Composite laser cutting device and cutting method

Abstract

The invention discloses a composite laser cutting device which comprises a first light source, a second light source, a first reflecting mirror, a spectroscope, a focusing mirror, a first energy distribution adjusting assembly and a second energy distribution adjusting assembly, and further discloses a composite laser cutting method which comprises the following steps that a light beam is emitted, and energy distribution of the composite light beam is controlled. The method has the beneficial effects that distribution control and application of multi-level energy are achieved, and the efficiency and quality of composite beam laser cutting can be rapidly improved by controlling the energy density of the whole body and the center. The laser cutting machine can be well applied to laser cutting, is particularly suitable for cutting thick plates and composite plates, can cut transparent materials with high efficiency, and can overcome the technical problem that a laser cutting machine in the prior art is difficult to effectively cut the transparent materials and superhard materials.

Description

Technical Field

[0001] This invention relates to the technical field of laser cutting devices, and specifically to a composite laser cutting device and cutting method. Background Technology

[0002] Laser cutting uses a focusing lens to focus a laser beam onto the surface of a material, melting it. The laser beam and the material move relative to each other along a specific trajectory, creating a kerf of a certain shape to cut the workpiece. Currently, the most common laser processing uses a single-wavelength laser, with energy control and focus adjustment achieved through specialized optical elements. Single-wavelength lasers are mainly used for homogeneous materials. However, due to the different absorption rates of laser energy in different materials and the varying temperatures required for laser cutting, a single-wavelength laser cannot simultaneously meet the cutting process requirements of different materials in composite material workpieces.

[0003] To meet diverse processing needs, Chinese utility model patent CN209050272U discloses a femtosecond laser processing system with multiple wavelengths and processing methods. The system includes a multi-wavelength laser arranged along the optical path, an optical path switching device, a beam shaping device, and a processing platform. The multi-wavelength laser emits one or more laser wavelengths at a time. The optical path switching device allows the laser of one or more wavelengths to pass through, reflect, or split. The beam shaping device expands, collimates, focuses, scans with a galvanometer, or guides the laser beam into an optical fiber for shaping. The processing platform holds the product to be processed, corresponding to the material. Different laser wavelengths and processing methods are selected based on the characteristics of the different materials of the parts being processed.

[0004] While existing technologies can process workpieces using composite lasers of multiple different wavelengths, the lack of optimization of the energy distribution of the composite laser beam results in problems such as low cutting efficiency and poor cutting quality in current composite laser processing technologies. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a composite laser cutting device, comprising a first light source, a second light source, a first reflector, a beam splitter, a focusing lens, a first energy distribution adjustment component, and a second energy distribution adjustment component. It also provides a composite laser cutting method comprising the following steps: emitting a laser beam and controlling the energy distribution of the composite laser beam. This composite laser cutting device and method have the advantages of high cutting efficiency and good cutting quality.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0007] A composite laser cutting device includes a first light source, a second light source, a first reflector, a beam splitter, and a focusing lens. The first light source emits a first beam that passes sequentially through the beam splitter and the focusing lens. The second light source emits a second beam that passes sequentially through the first reflector, the beam splitter, and the focusing lens. The device also includes a first energy distribution adjustment component and a second energy distribution adjustment component. The first energy distribution adjustment component is located between the first light source and the beam splitter and is used to adjust the energy distribution of the first beam. The second energy distribution adjustment component is located between the second light source and the first reflector and is used to adjust the energy distribution of the second beam.

[0008] This setup enables multi-level energy distribution control and application. By controlling the overall and central energy density, it can rapidly improve the efficiency and quality of composite beam laser cutting. It is well-suited for laser cutting, especially for cutting thick plates and composite plates. It can cut transparent materials with high efficiency, overcoming the technical challenge of existing laser cutting machines' ineffective cutting of transparent and ultra-hard materials.

[0009] Preferably, the first energy distribution adjustment component includes a first collimating lens.

[0010] This setting allows for adjustment of the size of the light spot that the first beam illuminates on the workpiece.

