In-process laser machining head

Abstract

The application discloses an in-fiber laser processing head, and belongs to the technical field of laser processing. The in-fiber laser processing head comprises a first plane mirror, a second plane mirror and a focusing lens which are sequentially arranged along the direction of a laser light path. The first plane mirror and the second plane mirror each comprise a plurality of reflection planes with different inclination angles. The first plane mirror is used for splitting the collimated incident laser beam. The second plane mirror is used for reflecting the multiple laser beams obtained by splitting and making the multiple laser beams parallelly incident on the focusing lens. The reflected light rays of each reflection plane are focused on a working surface by the focusing lens, so that the wire / powder material coaxially fed by a feeding device is processed. Compared with the existing in-fiber laser processing head, the application significantly reduces the complexity of optical system design, and the number of optical components is small, the optical path stability is good, and an in-fiber laser processing head with a simple optical path structure and light coaxial wire / powder feeding is realized.

Description

Technical Field

[0001] This invention belongs to the field of laser processing technology, and more specifically, relates to a laser processing head for in-light material delivery. Background Technology

[0002] With the development of advanced laser manufacturing technology, higher demands are being placed on laser processing systems to meet the manufacturing needs of industries such as automobiles, electronics, electrical appliances, aerospace, metallurgy, and machinery manufacturing. In-light material feeding technology refers to using different beam splitting techniques to center and vertically spray material onto the processing surface, ensuring the laser beam is coaxial with the material's centerline. In-light material feeding laser processing heads offer superior processing performance due to their excellent material feeding directionality, uniform material heating, and strong laser-material coupling. Therefore, researching an in-light material feeding laser processing head is of great significance.

[0003] Existing laser processing heads with internal optical feeding generally use coaxial wire / powder feeding processing. Currently, coaxial wire / powder feeding processing mainly includes two methods: ring-shaped internal optical wire / powder feeding processing and beam-splitting internal optical wire / powder feeding processing. Traditional beam splitting methods generally use conical mirrors, prisms, adjustment mirrors, etc. for beam splitting, which requires many lenses, has poor optical path stability, and is not conducive to the lightweight and high-quality development of laser processing heads. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides an optical in-line material feeding laser processing head, the purpose of which is to provide a lightweight coaxial wire / powder in-line material feeding laser processing head with better optical path stability.

[0005] To achieve the above objectives, the present invention provides an optical in-light material delivery laser processing head, comprising: a first planar reflector, a second planar reflector, and a focusing lens arranged sequentially along the laser optical path;

[0006] The first plane mirror has N first reflecting planes as its reflecting surface; the second plane mirror has N second reflecting planes that correspond one-to-one with the N first reflecting planes as its reflecting surface, and the second plane mirror and the focusing lens are hollow for placing the material feeding device.

[0007] The tilt angles of the first reflective planes of the first plane mirror are all different, which are used to split the collimated incident laser beam to obtain N laser beams, which are then incident on the corresponding second reflective planes respectively.

[0008] The tilt angles of each of the second reflective planes of the second plane mirror are different, which are used to reflect N laser beams and then incident them parallel to the focusing lens.

[0009] A focusing lens is used to focus N parallel incident laser beams onto the working surface to process the material coaxially fed in by the feeding device;

[0010] Where N≥2; the feeding device includes: a wire feeding device or a powder feeding device.

[0011] More preferably, the tilt angles of each first reflecting plane of the first plane mirror and each second reflecting plane of the second plane mirror are determined in the following manner:

[0012] The vertex positions of N uniformly distributed fan-shaped light spots are preset on the same plane;

[0013] Take the light ray that passes through the center of the first reflector in the incident laser beam, and based on the light path process of the N light rays after passing through the first plane reflector and the second reflector to each vertex position, determine the incident light ray and the reflected light ray of each first reflector and the corresponding second reflector.

[0014] Calculate the direction of the angle bisector between the incident ray and the reflected ray of any first reflecting plane to obtain the direction of the normal vector of the first reflecting plane, and thus obtain the tilt angle of the first reflecting plane.

[0015] Calculate the direction of the angle bisector between the incident ray and the reflected ray of any second reflecting plane to obtain the direction of the normal vector of the second reflecting plane, and thus obtain the tilt angle of the second reflecting plane.

[0016] More preferably, the first reflecting plane is parallel to its corresponding second reflecting plane.

[0017] More preferably, the focusing lens has an aspherical surface shape, which is used to shape and focus N parallel incident laser beams onto the working surface.

