Laser welding device and flat wire motor welding method

Abstract

The invention relates to laser processing, and provides a laser welding device which comprises a laser, a light path assembly, a scanning welding head, a dust removal assembly, a first blowing assembly, a second blowing assembly and a dust removal assembly. An airflow layer of the first blowing assembly is close to the scanning welding head and acts on the lower side of a protection lens of the scanning welding head, and an airflow layer of the second blowing assembly is close to the working focal length face of the scanning welding head. The dust removal assembly quickly absorbs airflow layers output by the first blowing assembly and the second blowing assembly; the invention further provides a flat wire motor welding method. According to the welding device, through cooperation of the first air blowing assembly and the second air blowing assembly, the possibility that smoke dust and metal splashing particles generated in the laser welding process adhere to the protection lens can be greatly reduced, and the replacement frequency of the scanning welding head protection lens is remarkably reduced; and metal splashing particles can be effectively prevented from being attached to the to-be-welded workpiece again after welding, the shielding effect of welding smoke dust on laser can be effectively reduced, and the welding quality is guaranteed.

Description

Technical Field

[0001] The present invention relates to laser processing, and specifically to a laser welding device and a welding method for a flat wire motor. Background Art

[0002] When laser welding the stator of a flat wire motor, due to the characteristics of the high-energy laser beam, when the laser acts on the stator of the flat wire motor for welding, a large amount of welding slag and welding fume will be generated due to the "vaporization" of the copper winding due to local high temperature, and adhere to the protective lens of the laser scanning welding head, resulting in a sharp decrease in the welding quality (strength). For this reason, it is necessary to replace the protective lens of the scanning welding head frequently (every half month), which not only increases the later equipment maintenance cost and the frequency of line stop maintenance for customers, but also reduces the technical competitiveness of the welded products. Summary of the Invention

[0003] The purpose of the present invention is to provide a laser welding device and a welding method for a flat wire motor, which can at least solve some defects in the prior art.

[0004] To achieve the above purpose, an embodiment of the present invention provides the following technical solution: A laser welding device includes a laser, an optical path component, a scanning welding head, and a dust removal component. The laser is connected to the scanning welding head through the optical path component, and further includes a first blowing component and a second blowing component; The air flow layer of the first blowing component is close to the scanning welding head and acts on the outside of the protective lens of the scanning welding head, and the air flow layer of the second blowing component is close to the working focal plane of the scanning welding head; The dust removal component collects the air flow layers output by the first blowing component and the second blowing component.

[0005] Further, the second blowing component includes multiple layers of air knives, and the air flow layers generated by each layer of air knives are sequentially spaced along the laser beam emission direction.

[0006] Further, the second blowing component includes three layers of air knives, and the interval between the air flow layers generated by each layer of air knives is 36 - 38 mm.

[0007] Further, the dust removal component includes a first dust removal port and a second dust removal port. The first dust removal port is directly opposite to the first blowing component, and the second dust removal port is directly opposite to the second blowing component.

[0008] Further, the dust removal flow rate of the first dust removal port is greater than the blowing flow rate of the first blowing component, and the dust removal flow rate of the second dust removal port is greater than the blowing flow rate of the second blowing component.

[0009] Further, the laser emits a laser beam with a Gaussian or quasi-Gaussian distribution. The laser beam with a Gaussian or quasi-Gaussian distribution is output to a scanning welding head through a beam shaper, and the output spot of the scanning welding head is an annular spot or a dot-ring spot.

[0010] Further, the beam quality of the laser beam with a Gaussian or quasi-Gaussian distribution is less than 1.8, and the wavelength of the laser beam is infrared light or green light.

[0011] Further, the laser includes a dual-laser module. The dual-laser beams emitted by the dual-laser module are output to a scanning welding head through a beam combiner, and the output spot of the scanning welding head is an annular spot, a dot spot, or a dot-ring spot.

[0012] Further, when the scanning welding head welds a workpiece, a corresponding welding path is selected according to whether there is misalignment between the workpieces to be welded; And when there is no misalignment in both the horizontal and vertical directions of the workpieces to be welded, the welding path is annular.

[0013] The present invention provides another embodiment, a welding method for a flat wire motor, including the following steps: Weld the welding area of the flat wire motor with a laser, form a first air curtain outside the protective lens of the scanning welding head, and form a second air curtain on the upper surface of the welding area of the flat wire motor.

