Frequency converter sheet metal case laser welding device and method

Abstract

The invention discloses a laser welding device and method for a frequency converter sheet metal case, and relates to the technical field of laser welding. The frequency converter sheet metal case laser welding device comprises a machine tool, a laser emitter for emitting laser to conduct welding, a displacement sensor for measuring the distance between a workpiece and the laser emitter, a camera for shooting a welding seam and a spray head for spraying protective gas to the welding position. A clamping assembly used for changing the inclination angle of a machine box, a backflow assembly used for reutilizing protective gas and an adjusting assembly used for changing the angle of airflow sprayed out of the backflow assembly are arranged in the machine tool, and the backflow assembly comprises an air guide block located on the lateral upper portion of the machine box and used for collecting the protective gas sprayed out of a spray head; and the air outlet sleeve is fixed on the air guide block and is used for secondarily blowing the collected protective gas to the case, so that the cooling speed of the molten pool can be slowed down, the formation of air holes can be reduced, the shrinkage stress caused by rapid cooling can be reduced, and the risk of hot cracks can be further reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of laser welding, and particularly to a laser welding device and method for a frequency converter sheet metal chassis. Background Technique

[0002] A frequency converter is a power control device that applies frequency conversion technology and microelectronics technology to control an AC motor by changing the working power frequency of the motor. The chassis is an indispensable component in the frequency converter, mainly protecting the electrical components inside the frequency converter. The existing frequency converter chassis is mainly a sheet metal chassis. By bending a whole metal plate into the shape of the chassis and welding the joints of the metal plate together, the manufacturing of the frequency converter chassis can be completed. During the welding of the sheet metal chassis, a laser welding device is mainly used. However, during welding, due to the deep and narrow molten pool of laser welding and the very fast cooling speed, the gas in the liquid molten pool does not have enough time to escape, resulting in pores and cracks easily appearing on the surface of the weld seam. For example, a laser welding device for a frequency converter sheet metal chassis disclosed in the patent with the publication number CN219402797U. Although this application fixes the chassis body by driving a pressing plate with an electric telescopic rod and cooperating with a U-shaped rod, it does not adopt effective means to process the workpiece, and pores and cracks will still appear in the weld seam due to the fast cooling speed of the molten pool. A laser composite welding emission device disclosed in the patent with the publication number CN107052580B, although preheating the workpiece with a semiconductor laser to reduce the probability of pores and cracks appearing, the cooling rate at the weld position has not been changed, resulting in the phenomenon of pores and cracks still being prone to occur. Therefore, a laser welding device and method for a frequency converter sheet metal chassis are proposed. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a laser welding device and method for a frequency converter sheet metal chassis, which solves the problems raised in the background technique.

[0004] To achieve the above objectives, the present invention is realized through the following technical solutions: A laser welding device for a frequency converter sheet metal chassis includes a machine tool, a laser emitter that emits laser for welding, a displacement sensor that measures the distance between the workpiece and the laser emitter, a camera that takes pictures of the weld seam, and a nozzle that sprays protective gas to the welding area. A clamping assembly for changing the inclination angle of the chassis, a reflux assembly for reusing the protective gas, and an adjustment assembly for changing the jet angle of the gas ejected by the reflux assembly are arranged inside the machine tool. The reflux assembly includes: a wind guiding block, located above the side of the chassis, collecting the protective gas ejected by the nozzle; an air outlet sleeve, fixed on the wind guiding block, and blowing the collected protective gas onto the chassis for the second time.

[0005] Preferably, the reflux assembly further includes: an air guiding groove formed on the air guiding block for guiding the collected protective gas towards the air outlet sleeve.

[0006] Preferably, the adjusting assembly includes: a fixed rod with one end installed at the bottom of the air guiding block to provide support for the air guiding block; a limiting rod with the top fixed to the bottom of the fixed rod to provide support for the fixed rod; a support rod slidably sleeved on the limiting rod to limit the moving direction of the limiting rod.

[0007] Preferably, the adjusting assembly further includes: a fixed block with one end fixed to the side wall of the fixed rod; a telescopic rod with one end fixed to the fixed block to change the position of the fixed rod.

