Laser welding device and welding method

Abstract

The invention discloses a laser welding device and discloses a welding method applied to the laser welding device. The laser welding device comprises a laser input module, a first light path module and a second light path module, and the laser input module is used for providing a first laser beam and a second laser beam; the first light path module is used for guiding the first laser beam and outputting a first laser focusing spot; the second light path module is used for guiding the second laser beam and outputting a second laser focusing spot; wherein the first laser focusing light spot and the second laser focusing light spot are arranged front and back in the welding direction, the first laser focusing light spot is used for melting a welding material, the second laser focusing light spot is used for continuously inputting energy to the surface of a welding melt, and the laser energy of the first laser focusing light spot is larger than that of the second laser focusing light spot. According to the laser welding device, the defects of air holes and cracks in laser welding can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of laser welding, and in particular to a laser welding device and a welding method. Background Art

[0002] Laser welding is a welding method that uses a focused laser beam as energy to generate heat to bombard the weldment. In recent years, laser has been widely used as a processing tool in cutting, welding, additive manufacturing and other fields.

[0003] A high-energy laser beam is an ideal welding heat source. Laser welding has the advantages of deep penetration, large aspect ratio, small heat input, small deformation and easy automation. The welding quality and efficiency are greatly improved compared with traditional melting welding.

[0004] In the related art, laser welding generally uses single laser beam welding.

[0005] However, defects such as pores and welding cracks are easily generated during single laser beam welding. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a laser welding device that can effectively reduce pores and cracks in laser welding.

[0007] The present invention also provides a welding method applied to the above-mentioned laser welding device.

[0008] A laser welding device according to a first aspect of an embodiment of the present invention includes: A laser input module, used for providing a first laser beam and a second laser beam; A first optical path module, used for guiding the first laser beam and outputting a first laser focus spot; A second optical path module, used for guiding the second laser beam and outputting a second laser focus spot; Among them, the first laser focused spot and the second laser focused spot are arranged front and back along the welding direction, the first laser focused spot is used to melt the welding material, and the second laser focused spot is used to continuously input energy to the surface of the welding melt, and the laser energy of the first laser focused spot is greater than the laser energy of the second laser focused spot.

[0009] A laser welding device according to an embodiment of the present invention has at least the following beneficial effects: 1. The present invention sets a first optical path module and a second optical path module, the first optical path module is used to guide the first laser beam and output the first laser focused spot, the second optical path module is used to guide the second laser beam and output the second laser focused spot, the first laser focused spot and the second laser focused spot are arranged front and back along the welding direction, the first laser focused spot is used to melt the welding material, and the second laser focused spot is used to continuously input energy to the surface of the welding melt. It can be understood that when laser welding starts, the first laser focused spot melts the welding material and forms bubbles at the bottom of the molten pool due to the collapse of the welding keyhole. Then, the second laser focused spot acts on the surface of the welding melt to continuously input energy, which can avoid rapid cooling of the upper surface of the molten pool, so that the bubbles generated at the bottom due to the collapse of the welding keyhole have sufficient time to float to the surface of the molten pool, thereby reducing the generation of welding pores.

[0010] 2. The present invention makes the laser energy of the first laser focused spot greater than the laser energy of the second laser focused spot. It can be understood that the second laser focused spot with weaker laser energy acts behind the first laser focused spot, which can reduce the welding temperature gradient at the welding position, reduce the generation of welding cracks, and effectively improve the welding quality.

[0011] According to some embodiments of the present invention, the second optical path module is provided with a DOE lens, and the DOE lens is used to shape the second laser beam so that the second laser focusing spot is elliptical, and the length direction of the second laser focusing spot is arranged along the welding direction.

[0012] Advantageously, the present invention arranges a DOE lens, i.e., a diffractive optical element lens, in the second optical path module. The DOE lens is used to shape the second laser beam so that the second laser focusing spot is elliptical. The length direction of the second laser focusing spot is arranged along the welding direction, thereby making the second laser focusing spot have a longer length along the welding direction, which is beneficial for the second laser focusing spot to keep the liquid phase area of ​​the molten pool at a larger area and for a longer time, so that the bubbles generated at the bottom due to the collapse of the welding keyhole have more sufficient time to float to the surface of the molten pool, thereby further reducing the generation of welding pores.

