Laser welding device and flat wire motor welding method

Abstract

The present invention relates to laser processing and provides a laser welding device, including a laser, an optical path component, a scanning welding head, a dust removal component, a first air blowing component, a second air blowing component, and a dust removal component. The airflow layer of the first air blowing component 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 component is close to the working focal length surface of the scanning welding head. The dust removal component quickly absorbs the airflow layers output by the first and second air blowing components. The present invention also provides a flat wire motor welding method. The welding device of the present invention, through the cooperation of the first and second air blowing components, can greatly reduce the possibility of smoke and metal spatter particles generated during laser welding adhering to the protective lens, significantly reducing the frequency of replacement of the scanning welding head protective lens, and not only effectively preventing metal spatter particles from reattaching to the workpiece to be welded after welding, but also effectively reducing the shielding effect of welding smoke on the laser, thereby ensuring welding quality.

Description

Technical Field

[0001] The invention relates to laser processing, in particular to a laser welding device and a flat wire motor welding method. 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, the copper winding will "vaporize" due to the local high temperature, which will produce a large amount of welding slag and welding smoke. The smoke adheres to the protective lens of the laser scanning welding head, causing the welding quality (strength) to drop sharply. Therefore, the protective lens of the scanning welding head needs to be replaced frequently (every half a month), which not only increases the customer's subsequent equipment maintenance costs and the frequency of line shutdowns and maintenance, but also reduces the technical competitiveness of the welding products. Summary of the Invention

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

[0004] To achieve the above objectives, an embodiment of the present invention provides the following technical solution: 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 via the optical path component, and further comprising a first air blowing component and a second air blowing component;

[0005] The air flow layer of the first blowing assembly is close to the scanning welding head and acts on the outer side of the protective lens of the scanning welding head, and the air flow layer of the second blowing assembly is close to the working focal length plane of the scanning welding head;

[0006] The dust removal component collects the air flow layers output by the first air blowing component and the second air blowing component.

[0007] Furthermore, the second air blowing assembly includes multiple layers of air knives, and the air flow layers generated by the air knives are sequentially spaced along the emitting direction of the laser beam.

[0008] Furthermore, the second air blowing assembly includes three layers of air knives, and the interval between the air flow layers generated by the air knives in each layer is 36-38 mm.

[0009] Furthermore, the dust removal component includes a first dust removal port and a second dust removal port, the first dust removal port is arranged in a straight line opposite to the first air blowing component, and the second dust removal port is arranged in a straight line opposite to the second air blowing component.

[0010] Furthermore, 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.

[0011] Furthermore, the laser emits a Gaussian or quasi-Gaussian distribution laser beam, which 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.

[0012] Furthermore, 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.

[0013] Furthermore, the laser includes a dual laser module, and the dual laser beams emitted by the dual laser module are output to the 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.

[0014] Furthermore, 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;

[0015] And when there is no misalignment in the horizontal and vertical directions of the workpieces to be welded, the welding path is circular.

[0016] The present invention provides another embodiment, a flat wire motor welding method, comprising the following steps:

[0017] 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.

[0018] Compared with the prior art, the present invention has the following advantages: a laser welding device is provided with a first air blowing assembly and a second air blowing assembly. During laser welding, the first air blowing assembly inputs dry, high-purity compressed air to the linear structure outlet, forming a layer of airflow that flows continuously and evenly in the horizontal direction, which can protect the welding field lens from welding fume contamination for a long time; the second air blowing assembly inputs dry, high-purity compressed air to the linear structure outlet group, forming multiple layers of airflow that flows stably and evenly in the horizontal direction. This not only promptly dissipates the plasma generated during high-power laser welding and reduces the shielding effect, but also promptly transports the metal spatter particles generated by welding to the dust removal assembly, preventing the metal spatter particles from reattaching to the motor after welding and causing a short circuit. This structure of the laser welding device can effectively protect the protective lens, reducing the replacement frequency of the protective lens by more than 6 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of a laser welding device provided in an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of an optical path using a shaper as an optical path component of a laser welding device provided in an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of an optical path of a laser welding device provided in an embodiment of the present invention using a beam combiner as an optical path component. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] See also Figure 1-Figure 3 An embodiment of the present invention provides a laser welding device that can be used to weld 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 to achieve laser welding of the area to be welded, and the dust removal component 3 can be used to remove smoke and dust 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 air flow layer generated is close to the outer surface of the protective lens; the second air blowing component 5 is set away from the protective lens. When the welding device is working, the second air blowing component 5 is close to the working focal length plane of the scanning welding head 2, and the air flow layer generated is located above the working surface of the workpiece to be welded.