[0014] Compared with the prior art, the beneficial effect of the present invention is: a laser welding device is provided with a first blowing component and a second blowing component. When performing laser welding processing, the first blowing component inputs dry and high-purity compressed air to the linear structure air outlet to form a continuously flowing and uniform air flow layer along the horizontal direction, which can keep the welding field lens free from welding fume pollution for a long time; the second blowing component inputs dry and high-purity compressed air to the linear structure air outlet group to form multiple layers of continuously flowing and uniform air flow layers along the horizontal direction, which can not only timely disperse the plasma generated during high-power laser welding, reduce the shielding effect, but also timely transport the metal splash particles generated by welding to the dust removal component, preventing the metal splash particles from reattaching to the motor after welding and causing a short circuit. Through the laser welding device with this structure, the protective lens can be effectively protected, and the replacement frequency of the protective lens is reduced by more than 6 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the laser welding device provided by the embodiment of the present invention; Figure 2 is a schematic optical path diagram of the optical path component of the laser welding device provided by the embodiment of the present invention using a shaper; Figure 3Optical path schematic diagram of the optical path component of the laser welding device provided by the embodiment of the present invention, which uses a beam combiner. Detailed implementation manners

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0017] Refer to Figures 1 - 3 , the embodiment of the present invention provides a laser welding device, which can be used for welding the stator of a flat wire motor. Specifically, the welding device includes a laser, an optical path component 1, a scanning welding head 2, and a dust removal component 3. The laser is used to generate a laser beam, which is transmitted to the scanning welding head 2 through the optical path component 1, thereby realizing laser welding of the area to be welded. The dust removal component 3 can be used to remove and suck the soot and the like generated during the laser welding process of the welding device. The welding device also includes a first air blowing component 4 and a second air blowing component 5. The first air blowing component 4 is close to the protective lens of the scanning welding head 2, and the generated air flow layer is close to the outer surface of the protective lens. The second air blowing component 5 is arranged away from the protective lens. When the welding device works, the second air blowing component 5 is close to the working focal plane of the scanning welding head 2, and the generated air flow layer is above the working surface of the workpiece to be welded.

[0018] In the present invention, the welding device is provided with two groups of air blowing components. The first air blowing component 4 is close to the protective lens, and the second air blowing component 5 is close to the working focal plane of the scanning welding head 2. The air flow layer is usually parallel to the working focal plane. For example, when the working surface is horizontal, both the first air blowing component 4 and the second air blowing component 5 generate a horizontal air flow layer. Therefore, the soot generated during the operation of the welding device is first affected by the air flow layer generated by the second air blowing component 5, which can avoid the escape of soot and metal splash particles generated by welding towards the protective lens of the scanning welding head 2. The dust removal component 3 can suck the soot and metal splash particles. And when even a small amount of soot or metal splash particles pass through the air flow layer of the second air blowing component 5, the air flow layer of the first air blowing component 4 can further prevent the soot and metal splash particles from adhering to the protective lens of the field lens 21, and can keep the welding field lens 21 free from welding soot pollution for a long time.

[0019] In addition, when the welding device welds the stator of the flat wire motor, since the second air blowing component 5 is close to the working focal plane of the scanning welding head 2, it can timely disperse the plasma generated during high-power laser welding, effectively reduce the shielding effect of welding soot on the laser, and at the same time can avoid the metal splash particles generated by welding from reattaching to the flat wire motor after welding to cause a short circuit.

[0020] Optimized embodiment, the second air blowing assembly 5 includes multiple layers of air knives 51, and the airflow layers generated by each layer of air knives 51 are sequentially spaced along the laser emission direction. In this embodiment, the air knife 51 has a linear air outlet, and dry and high-purity compressed air, or argon, helium, carbon dioxide and corresponding mixed gases are input into the air knife 51, and the air knife 51 can generate a stable and uniform sheet-like airflow layer in the horizontal direction. And because the second air blowing assembly 5 has multiple layers of air knives 51, the second air blowing assembly 5 can form multiple layers of airflow layers, and the airflow layers are spaced apart. In a preferred solution, the interval between the airflow layers of adjacent air knives 51 is 36-38 mm, and when the welding device is working, the distance between the bottom air knife 51 of the second air blowing assembly 5 and the working surface of the workpiece to be welded is controlled. For example, when using the welding device to weld the stator of a flat wire motor, the second air blowing assembly 5 is controlled to move so that the distance between the bottom air knife 51 of the second air blowing assembly 5 and the working surface of the workpiece to be welded is 3-5 mm. In one embodiment, a height detection component is provided at the second air blowing assembly 5 to detect the distance between the standard position of the second air blowing assembly 5 and the working surface of the workpiece to be welded. Continuing to optimize the above embodiment, when using the welding device to laser-weld the stator of a flat wire motor, metal splash particles of about 1 mm will be generated. Therefore, the second air blowing assembly 5 is provided with three layers of air knives 51, and at the same time, the air outlet of each air knife 51 has a slit width of 0.5 mm, which can ensure that the metal splash particles are difficult to penetrate through the three layers of airflow layers (it is difficult for two layers of airflow layers to ensure that 1-mm metal splash particles are collected by the dust removal assembly 3), and at the same time, it can prevent the metal splash particles from reattaching to the motor after welding.