[0008] Preferably, the adjusting assembly further includes: a fixed magnet with one end fixed to the fixed rod; a moving magnet located above the fixed magnet and magnetically cooperating with the fixed magnet; a guiding rod with one end fixed to the fixed rod and the other end slidably passing through the moving magnet to limit the moving direction of the moving magnet; a power rod with one end fixed to the top of the moving magnet and the other end fixed to the top of the air outlet sleeve; an adjusting shaft with one end fixed to the bottom of the air guiding block; an adjusting motor with the output end fixed to the other end of the adjusting shaft to provide power for changing the angle of the air guiding block.

[0009] Preferably, the clamping assembly includes: a power motor installed in the machine tool through a motor box to provide power for changing the inclination angle of the machine box; a rotating shaft with one end fixed to the output end of the power motor; a winding wheel with the side wall fixed to the other end of the rotating shaft; a traction rope with one end fixed to the winding wheel; a first guiding wheel and a second guiding wheel with the side walls both abutted against the traction rope to limit the moving direction of the traction rope.

[0010] Preferably, the clamping assembly further includes: a rotating motor connected to the other end of the traction rope through a motor box; a rotating shaft with one end fixed to the output end of the rotating motor; a sliding seat rotatably sleeved outside the rotating shaft through a bearing; a support plate with the side wall fixed to the other end of the rotating shaft; a clamping plate installed on the support plate to fix the machine box to be welded; a limiting block with one end fixed to the side wall of the clamping plate; a sliding rod with one end slidably passing through the limiting block; an upper magnet with the side wall fixed to the clamping plate; a lower magnet located below the upper magnet and magnetically cooperating with the upper magnet; a guiding rail fixed in the machine tool and slidably cooperating with the sliding seat to limit the moving direction of the sliding seat.

[0011] Preferably, the nozzle is connected to a heating box through an air delivery pipe. The heating box is used for heating the protective gas. A gas storage tank for storing the protective gas is connected to the heating box, and the gas storage tank is installed in the machine tool.

[0012] The present invention also provides an operation method applicable to a laser welding device for a frequency converter sheet metal chassis, including the following steps: S1. Fix the chassis to be welded using the clamping assembly, start the laser emitter for welding using the control panel, spray a shielding gas onto the welding area using the nozzle, and determine the flow rate of the shielding gas based on the distance measured by the displacement sensor; S2. Start the laser emitter for welding using the control panel. Meanwhile, the camera takes a photo of the welding area and transmits it to the image recognition system installed in the control panel; S3. Reuse the shielding gas using the recycling assembly; S4. The image recognition system recognizes the received photo and determines the adjustment timing of the adjustment assembly and the clamping assembly; S5. After welding is completed, replace it with the next chassis.

[0013] Preferably, the range within which the clamping assembly changes the angle of the chassis is between 35° and 55°.

[0014] The present invention provides a laser welding device and method for a frequency converter sheet metal chassis. Compared with the prior art, it has the following beneficial effects: (1). In this laser welding device and method for a frequency converter sheet metal chassis, after heating the shielding gas and then blowing it onto the welding area, the cooling rate of the molten pool can be slowed down, allowing more time for the gas dissolved in the molten pool to escape. This helps reduce the formation of pores, can reduce the shrinkage stress caused by rapid cooling, thereby reducing the risk of hot cracks, and can also reduce the hardening phenomenon caused by uneven cooling, thus reducing the possibility of cold cracks. As a result, pores and cracks at the weld of the frequency converter sheet metal chassis can be avoided, improving the welding quality and thus enhancing the product quality.

[0015] (2). In this laser welding device and method for a frequency converter sheet metal chassis, by adjusting the angle of the workpiece, the shielding gas can more effectively cover the molten pool, ensuring that harmful gases (such as hydrogen, oxygen, etc.) can be discharged in a timely manner. It can prevent gas from remaining in the molten pool and forming pores after cooling, can make the shielding gas sprayed by the nozzle act more directly on the welding area, ensuring the best gas coverage, helping to better remove the harmful gases generated during the welding process, reducing the formation of defects such as pores, improving the welding quality and the finished product rate, reducing the rework situation caused by welding defects, thereby reducing the material cost and production time. At the same time, it also changes the welding angle, reducing the transverse shrinkage stress to a certain extent and improving the welding quality.