[0013] According to some embodiments of the present invention, the laser input module comprises: A laser input device, used for inputting an original laser beam; The beam splitter is used to split the original laser beam into the first laser beam and the second laser beam.

[0014] Advantageously, the present invention enables the laser input module to include a laser input device and a beam splitter lens, wherein the laser input device is used to input the original laser beam, and the beam splitter lens is used to separate the original laser beam into a first laser beam and a second laser beam. It can be understood that by using the beam splitter lens to separate the original laser beam input by the laser input device into the first laser beam and the second laser beam, on the one hand, the setting of the laser input device can be reduced, which is beneficial to simplifying the structure of the laser welding device, and on the other hand, it is beneficial to ensure the laser energy stability of the first laser beam and the second laser beam, thereby ensuring the quality stability of the welding.

[0015] According to some embodiments of the present invention, the beam splitter lens separates 70%-80% of the laser energy of the original laser beam to form the first laser beam, and the beam splitter lens separates the remaining laser energy of the original laser beam to form the second laser beam.

[0016] Advantageously, the present invention utilizes a beam splitter to separate 70%-80% of the laser energy of the original laser beam to form a first laser beam, and the beam splitter separates the remaining laser energy of the original laser beam to form a second laser beam, thereby achieving a difference in laser energy between the first laser focusing spot and the second laser focusing spot, so that the laser energy of the first laser focusing spot and the second laser focusing spot decreases gradually, so that the welding position of the object to be welded that passes through the first laser focusing spot and the second laser focusing spot in sequence can pass through the welding temperature with decreasing laser energy and then leave the welding area, avoiding the welding position of the object to be welded directly leaving the welding area after passing through the high temperature of laser welding, resulting in a sudden drop in the temperature of the welding position of the object to be welded, and further achieving the effect of reducing the welding temperature gradient of the welding position, reducing the generation of welding cracks, and effectively improving the welding quality.

[0017] According to some embodiments of the present invention, the beam splitter lens transmits the original laser beam to form the first laser beam, the beam splitter lens refracts the original laser beam to form the second laser beam, and the second optical path module is provided with a reflective lens, and the reflective lens is used to reflect the second laser beam so that the second laser focusing spot is formed behind the first laser focusing spot along the welding direction.

[0018] Advantageously, the present invention transmits the original laser beam to form a first laser beam through a beam splitting lens, and the beam splitting lens refracts the original laser beam to form a second laser beam. The second optical path module is provided with a reflecting lens, and the reflecting lens is used to reflect the second laser beam so that the second laser focusing spot is formed behind the first laser focusing spot along the welding direction. Thus, it is convenient to guide the second laser beam by using the reflecting lens, so that the second laser focusing spot can be formed behind the first laser focusing spot along the welding direction, which is beneficial to eliminate the gap between the first laser focusing spot and the second laser focusing spot, and further, the first laser focusing spot and the second laser focusing spot can act on the welding position of the object to be welded in turn.

[0019] According to some embodiments of the present invention, a collimating lens is provided between the laser input device and the beam splitting lens, and the collimating lens is used to convert the original laser beam input by the laser input device into parallel light.

[0020] Advantageously, the present invention provides a collimating lens between the laser input device and the beam splitting lens, and the collimating lens is used to convert the original laser beam input by the laser input device into parallel light, thereby effectively focusing the original laser beam, reducing the scattering of the original laser beam, and improving the energy density and beam quality of the original laser beam, thereby improving the welding efficiency and welding quality.

[0021] According to some embodiments of the present invention, the first optical path module is provided with a first focusing lens, and the second optical path module is provided with a second focusing lens, and the first focusing lens and the second focusing lens are used to focus the first laser beam and the second laser beam, respectively.

[0022] Advantageously, the present invention provides a first focusing lens in the first optical path module and a second focusing lens in the second optical path module, and the first focusing lens and the second focusing lens are used to focus the first laser beam and the second laser beam respectively, so that the first focusing lens and the second focusing lens can respectively focus the first laser beam and the second laser beam to a small point, which can significantly increase the welding speed and is beneficial to improving production efficiency. At the same time, the first focusing lens and the second focusing lens can respectively make the first laser beam and the second laser beam more accurately irradiate the weld, making the welding quality more stable and controllable.