[0024] In the present invention, the welding device is provided with two groups of blowing components, wherein the first blowing component 4 is close to the protective lens, and the second blowing component 5 is close to the working focal length plane of the scanning welding head 2. The air flow layer is usually parallel to the working focal length plane. For example, when the working plane is horizontal, the first blowing component 4 and the second blowing component 5 both generate horizontal air flow layers. As a result, the smoke generated when the welding device is working is first affected by the air flow layer generated by the second blowing component 5, which can prevent the smoke and metal splash particles generated by welding from escaping toward the protective lens of the scanning welding head 2, and the dust removal component 3 can absorb the smoke and metal splash particles. Even when a small amount of smoke or metal splash particles passes through the air flow layer of the second blowing component 5, the air flow layer of the first blowing component 4 can further prevent the smoke and metal splash particles from adhering to the protective lens of the field lens 21, and can keep the welding field lens 21 from being contaminated by welding smoke for a long time.

[0025] In addition, when the welding device welds the stator of the flat wire motor, since the second blowing assembly 5 is close to the working focal plane of the scanning welding head 2, it can promptly disperse the plasma generated during high-power laser welding, effectively reduce the shielding effect of welding smoke on the laser, and at the same time avoid the metal splash particles generated by welding from re-attaching to the flat wire motor after welding to cause a short circuit.

[0026] In an optimized embodiment, the second air blowing assembly 5 includes multiple layers of air knives 51. The air flow layers generated by each layer of air knives 51 are sequentially spaced along the laser emission direction. In this embodiment, the air knives 51 have linear outlets. Dry, high-purity compressed air, or argon, helium, carbon dioxide, or a corresponding gas mixture, is fed into the air knives 51 to produce a horizontally stable and uniform sheet-like air flow layer. Because the second air blowing assembly 5 includes multiple layers of air knives 51, it can form multiple air flow layers, each spaced apart. In a preferred embodiment, the air flow layer spacing between adjacent air knives 51 is 36-38 mm. When the welding device is in operation, 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 welding the stator of a flat wire motor using the welding device, the second air blowing assembly 5 is controlled to maintain a distance of 3-5 mm between the bottom air knife 51 of the second air blowing assembly 5 and the working surface of the workpiece to be welded. In one embodiment, a height detector 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. Further optimizing the above embodiment, when laser welding the stator of a flat wire motor using a welding device, metal spatter particles approximately 1 mm in size are generated. Therefore, the second air blowing assembly 5 is provided with three layers of air knives 51, each with a 0.5 mm air outlet. This ensures that metal spatter particles are difficult to penetrate the three air flow layers (two air flow layers make it difficult to ensure that metal spatter particles 1 mm in size are collected by the dust removal assembly 3). This also prevents metal spatter particles from reattaching to the motor after welding.

[0027] 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 is linearly opposite to the first air blowing assembly 4, and the second dust removal port 32 is linearly opposite to the second air blowing assembly 5. In this embodiment, the dust removal assembly 3 is provided with multiple dust removal ports, which are linearly opposite to the corresponding air blowing assemblies. The airflow layer generated by the first air blowing assembly 4 can be directly sucked in by the corresponding first dust removal port 31, and the airflow layer generated by the second air blowing assembly 5 can be directly sucked in by the corresponding second dust removal port 32. The first air blowing assembly 4 includes a layer of air knife 51. The first dust removal port 31 is opposite to the air outlet of the layer of air knife 51. The protective lens of the scanning welding head 2 is located between the two. In the preferred embodiment, the distance between the airflow layer generated by the 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 . Thus, the second dust removal port 32 is open toward the air knives 51 and gradually expands in the direction approaching the air knives 51 .