[0011] Preferably, the second energy distribution adjustment component includes a second collimating lens.

[0012] This setting allows for adjustment of the size of the light spot that the second beam illuminates on the workpiece.

[0013] Preferably, the system also includes a mounting base on which a second reflector and a third reflector are mounted. The second reflector is located between the first reflector and the beam splitter, and the third reflector is located between the beam splitter and the focusing lens.

[0014] This design makes the structure more compact, adjusts the direction of the light beam, and directs the beam onto the workpiece, thus facilitating its use.

[0015] Preferably, the system also includes a first prism and a second prism, both of which are located on the side of the focusing lens away from the beam splitter, with the first prism positioned between the focusing lens and the second prism.

[0016] By rotating the first and second prisms, the energy distribution of the light spot can be altered.

[0017] A composite laser cutting method, employing the composite laser cutting device described above, includes the following steps:

[0018] S1. Emitting a beam: The first light source emits a first beam that illuminates the beam splitter, and the second light source emits a second beam that is reflected by the first reflector and illuminates the beam splitter. The first beam and the second beam converge and overlap on the beam splitter to form a composite beam, which is then focused onto the workpiece by the focusing lens.

[0019] S2. Controlling the energy distribution of the composite beam: Adjusting the spot size, focal position, and energy density of the first beam through the first light source and the first energy distribution adjustment component, and adjusting the spot size, focal position, and energy density of the second beam through the second light source and the second energy distribution adjustment component, thereby optimizing the heat flow range of the composite beam.

[0020] This setup enables multi-level energy distribution control and application. By controlling the overall and central energy density, it can rapidly improve the efficiency and quality of composite beam laser cutting. It is well-suited for laser cutting, especially for cutting thick plates and composite plates. It can cut transparent materials with high efficiency, overcoming the technical challenge of existing laser cutting machines' ineffective cutting of transparent and ultra-hard materials.

[0021] Preferably, step S2 further includes the following step:

[0022] The focal point of the second beam is located inside the workpiece and is one-third of the workpiece thickness from the top of the workpiece.

[0023] This setup improves laser cutting efficiency and the flatness of the cut surface, reduces the temperature difference between the top and bottom of the workpiece, effectively increases the laser cutting depth, and controls the width of the cutting kerf.

[0024] Preferably, step S2 further includes the following step:

[0025] The energy ratio of the first beam and the second beam in the composite beam is adjusted by the first light source and the second light source, respectively.

[0026] This setup improves applicability while ensuring cutting efficiency and surface smoothness for different materials.

[0027] Preferably, step S2 further includes the following step:

[0028] The wavelength of the first beam is shorter than that of the second beam, and the first beam illuminates the workpiece in a defocused manner.

[0029] This setup improves applicability while ensuring cutting efficiency and surface smoothness for different materials.

[0030] Preferably, step S2 further includes the following step:

[0031] Establish the relationship between melt volume and impact energy to obtain volumetric efficiency. Where V s E is the melt volume. t Impact energy;

[0032] Establish the relationship between melting depth and impact energy to obtain depth efficiency. Where T s This represents the melting depth.

[0033] Define the volumetric efficiency R using the following settings: eV and depth efficiency R eT Thus, it is possible to determine the value of R. eV and depth efficiency R eT The relationship between cutting rate and processing depth is further optimized to improve processing efficiency and increase the thickness of workpieces that can be cut, while ensuring that the requirements of cutting processing technology are met.

[0034] Compared with the prior art, the present invention has achieved beneficial technical effects:

[0035] 1. It achieves multi-level energy distribution control and application. By controlling the overall and central energy density, it can rapidly improve the efficiency and quality of composite beam laser cutting. It can be well applied in laser cutting, especially suitable for cutting thick plates, composite plates, and transparent materials, and can cut them with high efficiency.

