Laser beam combiner and laser welding equipment

Abstract

The embodiment of the utility model discloses a laser beam combiner and laser welding equipment. The laser beam combiner comprises an input optical fiber, the input optical fiber comprises a central optical fiber and a plurality of outer ring optical fibers, the plurality of outer ring optical fibers are arranged around the central optical fiber, and the power of the outer ring optical fibers is smaller than that of the central optical fiber; the output optical fiber is an annular optical fiber and is used for outputting an annular light spot; the welding module is used for welding and fixing the input optical fiber and the output optical fiber; and the cavity is used for accommodating the welding module, the partial area, close to the welding module, of the input optical fiber and the partial area, close to the welding module, of the output optical fiber. According to the laser beam combiner and the laser welding equipment, the welding efficiency can be improved.

Description

Technical Field

[0001] The present application relates to the field of laser welding, and more specifically, to a laser beam combiner and laser welding equipment. Background Art

[0002] As a new type of welding process, laser welding plays an increasingly important role in actual industrial production. The so-called laser welding is to use a high-intensity laser beam to irradiate the metal surface, melt the metal to be welded, and then weld the metals to be welded together.

[0003] During the welding process, existing laser welding technology often has defects such as large metal particle splashing, explosion holes and cracks, which seriously affect the quality and production efficiency of the welded objects. Utility Model Content

[0004] The embodiments of the present application provide a laser beam combiner and laser welding equipment, which can improve welding efficiency.

[0005] In a first aspect, a laser beam combiner is provided, comprising: an input optical fiber, the input optical fiber comprising a central optical fiber and a plurality of outer ring optical fibers, the plurality of outer ring optical fibers being arranged around the central optical fiber, the power of the outer ring optical fibers being less than the power of the central optical fiber; an output optical fiber, the output optical fiber being a ring optical fiber for outputting a ring-shaped light spot; a fusion splicing module, for fusion splicing and fixing the input optical fiber and the output optical fiber; and a cavity, for accommodating the fusion splicing module, a partial area of ​​the input optical fiber close to the fusion splicing module, and a partial area of ​​the output optical fiber close to the fusion splicing module.

[0006] Therefore, the laser beam combiner of the embodiment of the present application can output an annular spot. When the annular spot is used for laser welding, the amount of metal particle splash generated during the welding process is significantly reduced compared with the traditional single-spot laser method, thereby improving the welding quality and efficiency and reducing welding cracks and holes. In addition, the overall structural design of the laser beam combiner is sophisticated and stable, and can be used in a variety of application scenarios, for example, it can be applied to high-power laser welding equipment.

[0007] In some embodiments, along the length direction of the input optical fiber, the input optical fiber includes a connected beam-forming region, a tapered region and a tapered waist region, and the tapered region is located between the beam-forming region and the tapered waist region; wherein, in the tapered region, the radial dimension of the input optical fiber gradually decreases from the first end of the tapered region connected to the beam-forming region to the second end connected to the tapered waist region, and / or, in the tapered region, the radial dimension of the central optical fiber gradually decreases from the first end of the tapered region connected to the beam-forming region to the second end connected to the tapered waist region. The input optical fiber can be fused and fixed with the output optical fiber after the tapered process, which can effectively improve the heat dissipation performance of the laser beam combiner, so that the laser beam combiner can transmit high-power lasers, and thus the laser beam combiner can be applied to scenes requiring high-power welding.

[0008] In some embodiments, the ratio of the radial dimension of the input optical fiber at the first end to the radial dimension of the input optical fiber at the second end is in the range of [3, 5]; and / or the ratio of the radial dimension of the central optical fiber at the first end to the radial dimension of the central optical fiber at the second end is in the range of [3, 5]. By adjusting the appropriate ratio, the transmission efficiency of the laser and the performance of the laser beam combiner can be improved.

[0009] In some embodiments, the length of the tapered region ranges from [8mm, 15mm]. Appropriately increasing the length of the tapered region can improve the laser transmission efficiency and the performance of the laser beam combiner, while limiting the length of the tapered region so that the length of the tapered region is not too large can improve the structural strength of the tapered region and reduce the risk of fracture.

[0010] In some embodiments, the output optical fiber includes a central core and a ring core, wherein the central core is located inside the ring core. The output optical fiber is a ring optical fiber, so as to output a ring light spot and improve the laser transmission efficiency.

[0011] In some embodiments, the ratio of the outer diameter of the ring core to the diameter of the core is in the range of [3, 6] to improve the performance of the output optical fiber.

[0012] In some embodiments, the diameter of the central core is in the range of [25mm, 300mm], and the outer diameter of the ring core is in the range of [100mm, 600mm], which can not only meet the design requirements of the laser beam combiner, but also improve the output optical fiber performance of the laser beam combiner.

[0013] In some embodiments, the central axis of the central optical fiber substantially coincides with the central axis of the core, so as to improve the laser transmission efficiency and reduce the loss during the transmission process after the input optical fiber and the output optical fiber are fused.

[0014] In some embodiments, the radial dimension of the input optical fiber at one end of the tapered waist region close to the output optical fiber is smaller than the outer diameter of the ring core; the radial dimension of the central optical fiber at one end of the tapered waist region close to the output optical fiber is smaller than the diameter of the core. The radial dimension of the input optical fiber at one end of the tapered waist region close to the output optical fiber is smaller than the outer diameter of the core, so that the output optical fiber can receive almost all the energy transmitted by the input optical fiber, reduce the energy loss caused by the laser entering the outer cladding of the output optical fiber, and improve the coupling efficiency. Furthermore, the radial dimension of the central optical fiber at one end of the tapered waist region close to the output optical fiber can also be set to be smaller than the diameter of the core to further improve the laser transmission efficiency.