[0023] According to some embodiments of the present invention, the first optical path module is provided with a first air curtain assembly, and the second optical path module is provided with a second air curtain assembly, and the first air curtain assembly and the second air curtain assembly are used to protect the first focusing lens and the second focusing lens, respectively.

[0024] Advantageously, the present invention provides a first air curtain assembly on the first optical path module and a second air curtain assembly on the second optical path module, and the first air curtain assembly and the second air curtain assembly are used to protect the first focusing lens and the second focusing lens, respectively. Thus, it is convenient to use the first air curtain assembly and the second air curtain assembly to protect the first focusing lens and the second focusing lens from being contaminated by splashes and smoke during the welding process, thereby ensuring that the first focusing lens and the second focusing lens can work normally, thereby ensuring the welding quality.

[0025] According to some embodiments of the present invention, a visual detection module is further included, and the visual detection module is used to monitor the welding process in real time.

[0026] Advantageously, the present invention provides a visual inspection module, which is used to monitor the welding process in real time, thereby facilitating visual monitoring of the welding process and, further, facilitating timely detection of welding defects during the welding process.

[0027] A welding method according to an embodiment of the second aspect of the present invention is applied to a laser welding device according to an embodiment of the first aspect of the present invention, comprising the following steps: Placing the object to be welded under the laser welding device; Use a laser input module to input a first laser beam and a second laser beam into the first optical path module and the second optical path module respectively; The first optical path module and the second optical path module respectively guide the first laser beam and the second laser beam to output a first laser focus spot and a second laser focus spot arranged in a front-to-back direction along a welding direction to the surface of the object to be welded, and the laser energy of the first laser focus spot is greater than the laser energy of the second laser focus spot; The laser welding device and the object to be welded are moved relative to each other, the first laser focused spot melts the welding material on the surface of the object to be welded, and the second laser focused spot continuously inputs energy to the welding molten surface of the object to be welded.

[0028] A welding method according to an embodiment of the present invention has at least the following beneficial effects: 1. The present invention uses a first optical path module and a second optical path module to guide the first laser beam and the second laser beam respectively to output a first laser focus spot and a second laser focus spot arranged front and back along the welding direction to the surface of the object to be welded. When the laser welding device and the object to be welded move relative to each other, the first laser focus spot melts the welding material on the surface of the object to be welded, and bubbles are formed at the bottom of the molten pool due to the collapse of the welding keyhole. Then, the second laser focus spot continuously inputs energy to the welding molten surface of the object to be welded, avoiding rapid cooling of the upper surface of the molten pool, so that the bubbles generated at the bottom due to the collapse of the keyhole have sufficient time to float to the surface of the molten pool, thereby reducing the generation of welding pores.

[0029] 2. The present invention makes the laser energy of the first laser focused spot greater than the laser energy of the second laser focused spot. Thus, the second laser focused spot with weaker laser energy acts behind the first laser focused spot, which can reduce the welding temperature gradient at the welding position, reduce the generation of welding cracks, and effectively improve the welding quality.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic structural diagram of a laser welding device according to an embodiment of the present invention; Figure 2 for Figure 1 A schematic cross-sectional view of the structure is shown; Figure 3 A schematic diagram of the shapes and positions of a first laser focusing spot and a second laser focusing spot of a laser welding device according to an embodiment of the present invention; Figure 4 The figure is a flow chart of a welding method according to an embodiment of the present invention.

[0033] Figure numerals: 100-laser input module, 110-first laser beam, 120-second laser beam, 130-first optical path module, 140-first laser focusing spot, 150-second optical path module, 160-second laser focusing spot, 170-DOE lens, 180-laser input device, 190-original laser beam, 200-beam splitting lens, 210-reflecting lens, 220-collimating lens, 230-first focusing lens, 240-second focusing lens, 250-first air curtain assembly, 260-second air curtain assembly, 270-visual detection module. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] In the description of the present invention, it is necessary to understand that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do 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 invention.

[0036] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of first and second, this is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation, connection and connection" 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 mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] A laser welding device and a welding method according to an embodiment of the present invention are described below with reference to the accompanying drawings.

[0039] The present invention aims to provide an embodiment of a laser welding device and a welding method.

[0040] In a first aspect, the present invention provides an embodiment of a laser welding device.

[0041] Reference Figure 1 In this embodiment, a laser welding device mainly includes a laser input module 100, a first optical path module 130, a second optical path module 150 and a visual detection module 270.