[0016] (3) The laser welding device and method for the sheet metal chassis of the frequency converter can slow down the cooling rate of the weld and its surrounding area by blowing protective gas for the second time to keep warm, thereby reducing the risk of cracks. The slower cooling rate helps to form a more uniform and stable metal microstructure, reducing brittle phases (such as martensite) generated by rapid cooling, thus improving the mechanical properties of the weld. Through the heat preservation measures, the weld area can be kept at a relatively high temperature for a slightly longer time, providing more opportunities for residual gas to escape, further reducing the occurrence probability of pores. The heat preservation process can help the weld area solidify more evenly, avoiding uneven weld surface or internal defects caused by rapid cooling, thereby obtaining better weld appearance and internal quality. By adjusting the flow direction of the heat preservation gas, it can ensure that the gas always accurately covers the weld area being cooled, providing the best protection effect. It can be used not only for straight welding but also for various welding scenarios such as circumferential welding and fillet welding, with wide applicability.

[0017] Other features and advantages of the present invention will be described in the following specification, and some of them will be obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in the written specification and the drawings. Brief Description of the Drawings

[0018] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is another perspective view of the overall structure of the present invention; Figure 3 is a sectional view of the machine tool of the present invention; Figure 4 is a structural diagram of the position of the gas storage cylinder of the present invention; Figure 5 is a structural diagram of the position of the power motor of the present invention; Figure 6 is a schematic diagram of the clamping plate of the present invention clamping the sheet metal chassis of the frequency converter; Figure 7 is a schematic diagram of the position of the clamping plate of the present invention; Figure 8 is a schematic diagram of the position of the guide rail of the present invention; Figure 9 is a schematic diagram of the position of the telescopic rod of the present invention; Figure 10 is an exploded view of the support rod of the present invention; Figure 11 is a schematic diagram of the position of the adjustment motor of the present invention; Figure 12 is a sectional view of the air guide block of the present invention; Figure 13This is another perspective cross-sectional structure diagram of the air guiding block of the present invention.

[0019] In the figure: 1, machine tool; 11, laser emitter; 12, displacement sensor; 13, camera; 14, gas storage tank; 15, heating box; 16, nozzle; 2, power motor; 21, rotating shaft; 22, winding wheel; 23, towing rope; 24, guide wheel 1; 241, guide wheel 2; 25, rotating motor; 26, rotating shaft; 27, sliding seat; 28, support plate; 29, clamping plate; 210, limiting block; 211, sliding rod; 212, upper magnet; 213, lower magnet; 214, guide rail; 3, support rod; 31, limiting rod; 32, fixing rod; 33, fixing block; 34, telescopic rod; 35, air guiding block; 351, air guiding groove; 36, air outlet sleeve; 37, fixed magnet; 38, moving magnet; 39, guide rod; 310, power rod; 4, adjusting motor; 41, adjusting shaft. Specific embodiments

[0020] 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] Please refer to Figures 1 to 13 , the present invention provides the following technical solutions: Embodiment 1: A laser welding device for a frequency converter sheet metal chassis, including a machine tool 1, a laser emitter 11 installed on the machine tool 1 through a movable guide rail for emitting laser for welding, a displacement sensor 12 for measuring the distance between the workpiece and the laser emitter 11, a camera 13 for photographing the weld seam, and a nozzle 16 for spraying a protective gas at the welding site. The nozzle 16 is connected to a heating box 15 through an air pipe. The heating box 15 is fixedly installed on the base of the laser emitter 11. The heating box 15 is used for heating the protective gas. A gas storage tank 14 for storing the protective gas is connected to the heating box 15. The gas storage tank 14 is detachably installed in the machine tool 1. The angle between the protective gas blown out by the nozzle 16 and the chassis is between 30° and 50°.