[0015] In some embodiments, the output power of the central core is greater than or equal to 3000W; and / or; the output power of the ring core is greater than or equal to 1000W. The output power of the central core is relatively large to meet the requirements of the welding process, and can concentrate the energy of the laser beam, quickly open the molten pool of the welded object during the welding process, form a weld with deep and wide fusion, and realize the connection of different parts. The output power of the ring core is relatively small, which can be used to preheat the welded object and effectively reduce the splash of metal particles.

[0016] In some embodiments, the fiber numerical aperture of the input optical fiber is NA, the beam convergence angle of the laser input to the input optical fiber is θ, and NA and θ satisfy: θ≤arcsin(NA). If θ>arcsin(NA), the incident angle of part of the laser beam input by the laser pump source is too large, and the total reflection condition cannot be met at the interface between the outer ring fiber and the cladding layer of the input optical fiber, and part of the laser will leak into the cladding layer and be lost, reducing the laser transmission efficiency.

[0017] In some embodiments, the cavity includes two through grooves, and the two through grooves are interlocked to form the cavity, which has a simple structure and is easy to implement.

[0018] In a second aspect, a laser welding device is provided, comprising: the laser beam combiner described in the first aspect or any one embodiment of the first aspect, wherein the laser output by the output optical fiber of the laser beam combiner is used for welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a laser beam combiner according to an embodiment of the present application;

[0020] Figure 2 This is a schematic diagram of the internal structure of a laser beam combiner according to an embodiment of the present application;

[0021] Figure 3 This is a schematic diagram of the exploded structure of a laser beam combiner according to an embodiment of the present application;

[0022] Figure 4 A schematic diagram of a partial structure of a cavity of a laser beam combiner according to an embodiment of the present application;

[0023] Figure 5 This is a schematic diagram of the connection between the input optical fiber and the output optical fiber according to an embodiment of the present application;

[0024] Figure 6 A cross-sectional schematic diagram of a bundling region of input optical fibers according to an embodiment of the present application;

[0025] Figure 7 A schematic cross-sectional view of a second end of a tapered region of an input optical fiber according to an embodiment of the present application;

[0026] Figure 8 A cross-sectional schematic diagram of an output optical fiber according to an embodiment of the present application;

[0027] Fig. 9 A schematic diagram of laser transmission according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; 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 terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0031] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0032] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0033] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0034] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0035] The term "multiple" as used in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets).

[0036] Laser welding uses laser as a heating light source to convert radiation energy into heat energy at the welding position to complete the melting, fusion and cooling process of the material. Existing laser welding technology usually uses a single-spot laser. During the welding process, there are often defects such as large metal particle splashes, blast holes and cracks, which seriously affect the quality and production efficiency of the welded objects.

[0037] Based on this, the embodiment of the present application provides a laser beam combiner and laser welding equipment, which can solve the above problems. The laser beam combiner of the embodiment of the present application includes: an input optical fiber, an output optical fiber, a fusion module and a cavity. Specifically, the input optical fiber includes a central optical fiber and a plurality of outer ring optical fibers, and the plurality of outer ring optical fibers are arranged around the central optical fiber. The power of the outer ring optical fiber is less than the power of the central optical fiber, that is, the power of the outer ring optical fiber and the power of the central optical fiber can be adjusted separately. The output optical fiber is a ring optical fiber for outputting a ring light spot. Corresponding to the input optical fiber, the power of different areas of the output ring light spot is different. The fusion module is used to fuse and fix the input optical fiber and the output optical fiber; the cavity is used to accommodate the fusion module, the partial area of ​​the input optical fiber close to the fusion module, and the partial area of ​​the output optical fiber close to the fusion module to reduce the interference of the external environment. The laser beam combiner can output a ring light spot. When the ring light spot is used for laser welding, the amount of metal particle splashing generated during the welding process is significantly reduced compared with the traditional single-spot laser method, which improves the welding quality and reduces welding cracks and holes. In addition, the overall structural design of the laser beam combiner is sophisticated and stable, and can be used in a variety of application scenarios, for example, it can be applied to high-power laser welding equipment.

[0038] Figure 1 A schematic structural diagram of a laser beam combiner 10 according to an embodiment of the present application is shown; Figure 2 A schematic diagram of the internal structure of the laser beam combiner 10 according to an embodiment of the present application is shown; Figure 3 FIG. 1 shows a schematic diagram of the exploded structure of the laser beam combiner 10 of the present application. Figures 1 to 3 As shown, the laser beam combiner 10 of the embodiment of the present application includes: an input optical fiber 11, an output optical fiber 12, a fusion module 13 and a cavity 14. Specifically, the input optical fiber 11 includes a central optical fiber 111 and a plurality of outer ring optical fibers 112, the plurality of outer ring optical fibers 112 are arranged around the central optical fiber 111, and the power of the outer ring optical fibers 112 is less than the power of the central optical fiber 111; the output optical fiber 12 is a ring optical fiber for outputting a ring-shaped light spot; the fusion module 13 is used to fuse and fix the input optical fiber 11 and the output optical fiber 12; the cavity 14 is used to accommodate the fusion module 13, a partial area of ​​the input optical fiber 11 close to the fusion module 13, and a partial area of ​​the output optical fiber 12 close to the fusion module 13.