[0036] 2. This invention can also optimize the energy distribution of the composite beam for pulse processing of transparent and superhard materials, thus overcoming the technical difficulty of laser cutting machines in the prior art in effectively cutting and processing transparent and superhard materials. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a composite laser cutting device according to an embodiment of the present invention;

[0038] Figure 2 This illustrates the relationship between the melting depth and beam energy of different light beams in embodiments of the present invention.

[0039] Figure 3 This illustrates the relationship between the melting volume and beam energy of different light beams in embodiments of the present invention.

[0040] Figure 4aThis is a thermal jet simulation diagram of a composite laser cutting method used in an embodiment of the present invention;

[0041] Figure 4b It is a simulation diagram of a thermal jet using a single wavelength beam.

[0042] The technical features referred to by the various reference numerals in the accompanying drawings are as follows:

[0043] 11. First light source; 12. First collimating lens; 13. Beam splitter; 21. Second light source; 22. Second collimating lens; 23. First reflecting mirror; 24. Mounting base; 25. Second reflecting mirror; 26. Third reflecting mirror; 31. Focusing lens; 32. First prism; 33. Second prism. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. However, the scope of protection of this invention is not limited to the specific embodiments described below.

[0045] refer to Figure 1 A composite laser cutting device includes a first light source 11, a second light source 21, a first reflector 23, a beam splitter 13, a focusing lens 31, a mounting base 24, a first energy distribution adjustment component, and a second energy distribution adjustment component. The first light source 11 emits a first beam that passes sequentially through the beam splitter 13 and the focusing lens 31. The second light source 21 emits a second beam that passes sequentially through the first reflector 23, the beam splitter 13, and the focusing lens 31. The first energy distribution adjustment component is located between the first light source 11 and the beam splitter 13 and is used to adjust the energy distribution of the first beam. The second energy distribution adjustment component is located between the second light source 21 and the first reflector 23 and is used to adjust the energy distribution of the second beam. The first energy distribution adjustment component includes a first collimating lens 12, and the second energy distribution adjustment component includes a second collimating lens 22. By moving the first collimating lens 12 and the second collimating lens 22, the diameters of the first and second beams can be adjusted, thereby adjusting the size of the spot irradiated on the workpiece. By moving the focusing lens 31, the focal point position can be adjusted.

[0046] Mounting base 24 is equipped with a second reflector 25 and a third reflector 26. The second reflector 25 is located between the first reflector 23 and the beam splitter 13, and the third reflector 26 is located between the beam splitter 13 and the focusing lens 31. It also includes a first prism 32 and a second prism 33, both of which are located on the side of the focusing lens 31 away from the beam splitter 13. The first prism 32 is located between the focusing lens 31 and the second prism 33.

[0047] A composite laser cutting method, employing the composite laser cutting device described above, includes the following steps:

[0048] S1. Emitting a beam: The first light source 11 emits a first beam that illuminates the beam splitter 13, and the second light source 21 emits a second beam that is reflected by the first reflector 23 and illuminates the beam splitter 13. The first beam and the second beam converge and overlap on the beam splitter 13 to form a composite beam. The composite beam is focused onto the workpiece by the focusing lens 31. In this embodiment, the wavelength of the first beam is 0.647 μm and the wavelength of the second beam is 1.08 μm, which is suitable for laser cutting of composite materials and meets the different requirements of the substrate and coating in the composite material for laser processing in terms of thermal and optical properties.