[0028] The above embodiment is optimized, the dust removal flow rate of the second blowing component 5 is smaller than the blowing flow rate of the first blowing component 4, and the distance between the air outlet of the second blowing component 5 and the second dust removal port 32 is smaller than the distance between the air outlet of the first blowing component 4 and the first dust removal port 31. Specifically, for example, the distance between the air outlet of the first blowing component 4 and the first dust removal port 31 is 200 mm, and the distance between the air outlet of the second blowing component 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 blowing flow rate of the first blowing component 4, and the dust removal flow rate of the second dust removal port 32 is greater than the blowing flow rate of the second air to component. Specifically, the air knife 51 of the first air blowing assembly 4 has an air flow rate of 1500-2000 L / min, and the dust removal flow rate of the first dust removal port 31 is greater than 15,000 L / min; the air knife 51 of the second air blowing assembly 5 has an air flow rate of 800-1200 L / min, and the dust removal wind pressure of the second dust removal port 32 is greater than 21,000 L / min. In addition, the air 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. This airflow coordination method can greatly prevent the smoke and metal splash particles generated during the welding process from being sucked into the first dust removal port 31 and the second dust removal port 32. Based on the production conditions of 1200 stators produced 24 hours a day, the traditional air knife 51 arrangement requires the protective lens to be replaced every two weeks, while this structure can achieve a replacement of the protective lens every three months, and the effective dust removal range is compatible with an area of ​​60mmx40mm~60x120mm. In the preferred embodiment, for the three layers of air knives 51 of the second blowing assembly 5, the blowing flow rates of the air knives 51 of each layer are distributed in a gradient, and the air knife 51 close to the workpiece to be welded (at the bottom layer) has the largest flow rate, the air knife 51 of the middle layer has the second largest flow rate, and the air knife 51 at the top has the smallest flow rate. Specifically, for example, the flow rate of the lower layer of air knife 51 is 1200 L / min, the flow rate of the middle layer of air knife 51 is 1000 L / min, and the flow rate of the air knife 51 at the top is 800 L / min, so that the second blowing assembly 5 produces three layers of air flow with unequal speeds. Of course, there is a spacing between the air knives 51 of each layer, such as the aforementioned 36-38 mm. There is a certain spacing between the three layers of air flow layers, which can avoid turbulence between adjacent air flow layers. At the same time, the distribution of smoke and metal splash particles during the laser welding process can be used to more effectively suppress their escape, thereby increasing the service life of the protective lens and reducing energy consumption.

[0029] Specifically, the dual-air blowing component solution provided by the embodiment of the present invention has a significantly improved effect compared to the traditional single-air blowing component solution. See the experimental data in the table below:

[0030]

[0031] The laser beam emitted by the laser is transmitted to the scanning welding head 2 through the optical path component 1, wherein the optical path component 1 has the function of optical path shaping.

[0032] See also Figure 1 as well as Figure 2 In one embodiment, the laser of the welding device emits a Gaussian or quasi-Gaussian distributed laser beam. The laser is a single laser, and the laser beam is shaped by a shaper 13 so that the output light spot of the scanning welding head 2 is an annular light spot or a point ring light spot (the annular light spot has a point light spot in the middle of the ring hole). 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. The Gaussian or quasi-Gaussian distributed laser beam emitted by the laser is sequentially collimated, beam splittered, reflected, and shaped before entering the galvanometer 14 and field lens 21 for scanning welding. The optical path between the laser and the collimator 11 is transmitted using 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 light spot or a point ring light spot. Specifically, the scanning welding head 2 can output a point ring light spot or an annular light spot as needed. For the point ring light spot, the shaper 13 can be adjusted as needed to achieve different point ring powers. 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, so as to ensure the processing quality of the flat wire motor by the welding device.

[0033] See also Figure 1 as well as Figure 3 In another embodiment, the laser includes a dual laser module. The dual laser module can emit two laser beams, and the two laser beams are shaped and output to the scanning welding head 2 through a beam combiner and a special optical fiber. The output light spot of the scanning welding head 2 is a ring light spot, a point light spot, or a point ring light 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 a special optical fiber. The special optical fiber is a ring optical fiber, forming a ring light spot, a point light spot, or a point ring light spot. After collimation and spectroscopic reflection, they enter the galvanometer 14 and the field lens 21 for scanning welding. Specifically, since the dual laser module outputs dual laser beams, when a point ring light spot is used, the point ring power of the point ring light spot can be flexibly adjusted, for example, it can be adjusted arbitrarily from 10% to 100%.

[0034] With respect to the above two embodiments, when the welding device performs laser welding on the stator of the flat wire motor, a point-ring light spot is used for processing, and the ratio of the point-ring power is 1-2 (the power ratio between the point light spot and the ring light spot). The outer ring light spot can increase the size of the welding keyhole, balance the internal and external pressures of the keyhole, and prevent welding spatter.

[0035] To optimize the above embodiment, when the scanning welding head 2 is welding the workpieces to be welded, it selects a corresponding welding path based on whether there is any misalignment between the workpieces to be welded. When the workpieces to be welded are misaligned in both the horizontal and vertical directions, the welding path is annular. In this embodiment, the misalignment of the workpieces to be welded can be determined based on the splicing gap. For example, if the welding gap between two adjacent workpieces to be welded is less than 0.2mm, it is determined that there is no misalignment. When it is determined that there is no misalignment between the two, a corresponding annular welding path is selected based on 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 annular welding path can be square or elliptical, and when the thickness of the workpiece to be welded is large, a square welding path is used. Of course, when welding, it is necessary to repeat the welding according to the welding path, and the preferred number of repetitions is 6-8 times.