[0018] More preferably, the reflective surface of the first planar mirror is coated with a high-reflectivity film.

[0019] More preferably, the reflective surface of the second planar mirror is coated with a high-reflectivity film.

[0020] More preferably, the first planar reflector is provided with a water-cooling channel.

[0021] More preferably, the second planar reflector is provided with a water-cooling channel.

[0022] More preferably, the above-mentioned optical in-line material delivery laser processing head further includes a protective mirror disposed along the optical path direction after the focusing lens and before the working surface.

[0023] More preferably, the protective mirror is a hollow ring-shaped protective mirror, which is composed of multiple independently pluggable fan-shaped protective mirrors;

[0024] Alternatively, the protective mirror is a hollow double-layer protective mirror structure, including an inner protective mirror away from the working surface and an outer protective mirror close to the working surface; wherein, the inner protective mirror is a hollow annular protective mirror; the outer protective mirror is a hollow annular protective mirror, which is spliced ​​together from multiple independently pluggable fan-shaped protective mirrors.

[0025] More preferably, the above-mentioned optical in-line material delivery laser processing head further includes: a collimating lens disposed in front of the first planar reflector along the optical path direction, for collimating the incident laser beam.

[0026] More preferably, N = 4.

[0027] In summary, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0028] 1. This invention provides an optical in-line material feeding laser processing head, comprising a first planar reflector, a second planar reflector, and a focusing lens arranged sequentially along the laser beam path; both the first and second planar reflectors include multiple reflective planes with different tilt angles; the first planar reflector is used to split the collimated incident laser beam; the second planar reflector is used to reflect the multiple laser beams obtained by the split beam and then incident them parallel to the focusing lens, which focuses the reflected light from each reflective plane onto the working surface, thereby realizing the processing of the wire / powder material coaxially fed by the feeding device; compared with existing optical in-line material feeding laser processing heads, this invention significantly reduces the complexity of the optical system design, while having fewer optical components and better optical path stability, realizing a lightweight coaxial wire / powder feeding optical in-line material feeding laser processing head with a simple optical path structure.

[0029] 2. Furthermore, the laser processing head for in-light material delivery provided by the present invention can accurately design the tilt angles of each first reflective plane of the first planar reflector and each second reflective plane of the second planar reflector, and improves the processing accuracy through integrated processing.

[0030] 3. Furthermore, the laser processing head for in-light material delivery provided by the present invention has a high-reflectivity film coated on the reflective surface of the first and / or second planar reflectors, which can further improve the reflectivity and reduce the light loss.

[0031] 4. Furthermore, the optical in-feed laser processing head provided by the present invention has a water-cooling channel provided on the first plane mirror and / or the second plane mirror, which can cool the reflecting surface of the mirror, thereby improving the heat resistance efficiency of the optical in-feed laser processing head.

[0032] 5. Furthermore, the optical in-feed laser processing head provided by the present invention further includes: a protective mirror disposed along the optical path direction after the planar reflector and before the working surface, to prevent dust from contaminating the optical in-feed laser processing head.

[0033] 6. Furthermore, the protective mirror used in the laser processing head for internal material feeding provided by the present invention is a hollow ring-shaped protective mirror, which is composed of multiple independently pluggable fan-shaped protective mirrors, making it convenient and flexible to disassemble and avoiding the difficulty of disassembling and replacing the protective mirror.

[0034] 7. Furthermore, the protective mirror used in the laser processing head for internal material feeding provided by the present invention is a hollow double-layer protective mirror structure. The outer protective mirror is a hollow annular protective mirror, which is spliced ​​together by multiple independently pluggable fan-shaped protective mirrors, making it convenient and flexible to disassemble. The inner layer is a hollow annular protective mirror, which is used to protect the optical path, and the optical path will not be contaminated when the protective mirror is replaced. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a laser processing head for in-light material delivery, provided in an embodiment of the present invention.

[0036] Figure 2 A schematic diagram showing the tilt angles of two planar reflectors provided in an embodiment of the present invention;

[0037] Figure 3 A schematic diagram of the spotlight at various locations provided in an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the structure of the protective mirror provided in an embodiment of the present invention. Detailed Implementation

[0039] 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 accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0040] To achieve the above objectives, the present invention provides an optical in-light material delivery laser processing head, comprising: a first planar reflector, a second planar reflector, and a focusing lens arranged sequentially along the laser optical path;

[0041] The first plane mirror has N first reflecting planes as its reflecting surface; the second plane mirror has N second reflecting planes that correspond one-to-one with the N first reflecting planes as its reflecting surface, and the second plane mirror and the focusing lens are hollow for placing the material feeding device.