[0022] During use, place the inverter sheet metal chassis to be welded at the welding position. Subsequently, start the laser emitter 11, displacement sensor 12, camera 13, and pneumatic components through the control panel. Emit laser through the laser emitter 11 to perform welding operations on the inverter sheet metal chassis. Measure the distance between the inverter sheet metal chassis being welded and the laser emitter 11 through the displacement sensor 12 to adjust the flow rate of the shielding gas. At the same time, use the pneumatic components to transport the shielding gas stored in the gas storage tank 14 to the nozzle 16 through the gas pipeline and spray it out. Use the shielding gas sprayed out by the nozzle 16 to cover the surface of the workpiece at the welding position, thus effectively preventing oxidation at the welding position; Use the heating box 15 to temporarily store and heat the gas transported from the gas storage tank 14 to the nozzle 16. After the shielding gas is heated, it is transported to the nozzle 16 through the gas pipeline and sprayed out, so that the heated shielding gas can preheat and keep warm the welding position and a small area around the workpiece, thereby reducing the temperature difference between the workpiece surface and the surrounding environment and reducing the temperature gradient between the welding area and the unheated area. After welding is completed, take out the welded inverter sheet metal chassis and replace it with the next one.

[0023] Embodiment 2. The technical solution of this embodiment different from that of Embodiment 1 includes: a clamping assembly for changing the inclination angle of the chassis is provided in the machine tool 1. The clamping assembly includes: a power motor 2, a rotating shaft 21, a winding wheel 22, a traction rope 23, a first guide wheel 24, a second guide wheel 241, a rotating motor 25, a rotating shaft 26, a sliding seat 27, a support plate 28, a clamping plate 29, a limiting block 210, a sliding rod 211, an upper magnet 212, a lower magnet 213, and a guide rail 214; The side wall of the power motor 2 is fixedly installed in the machine tool 1 through a motor box. The power motor 2 is used to provide power for changing the inclination angle of the chassis. One end of the rotating shaft 21 is fixedly installed on the output end of the power motor 2 through a coupling. The side wall of the winding wheel 22 is fixedly installed at the other end of the rotating shaft 21. The number of traction ropes 23 is two. One ends of the two traction ropes 23 are fixedly installed on the winding wheel 22. The two traction ropes 23 are wound around the winding wheel 22 in opposite directions. The side wall of the first guide wheel 24 is slidably abutted against the traction rope 23 located below the winding wheel 22. The side wall of the second guide wheel 241 is also slidably abutted against the traction rope 23 located below the winding wheel 22. The moving directions of the traction ropes 23 are restricted by the first guide wheel 24 and the second guide wheel 241; The side wall of the rotating motor 25 is fixedly installed on the motor box. The top of the motor box is fixedly connected to the other end of the traction rope 23 located below the winding wheel 22, and the bottom of the motor box is fixedly connected to the other end of the traction rope 23 located above the winding wheel 22. One end of the rotating shaft 26 is fixedly installed on the output end of the rotating motor 25 through a coupling. The inner wall of the sliding seat 27 is movably sleeved outside the rotating shaft 26 through a bearing. One end of the rotating shaft 26 penetrates out of the sliding seat 27. The side wall of the support plate 28 is fixedly connected to the other end of the rotating shaft 26. The number of the clamping plates 29 is two groups, and the number of the inner clamping plates 29 in a single group is two. One end of one of the clamping plates 29 in both groups of clamping plates 29 is fixedly installed on the side wall of the support plate 28, and the other clamping plate 29 in both groups of clamping plates 29 is correspondingly slidably arranged outside the support plate 28. The chassis to be welded is fixed by the cooperation of the two groups of clamping plates 29; One end of the limit block 210 is fixed on the side wall of the clamping plate 29 fixedly connected to the support plate 28. The lower magnet 213 is located below the upper magnet 212 and is magnetically matched with the upper magnet 212. One end of the lower magnet 213 is also fixedly installed on the side wall of this clamping plate 29; One end of the sliding rod 211 is slidably penetrated in the limit block 210. The other end of the sliding rod 211 is fixedly installed on the side wall of the clamping plate 29 slidably arranged outside the support plate 28. The side wall of the upper magnet 212 is also fixedly installed on the side wall of this clamping plate 29; One end of the guide rail 214 is fixedly installed in the machine tool 1. The guide rail 214 is slidably matched with the sliding seat 27. The guide rail 214 is used to limit the moving direction of the sliding seat 27.