[0021] In one embodiment, the dust removal assembly 3 includes a first dust removal port 31 and a second dust removal port 32. The first dust removal port 31 and the first air blowing assembly 4 are linearly opposed, and the second dust removal port 32 and the second air blowing assembly 5 are linearly opposed. In this embodiment, the dust removal assembly 3 is provided with multiple dust removal ports and is linearly opposed to the corresponding air blowing assembly. The airflow layer generated by the first air blowing assembly 4 can be directly sucked by the corresponding first dust removal port 31, and the airflow layer generated by the second air blowing assembly 5 can be directly sucked by the corresponding second dust removal port 32. The first air blowing assembly 4 includes one layer of air knife 51, and the first dust removal port 31 is opposed to the air outlet of this layer of air knife 51, and the protective lens of the scanning welding head 2 is located between the two. In a preferred solution, the distance between the airflow layer generated by this layer of air knife 51 and the protective lens is 15-20 mm. Since the second air blowing assembly 5 has three layers of air knives 51, the second dust removal port 32 corresponds to the three layers of air knives 51 at the same time. Therefore, the second dust removal port 32 is an open port facing the air knife 51 and is tapered in the direction close to the air knife 51.

[0022] Optimize the above embodiments. The dust removal flow rate of the second air blowing assembly 5 is less than the air blowing flow rate of the first air blowing assembly 4, and the distance between the air outlet of the second air blowing assembly 5 and the first dust removal port 31 is less than the distance between the air outlet of the first air blowing assembly 4 and the second dust removal port 32. Specifically, for example, the distance between the air outlet of the first air blowing assembly 4 and the first dust removal port 31 is 200 mm, and the distance between the air outlet of the second air blowing assembly 5 and the second dust removal port 32 is 100 mm; and the dust removal flow rate of the first dust removal port 31 is greater than the air blowing flow rate of the first air blowing assembly 4, and the dust removal flow rate of the second dust removal port 32 is greater than the air blowing flow rate of the second air blowing assembly. Specifically, the air blowing flow rate of the air knife 51 of the first air blowing assembly 4 is 1500 - 2000 L / min, and the dust removal flow rate of the first dust removal port 31 is greater than 15000 L / min; the air blowing flow rate of the air knife 51 of the second air blowing assembly 5 is 800 - 1200 L / min, and the dust removal air pressure of the second dust removal port 32 is > 21000 L / min. In addition, the air blowing pressure of the first air blowing assembly 4 and the second air blowing assembly 5 is greater than the degassing pressure of the first dust removal port 31 and the second dust removal port 32. Through this air flow cooperation method, it can greatly avoid the dust and metal splash particles generated during the welding process from being sucked by the first dust removal port 31 and the second dust removal port 32. Calculated based on the production condition of producing 1200 stator pieces in 24 hours a day, the traditional air knife 51 layout method requires replacing the protection lens once every two weeks, while this structure can achieve replacing the protection lens once every three months, and the effective dust removal range is compatible with the area of 60 mm x 40 mm to 60 x 120 mm. In the preferred solution, for the three-layer air knife 51 of the second air blowing assembly 5, the air blowing flow rates of each layer of air knife 51 are distributed in a gradient manner, and the air knife 51 closest to the workpiece to be welded (at the bottom layer) has the largest flow rate, the flow rate of the middle layer air knife 51 is the second, and the flow rate of the air knife 51 at the top layer is the smallest. Specifically, for example, the flow rate of the lower layer air knife 51 is 1200 L / min, the flow rate of the middle layer air knife 51 is 1000 L / min, and the flow rate of the upper layer air knife 51 is 800 L / min, so that the second air blowing assembly 5 generates three layers of air flow layers with unequal speeds. Of course, there is a spacing between each layer of air knife 51, such as the aforementioned 36 - 38 mm, and there is a certain spacing between the three layers of air flow layers, which can avoid the generation of turbulence between adjacent air flow layers. At the same time, by utilizing the distribution of dust and metal splash particles during the laser welding process, it can more effectively suppress their dispersion, improve the service life of the protection lens, and reduce energy consumption.

