Laser device and laser processing device

Abstract

The invention relates to the technical field of laser processing, and provides a laser and a laser processing device.The laser comprises a light emitting module, a collimation and beam shrinkage module and a focusing module which are arranged in sequence, and the light emitting module is used for emitting an initial laser beam; the collimation and beam contraction module adjusts the initial laser beam into a collimation and beam contraction light beam; and the focusing module focuses the straight and shrunk beam to obtain a laser beam which can be directly used for processing, and the spot radius distribution of the laser beam meets a specific function relationship. According to the laser beam which is formed by the laser device and meets the specific function relation and is used for machining, on one hand, during laser machining, the laser machining beam with the extremely small light spot diameter can be formed in a to-be-machined area, the laser machining beam which is embodied as a filament-shaped laser machining beam can be formed, higher energy density and a better focusing effect are achieved, and on the other hand, the machining efficiency is improved; therefore, the processing speed and the processing quality are improved; and on the other hand, compared with a common laser processing beam, the laser processing beam provided by the laser has a longer effective working area, more focus positions can be provided when a focus is found, and the processing efficiency is greatly improved.

Description

Technical Field

[0001] The present application relates to the field of laser processing technology, and in particular to a laser and a laser processing device. Background Art

[0002] Laser processing technology has been widely used in precision manufacturing, microelectronics, aerospace and other fields due to its advantages such as non-contact processing, high precision and good controllability. The optical path in a traditional laser is usually composed of a laser source, a collimator and a focusing lens. Its core goal is to focus the laser beam into a high-energy density spot to achieve material processing. It has important applications in laser cutting, welding, drilling and other scenarios.

[0003] However, as modern manufacturing industry's demand for processing efficiency and complex structure processing capabilities continues to increase, the improvement of laser energy density is limited by the contradiction between the characteristics of the beam transmission process and the spot size. The conventional optical path structure with only collimating lenses and focusing lenses does not support the adjustment of the processing beam spot over a large range, and the power density of the laser at the focus position can be improved to a limited extent.

[0004] Therefore, how to achieve efficient collimation and beam reduction of the laser beam and increase its energy density under the premise of low cost and low complexity remains a key technical problem that restricts laser processing efficiency. Summary of the invention

[0005] In view of the shortcomings of the prior art mentioned above, the purpose of the present application is to provide a laser and a laser processing device, which can form a filament-shaped laser beam for processing, with a small laser spot diameter and a more reasonable distribution of the laser spot diameter in the laser transmission direction. At the same time, the laser beam has a high energy density, which can solve the technical problems of low laser output energy density and low processing efficiency of traditional lasers.

[0006] To achieve the above-mentioned purpose and other related purposes, the present application provides a laser, which includes a light output module, a collimating and shrinking module, and a focusing module. The light output module is used to emit an initial laser beam; The collimated beam shrinking module is arranged in the light emitting direction of the initial laser beam, and is used to adjust the initial laser beam and form a collimated beam shrinking beam. The collimated beam shrinking beam can form a laser beam for processing after being focused by the focusing module. The laser spot radius of the laser beam for processing satisfies the following relationship in a specific area of ​​0<x<2: k*(0.0053*x2 + 0.0018*x + 0.0762)≤y<0.0048*x2 - 0.0026*x + 0.1175 Wherein, x represents the longitudinal position value of the light beam, y represents the laser spot radius value corresponding to the longitudinal position of the light beam, the physical units of the longitudinal position and the laser spot radius corresponding to the longitudinal position of the light beam are mm, k is the correction coefficient, 0 <k≤1; A focusing module is arranged at the output end of the collimating and beam-shrinking module.

[0007] As a preferred solution, the focusing module includes a focusing mirror, and the curvature radius of the incident surface of the focusing mirror is greater than the curvature radius of the exit surface of the focusing mirror.

[0008] As a preferred solution, the collimated beam shrinking module includes a first lens and a second lens arranged in sequence along the initial laser beam emission direction. The first lens is used to change the spot diameter of the initial laser beam, and the second lens is used to collimate the beam output from the first lens to form a collimated beam.

[0009] As a preferred solution, the first lens is a biconvex lens, and the biconvex lens is provided with convex surfaces at both ends in the light path direction.

[0010] As a preferred solution, the second lens is a double concave lens, and the double concave lens is provided with concave surfaces at both ends of the optical path direction.

[0011] As a preferred solution, the focusing mirror adopts a double convex lens or a positive meniscus lens.