[0039] The input optical fiber 11 of the embodiment of the present application includes a central optical fiber 111 and a plurality of outer ring optical fibers 112, and the number of the plurality of outer ring optical fibers 112 can be flexibly set according to the actual application. The radial dimension of the central optical fiber 111 can be flexibly set according to the actual application, and the radial dimension of the outer ring optical fiber 112 can also be flexibly set according to the actual application, and the radial dimension of the central optical fiber 111 and the radial dimension of the outer ring optical fiber 112 can be the same or different.

[0040] The fusion module 13 of the embodiment of the present application can fuse and fix the input optical fiber 11 and the output optical fiber 12. The power of the outer ring optical fiber 112 of the input optical fiber 11 is less than the power of the central optical fiber 111 of the input optical fiber 11, that is, the power of the outer ring optical fiber 112 and the power of the central optical fiber 111 can be adjusted respectively according to actual needs. The output optical fiber 12 of the laser combiner 10 is a ring optical fiber, which can output a ring-shaped light spot. Corresponding to the input optical fiber, the power of different areas of the output ring-shaped light spot is different. For example, the power of the outer ring area of ​​the output ring-shaped light spot is relatively low, which is mainly used to preheat the object to be welded during the welding process and reduce metal splashing during the welding process. The middle area of ​​the output ring-shaped light spot has a higher power, which can concentrate the energy of the laser beam, quickly open the molten pool of the object to be welded during the welding process, form a weld with deep and wide fusion, and realize the connection between different parts.

[0041] In some embodiments, the power of the outer ring fiber 112 of the input optical fiber 11 is different from the power of the central optical fiber 111 of the input optical fiber 11, which can be achieved in a variety of ways. For example, multiple laser pump sources can be set to output lasers of different powers to the outer ring optical fiber 112 and the central optical fiber 111, respectively. Alternatively, the laser pump source can include multiple laser modules, and different laser modules correspond to different optical fibers to output lasers of different powers, but the embodiments of the present application are not limited thereto.

[0042] The cavity 14 of the embodiment of the present application is a hollow structure, which can provide a accommodating space inside. The accommodating space can be used to accommodate the fusion module 13, a partial area of ​​the input optical fiber 11 close to the fusion module 13, and a partial area of ​​the output optical fiber 12 close to the fusion module 13 to reduce interference from the external environment.

[0043] Therefore, the laser beam combiner 10 of the embodiment of the present application can output an annular spot. When the annular spot is used for laser welding, the amount of metal particle spatter generated during the welding process is significantly reduced compared with the traditional single-spot laser method. For example, when the power of the central area of ​​the annular spot output by the laser beam combiner 10 of the embodiment of the present application is consistent with the output power when a single-spot laser is used for welding, the amount of metal particle spatter generated by the laser beam combiner 10 of the embodiment of the present application during the welding process can be reduced by about 70% compared with a single spot, effectively improving the welding quality and reducing welding cracks and holes. In addition, the overall structural design of the laser beam combiner is sophisticated and stable, and can be used in a variety of application scenarios, for example, it can be applied to high-power laser welding equipment.

[0044] It should be understood that the laser beam combiner 10 of the embodiment of the present application can be applied to laser welding equipment, and the laser welding equipment can weld objects using the laser output by the laser beam combiner 10 , for example, the laser output by the output optical fiber 12 of the laser beam combiner 10 .

[0045] The welded object of the embodiment of the present application may be any object. Exemplarily, the welded object of the embodiment of the present application may be a battery. The battery mentioned in the embodiment of the present application refers to a single physical module including one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack, etc. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0046] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a cathode electrode sheet, an anode electrode sheet and a separator. A battery cell mainly relies on the movement of metal ions between the cathode electrode sheet and the anode electrode sheet to work. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed back and forth between the positive and negative electrodes. The separator is set between the positive and negative electrodes to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0047] The laser welding equipment of the embodiment of the present application can be used for welding during the processing and assembly of the battery. For example, the shell and cover plate of the battery cell inside the battery are interlocked, and can be welded by the laser welding equipment of the embodiment of the present application to connect and fix the shell and cover plate. For another example, the electrical connection between multiple battery cells in the battery can be achieved through the busbar component and the electrode terminal, and the busbar component and the electrode terminal can be welded by the laser welding equipment of the embodiment of the present application to achieve the connection, but the embodiment of the present application is not limited to this.

[0048] The processing and assembly process of the battery has high requirements on welding accuracy and welding effect. Using laser welding equipment including the laser beam combiner 10 of the embodiment of the present application to weld the battery components can effectively improve the processing efficiency of the battery, increase the product qualification rate and reduce costs.

[0049] The laser beam combiner 10 according to the embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0050] It should be understood that the cavity 14 of the embodiment of the present application can provide a receiving space, and the cavity 14 can be implemented in a variety of ways. For example, the cavity 14 includes two through grooves 141, and the two through grooves 141 are engaged with each other to form the cavity 14, which has a simple structure and is easy to implement. Figure 4 The schematic diagram of the partial structure of the cavity 14 of the embodiment of the present application is shown. Figure 4 It can represent any through groove 141 included in the cavity 14. Specifically, Figures 1 to 4As shown, the cavity 14 of the embodiment of the present application may include two through slots 141 with the same or similar structures. The through slot 141 includes two side walls 1411 arranged opposite to each other, and the through slot 141 also includes a bottom wall 1412 connecting the two side walls 1411. Further, the through slot 141 may include a first opening 1413 opposite to the bottom wall 1412, and two second openings 1414 arranged opposite to each other, and the first opening 1413 is connected to the two second openings 1414, thereby forming a through slot 141 with openings at three ends.