[0023] Specifically, compared with the traditional single air blowing assembly solution, the effect of adopting the double air blowing assembly solution provided by the embodiments of the present invention is significantly improved. See the experimental data in the following table:

[0024] The laser emits a laser beam, which is transmitted to the scanning welding head 2 through the optical path component 1, where the optical path component 1 has the function of shaping the optical path.

[0025] See Figure 1 and Figure 2 , in one embodiment, the laser of the welding device emits light as a Gaussian or quasi-Gaussian distributed laser beam. The laser is a single laser, and the laser beam is shaped by the shaper 13 so that the output spot of the scanning welding head 2 is an annular spot or a dot-ring spot (there is a dot spot in the middle of the ring hole of the annular spot). In this embodiment, the optical path component 1 includes a collimator 11, a shaper 13, a beam splitter 12, a galvanometer 14, and a field lens 21. Thus, the Gaussian or quasi-Gaussian distributed laser beam emitted by the laser passes through collimation, beam splitting and reflection, and shaping in sequence and then enters the galvanometer 14 and the field lens 21 for scanning welding. The optical path between the laser and the collimator 11 is transmitted by a conventional optical fiber. The shaper 13 uses a DOE diffraction element or an optical field control phase component to adjust the Gaussian beam spot to an annular spot or a dot-ring spot. Specifically, it is possible to output a dot-ring spot or an annular spot at the scanning welding head 2 according to needs. For the dot-ring spot, the shaper 13 can be adjusted according to needs to achieve different dot-ring powers. For a Gaussian or quasi-Gaussian distributed laser beam, the beam quality is less than 1.8, and the wavelength of the laser beam is infrared light or green light to ensure the processing quality of the welding device for the flat wire motor.

[0026] See Figure 1 and Figure 3 , in another embodiment, the laser includes a dual laser module, and the dual laser module can emit two laser beams. The two laser beams are combined by a beam combiner and shaped by a special optical fiber and output to the scanning welding head 2. The output spot of the scanning welding head 2 is an annular spot, a dot spot or a dot-ring spot. In this embodiment, the optical path component 1 includes a beam combiner, a special optical fiber, a collimator 11, a beam splitter 12, a galvanometer 14, and a field lens 21. The dual laser module emits dual laser beams. After the dual laser beams are combined by the beam combiner, they are shaped and transmitted through the special optical fiber. The special optical fiber is an annular optical fiber to form an annular spot, a dot spot or a dot-ring spot, and after collimation and beam splitting and reflection, it enters the galvanometer 14 and the field lens 21 for scanning welding. Specifically, since the dual laser module outputs dual laser beams, when a dot-ring spot is used, the dot-ring power of the dot-ring spot can be flexibly adjusted, for example, it can be adjusted arbitrarily from 10% to 100%.

[0027] For the above two embodiments, when the welding device performs laser welding on the stator of the flat wire motor, a dot-ring spot is used for processing, and the ratio of the dot-ring power is 1-2 (the power ratio between the dot spot and the ring spot). The outer annular spot can increase the size of the welding keyhole, balance the internal and external pressures of the keyhole, and prevent welding spatter.

[0028] Optimize the above embodiment. When the scanning welding head 2 welds the workpieces to be welded, it selects the corresponding welding path according to whether there is misalignment between the workpieces to be welded. And when both the horizontal and vertical directions of the workpieces to be welded are misaligned, the welding path is circular. In this embodiment, the misalignment of the workpieces to be welded can be determined according to the splicing gap. For example, if the welding gap between two adjacent workpieces to be welded is less than 0.2 mm, it is considered that there is no misalignment. And when it is determined that there is no misalignment between the two, the corresponding circular welding path is selected according to the welding depth and the thickness of the workpiece to be welded (when welding the stator of a flat wire motor, the thickness of the copper wire is determined). The circular welding path can be square or elliptical. And when the thickness of the workpiece to be welded is relatively large, a square welding path is adopted. Of course, during welding, repeated welding needs to be carried out according to the welding path, and the preferred number of repetitions is 6 - 8 times.