[0042] Reference Figure 2 , for the laser input module 100 , the laser input module 100 is used to provide a first laser beam 110 and a second laser beam 120 .

[0043] Specifically, the laser input module 100 includes a laser input device 180 and a beam splitter lens 200 . The laser input device 180 is used to input an original laser beam 190 ; the beam splitter lens 200 is used to separate the original laser beam 190 into a first laser beam 110 and a second laser beam 120 .

[0044] It can be understood that by using the beam splitter lens 200 to separate the original laser beam 190 input by the laser input device 180 into the first laser beam 110 and the second laser beam 120, on the one hand, it can reduce the setting of the laser input device 180, which is beneficial to simplify the structure of the laser welding device. On the other hand, it is beneficial to ensure the laser energy stability of the first laser beam 110 and the second laser beam 120, and ensure the quality stability of the welding.

[0045] Specifically, the laser input device 180 is configured as a QBH head, that is, an optical fiber output device, which can output the laser beam from the optical fiber and send it into the welding head.

[0046] In some specific embodiments, the beam splitter lens 200 separates 70%-80% of the laser energy of the original laser beam 190 to form the first laser beam 110, and the beam splitter lens 200 separates the remaining laser energy of the original laser beam 190 to form the second laser beam 120, thereby achieving a difference in laser energy between the first laser focusing spot 140 and the second laser focusing spot 160, so that the laser energy of the following first laser focusing spot 140 and the following second laser focusing spot 160 decreases gradually, so that the welding position of the object to be welded that passes through the first laser focusing spot 140 and the second laser focusing spot 160 in sequence can pass through the welding temperature with decreasing laser energy and then leave the welding area, avoiding the welding position of the object to be welded directly leaving the welding area after passing through the high temperature of laser welding, resulting in a sudden drop in the temperature of the welding position of the object to be welded, and further achieving the effect of reducing the welding temperature gradient of the welding position, reducing the generation of welding cracks, and effectively improving the welding quality.

[0047] In some specific embodiments, the beam splitter lens 200 transmits the original laser beam 190 to form the first laser beam 110, and the beam splitter lens 200 refracts the original laser beam 190 to form the second laser beam 120. The second optical path module 150 is provided with a reflecting lens 210, and the reflecting lens 210 is used to reflect the second laser beam 120 so that the second laser focusing spot 160 is formed behind the first laser focusing spot 140 along the welding direction. Therefore, it is convenient to use the reflecting lens 210 to guide the second laser beam 120, so that the second laser focusing spot 160 can be formed behind the first laser focusing spot 140 along the welding direction, which is conducive to eliminating the gap between the first laser focusing spot 140 and the second laser focusing spot 160, and then, the first laser focusing spot 140 and the second laser focusing spot 160 can act on the welding position of the object to be welded in sequence.

[0048] In some specific embodiments, a collimating lens 220 is arranged between the laser input device 180 and the beam splitting lens 200. The collimating lens 220 is used to convert the original laser beam 190 input by the laser input device 180 into parallel light, thereby effectively focusing the original laser beam 190, reducing the scattering of the original laser beam 190, and improving the energy density and beam quality of the original laser beam 190, thereby improving the welding efficiency and welding quality.

[0049] As for the first optical path module 130 , the first optical path module 130 is used to guide the first laser beam 110 and output a first laser focusing spot 140 .

[0050] As for the second optical path module 150 , the second optical path module 150 is used to guide the second laser beam 120 and output a second laser focusing spot 160 .

[0051] Among them, the first laser focusing spot 140 and the second laser focusing spot 160 are arranged front and back along the welding direction, the first laser focusing spot 140 is used to melt the welding material, and the second laser focusing spot 160 is used to continuously input energy to the surface of the welding melt, and the laser energy of the first laser focusing spot 140 is greater than the laser energy of the second laser focusing spot 160.

