiece 6 to follow curves or irregular complex lines, such as "8" or "S" lines. When the first beam splitter 3 rotates in this embodiment, the rotation can be flexibly controlled by the control mechanism to match the processing line. The thickness on the side closer to the pre-processing direction can be thinned or thickened. This flexible structural change capability allows the ring beam L1 to preheat the workpiece 6 in advance, better reducing problems such as workpiece curling, splashing, bubbles and cracks during laser processing. Based on the actual production and processing requirements for the size and shape of the spot of the ring beam L1 acting on the workpiece 6, as well as the deviation between the center of the spot of the ring beam L1 acting on the workpiece 6 and the center of the spot of the central beam L2 acting on the workpiece 6, the curvature values ​​of R1, R2, R3, R4, R5, and R6 can be specifically designed, that is, the curvature at different positions can be specifically designed to achieve this.

[0032] In other embodiments, the above-mentioned features can be further achieved or improved by designing a special structure for the second beam splitter 4. Figure 3 and Figure 4 The special structural design of the first beam splitter 3 in the embodiment aims to achieve technical effects such as changes in the shape of the ring beam L1 and the offset of the beam center point. In other words, the second reflective film 41 of the second beam splitter 4 can also have a similar structure to the first reflective film 31 of the first beam splitter 3, only with opposite orientations. The principles described above are similar and will not be elaborated upon here.

[0033] Please see Figure 5 , Figure 5 This is a schematic diagram of the third structure of the composite laser provided in this application. The composite laser, in... Figure 1 Based on the composite laser, it also includes a dimming mirror 9, which is located between the collimator 2 and the focusing lens 4 (in this embodiment, the beam splitter 8 is located between the collimator 2 and the second beam splitter 4; in other embodiments, the beam splitter 8 may also be located between the second beam splitter 4 and the first beam splitter 3, or between the first beam splitter 3 and the focusing lens 5). The dimming mirror 9 has a cylindrical structure with a dimming hole 91 in the center. A third reflective film 92 is provided on the dimming hole 91 inside the dimming mirror 9. The dimming mirror 9 can deflect back and forth in the optical path direction. When the dimming mirror 9 is aligned with the central beam L2, it can be used to adjust the beam direction. When the output direction is perpendicular, the central beam L2 can be completely output to the next optical device through the dimming aperture 91. When the dimming mirror 9 is deflected to a position that is not perpendicular to the output direction of the central beam L2, part of the central beam L2 is reflected by the third reflective film 92 on the dimming aperture 91. Then, most of the reflected beam is deflected to the output direction contained in the ring beam L1. Different deflection angles affect the proportion of the central beam L2. That is, the proportion of the ring beam L1 that finally generates auxiliary heating and the central beam L2 that performs laser processing can be flexibly redistributed through the deflection of the dimming mirror 9.

[0034] This application also provides a laser processing system, which includes the aforementioned composite laser, a workpiece 6, and a moving stage (not shown in the figure), the moving stage being used to move the annular beam L1 and the central beam L2 and the workpiece 6 relative to each other on at least two different axes.

[0035] Please see Figure 6 , Figure 6This is a first structural schematic diagram of the laser processing system provided in this application. Based on the aforementioned laser processing system, this system further includes a first reflecting mirror 7 and a second reflecting mirror 8. The first reflecting mirror 7 and the second reflecting mirror 8 are located between the first beam splitter 3 and the focusing lens 5. The movement of the first reflecting mirror 7 and the second reflecting mirror 8 can control the movement of the annular beam L1 and the central beam L2 on at least two different axes relative to each other. In this embodiment, the first reflecting mirror 7, the second reflecting mirror 8, and the moving stage can coexist and simultaneously control the movement of the annular beam L1, the central beam L2, and the workpiece 6 relative to each other on at least two different axes. However, the first reflecting mirror 7 and the second reflecting mirror 8 only control the annular beam L1 and the central beam L2 to oscillate or move within a small angle range, such as 2 to 5 degrees. The moving stage, on the other hand, can control the annular beam L1, the central beam L2, and the workpiece 6 to move over a large range relative to each other on at least two different axes. Because when the processing range is large, the large-scale swinging or movement of the ring beam L1 and the central beam L2 controlled by the first reflector 7 and the second reflector 8 will greatly increase the overall size and weight of the laser, and increase the cost of production and use.

[0036] In a preferred embodiment, the axes through which the first reflector 7 and the second reflector 8 control the movement of the annular beam L1 and the central beam L2 are perpendicular to each other.

[0037] In an optional embodiment, the laser processing system provided in this application also includes a temperature feedback adjustment mechanism (not shown in the figure). This temperature feedback adjustment mechanism can detect the temperature of the processing position and the temperature auxiliary field position of the workpiece 6 by infrared detection, and can adjust the ring beam L1 and the central beam L2 according to the real-time temperature feedback to the control mechanism to meet the good processing requirements of the workpiece 6.