[0012] As a preferred solution, the surface of the first lens and / or the second lens is coated with an anti-reflection film for improving the transmittance of the lens, and the anti-reflection film has a preset anti-damage threshold.

[0013] As a preferred solution, the waist diameter of the light beam emitted from the self-focusing mirror is less than 0.21 mm.

[0014] As a preferred solution, the correction coefficient k satisfies: 0.1 <k≤1。

[0015] As another aspect of the present application, a laser processing device is also proposed for laser processing a workpiece to be processed, wherein the laser processing device includes a laser in any of the above-mentioned solutions.

[0016] As described above, a laser and a laser processing device provided by the present application can be used in the fields of laser cutting and laser welding, including but not limited to, wherein the laser includes a light-emitting module, a collimated beam-shrinking module and a focusing module, wherein the light-emitting module is used to emit an initial laser beam; the collimated beam-shrinking module is arranged in the light-emitting direction of the initial laser beam to adjust the initial laser beam to form a collimated beam-shrinking beam; the focusing module is used to focus the collimated beam-shrinking beam to obtain a laser beam that can be directly used for processing, and the spot radius of the laser beam satisfies a specific functional relationship. The laser beam for processing that satisfies a specific functional relationship formed by the laser of the present application, on the one hand, can form a very small spot diameter of the laser processing beam in the area to be processed during laser processing, which is reflected as a "filament-like" laser processing beam, achieving higher energy density and better focusing effect, thereby improving processing speed and processing quality; on the other hand, compared with ordinary laser processing beams, the laser processing beam provided by the laser of the present application has a longer effective working area, and can have more focus positions when looking for the focus, which greatly improves the processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0018] Figure 1 is a schematic diagram of the structure of the laser in the embodiment of the present application; Figure 2 Schematic diagram of energy density profiles of three laser beams used for processing; Figure 3 It is a schematic diagram of the spot radius distribution of the output light beam of the laser of the present application in some embodiments.

[0019] Among them, 10, light output module; 11, first lens; 12, second lens; 13, focusing module. DETAILED DESCRIPTION

[0020] In order to facilitate the understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or one or more centered elements can exist between them. When an element is described as "electrically connected" to another element, it can be directly connected to the other element, or one or more centered elements can exist between them. The terms "upper", "lower", "inner", "outer", "bottom", etc. used in this specification indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0021] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0022] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0023] The internal optical path of a conventional laser only has a collimator and a focusing lens, and the processing light beam formed after focusing has a large divergence angle, which causes the laser to be unable to effectively converge energy. The low energy utilization rate leads to low processing efficiency and quality. In order to overcome the above-mentioned defects in the prior art, the embodiment of the present application provides a laser, please refer to Figure 1 The laser comprises a light-emitting module 10, a collimated beam-shrinking module and a focusing module 13. The light-emitting module is used to emit an initial laser beam. The collimated beam-shrinking module is arranged in the light-emitting direction of the initial laser beam, and is used to adjust the initial laser beam and form a collimated beam-shrinking beam. The collimated beam-shrinking beam can form a laser beam for processing after being focused by the focusing module. The laser spot radius of the laser beam for processing satisfies the following relationship in a specific region of 0<x<2: k*(0.0053*x2 + 0.0018*x + 0.0762)≤y<0.0048*x2 - 0.0026*x + 0.1175 Among them, x represents the longitudinal position value of the light beam, y represents the laser spot radius value corresponding to the longitudinal position of the light beam. The physical quantity units of the longitudinal position and the laser spot radius corresponding to the longitudinal position of the light beam are mm, k is a correction coefficient, and 0 < k ≤ 1; a focusing module, which is arranged at the output end of the collimating and beam-reducing module.

[0024] Please refer to again Figure 2 , Figure 2 FIG. is a schematic diagram of the energy density profiles of three laser beams for processing. Among them, the left figure is a schematic diagram of the profile of a conventional laser beam. It can be clearly seen that the profile area on both the upper and lower sides of the conventional laser beam is relatively large; the right figure is a schematic diagram of the profile of the laser beam (laser filament) of the present application. There will be no problem of a relatively large area on both the upper and lower sides of the laser beam of the present application. Overall, the area distribution is reasonable, the energy density will be relatively higher than that of the conventional laser beam, the spot radius is more evenly distributed in the laser transmission direction, and the energy density of the laser beam will be higher, which is beneficial to faster laser processing; the middle figure is a multi-focus laser beam. Although the energy density of this laser beam has been improved and the spot radius distribution has been improved (not as large as the change in the spot radius of the conventional beam), it is still not sufficient to meet the requirements of rapid laser processing. In addition, Figure 2 The effective working area (indicated by a dotted line) is also shown. It can be seen that the effective working area of the conventional beam on the left is the shortest, the multi-focus beam in the middle is the second, and the laser filament beam (the solution of the present application) on the right has the longest effective working area. The energy density of the laser beam in this effective working area of the laser filament beam on the right is relatively higher than that of the conventional beam, meeting the laser energy required for rapid processing.