[0029] See Figure 1 In addition, an embodiment of the present invention also provides a welding method for a flat wire motor. Corresponding to the above welding device, the stator of the flat wire motor is welded by the welding device. And an air curtain layer is formed outside the protective lens by the airflow discharged from the first air blowing component 4, and an air curtain layer is formed on the upper surface of the welding area of the stator of the flat wire motor by the airflow discharged from the second air blowing component 5. In this embodiment, laser welding is performed on the stator of the flat wire motor, and an air curtain layer is formed outside the protective lens by the first air blowing component 4. Generally, the first air curtain layer includes a single layer of airflow. The second air blowing component 5 forms a second air curtain above the welding area of the stator of the flat wire motor, and the second air curtain includes multiple layers of airflow, preferably three layers of airflow. And there is a certain gap between each layer of airflow. Thus, the dust and metal splash particles generated during the welding process need to pass through the second air curtain with multiple layers of airflow and the first air curtain with a single layer of airflow in sequence before adhering to the outer surface of the protective lens, thereby greatly reducing the replacement frequency of the protective lens. Compared with the traditional semi-monthly replacement frequency, the maintenance cost of the protective lens is greatly reduced. Both the first air curtain and the second air curtain adopt oppositely arranged dust removal ports, and the dust and metal splash particles can be timely collected by the dust removal component 3. Combining with the multi-layer airflow structure of the second air curtain, the plasma generated during welding can be timely collected, reducing the shielding effect, and the metal splash particles basically will not reattach to the flat wire motor, ensuring the quality of laser welding.

[0030] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made in these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A laser welding device, comprising a laser, an optical path component, a scanning welding head and a dust removal component, wherein the laser is connected to the scanning welding head through the optical path component, and is characterized in that: Also includes a first blowing assembly and a second blowing assembly; The airflow layer of the first air blowing assembly is close to the scanning welding head and acts on the lower side of the protective lens of the scanning welding head, and the airflow layer of the second air blowing assembly is close to the working focal length surface of the scanning welding head; The dust removal component collects the air flow layers output by the first air blowing component and the second air blowing component.

2. The laser welding device according to claim 1, characterized in that: The second air blowing assembly comprises multiple layers of air knives, and the air flow layers generated by the air knives are sequentially spaced and distributed along the emitting direction of the laser beam.

3. The laser welding device according to claim 2, characterized in that: The second air blowing assembly includes three layers of air knives, and the interval between the air flow layers generated by the air knives at each layer is 36-38 mm.

4. The laser welding device according to claim 1, characterized in that: The dust removal assembly includes a first dust removal port and a second dust removal port. The first dust removal port and the first air blowing assembly are linearly arranged opposite to each other, and the second dust removal port and the second air blowing assembly are linearly arranged opposite to each other.

5. The laser welding device according to claim 4, characterized in that: The dust removal flow rate of the first dust removal port is greater than the air blowing flow rate of the first air blowing component, and the dust removal flow rate of the second dust removal port is greater than the air blowing flow rate of the second air blowing component.

6. The laser welding device according to claim 1, characterized in that: The laser emits a Gaussian or quasi-Gaussian distribution laser beam, and the Gaussian or quasi-Gaussian distribution laser beam is output to a scanning welding head through a beam shaper, and the output light spot of the scanning welding head is a ring light spot or a point ring light spot.

7. The laser welding device according to claim 6, characterized in that: The beam quality of the Gaussian or quasi-Gaussian distribution laser beam is less than 1.8, and the wavelength of the laser beam is infrared light or green light.

8. The laser welding device according to claim 1, characterized in that: The laser comprises a dual laser module, and the dual laser beams emitted by the dual laser module are output to a scanning welding head through a beam combiner, and the output light spot of the scanning welding head is a ring light spot, a point light spot or a point ring light spot.

9. The laser welding device according to claim 1, characterized in that: When the scanning welding head welds the workpieces, the corresponding welding path is selected according to whether there is misalignment between the workpieces to be welded; When there is no misalignment in the horizontal and vertical directions of the workpieces to be welded, the welding path is circular.

10. A flat wire motor welding method, characterized in that: Laser is used to weld the welding area of ​​the flat wire motor, a first air curtain is formed outside the protective lens of the scanning welding head, and a second air curtain is formed on the upper surface of the welding area of ​​the flat wire motor.

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