[0042] The tilt angles of the first reflective planes of the first plane mirror are all different, which are used to split the collimated incident laser beam to obtain N laser beams, which are then incident on the corresponding second reflective planes respectively.

[0043] The tilt angles of each of the second reflective planes of the second plane mirror are different, which are used to reflect N laser beams so that the N rays are incident on the focusing lens in parallel.

[0044] A focusing lens is used to focus N parallel incident laser beams onto the working surface to process the material coaxially fed in by the feeding device;

[0045] Wherein, N≥2; the feeding device includes: a wire feeding device or a powder feeding device, such as a hollow tube for guiding wire or powder, i.e., a wire feeding tube or a powder feeding tube, to ensure that the powder feeding (wire feeding) structure is coaxial with the laser beam.

[0046] To achieve precise control, the tilt angles of each first reflecting plane of the first plane mirror and each second reflecting plane of the second plane mirror can be designed, specifically determined in the following way:

[0047] The vertex positions of N uniformly distributed fan-shaped light spots are preset on the same plane;

[0048] Take the light ray that passes through the center of the first reflector in the incident laser beam, and based on the light path process of the N light rays after passing through the first plane reflector and the second reflector to each vertex position, determine the incident light ray and the reflected light ray of each first reflector and the corresponding second reflector.

[0049] Calculate the direction of the angle bisector between the incident ray and the reflected ray of any first reflecting plane to obtain the direction of the normal vector of the first reflecting plane, and thus obtain the tilt angle of the first reflecting plane.

[0050] Calculate the direction of the angle bisector between the incident ray and the reflected ray of any second reflecting plane to obtain the direction of the normal vector of the second reflecting plane, and thus obtain the tilt angle of the second reflecting plane.

[0051] In the above process, the tilt angle of the first reflecting plane can be preset to a suitable angle first, and then the tilt angle of the second reflecting plane can be calculated according to the above process; similarly, the tilt angle of the second reflecting plane can be preset to a suitable angle first, and then the tilt angle of the first reflecting plane can be calculated according to the above process.

[0052] In one alternative implementation, the first reflecting plane is parallel to its corresponding second reflecting plane to further improve control accuracy.

[0053] The focusing lens can be a regular lens that focuses a parallel-incident laser beam onto a point on the working surface, or it can be an aspherical lens that uses the law of conservation of energy and the principle of equal optical path length to shape the parallel-incident laser beam into a flat-topped or concave spot. Preferably, in one optional embodiment, the focusing lens has an aspherical surface shape and is used to shape and focus N parallel-incident laser beams onto the working surface.

[0054] In one alternative implementation, a high-reflectivity film is coated on the reflective surface of the first planar mirror to improve reflectivity and reduce light loss.

[0055] In one alternative implementation, a high-reflectivity film is coated on the reflective surface of the second planar mirror to improve reflectivity and reduce light loss.

[0056] In one alternative implementation, a water-cooling channel is provided on the first planar reflector to cool the reflective surface of the first planar reflector, thereby improving the heat resistance efficiency of the laser processing head for in-light material delivery.

[0057] In one alternative implementation, a water-cooling channel is provided on the second planar reflector to cool the reflecting surface of the second planar reflector, thereby improving the heat resistance efficiency of the laser processing head for in-light material delivery.

[0058] In one optional embodiment, the aforementioned optical in-feed laser processing head further includes a protective mirror disposed along the optical path direction after the focusing lens and before the working surface to prevent dust from contaminating the optical in-feed laser processing head.

[0059] In one optional embodiment, the protective lens is a hollow annular protective lens, composed of multiple independently pluggable fan-shaped protective lenses, facilitating flexible disassembly and avoiding the difficulty of replacing the protective lens. In another optional embodiment, the protective lens can also adopt a double-layer protective lens structure. The outer protective lens is a hollow annular protective lens with a drawer-type split structure, composed of multiple independently pluggable fan-shaped protective lenses, facilitating flexible disassembly; the inner layer is a hollow annular protective lens, used to protect the optical path, ensuring that the optical path is not contaminated when replacing the protective lens.