[0051] In some embodiments, the cavity 14 may include two through slots 141, and the two through slots 141 are interlocked, that is, the first opening 1413 of one through slot 141 corresponds to the first opening 1413 of the other through slot 141, so that the bottom walls 1412 of the two through slots 141 are arranged opposite to each other, thereby forming a through hole that penetrates the cavity 14 along the length direction X of the cavity 14, and the two ends of the through hole are respectively formed by the second openings 1414 of the two through slots 141 interlocking with each other. In this way, the input optical fiber 11 and the output optical fiber 12 can extend out of the cavity 14 through the through hole, the fusion module 13 is located inside the through hole, and the two ends of the through hole of the cavity 14 can be filled with the input optical fiber 11 and the output optical fiber 12, thereby forming a sealed or almost sealed accommodation space inside the cavity 14.

[0052] In some embodiments, the connection method of the two through slots 141 of the cavity 14 can be set according to the actual application. For example, the two through slots 141 can be connected in a detachable connection method, for example, the detachable connection method can include at least one of the following: bolt connection, plug connection and pin connection. Figures 1 to 4 As shown, the two through slots 141 may be connected by a plurality of bolts 142. For another example, the two through slots 141 may also be connected in a non-detachable connection manner, for example, the two through slots 141 may be connected by welding, riveting or gluing, etc., but the embodiments of the present application are not limited thereto.

[0053] In some embodiments, different from Figure 4 As shown, the cavity 14 of the embodiment of the present application can also be formed by other structures. For example, the sealed cavity 14 can include a through groove 141 and a plate-like structure, and the plate-like structure covers the first opening 1413 of the through groove 141 to form the cavity 14, but the embodiment of the present application is not limited thereto.

[0054] For ease of description, the present embodiment defines three directions. Taking the rectangular cavity 14 as an example, the length direction X, width direction Y and height direction Z of the cavity 14 are perpendicular to each other. Among them, the height direction Z of the cavity 14 is perpendicular to the plane where the first opening 1413 of the through slot 141 is located, and the width direction Y of the cavity 14 is parallel to the plane where the first opening 1413 of the through slot 141 is located.

[0055] Figure 5 The schematic diagram of the partial structure of the input optical fiber 11 and the output optical fiber 12 of the embodiment of the present application is shown. Figure 5 The input optical fiber 11 and the output optical fiber 12 shown can be respectively as follows Figures 1 to 3 The laser beam combiner 10 shown includes an input optical fiber 11 and an output optical fiber 12 .

[0056] In the embodiment of the present application, along the length direction X of the input optical fiber 11, the input optical fiber 11 includes a connected beam combining region 113, a tapered region 114 and a tapered waist region 115, and the tapered region 114 is located between the beam combining region 113 and the tapered waist region 115. The input optical fiber 11 can be fused and fixed with the output optical fiber 12 after being tapered, which can effectively improve the heat dissipation performance of the laser beam combiner 10, so that the laser beam combiner 10 can transmit high-power lasers, and further the laser beam combiner 10 can be applied to scenes requiring high-power welding.

[0057] Specifically, after the input optical fiber 11 is subjected to the tapering treatment, according to the change of the radial dimension of the input optical fiber 11, along the length direction X, the input optical fiber 11 may include a bundle-forming region 113, a tapered region 114 and a tapered waist region 115, wherein the tapered region 114 is located between the bundle-forming region 113 and the tapered waist region 115. A plurality of outer ring optical fibers 112 are bundled around the central optical fiber 111, and the bundled plurality of outer ring optical fibers 112 and the central optical fiber 111 are subjected to the tapering treatment, wherein the bundle-forming region 113 is a section of the input optical fiber 11 along the length direction X that is not subjected to the tapering treatment, the bundle-forming region 113 is connected to the tapered region 114, the tapered region 114 is a section of the input optical fiber 11 where the radial dimension is changed, and the tapered waist region 115 is a section of the input optical fiber 11 where the radial dimension is the smallest.

[0058] In the bundled area 113, the size of the input optical fiber 11 can be set according to the actual application. The radial size R2 of the outer ring optical fiber 112 can be the same as or different from the radial size R1 of the central optical fiber 111. For example, Figure 6 A schematic cross-sectional view of one end of the bundle combining region 113 of the input optical fiber 11 in the embodiment of the present application close to the tapered region 114 is shown, and the cross-section is perpendicular to the length direction X of the input optical fiber 11 .

[0059] like Figure 5 and Figure 6 As shown, a plurality of outer ring optical fibers 112 may be arranged around the central optical fiber 111, and the plurality of outer ring optical fibers 112 are arranged tangent to the central optical fiber 111. In some embodiments, the radial dimension R2 of the outer ring optical fiber 112 may be the same as the radial dimension R1 of the central optical fiber 111, so as to facilitate processing and assembly; or, the radial dimension R2 of the outer ring optical fiber 112 may be different from the radial dimension R1 of the central optical fiber 111, so as to facilitate adjustment according to actual applications.