[0049] S2. Controlling the energy distribution of the composite beam: The spot size, focal position, and energy density of the first beam are adjusted by the first light source 11 and the first energy distribution adjustment component; the spot size, focal position, and energy density of the second beam are adjusted by the second light source 21 and the second energy distribution adjustment component to optimize the heat flow range of the composite beam; the focal point of the second beam is set inside the workpiece and the distance from the top of the workpiece is 1 / 3 of the workpiece thickness; the energy ratio of the first beam and the second beam in the composite beam is adjusted by the first light source 11 and the second light source 21 respectively; the wavelength of the first beam is shorter than the wavelength of the second beam, and the first beam illuminates the workpiece in a defocused manner; Reference Figure 2 and Figure 3 The relationship between melt volume and impact energy was established to obtain the volumetric efficiency. Where V s E is the melt volume. t The impact energy is used to establish the proportional relationship between melting depth and impact energy, thus obtaining the depth efficiency. Where T s The ablation depth is defined by induced energy function to ensure the stability of the melt flow during processing, thus determining the relationship between ablation volume and ablation depth. As the induced energy increases, the ablation depth also increases, exhibiting significant nonlinear behavior. Therefore, the speed stability and quality of the cutting process are optimized based on the combined effects of different wavelengths of laser beams. By controlling the laser beam source energy, focal position, spot diameter, and the configuration and proportion of different wavelengths, the functional relationship between ablation depth and ablation volume and energy is optimized through parameter control, resulting in a shorter interaction time between the laser and the material, and higher intensity at the same laser power level.

[0050] The melting depth has a non-linear relationship with the laser excitation energy; increasing the excitation energy increases the ablation depth. Since different wavelengths of laser light emitted from the laser beam source result in different spot diameters, a specific point energy Es is introduced to account for the influence of the beam source on the action area. Cutting efficiency is another parameter describing the laser cutting process. R eR is described as the ratio between the mass of the ablation material and the impact energy Et. Since the mass of the ablation material is difficult to determine, R... e The relationship is adjusted to the ratio between the ablation volume Vs and the impact energy Et. Since the laser wavelength decreases, the laser spot size also decreases, such as... Figure 2 As shown, as the focal spot size decreases, the interaction time between the laser and the material is significantly shortened. At the same laser power, the interaction time between the laser and the material is shorter and the intensity is higher. The significantly shortened interaction time at the same laser power level means that the required beam energy Es is lower.

[0051] A simulation model of the thermal jet flow after using the composite laser cutting method of this invention is as follows: Figure 4a As shown, the thermal jet has a longer operating length and a smooth, clear edge, which is beneficial for cutting thicker workpieces and results in a flat cross-section. In contrast, the thermal jet simulation model using a single-wavelength laser for cutting under the same conditions is shown below. Figure 4b The hot jet has a short working length and uneven edges, making it difficult to cut thick plates during the cutting process, and the resulting cross-section quality is poor.

[0052] This embodiment has the following advantages:

[0053] This technology enables multi-level energy distribution control and application. By controlling the overall and central energy density, it can rapidly improve the efficiency and quality of composite beam laser cutting. It is well-suited for laser cutting, especially for cutting thick plates, composite plates, and transparent materials, and can cut these materials with high efficiency.

[0054] Laser ablation is suitable for processing fiber-reinforced polymers with a small heat-affected zone. Glass fibers have uneven thermal conductivity and sublimation temperature between the matrix and fiber materials. The sublimation temperature of the glass fiber matrix is ​​2600℃, while the decomposition temperature of the fiber coating is 300-400℃. Furthermore, the absorption rates of laser energy by the fiber coating and the matrix are also different. This application can adjust the energy density and spot size of the first and second light beams respectively through the first light source 11 and the second light source 21, and adjust the spot size of the first and second light beams irradiating the workpiece respectively through the first energy distribution adjustment component and the second energy distribution adjustment component, so that the first beam irradiates the workpiece in a defocused manner, thereby controlling the energy density of the beam and adjusting the spot of the first beam irradiating the workpiece surface to be larger than the spot of the second beam, so that the spot of the second beam is located within the spot of the first beam. During the feeding process, the first beam first irradiates the workpiece surface and decomposes the fiber coating, so that the second beam can be focused onto the workpiece to cut the substrate, which greatly improves the cutting efficiency of glass fiber, realizes the cutting of composite materials, and avoids the instability of the cutting process caused by excessively high fiber coating temperature, prevents overheating of the heat-affected zone, and effectively improves the flatness of the cut surface and improves the quality of the cut surface.