[0038] In an optional scheme, the diameter of the spot of the annular beam L1 generated by the laser processing system of this application on the workpiece 6 is D (if the spot of the annular beam L1 on the workpiece 6 is elliptical or approximately elliptical, D here can be understood as including the diameter D1 in the major axis direction and the diameter D2 in the minor axis direction), and the diameter of the spot of the central beam L2 on the workpiece 6 is d. In order to obtain a better auxiliary heating field, it is necessary to satisfy 2d≤D≤10d.

[0039] In alternative solutions, the composite laser and laser processing system described in this application can be used in a variety of laser processing applications such as laser cutting, laser welding, laser engraving, laser cleaning, and laser additive manufacturing.

[0040] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0041] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made to this application, as well as combinations of the various embodiments in this application, without departing from the principles of this application. These improvements, modifications, and combinations also fall within the protection scope of the claims of this application.

Claims

1. A composite laser, characterized in that, It includes, in sequence, a laser (1), a collimator (2), a second beam splitter (4), a first beam splitter (3), and a focusing lens (5); The first beam splitter (3) has a first reflective film (31) on the periphery of the second beam splitter (4) and the second beam splitter (4) has a second reflective film (41) on the periphery of the side of the second beam splitter (3) close to the first beam splitter (3). Both the first beam splitter (3) and the second beam splitter (4) have through holes. A collimator (2) is provided in the output optical path of the laser (1). The collimator (2) is used to adjust the laser emitted by the laser (1) into collimated parallel light (L). The collimator (2) is provided with a second beam splitter (4) and a first beam splitter (3) in sequence on the output optical path. The collimated parallel laser beam output by the collimator (2) is split into beams. A portion of the beam passes through the through hole of the second beam splitter (4), reaches the first reflective film (31) of the first beam splitter (3), and is reflected and expanded to the second reflective film (41) of the second beam splitter (4). It is then reflected and expanded by the second reflective film (41) into a ring beam (L1). Another portion of the beam passes through the through holes of the second beam splitter (4) and the first beam splitter (3), reaches the focusing lens (5), and is focused into a central beam (L2). The central beam (L2) mentioned above is used for laser processing, and the ring beam (L1) is used for auxiliary heating; The through-hole of the second beam splitter (4) is larger than the through-hole of the first beam splitter (3); The curvature of the first beam splitter (3) gradually decreases from the inside to the outside, and the first reflective film (31) of the first beam splitter (3) tilts from the inside to the outside towards the side away from the second reflective film (41); The first beam splitter (3) rotates around the collimated parallel light (L) output direction as the rotation axis. When rotating, the first beam splitter (3) exhibits a change in thickness and curvature from the center to a fixed direction.

2. The composite laser according to claim 1, characterized in that, At least one of the first beam splitter (3) and the second beam splitter (4) can move back and forth in the optical path output direction.

3. The composite laser according to claim 1, characterized in that, It also includes a dimming mirror (9), which is located between the collimator (2) and the focusing lens (5). The dimming mirror (9) has a cylindrical structure with a dimming hole (91) in the center. A third reflective film (92) is provided on the dimming hole (91) inside the dimming mirror (9). The dimming mirror (9) deflects back and forth in the optical path direction.

4. A laser processing system, characterized in that, The composite laser includes any one of claims 1-3, and further includes a workpiece (6) and a moving stage for moving the ring beam (L1), the central beam (L2) and the workpiece (6) relative to each other on at least two different axes.

5. The laser processing system according to claim 4, characterized in that, It also includes a first reflector (7) and a second reflector (8), which are located between the first beam splitter (3) and the focusing lens (5), and the movement of the annular beam (L1) and the central beam (L2) on at least two different axes on the workpiece (6) is controlled by the swinging or moving of the first reflector (7) and the second reflector (8).

6. The laser processing system as described in claim 5, characterized in that, The axes by which the first reflector (7) and the second reflector (8) control the movement of the annular beam (L1) and the central beam (L2) are perpendicular to each other.

7. The laser processing system as described in claim 4, characterized in that, The diameter of the spot on the workpiece (6) of the ring beam (L1) generated by the laser processing system is D, and the diameter of the spot on the workpiece (6) of the central beam (L2) is d, satisfying 2d≤D≤10d.

8. The laser processing system as described in claim 4, characterized in that, It also includes a temperature feedback adjustment mechanism, which detects the temperature of the processing position of the workpiece (6) and the temperature auxiliary field position by infrared detection, and adjusts the ring beam (L1) and the central beam (L2) according to the real-time temperature feedback.

Images