[0036] See also Figure 1 An embodiment of the present invention further provides a flat wire motor welding method. Corresponding to the aforementioned welding device, the stator of the flat wire motor is welded using the welding device, and the airflow layer discharged by the first air blowing assembly 4 forms a first air curtain on the outer side of the protective lens, and the airflow layer discharged by the second air blowing assembly 5 forms a second air curtain on the upper surface of the welding area of ​​the flat wire motor stator. In this embodiment, laser welding is performed on the stator of the flat wire motor, and the first air blowing assembly 4 forms a first air curtain on the outer side of the protective lens. Generally, the first air curtain includes a single airflow layer, and the second air blowing assembly 5 forms a second air curtain above the welding area of ​​the flat wire motor stator. The second air curtain includes multiple airflow layers, preferably three airflow layers, with gaps between each airflow layer. Therefore, smoke and metal spatter particles generated during the welding process must sequentially pass through the second air curtain having multiple airflow layers and the first air curtain having a single airflow layer before adhering to the outer surface of the protective lens. This significantly reduces the replacement frequency of the protective lens and significantly reduces the maintenance cost of the protective lens compared to the traditional biweekly replacement frequency. The first air curtain and the second air curtain both use dust removal ports that are relatively set, so smoke and metal splash particles can be collected in the dust removal component 3 in a timely manner. Combined with the multi-layer air flow layer structure of the second air curtain, the plasma generated during welding can be collected in a timely manner to reduce the shielding effect, and the metal splash particles will basically not re-attach to the flat wire motor, thereby ensuring the quality of laser welding.

[0037] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A laser welding device for laser welding flat wire motors, 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 via the optical path component, and is characterized in that: Also includes a first blowing assembly and a second blowing assembly; The air flow 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 air flow layer of the second air blowing assembly is close to the working focal length plane of the scanning welding head; The dust removal component collects the airflow layers output by the first air blowing component and the second air blowing component, and the dust removal component includes a first dust removal port and a second dust removal port, the first dust removal port and the first air blowing component are arranged linearly relative to each other, and the second dust removal port and the second air blowing component are arranged linearly relative to each other; The blowing flow rate of the second blowing component is smaller than the blowing flow rate of the first blowing component, and the distance between the air outlet of the second blowing component and the second dust removal port is smaller than the distance between the air outlet of the first blowing component and the first dust removal port; The second air blowing assembly includes three layers of air knives, and the air flow layers generated by the air knives in each layer are spaced in sequence along the direction of the laser beam emission, and the intervals between the air flow layers generated by the air knives in each layer are 36-38 mm; the air blowing flow of the air knives in each layer is gradiently distributed, and the air knife in the bottom layer has the largest flow, and the air knife in the top layer has the smallest flow.

2. The laser welding device according to claim 1, wherein: 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.

3. The laser welding device according to claim 1, wherein: The laser emits a Gaussian or quasi-Gaussian distribution laser beam, which is output to a scanning welding head through a beam shaper. The output light spot of the scanning welding head is a ring light spot or a point ring light spot.

4. The laser welding device according to claim 3, wherein: 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.

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

6. The laser welding device according to claim 1, wherein: 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; And when there is no misalignment in the horizontal and vertical directions of the workpieces to be welded, the welding path is circular.

7. A flat wire motor welding method, characterized in that: Laser welding is used to weld the welding area of ​​the flat wire motor, forming a first air curtain outside the protective lens of the scanning welding head and a second air curtain on the upper surface of the welding area of ​​the flat wire motor; The second air curtain includes three air flow layers, each of which is spaced apart in the direction of the laser beam, and the interval between the air flow layers is 36-38 mm. The air flow rate of each air flow layer is distributed in a gradient, with the air flow rate of the bottom air flow layer being the largest and the air flow rate of the top air flow layer being the smallest. The airflow of the first air curtain is sucked by a first dust removal port, and the airflow of the second air curtain is sucked by a second dust removal port; Moreover, the blowing flow rate of each air flow layer of the second air curtain is smaller than the blowing flow rate of the first air curtain, and the distance between the air outlet of the second blowing component corresponding to the second air curtain and the second dust removal port is smaller than the distance between the air outlet of the first blowing component corresponding to the first air curtain and the first dust removal port.

Images