[0060] In some embodiments, the number of the outer ring optical fibers 112 can be set according to actual applications. For example, the number of the outer ring optical fibers 112 is related to the radial dimension R2 of the outer ring optical fibers 112, or it can be related to the radial dimension R1 of the central optical fiber 111. Figure 6 As shown, in the embodiment of the present application, the radial dimension R2 of the outer ring optical fiber 112 is the same as the radial dimension R1 of the central optical fiber 111 , and 6 outer ring optical fibers 112 are set as an example, but the embodiment of the present application is not limited thereto.

[0061] In the embodiment of the present application, the input optical fiber 11 may further include a cladding layer 116, which is used to clad the plurality of outer ring optical fibers 112 and the central optical fiber 111, so as to fix the plurality of outer ring optical fibers 112 around the central optical fiber 111 and protect the outer ring optical fibers 112 and the central optical fiber 111. Exemplarily, the material of the cladding layer 116 may be selected according to the actual application. For ease of explanation, the radial dimension of the input optical fiber 11 in the embodiment of the present application does not include the cladding layer 116, that is, the radial dimension of the input optical fiber 11 corresponds to the dimension of the optical fiber inside the cladding layer 116.

[0062] In some embodiments, in the tapered region 114, the radial dimension of the input optical fiber 11 gradually decreases from the first end 1141 of the tapered region 114 connected to the bundle assembly region 113 to the second end 1142 connected to the tapered waist region 115. Figure 5 and Figure 6 As shown, the first end 1141 of the tapered region 114 is connected to the bundle assembly region 113. For ease of description, the embodiment of the present application takes the end surface of the first end 1141 of the tapered region 114 as an example in which the end surface of the bundle assembly region 113 connected to the tapered region 114 is consistent with the end surface of the bundle assembly region 113. That is, Figure 6 It can represent the end of the beam-forming region 113 connected to the tapered region 114, or the first end 1141 of the tapered region 114. Correspondingly, if the radial dimension of the input optical fiber 11 at the first end 1141 is R3, then the radial dimension of the input optical fiber 11 at the end of the beam-forming region 113 connected to the tapered region 114 is also R3. In addition, in different regions of the beam-forming region 113, the radial dimensions of the input optical fiber 11 are usually equal or vary slightly, for example, Figure 5 The example mainly takes the case where the radial dimensions of the input optical fiber 11 in different regions of the beam combining region 113 are equal.

[0063] Similarly, the second end 1142 of the tapered region 114 is connected to the waist region 115 . For ease of description, the embodiment of the present application takes the example that the end face of the second end 1142 of the tapered region 114 is consistent with the end face of the waist region 115 connected to one end of the tapered region 114 . Figure 7 FIG. 1 shows a cross-sectional schematic diagram of the second end 1142 of the tapered region 114 of the embodiment of the present application, wherein the cross-section is perpendicular to the length direction X of the input optical fiber 11. Figure 7 It can also represent the end face of one end of the tapered waist region 115 connected to the tapered region 114. Correspondingly, if the radial dimension of the input optical fiber 11 at the second end 1142 is R4, then the radial dimension of the input optical fiber 11 at one end of the tapered waist region 115 connected to the tapered region 114 is also R4. In addition, in different regions of the tapered waist region 115, the radial dimensions of the input optical fiber 11 are usually equal or vary slightly, for example, Figure 5 The example mainly takes the case where the radial dimensions of different regions of the input optical fiber 11 in the tapered waist region 115 are equal.

[0064] In the tapered region 114, the radial dimension of the input optical fiber 11 gradually decreases from the first end 1141 to the second end 1142, that is, the maximum radial dimension of the input optical fiber 11 in the tapered region 114 is the radial dimension R3 at the first end 1141, and the minimum radial dimension of the input optical fiber 11 in the tapered region 114 is the radial dimension R4 at the second end 1142.

[0065] In some embodiments, in the tapered region 114, the radial dimension of the central optical fiber 111 gradually decreases from the first end 1141 of the tapered region 114 connected to the beam combining region 113 to the second end 1142 of the tapered region 114 connected to the tapered waist region 115. Figures 5 to 7 As shown, after the taper treatment, the radial dimensions of the central optical fiber 111 and the outer ring optical fiber 112 of the input optical fiber 11 will change. Exemplarily, for the central optical fiber 111, its radial dimension is basically consistent with the change of the radial dimension of the entire input optical fiber 11, that is, the radial dimension of the central optical fiber 111 gradually decreases from the first end 1141 to the second end 1142. Among them, the maximum radial dimension of the central optical fiber 111 in the tapered area 114 is the radial dimension R1 at the first end 1141, and the minimum radial dimension of the central optical fiber 111 in the tapered area 114 is the radial dimension R5 at the second end 1142.

[0066] It should be understood that the radial dimensions of different areas of the input optical fiber 11 of the embodiment of the present application can be set according to actual needs. For example, the radial dimension R3 of the input optical fiber 11 at the first end 1141 can be set according to actual needs, and similarly, the radial dimension R4 at the second end 1142 can also be set according to actual needs. For example, the radial dimension R3 of the input optical fiber 11 at the first end 1141 and the radial dimension R4 at the second end 1142 may be related to at least one of the following conditions: related to the radial dimension R1 of the central optical fiber 111, related to the radial dimension R2 of the outer ring optical fiber 112, related to the number of the outer ring optical fiber 112, related to the transmitted laser power, and related to the tapering process, and the embodiment of the present application is not limited thereto.