[0060] In one optional embodiment, the above-mentioned optical in-feed laser processing head further includes: a collimating lens disposed in front of the first planar reflector along the optical path direction, for collimating the incident laser beam.

[0061] It should be noted that N is an integer greater than or equal to 2, and can take values ​​of 3, 4, 5, 6, 7, 8, etc., without limitation here; preferably, N = 4.

[0062] In summary, this invention significantly reduces the complexity of optical system design, while having fewer optical components and better optical path stability. It can significantly reduce the assembly difficulty of the optical in-light material feeding laser processing head, and the radial energy distribution of the light spot can be designed, further enhancing the flexibility of the optical in-light material feeding laser processing head. It is suitable for high-power laser processing cladding and welding processes and can be widely used in the field of laser processing.

[0063] To further illustrate the optical in-optical material delivery laser processing head provided by the present invention, the following detailed description is provided in conjunction with specific embodiments:

[0064] like Figure 1 As shown, this embodiment provides a multi-beam optical coaxial powder (wire) feeding laser processing head. Taking a four-beam (N=4) configuration as an example, its principle and process are described in detail. The optically fed laser processing head in this embodiment includes: an optical fiber connector 1, a collimating lens 2, a first plane mirror 3, a second plane mirror 4, a focusing lens 5, a working surface 6, a transmission surface 7, and a wire (powder) feeding tube 8;

[0065] Fiber optic connector 1 is connected to the fiber laser, and a high-power laser beam is input. After passing through the collimating lens, the laser beam becomes a parallel laser beam.

[0066] The four first reflective planes of the first plane mirror 3 are tilted at different angles, which divides the laser beam into four quarters and forms four fan-shaped light spots. After the laser beam is divided into quarters, it passes through the second plane mirror 4, which can deflect the laser beam again and emit it in parallel.

[0067] like Figure 2 The diagram shown illustrates the method for determining the tilt angle of two plane mirrors.

[0068] The vertex positions of N uniformly distributed fan-shaped light spots are preset on the same plane; the light rays passing through the center of the first reflector in the incident laser beam are taken, and based on the light path process of the N light rays after passing through the first plane reflector and the second reflector to each vertex position, the incident light rays and reflected light rays of each first reflector and the corresponding second reflector are determined; the direction of the angle bisector of the incident light ray and the reflected light ray of any first reflector is calculated to obtain the normal vector direction of the first reflector, thereby obtaining the tilt angle of the first reflector; the direction of the angle bisector of the incident light ray and the reflected light ray of any second reflector is calculated to obtain the normal vector direction of the second reflector, thereby obtaining the tilt angle of the second reflector.

[0069] Specifically, ray AB exits through the first plane mirror as ray BC, ray BC exits through the second plane mirror as ray CD, point D is one of four uniform points on the target surface, where point B is the center of the first plane mirror and point E is the center of the second plane mirror, the angle bisector of ray BA and ray BC is the normal to the corresponding reflecting plane of the first plane mirror, and the angle bisector of ray CB and ray CD is the normal to the corresponding reflecting plane of the second plane mirror.

[0070] Four beams are incident in parallel onto the focusing lens. The focusing lens can be a regular plano-convex lens to focus the incident beams onto a single point spot, or it can be an aspherical lens to shape the parallel incident beams into a flat-topped ring spot or a concave ring spot.

[0071] like Figure 3 The diagram shows the light spots at various points where the light spot is formed. The circular light spot is divided into four fan-shaped light spots after passing through the first plane mirror. After passing through the second plane mirror, the light spot is deflected and then focused into a point light spot on the working surface after passing through the transmission focusing mirror.

[0072] Figure 4 This is a schematic diagram of the protective lens structure. It uses a double protective lens structure. The inner ring-shaped protective lens protects the optical path and will not contaminate the optical path when the protective lens is replaced. The outer protective lens adopts a drawer-type split structure, which is composed of N fan-shaped protective lenses that can be independently plugged in and out, making it convenient and flexible to disassemble.

[0073] This invention simplifies optical system design and significantly reduces the number of optical components while ensuring beam splitting quality, and enhances the flexibility of the laser processing head with in-optical material delivery. The advantages of the optical mechanism method proposed in this invention are:

[0074] (1) Compared with existing laser processing heads, the present invention has a simple structure, low design difficulty, low manufacturing process requirements, and can be widely used in the design of laser processing heads. At the same time, the number of optical components is small and the optical path stability is good.