[0055] Calculate the focal spot size based on process parameters It can optimize the focal spot size of the first beam and the second beam separately, where d f M represents the size of the focal spot. 2 Let λ represent the beam quality, λ be the wavelength of the corresponding beam, f be the focal length of the lens, and D be the diameter of the incident beam. By optimizing the global energy distribution characteristics through beam splitting, the control of the thermal effects on the laser action area can be further optimized, thereby enabling more efficient and accurate adjustment and optimization of laser beams with different materials and thicknesses.

[0056] During the cutting of thick workpieces, the focal positions of the first and second beams can be adjusted according to the workpiece thickness to achieve dynamic focusing based on the workpiece thickness. The heat flow range of the composite beam is also optimized, thus adapting to different workpieces. This improves applicability, increases processing efficiency, and ensures that the cutting depth meets the processing requirements of the workpiece.

[0057] It can optimize the energy distribution of the composite beam for pulse processing of transparent and superhard materials, and overcome the technical difficulties of existing laser cutting machines in effectively cutting transparent and superhard materials.

[0058] By setting the first collimating lens 12, the size of the light spot that the first beam illuminates on the workpiece can be adjusted.

[0059] The second collimating lens 22 can be used to adjust the size of the spot on the workpiece illuminated by the second beam.

[0060] By mounting the second reflector 25 and the third reflector 26 on the mounting base 24, the structure can be made more compact. The second reflector 25 reflects the second beam onto the beam splitter 13, which facilitates the adjustment of the second beam's illumination direction and makes it easier for the second beam to coincide with the first beam to form a composite beam. The third reflector 26 is used to adjust the illumination direction of the composite beam, allowing the composite beam to change its illumination direction and illuminate the workpiece, thus facilitating its use.

[0061] Rotating the first prism 32 and the second prism 33 can change the energy distribution of the light spot, thereby adjusting the energy distribution of the light beam through the first prism 32 and the second prism 33. This facilitates the adjustment of the light beam energy distribution for workpiece processing and can also improve processing efficiency.

[0062] Considering the impact of ablation depth on cutting efficiency, the second beam focal point is set below the top surface of the material. This ensures that the second beam produces high and more uniform energy densities at both the top and bottom of the workpiece, improving laser cutting efficiency and the smoothness of the cut surface. Setting the second beam focal point near the top of the workpiece in the middle allows the material at the top to melt, generating heat flow. This heat flow, combined with the laser beam, heats the material at the bottom of the workpiece, reducing the temperature difference between the top and bottom. This significantly increases the laser cutting depth and helps control the kerf width.

[0063] By adjusting the energy ratio of the first beam and the second beam in the composite beam using the first light source 11 and the second light source 21, the energy density of the first beam, the second beam, and the composite beam can be adjusted. This allows for processing of different materials, improving applicability while ensuring cutting efficiency and surface smoothness for various materials. In this embodiment, the energy ratio of the first beam in the composite beam can be configured as 25%, 50%, or 75%, and the corresponding energy ratio of the second beam in the composite beam can be configured as 75%, 50%, or 25%, thus adapting to different processing requirements through different energy ratio configurations.

[0064] The first beam illuminates the workpiece through defocusing, which controls the beam's energy density and provides support for controlling the global energy distribution of the composite beam. This allows the composite beam to be applied to the processing of different materials, improving its applicability while ensuring cutting efficiency and surface smoothness for different materials.

[0065] The efficient process of molten volume does not necessarily imply an efficient process regarding the depth of cut. Therefore, cutting efficiency is applicable when considering the relationship between the depth of cut and impact energy. Impact energy is accompanied by an increase in the thermal effect region and the stability of the thermal flow within that region. By controlling the energy distribution and wavelength of the composite beam through the corresponding interaction relationship, the volumetric efficiency R is defined. eV and depth efficiency R eT Thus, it is possible to determine the value of R. eV and depth efficiency R eT The relationship between cutting rate and processing depth is further optimized to improve processing efficiency and increase the thickness of workpieces that can be cut, while ensuring that the requirements of cutting processing technology are met.