[0067] In some embodiments, the ratio of the radial dimension R3 of the input optical fiber 11 at the first end 1141 to the radial dimension R4 at the second end 1142 is in the range of [3, 5]. The ratio of the dimension R3 to the dimension R4 can represent the taper ratio. By adjusting the appropriate taper ratio, the transmission efficiency of the laser and the performance of the laser beam combiner 10 can be improved. For example, the ratio of the dimension R3 to the dimension R4 can be 3, 3.3, 3.5, 3.8, 4, 4.3, 4.5, 4.8 or 5, or can be the middle value of any two of the above values.

[0068] Similarly, the ratio of the radial dimension R1 of the center optical fiber 111 at the first end 1141 to the radial dimension R5 at the second end 1142 is in the range of [3, 5], so as to keep consistent with the overall size change of the input optical fiber 11, and improve the performance of the laser beam combiner 10. For example, the ratio of the dimension R1 to the dimension R5 can be 3, 3.3, 3.5, 3.8, 4, 4.3, 4.5, 4.8 or 5, or can be the middle value of any two of the above values.

[0069] In the embodiment of the present application, the length of each region of the input optical fiber 11 can be flexibly set according to the actual application. For example, the length L of the tapered region 114 has a value range of [8mm, 15mm]. Properly increasing the length L of the tapered region 114 can improve the transmission efficiency of the laser and the performance of the laser beam combiner 10, while limiting the length L of the tapered region 114 so that the length L of the tapered region 114 is not too large, which can improve the structural strength of the tapered region 114 and reduce the risk of breakage.

[0070] The end of the tapered waist region 115 of the input optical fiber 11 of the embodiment of the present application, which is away from the tapered region 114, is used for fusion splicing with the output optical fiber 12. Figure 5 As shown, in order to facilitate the illustration of the input optical fiber 11 and the output optical fiber 12, Figure 5 The welding module 13 is not shown. Figure 8FIG. 1 shows a schematic cross-sectional view of the output optical fiber 12 of an embodiment of the present application, wherein the cross-section is perpendicular to the length direction X of the output optical fiber 12. For example, Figure 8 The output optical fiber 12 shown may be Figures 1 to 3 The output optical fiber 12 shown may also be Figure 5 The output optical fiber 12 is shown.

[0071] In some embodiments, the output optical fiber 12 includes a core 121 and a ring core 122, and the core 121 is located inside the ring core 122. The output optical fiber 12 is a ring optical fiber, so as to output a ring light spot and improve the laser transmission efficiency. In addition, the diameter R6 of the core 121 located inside is usually less than or equal to the inner diameter R7 of the ring core 122. For example, the diameter R6 of the core 121 can be set to be smaller than the inner diameter R7 of the ring core 122, and a filling material can be provided between the core 121 and the ring core 122 to improve the performance of the output optical fiber 12, but the embodiments of the present application are not limited thereto.

[0072] In some embodiments, the outermost layer of the output optical fiber 12 may further include a protective layer, which is used to cover the central core 121 and the ring core 122 to protect the central core 121 and the ring core 122. For ease of description, the protective layer is not shown in the figure, and the radial dimension of the output optical fiber 12 in the embodiment of the present application does not include the protective layer of the output optical fiber 12.

[0073] It should be understood that the radial size of the core 121 of the embodiment of the present application can be set according to the actual application, and the radial size of the ring core 122 can also be set according to the actual application. For example, the output power of the laser can be set according to the needs of the laser welding equipment, and the core 121 and the ring core 122 of appropriate sizes can be selected.

[0074] In some embodiments, the ratio of the outer diameter R8 of the ring core 122 to the diameter R6 of the core 121 is in the range of [3, 6] to improve the performance of the output optical fiber 12. For example, the ratio of the outer diameter R8 of the ring core 122 to the diameter R6 of the core 121 can be 3, 3.3, 3.5, 3.8, 4, 4.3, 4.5, 4.8, 5, 5.3, 5.5, 5.8 or 6, or can be the middle value of any two of the above values.

[0075] In some embodiments, the diameter R6 of the core 121 has a value range of [25mm, 300mm], and the outer diameter R8 of the ring core 122 has a value range of [100mm, 600mm], which can not only meet the design requirements of the laser beam combiner 10, but also improve the performance of the output optical fiber 12 of the laser beam combiner 10. For example, when the diameter R6 of the core 121 is 50mm, the outer diameter R8 of the ring core 122 can be 150mm or 200mm; for another example, when the diameter R6 of the core 121 is 100mm, the outer diameter R8 of the ring core 122 can be 300mm or 600mm, and the embodiments of the present application are not limited thereto.

[0076] It should be understood that the central axis of the central optical fiber 111 is substantially coincident with the central axis of the core 121, so as to improve the laser transmission efficiency and reduce the loss during the transmission after the input optical fiber 11 is fused with the output optical fiber 12. For example, the laser transmission efficiency of the central area and the laser transmission efficiency of the outer ring area of ​​the embodiment of the present application can be greater than or equal to 98%.