[0052] In this embodiment, a first optical path module 130 and a second optical path module 150 are provided. The first optical path module 130 is used to guide the first laser beam 110 and output a first laser focused spot 140. The second optical path module 150 is used to guide the second laser beam 120 and output a second laser focused spot 160. The first laser focused spot 140 and the second laser focused spot 160 are arranged front and back along the welding direction. The first laser focused spot 140 is used to melt the welding material, and the second laser focused spot 160 is used to continuously input energy to the surface of the welding melt. It can be understood that when laser welding starts, the first laser focused spot 140 melts the welding material and forms bubbles at the bottom of the molten pool due to the collapse of the welding keyhole. Then, the second laser focused spot 160 acts on the surface of the welding melt to continuously input energy, which can avoid the rapid cooling of the upper surface of the molten pool, so that the bubbles generated at the bottom due to the collapse of the welding keyhole have sufficient time to float to the surface of the molten pool, thereby reducing the generation of welding pores.

[0053] In this embodiment, the laser energy of the first laser focusing spot 140 is made greater than the laser energy of the second laser focusing spot 160. It can be understood that the second laser focusing spot 160 with weaker laser energy acts behind the first laser focusing spot 140, which can reduce the welding temperature gradient at the welding position, reduce the generation of welding cracks, and effectively improve the welding quality.

[0054] Reference Figure 3In some specific embodiments, the second optical path module 150 is provided with a DOE lens 170, which is used to shape the second laser beam 120 so that the second laser focusing spot 160 is elliptical. The length direction of the second laser focusing spot 160 is arranged along the welding direction, so that the second laser focusing spot 160 has a longer length along the welding direction, which is beneficial for the second laser focusing spot 160 to keep the liquid phase state area of ​​the molten pool at a larger area and for a longer time, so that the bubbles generated at the bottom due to the collapse of the welding keyhole have more sufficient time to float to the surface of the molten pool, thereby further reducing the generation of welding pores.

[0055] In some specific embodiments, the first optical path module 130 is provided with a first focusing lens 230, and the second optical path module 150 is provided with a second focusing lens 240. The first focusing lens 230 and the second focusing lens 240 are respectively used to focus the first laser beam 110 and the second laser beam 120, so that the first focusing lens 230 and the second focusing lens 240 can respectively focus the first laser beam 110 and the second laser beam 120 to a small point, which can significantly increase the welding speed and is conducive to improving production efficiency. At the same time, the first focusing lens 230 and the second focusing lens 240 can respectively make the first laser beam 110 and the second laser beam 120 more accurately irradiate the weld, making the welding quality more stable and controllable.

[0056] In some specific embodiments, the first optical path module 130 is provided with a first air curtain assembly 250, and the second optical path module 150 is provided with a second air curtain assembly 260. The first air curtain assembly 250 and the second air curtain assembly 260 are respectively used to protect the first focusing lens 230 and the second focusing lens 240, thereby facilitating the use of the first air curtain assembly 250 and the second air curtain assembly 260 to respectively protect the first focusing lens 230 and the second focusing lens 240 from being contaminated by splashes and smoke during the welding process, ensuring that the first focusing lens 230 and the second focusing lens 240 can work normally, thereby ensuring the welding quality.

[0057] As for the visual inspection module 270, the visual inspection module 270 is used to monitor the welding process in real time, thereby facilitating visual monitoring of the welding process and, further, facilitating timely detection of welding defects during the welding process.

[0058] In some specific embodiments, the laser welding device further includes a housing, and the laser input module 100, the first optical path module 130, the second optical path module 150 and the visual detection module 270 are all arranged in the housing, thereby facilitating the protection of the laser beam.

[0059] Furthermore, the shell has two copper nozzles, which are respectively located at the first laser module and the second laser module, and are used to output the first laser focusing spot 140 and the second laser focusing spot 160 respectively.

[0060] In a second aspect, the present invention provides an embodiment of a welding method.

[0061] Reference Figure 4 In this embodiment, a welding method is applied to the laser welding device of the first embodiment of the present invention, comprising the following steps: S1: Place the object to be welded under the laser welding device.

[0062] S2: Use the laser input module 100 to input the first laser beam 110 and the second laser beam 120 to the first optical path module 130 and the second optical path module 150 respectively.

[0063] S3: The first optical path module 130 and the second optical path module 150 respectively guide the first laser beam 110 and the second laser beam 120 to output the first laser focusing spot 140 and the second laser focusing spot 160 arranged front and back along the welding direction to the surface of the object to be welded, and the laser energy of the first laser focusing spot 140 is greater than the laser energy of the second laser focusing spot 160.

[0064] S4: The laser welding device and the object to be welded are moved relative to each other, the first laser focusing spot 140 melts the welding material on the surface of the object to be welded, and the second laser focusing spot 160 continuously inputs energy to the welding molten surface of the object to be welded.