[0066] Since different wavelengths emitted by the laser beam source result in different spot diameters, in this embodiment, the second light source generates a larger spot using a second beam with a wavelength of 1.08 μm, which increases the evaporation volume, thus allowing the corresponding ablation depth and volume to be determined. The first light source emits a first beam with a wavelength of 0.64 μm to optimize the workpiece's absorption rate of laser energy, thereby controlling the increase in absorption rate and absorption power and optimizing cutting efficiency. Under the action of the composite beam, the composite beam can penetrate deep into the cutting edge without interacting with it, increasing the material removal rate at the root of the cut. By optimizing the characteristic beam parameters of the first and second beams, the stability of the thermal zone and the depth of material removal can be optimized.

[0067] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the invention.

Claims

1. A composite laser cutting device, comprising a first light source (11), a second light source (21), a first reflector (23), a beam splitter (13), and a focusing lens (31), wherein the first light source (11) emits a first beam that passes sequentially through the beam splitter (13) and the focusing lens (31), and the second light source (21) emits a second beam that passes sequentially through the first reflector (23), the beam splitter (13), and the focusing lens (31), characterized in that: It also includes a first energy distribution adjustment component and a second energy distribution adjustment component. The first energy distribution adjustment component is located between the first light source (11) and the beam splitter (13) and is used to adjust the energy distribution of the first beam. The second energy distribution adjustment component is located between the second light source (21) and the first reflector (23) and is used to adjust the energy distribution of the second beam.

2. The composite laser cutting device according to claim 1, characterized in that: The first energy distribution adjustment component includes a first collimating lens (12).

3. The composite laser cutting device according to claim 1, characterized in that: The second energy distribution adjustment component includes a second collimating lens (22).

4. The composite laser cutting device according to claim 1, characterized in that: It also includes a mounting base (24) on which a second reflector (25) and a third reflector (26) are mounted. The second reflector (25) is located between the first reflector (23) and the beam splitter (13), and the third reflector (26) is located between the beam splitter (13) and the focusing lens (31).

5. The composite laser cutting device according to claim 1, characterized in that: It also includes a first prism (32) and a second prism (33), both of which are located on the side of the focusing lens (31) away from the beam splitter (13), with the first prism (32) located between the focusing lens (31) and the second prism (33).

6. A composite laser cutting method, characterized in that, Using the composite laser cutting apparatus according to any one of claims 1 to 5, the method includes the following steps: S1. Emitting a beam: The first light source (11) emits a first beam that illuminates the beam splitter (13), and the second light source (21) emits a second beam that is reflected by the first reflector (23) and illuminates the beam splitter (13). The first beam and the second beam converge and overlap on the beam splitter (13) to form a composite beam. The composite beam is focused onto the workpiece by the focusing lens (31). S2. Control the energy distribution of the composite beam: Adjust the spot size, focal position and energy density of the first beam through the first light source (11) and the first energy distribution adjustment component, and adjust the spot size, focal position and energy density of the second beam through the second light source (21) and the second energy distribution adjustment component to optimize the heat flow range of the composite beam.

7. The composite laser cutting method according to claim 6, characterized in that, Step S2 further includes the following steps: The focal point of the second beam is located inside the workpiece and is one-third of the workpiece thickness from the top of the workpiece.

8. The composite laser cutting method according to claim 6, characterized in that, Step S2 further includes the following steps: The energy ratio of the first beam and the second beam in the composite beam is adjusted by the first light source (11) and the second light source (21), respectively.

9. The composite laser cutting method according to claim 6, characterized in that, Step S2 further includes the following steps: The wavelength of the first beam is shorter than that of the second beam, and the first beam illuminates the workpiece in a defocused manner.

10. The composite laser cutting method according to claim 6, characterized in that, Step S2 further includes the following steps: Establish the relationship between melt volume and impact energy to obtain volumetric efficiency. Where V s E is the melt volume. t Impact energy; Establish the relationship between melting depth and impact energy to obtain depth efficiency. Where T s This represents the melting depth.

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