[0077] Further, the radial dimension R9 of the input optical fiber 11 at one end of the tapered waist region 115 close to the output optical fiber 12 is smaller than the outer diameter R8 of the ring core 122; and / or, the radial dimension R5 of the central optical fiber 111 at one end of the tapered waist region 115 close to the output optical fiber 12 is smaller than the diameter R6 of the core 121. In this embodiment of the present application, the radial dimension of the central optical fiber 111 at one end of the tapered waist region 115 close to the output optical fiber 12 is the same as the radial dimension R5 of the central optical fiber 111 at one end of the tapered waist region 115 close to the tapered region 114 is taken as an example. In addition, considering that the radial dimensions of the input optical fiber 11 in different regions of the tapered waist region 115 can be the same, the radial dimension R9 of the input optical fiber 11 at one end of the tapered waist region 115 close to the output optical fiber 12 can be equal to the radial dimension R4 of the input optical fiber 11 at one end of the tapered waist region 115 close to the tapered region 114. Alternatively, in order to further improve the connection efficiency between the input optical fiber 11 and the output optical fiber 12, the radial dimension R9 at the end of the input optical fiber 11 in the tapered waist region 115 close to the output optical fiber 12 can be appropriately reduced, so that the radial dimension R9 at the end of the input optical fiber 11 in the tapered waist region 115 close to the output optical fiber 12 is slightly smaller than the radial dimension R4 at the end of the input optical fiber 11 in the tapered waist region 115 close to the tapered region 114. The embodiments of the present application are not limited to this.

[0078] In the embodiment of the present application, the fiber numerical aperture of the input optical fiber 11 is NA, the beam convergence angle of the laser input to the input optical fiber 11 is θ, and NA and θ satisfy: θ≤arcsin(NA). If θ>arcsin(NA), the incident angle of part of the laser beam input by the laser pump source is too large, and the total reflection condition cannot be met at the outermost fiber interface of the input optical fiber 11. For example, part of the laser will leak into the cladding layer of the input optical fiber 11 and be lost, reducing the laser transmission efficiency.

[0079] For example, Fig. 9 FIG. 1 shows a schematic diagram of laser transmission of the input optical fiber 11 and the output optical fiber 12 of the embodiment of the present application. Fig. 9 As shown, here, the central optical fiber 111 of the input optical fiber 11 is taken as an example, the beam convergence angle of the laser input to the central optical fiber 111 is θ1, and the optical fiber numerical aperture of the central optical fiber 111 is NA1, then NA1 and θ1 satisfy: θ1≤arcsin(NA1), so as to improve the transmission efficiency of the laser and reduce the loss. In addition, the beam of the laser input to the central optical fiber 111 is transmitted to the core 121 of the output optical fiber 12, and is transmitted in the core 121. The radial dimension of the laser is R10, and R10 is smaller than the diameter R6 of the core 121, so as to reduce the laser loss and improve the laser transmission efficiency.

[0080] Similarly, the outer ring fiber 112 of the input optical fiber 11 also satisfies the relevant settings. For example, the beam convergence angle of the laser input to the outer ring fiber 112 is θ2, and the fiber numerical aperture of the outer ring fiber 112 is NA2, then NA2 and θ2 satisfy: θ2≤arcsin(NA2). And the radial size of the laser beam transmitted to the output optical fiber 12 through the outer ring fiber 112 of the input optical fiber 11 is smaller than the outer diameter R8 of the ring core 122, so as to reduce laser loss and improve laser transmission efficiency.

[0081] It should be understood that the output power of the output optical fiber 12 of the embodiment of the present application can be set according to actual needs. For example, the output power of the core 121 is greater than or equal to 3000W; and / or; the output power of the ring core 122 is greater than or equal to 1000W. The output power of the core 121 is relatively large to meet the requirements of the welding process, and can concentrate the energy of the laser beam, quickly open the molten pool of the welded object during the welding process, form a weld with deep and wide fusion, and realize the connection between different parts. The output power of the ring core 122 is relatively small, which can be used to preheat the welded object and effectively reduce the splash of metal particles. Furthermore, the output power of the core 121 is greater than or equal to 4000W; and / or; the output power of the ring core 122 is greater than or equal to 2000W, so as to further improve the welding efficiency and be suitable for the welding needs of various application scenarios.

[0082] According to some embodiments of the present application, the present application further provides a laser welding device, comprising the laser beam combiner 10 described in any of the above schemes, wherein the laser beam combiner 10 outputs the laser output by the optical fiber 12 for welding.

[0083] According to some embodiments of the present application, the laser welding equipment of the embodiments of the present application can be used in the processing of batteries.

[0084] According to some embodiments of the present application, see Figures 1 to 9 The present application provides a laser beam combiner 10, which includes: an input optical fiber 11, which includes a central optical fiber 111 and a plurality of outer ring optical fibers 112, wherein the plurality of outer ring optical fibers 112 are arranged around the central optical fiber 111, and the power of the outer ring optical fibers 112 is less than the power of the central optical fiber 111; an output optical fiber 12, which is a ring optical fiber for outputting a ring-shaped light spot; a fusion module 13, which is used to fusion-fuse and fix the input optical fiber 11 and the output optical fiber 12; and a cavity 14, which is used to accommodate the fusion module 13, a partial area of ​​the input optical fiber 11 close to the fusion module 13, and a partial area of ​​the output optical fiber 12 close to the fusion module 13.

[0085] Along the length direction of the input optical fiber 11, the input optical fiber 11 includes a connected beam-forming region 113, a tapered region 114 and a tapered waist region 115, and the tapered region 114 is located between the beam-forming region 113 and the tapered waist region 115, wherein in the tapered region 114, the radial dimension of the input optical fiber 11 gradually decreases from a first end 1141 of the tapered region 114 connected to the beam-forming region 113 to a second end 1142 connected to the tapered waist region 115, and in the tapered region 114, the radial dimension of the central optical fiber 111 gradually decreases from the first end 1141 of the tapered region 114 connected to the beam-forming region 113 to a second end 1142 connected to the tapered waist region 115.