[0065] In this embodiment, the first optical path module 130 and the second optical path module 150 are used to guide the first laser beam 110 and the second laser beam 120 respectively to output the first laser focusing spot 140 and the second focusing spot arranged in the welding direction to the surface of the object to be welded. When the laser welding device and the object to be welded move relative to each other, the first laser focusing spot 140 melts the welding material on the surface of the object to be welded, and bubbles are formed at the bottom of the molten pool due to the collapse of the welding keyhole. Then, the second laser focusing spot 160 continuously inputs energy to the welding molten surface of the object to be welded to avoid rapid cooling of the upper surface of the molten pool, so that the bubbles generated at the bottom due to the collapse of the keyhole have sufficient time to float to the surface of the molten pool, thereby reducing the generation of welding pores.

[0066] In this embodiment, by making the laser energy of the first laser focusing spot 140 greater than the laser energy of the second laser focusing spot 160, the second laser focusing spot 160 with weaker laser energy acts behind the first laser focusing spot 140, thereby reducing the welding temperature gradient at the welding position, reducing the generation of welding cracks, and effectively improving the welding quality.

[0067] In some specific embodiments, step S2 specifically includes the following steps: The laser input module 100 uses the laser input device 180 to input the original laser beam 190, and then uses the beam splitter 200 to separate the original laser beam 190 into the first laser beam 110 and the second laser beam 120. The first laser beam 110 and the second laser beam 120 enter the first optical path module 130 and the second optical path module 150 respectively.

[0068] It can be understood that by using the beam splitter lens 200 to separate the original laser beam 190 input by the laser input device 180 into the first laser beam 110 and the second laser beam 120, on the one hand, it can reduce the setting of the laser input device 180, which is beneficial to simplify the structure of the laser welding device. On the other hand, it is beneficial to ensure the laser energy stability of the first laser beam 110 and the second laser beam 120, and ensure the quality stability of the welding.

[0069] Furthermore, step S2 specifically includes the following steps: The beam splitter 200 is used to separate 70%-80% of the laser energy of the original laser beam 190 to form the first laser beam 110 , and the beam splitter 200 separates the remaining laser energy of the original laser beam 190 to form the second laser beam 120 .

[0070] Therefore, a difference in laser energy is achieved between the first laser focused spot 140 and the second laser focused spot 160, so that the laser energy of the first laser focused spot 140 and the second laser focused spot 160 decreases gradually, so that the welding position of the object to be welded that passes through the first laser focused spot 140 and the second laser focused spot 160 in sequence can pass through the welding temperature with decreasing laser energy and then leave the welding area, avoiding the welding position of the object to be welded directly leaving the welding area after passing through the high temperature of laser welding, resulting in a sudden drop in the temperature of the welding position of the object to be welded, achieving the effect of reducing the welding temperature gradient of the welding position, reducing the generation of welding cracks, and effectively improving the welding quality.

[0071] In some specific embodiments, step S2 further includes the following steps: The beam splitter 200 transmits the original laser beam 190 to form the first laser beam 110 , and the beam splitter 200 refracts the original laser beam 190 to form the second laser beam 120 .

[0072] In some specific embodiments, step S3 specifically includes the following steps: The second optical path module 150 uses the reflective lens 210 to reflect the second laser beam 120 so that the second laser focusing spot 160 is formed behind the first laser focusing spot 140 along the welding direction.

[0073] It can be understood that the second laser beam 120 is guided by the reflective lens 210 so that the second laser focusing spot 160 can be formed behind the first laser focusing spot 140 along the welding direction, which is beneficial to eliminate the gap between the first laser focusing spot 140 and the second laser focusing spot 160, and further, the first laser focusing spot 140 and the second laser focusing spot 160 can act on the welding position of the object to be welded in turn.

[0074] In some specific embodiments, step S3 specifically includes the following steps: The second optical path module 150 uses the DOE lens 170 to shape the second laser beam 120 so that the second laser focusing spot 160 is elliptical, and the length direction of the second laser focusing spot 160 is set along the welding direction.