[0075] (2) The present invention uses a reflective mirror, which can be used for processing applications of higher power lasers, greatly expanding the application field;

[0076] (3) It can ensure that the wire or powder feeding tube does not need to be bent, and the wire (or powder) is fed into the center of the light spot in a coaxial manner, which improves the forming accuracy.

[0077] (4) The laser transmission process will not irradiate the wire feeder or powder feeder, ensuring the integrity of the laser spot, and there is no loss of the optical path due to the obstruction of the wire feeder or powder feeder.

[0078] (5) Dual protective lens structure: the outer protective lens adopts a drawer-type split structure, which is convenient and flexible to disassemble, and the inner ring protective lens protects the optical path. The optical path will not be contaminated when the protective lens is replaced.

[0079] (6) The combined plane mirror can adopt an integrated structure, and the accuracy is ensured through processing, which reduces the alignment difficulty of the system and improves the stability during use.

[0080] Those skilled in the art will readily understand that the above description is merely a preferred 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.

Claims

1. A laser processing head for in-light material delivery, characterized in that, include: A first plane mirror, a second plane mirror, and a focusing lens are placed sequentially along the laser beam path. The first planar reflector has N first reflective planes; the second planar reflector has N second reflective planes that correspond one-to-one with the N first reflective planes, and the second planar reflector and the focusing lens are hollow for placing the material feeding device. The tilt angles of the first reflective planes of the first planar reflector are all different, which are used to split the collimated incident laser beam into N laser beams, which are then incident on the corresponding second reflective planes respectively. The tilt angles of the second reflection planes of the second plane mirror are all different, which are used to reflect N laser beams and then incident them parallel to the focusing lens; The focusing lens is used to focus N parallel incident laser beams onto the working surface to process the material coaxially fed in by the feeding device. Wherein, N≥2; the feeding device includes: a wire feeding device or a powder feeding device.

2. The laser processing head for in-light material delivery according to claim 1, characterized in that, The tilt angles of each first reflecting plane of the first plane mirror and each second reflecting plane of the second plane mirror are determined in the following manner: The vertex positions of N uniformly distributed fan-shaped light spots are preset on the same plane; Take the light ray that passes through the center of the first reflector in the incident laser beam, and based on the light path process of the N light rays after passing through the first plane reflector and the second reflector to each vertex position, determine the incident light ray and the reflected light ray of each first reflector and the corresponding second reflector. Calculate the direction of the angle bisector between the incident ray and the reflected ray of any first reflecting plane to obtain the direction of the normal vector of the first reflecting plane, and thus obtain the tilt angle of the first reflecting plane. Calculate the direction of the angle bisector between the incident ray and the reflected ray of any second reflecting plane to obtain the direction of the normal vector of the second reflecting plane, and thus obtain the tilt angle of the second reflecting plane.

3. The laser processing head for in-light material delivery according to claim 2, characterized in that, The first reflecting plane is parallel to its corresponding second reflecting plane.

4. The laser processing head for in-light material delivery according to any one of claims 1-3, characterized in that, The focusing lens has an aspherical surface and is used to shape and focus N parallel incident laser beams onto the working surface.

5. The laser processing head for in-light material delivery according to any one of claims 1-3, characterized in that, The reflective surfaces of the first and second planar reflectors are coated with a high-reflectivity film.

6. The laser processing head for in-light material delivery according to any one of claims 1-3, characterized in that, Water-cooling channels are provided on the first and second planar reflectors.

7. The laser processing head for in-light material feeding according to any one of claims 1-3, characterized in that, Also includes: A protective lens is positioned along the optical path direction, after the focusing lens and before the working surface.

8. The laser processing head for in-light material delivery according to claim 7, characterized in that, The protective mirror is a hollow ring-shaped protective mirror, which is composed of multiple independently pluggable fan-shaped protective mirrors. Alternatively, the protective mirror is a hollow double-layer protective mirror structure, including an inner protective mirror that is far from the working surface and an outer protective mirror that is close to the working surface; The inner protective mirror is a hollow ring-shaped protective mirror; the outer protective mirror is a hollow ring-shaped protective mirror, which is composed of multiple independently pluggable fan-shaped protective mirrors.

9. The laser processing head for in-light material delivery according to any one of claims 1-3, characterized in that, Also includes: A collimating lens positioned in front of the first planar reflector along the optical path is used to collimate the incident laser beam.

10. The laser processing head for in-light material feeding according to any one of claims 1-3, characterized in that, N＝4。

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