[0086] The ratio of the radial dimension of the input optical fiber 11 at the first end 1141 to the radial dimension at the second end 1142 is in the range of [3, 5]; the ratio of the radial dimension of the central optical fiber 111 at the first end 1141 to the radial dimension at the second end 1142 is in the range of [3, 5]. The length of the tapered region 114 is in the range of [8 mm, 15 mm].

[0087] The output optical fiber 12 includes a core 121 and a ring core 122. The core 121 is located inside the ring core 122, and the diameter of the core 121 is smaller than the inner diameter of the ring core 122. The central axis of the central optical fiber 111 is substantially coincident with the central axis of the core 121. The radial dimension of the input optical fiber 11 at one end of the tapered waist region 115 close to the output optical fiber 12 is smaller than the outer diameter of the ring core 122; the radial dimension of the central optical fiber 111 at one end of the tapered waist region 115 close to the output optical fiber 12 is smaller than the diameter of the core 121.

[0088] The fiber numerical aperture of the input optical fiber 11 is NA, and the beam convergence angle of the laser input to the input optical fiber 11 is θ. NA and θ satisfy: θ≤arcsin(NA).

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A laser beam combiner, characterized in that: include: An input optical fiber (11), the input optical fiber (11) comprising a central optical fiber (111) and a plurality of outer ring optical fibers (112), the plurality of outer ring optical fibers (112) being arranged around the central optical fiber (111), the power of the outer ring optical fibers (112) being less than the power of the central optical fiber (111); An output optical fiber (12), wherein the output optical fiber (12) is a ring optical fiber and is used to output a ring-shaped light spot; A fusion splicing module (13), used for fusion splicing and fixing the input optical fiber (11) and the output optical fiber (12); The cavity (14) is used to accommodate the fusion splicing module (13), a partial area of ​​the input optical fiber (11) close to the fusion splicing module (13), and a partial area of ​​the output optical fiber (12) close to the fusion splicing module (13).

2. The laser beam combiner according to claim 1, characterized in that: Along the length direction of the input optical fiber (11), the input optical fiber (11) comprises a connected beam-forming region (113), a tapered region (114) and a tapered waist region (115), wherein the tapered region (114) is located between the beam-forming region (113) and the tapered waist region (115). Wherein, in the tapered region (114), the radial dimension of the input optical fiber (11) gradually decreases from the first end (1141) of the tapered region (114) connected to the beam combining region (113) to the second end (1142) of the tapered region (114) connected to the tapered waist region (115), and / or, In the tapered region (114), the radial dimension of the central optical fiber (111) gradually decreases from a first end (1141) of the tapered region (114) connected to the beam combining region (113) to a second end (1142) of the tapered region (114) connected to the tapered waist region (115).

3. The laser beam combiner according to claim 2, characterized in that: The ratio of the radial dimension of the input optical fiber (11) at the first end (1141) to the radial dimension at the second end (1142) is in the range of [3, 5]; and / or, The ratio of the radial dimension of the central optical fiber (111) at the first end (1141) to the radial dimension of the central optical fiber (111) at the second end (1142) is in the range of [3, 5].

4. The laser beam combiner according to claim 2, characterized in that: The length of the tapered region (114) ranges from [8 mm to 15 mm].

5. The laser beam combiner according to any one of claims 2 to 4, characterized in that: The output optical fiber (12) comprises a central core (121) and a ring core (122), wherein the central core (121) is located inside the ring core (122).

6. The laser beam combiner according to claim 5, characterized in that: The ratio of the outer diameter of the ring core (122) to the diameter of the central core (121) is in the range of [3, 6].

7. The laser beam combiner according to claim 6, characterized in that: The diameter of the central core (121) is in the range of [25 mm, 300 mm], and the outer diameter of the ring core (122) is in the range of [100 mm, 600 mm].

8. The laser beam combiner according to claim 5, characterized in that: The central axis of the central optical fiber (111) substantially coincides with the central axis of the core (121).

9. The laser beam combiner according to claim 8, characterized in that: The radial dimension of the input optical fiber (11) at one end of the tapered waist region (115) close to the output optical fiber (12) is smaller than the outer diameter of the ring core (122); The radial dimension of the central optical fiber (111) at one end of the tapered waist region (115) close to the output optical fiber (12) is smaller than the diameter of the core (121).

10. The laser beam combiner according to claim 5, characterized in that: The output power of the core (121) is greater than or equal to 3000W; and / or; The output power of the ring core (122) is greater than or equal to 1000W.

11. The laser beam combiner according to any one of claims 1 to 4, characterized in that: The optical fiber numerical aperture of the input optical fiber (11) is NA, the beam convergence angle of the laser input to the input optical fiber (11) is θ, and NA and θ satisfy: θ≤arcsin(NA).

12. The laser beam combiner according to any one of claims 1 to 4, characterized in that: The cavity (14) comprises two through grooves (141), and the two through grooves (141) are interlocked to form the cavity (14).

13. A laser welding device, characterized in that: It comprises the laser beam combiner as claimed in any one of claims 1 to 12, wherein the laser output by the output optical fiber (12) is used for welding.

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