[0075] Therefore, the second laser focusing spot 160 has a longer length along the welding direction, which is beneficial for the second laser focusing spot 160 to keep the liquid phase area of ​​the molten pool at a larger area and for a longer time, so that the bubbles generated at the bottom due to the collapse of the welding keyhole have more sufficient time to float to the surface of the molten pool, further reducing the generation of welding pores.

[0076] In the description of this specification, the description with reference to the terms "one embodiment, some embodiments, illustrative embodiments, examples, specific examples or some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0077] The terms "first, second, third, fourth", etc. (if any) in the specification and claims of this application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that shown or described herein.

[0078] It should also be noted that in the description of this specification, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0079] In addition, the terms "comprises" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may also include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0080] Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0081] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A laser welding device, characterized in that: include: A laser input module (100) for providing a first laser beam (110) and a second laser beam (120); A first optical path module (130), used for guiding the first laser beam (110) and outputting a first laser focus spot (140); A second optical path module (150), used for guiding the second laser beam (120) and outputting a second laser focus spot (160); The first laser focusing spot (140) and the second laser focusing spot (160) are arranged front and back along the welding direction, the first laser focusing spot (140) is used to melt the welding material, and the second laser focusing spot (160) is used to continuously input energy to the surface of the welding melt, and the laser energy of the first laser focusing spot (140) is greater than the laser energy of the second laser focusing spot (160).

2. A laser welding device according to claim 1, characterized in that: The second optical path module (150) is provided with a DOE lens (170), and the DOE lens (170) is used to shape the second laser beam (120) so that the second laser focusing spot (160) is elliptical, and the length direction of the second laser focusing spot (160) is arranged along the welding direction.

3. A laser welding device according to claim 1, characterized in that: The laser input module (100) comprises: A laser input device (180) for inputting an original laser beam (190); The beam splitting lens (200) is used to split the original laser beam (190) into the first laser beam (110) and the second laser beam (120).

4. A laser welding device according to claim 3, characterized in that: The beam splitter lens (200) separates 70%-80% of the laser energy of the original laser beam (190) to form the first laser beam (110), and the beam splitter lens (200) separates the remaining laser energy of the original laser beam (190) to form the second laser beam (120).

5. A laser welding device according to claim 3, characterized in that: The beam splitter lens (200) transmits the original laser beam (190) to form the first laser beam (110), and the beam splitter lens (200) refracts the original laser beam (190) to form the second laser beam (120). The second optical path module (150) is provided with a reflective lens (210), and the reflective lens (210) is used to reflect the second laser beam (120) so that the second laser focusing spot (160) is formed behind the first laser focusing spot (140) along the welding direction.

6. A laser welding device according to claim 3, characterized in that: A collimating lens (220) is provided between the laser input device (180) and the beam splitting lens (200), and the collimating lens (220) is used to convert an original laser beam (190) input by the laser input device (180) into parallel light.

7. The laser welding device according to claim 1, characterized in that: The first optical path module (130) is provided with a first focusing lens (230), and the second optical path module (150) is provided with a second focusing lens (240), and the first focusing lens (230) and the second focusing lens (240) are respectively used to focus the first laser beam (110) and the second laser beam (120).

8. A laser welding device according to claim 7, characterized in that: The first optical path module (130) is provided with a first air curtain assembly (250), and the second optical path module (150) is provided with a second air curtain assembly (260); the first air curtain assembly (250) and the second air curtain assembly (260) are used to protect the first focusing lens (230) and the second focusing lens (240), respectively.

9. The laser welding device according to claim 1, characterized in that: It also includes a visual detection module (270), wherein the visual detection module (270) is used to monitor the welding process in real time.

10. A welding method, characterized in that: A laser welding device according to any one of claims 1 to 9, comprising the following steps: Placing the object to be welded under the laser welding device; Using a laser input module (100) to input a first laser beam (110) and a second laser beam (120) into a first optical path module (130) and a second optical path module (150) respectively; The first optical path module (130) and the second optical path module (150) respectively guide the first laser beam (110) and the second laser beam (120) to output a first laser focus spot (140) and a second laser focus spot (160) arranged front to back along a welding direction to the surface of the object to be welded, the laser energy of the first laser focus spot (140) being greater than the laser energy of the second laser focus spot (160); The laser welding device and the object to be welded are moved relative to each other, the first laser focusing spot (140) melts the welding material on the surface of the object to be welded, and the second laser focusing spot (160) continuously inputs energy to the welding molten material surface of the object to be welded.

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