[0025] The following Table 1 and Table 2 are the distributions of the spot radius values corresponding to different longitudinal positions of the light beam, and the distributions of the spot radius values corresponding to different longitudinal positions of the conventional conventional scheme are also listed for comparison: Longitudinal position of light beam / mm Conventional scheme Spot radius / mm Present application Example 1 (spot radius / mm) Example 2 (spot radius / mm) 5 0.4371 0.6342 0.4285 4 0.3771 0.4285 0.3428 3 0.3171 0.3428 0.2914 2 0.2657 0.2571 0.2057 1 0.2314 0.1543 0.1457 0 0.2143 0.1029 0.1092 -1 0.2486 0.1371 0.1543 -2 0.2828 0.2400 0.2057 -3 0.3600 0.3257 0.2743 -4 0.4114 0.4028 0.3428 -5 0.4885 0.4371 0.3600 In addition, actual experiments developed by the applicant have shown that the laser light speed scheme corresponding to the above-mentioned embodiments 1 and 2 can increase the processing speed by more than 1.5-2 times that of traditional conventional laser beams in actual processing scenarios. Figure 3 The solid curve in the Figure 2 The left figure shows the laser beam profile and spot radius distribution of the conventional solution. The dotted curve corresponds to Figure 2 The right figure shows the laser beam profile and spot radius distribution of the laser wire solution. In comparison, the spot diameter formed at the beam waist of the laser wire solution is smaller than that of the conventional solution, and the entire beam is narrower and longer in the longitudinal direction, which is conducive to improving the processing speed and processing quality. In the actual processing process, embodiment 2 is preferred. It can be understood that Figure 3 The change and distribution of the spot diameter within 5 mm before and after the longitudinal position of the beam are shown.

[0026] In the embodiment of the present application, the light output module 10 may adopt one or more of a semiconductor light source, a solid light source, and a fiber laser light source, so as to output laser light of at least one or more wavelengths.

[0027] In one embodiment, the focusing module 13 includes a focusing mirror, the curvature radius of the incident surface of the focusing mirror is greater than the curvature radius of the exit surface of the focusing mirror, the surface with a smaller curvature radius faces the collimated light beam, and the surface with a larger curvature radius faces the converged light beam, so as to minimize the spherical aberration, thereby improving the quality of the laser beam output for processing. Optionally, in order to cooperate with the collimating beam reduction module, the focusing mirror provided in this embodiment adopts a double convex spherical lens or a positive meniscus lens to minimize the cost of the system and provide an excellent focusing effect.

[0028] Please continue to refer to Figure 1 The collimated beam shrinking module includes a first lens 11 and a second lens 12 sequentially arranged along the initial laser beam emission direction, and the first lens 11 and the second lens 12 are used to form a collimated beam shrinking light. In one embodiment, the first lens 11 is a biconvex lens, and the biconvex lens is respectively provided with convex surfaces at both ends of the light path direction; the second lens 12 is a biconcave lens, and the biconcave lens is respectively provided with concave surfaces at both ends of the light path direction. The arrangement of the second lens 12 in the light path can ultimately realize the specific laser beam output by the laser of the present application.

[0029] Optionally, the surfaces of the first lens 11 and the second lens 12 are coated with an anti-reflection film for improving the transmittance of the lens. The anti-reflection film has a preset anti-damage threshold to maintain good shaping performance under the condition of high-power laser output.

[0030] In the embodiment of the present application, the beam waist diameter of the beam emitted from the focusing lens is less than 0.21 mm. Here, the beam waist diameter is the diameter of the laser spot corresponding to x = 0.

[0031] As another aspect of the present application, a laser processing device is also proposed for laser processing of a workpiece to be processed. The laser processing device uses the laser as described in any of the above solutions. It can be understood that the laser processing device is applied to fields including but not limited to the cutting field and the welding field.

[0032] In summary, the laser and the laser processing device described in the present application change the traditional optical path, add a second lens, and finally change the laser spot radius distribution of the traditional laser beam in the laser transmission direction. The initial laser beam emitted from the light output module is adjusted by the collimation and beam reduction module to form a collimated and beam-reduced beam, and then the focusing module is used to focus the collimated and beam-reduced beam. Finally, a thin-filament laser beam that meets the specific requirements of the present application and can be directly used for processing is obtained, realizing the efficient collimation and beam reduction of the laser beam and the improvement of the energy density, which can improve the laser processing speed and efficiency. For the longitudinal position x of the beam, the following description is required. Refer to Figure 3 , the laser beam for processing output by the laser is symmetric along the longitudinal direction of the beam. The symmetric center is defined as the longitudinal position x = 0 of the beam. For the two parts where x < 0 and x > 0, the spot radius is symmetrically distributed about the symmetric center. Figure 3 Although -5 ≤ x ≤ 5 is shown, the present application does not focus on the entire region. The present application only focuses on the laser spot radius distribution in the region of 0 < x < 2. That is to say, for the region of 0 < x < 2, the laser spot radius value corresponding to the longitudinal position of the beam only needs to satisfy being equal to or greater than the above k*(0.010697x2 + 0.003502x + 0.10000), where 0 < k ≤ 1; and less than 0.009538x2 - 0.005221x + 0.234980. The laser radius distribution is the protection scope required by the present application. Preferably, the correction coefficient k satisfies: 0.1 < k ≤ 1.

[0033] In addition, the laser beam output by the laser of the present application has a small divergence and a low rate of change of the spot size. When the lens undergoes temperature drift, the laser beam has little effect on the consistency of the processed section. The laser of the present application solves the technical problems in the prior art that the laser output laser energy density is low, the processing efficiency is low, and rapid laser processing cannot be achieved to improve the processing efficiency, and has a high practical application value.

[0034] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A laser, comprising a light output module, a collimating and beam shrinking module and a focusing module, characterized in that: The light output module is used to emit an initial laser beam; The collimated beam shrinking module is arranged in the light emitting direction of the initial laser beam, and is used to adjust the initial laser beam and form a collimated beam shrinking beam. The collimated beam shrinking beam can form a laser beam for processing after being focused by the focusing module. The laser spot radius of the laser beam for processing satisfies the following relationship in a specific area of ​​0<x<2: k*(0.0053*x 2 + 0.0018*x + 0.0762)≤y<0.0048*x 2 - 0.0026*x + 0.1175 Wherein, x represents the longitudinal position value of the light beam, y represents the laser spot radius value corresponding to the longitudinal position of the light beam, the physical units of the longitudinal position and the laser spot radius corresponding to the longitudinal position of the light beam are mm, k is the correction coefficient, 0 <k≤1; A focusing module is arranged at the output end of the collimating and beam-shrinking module.

2. The laser according to claim 1, characterized in that The focusing module comprises a focusing mirror, and a curvature radius of an incident surface of the focusing mirror is greater than a curvature radius of an exit surface of the focusing mirror.

3. The laser according to claim 1, characterized in that The collimated beam shrinking module includes a first lens and a second lens sequentially arranged along the emission direction of the initial laser beam, the first lens is used to change the spot diameter of the initial laser beam, and the second lens is used to collimate the beam output from the first lens to form the collimated beam shrinking.

4. The laser according to claim 3, characterized in that The first lens is a double convex lens, and the double convex lens is provided with convex surfaces at both ends of the optical path direction.

5. The laser according to claim 3, characterized in that The second lens is a double concave lens, and the double concave lens is provided with concave surfaces at both ends in the light path direction.

6. The laser according to claim 5, characterized in that The focusing lens is a double convex lens or a positive meniscus lens.

7. The laser according to claim 3, characterized in that The surface of the first lens and / or the second lens is coated with an anti-reflection film for improving the transmittance of the lens, and the anti-reflection film has a preset anti-damage threshold.

8. The laser according to claim 7, characterized in that The beam waist diameter of the light beam emitted from the focusing mirror is less than 0.21 mm.

9. The laser according to claim 1, characterized in that Correction coefficient k satisfies: 0.1 <k≤1。 10. A laser processing device for laser processing a workpiece to be processed, characterized in that: The laser processing device comprises the laser according to any one of claims 1-8.

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