[0024] During use, when the nozzle 16 blows the shielding gas to the welding position, the camera 13 is used to take an image of the welded weld, and the image recognition system built into the control panel is used to recognize the picture taken by the camera 13, so as to judge the porosity and crack conditions at the weld; If there are fewer or no pores and cracks, the status quo is maintained; If the pores and cracks increase, the power motor 2 is controlled to start through the control panel; The power motor 2 drives the rotating shaft 21 to rotate. The rotating shaft 21 drives the winding wheel 22 to rotate, so that the winding wheel 22 drives the two traction ropes 23 to move, so that one end of one of the traction ropes 23 is wound onto the winding wheel 22, and the other end of the other traction rope 23 is released from the winding wheel 22. Initially, the number of the traction ropes 23 is two. One end of each of the two traction ropes 23 is fixed on the winding wheel 22 and is arranged with opposite winding directions. The other ends of the two traction ropes 23 are respectively fixed on the upper and lower outer walls of the rotating motor 25 box; When the towing rope 23 located above the winding wheel 22 winds onto the winding wheel 22, the towing rope 23 drives the movement of the rotating motor 25 box, the rotating motor 25 box drives the movement of the rotating shaft 26, the rotating shaft 26 drives the sliding seat 27 to move synchronously. The sliding seat 27 is in sliding fit with the guide rail 214, so that the sliding seat 27 slides along the guide rail 214 driven by the towing rope 23. The sliding seat 27 drives the support plate 28 to move, and the support plate 28 drives the clamping plate 29 to move, thereby driving the frequency converter sheet metal chassis clamped by the clamping plate 29 to move, changing the angle between the frequency converter sheet metal chassis and the protective gas blown out by the nozzle 16, thereby reducing the occurrence probability of pores and cracks; By correspondingly placing the two side plates of the frequency converter sheet metal chassis to be welded together between the clamping plates 29, controlling the change of the magnetism of the upper magnet 212 after being energized through the control panel, making the magnetism between the upper magnet 212 and the lower magnet 213 attract each other, using the suction force to drive the upper magnet 212 to move downward, so that the upper magnet 212 drives one of the clamping plates 29 in the same group to move. When the clamping plate 29 moves, it synchronously drives the sliding rod 211 to move. The sliding rod 211 is in sliding fit with the limit block 210, so that the sliding rod 211 can only move linearly along the limit block 210 under the action of an external force. By the mutual approach of the two clamping plates 29 in the same group, the clamping of the frequency converter sheet metal chassis is completed; Furthermore, the shape of the clamping plate 29 and the material of the contact surface can be adaptively changed according to different welded parts, thereby improving the clamping stability and firmness; After completing the welding of one side of the two side plates of the frequency converter sheet metal chassis, control the rotation motor 25 to start through the control panel. The rotation motor 25 drives the rotation shaft 26 to rotate, the rotation shaft 26 drives the support plate 28 to rotate, and the support plate 28 drives the two groups of clamping plates 29 and the corresponding limit blocks 210, sliding rods 211, upper magnets 212, and lower magnets 213 to rotate synchronously, so that the other side of the two side walls of the frequency converter sheet metal chassis is flipped to directly below the laser emitter 11, and then the welding operation can be continued. After the welding is completed, the next side plate of the frequency converter sheet metal chassis to be welded can be replaced.

[0025] Embodiment 3. The technical solution of this embodiment different from that of Embodiment 2 includes: a reflux assembly for reusing the protective gas and an adjustment assembly for changing the blowing angle of the airflow of the reflux assembly are provided in the machine tool 1. The reflux assembly includes: a wind guide block 35, an air outlet sleeve 36, and a wind guide groove 351; The air guiding block 35 is located at the upper side of the chassis. The bottom plane of the air guiding block 35 is parallel to the top plane of the chassis. The air guiding block 35 is used to collect the protective gas ejected by the nozzle 16. One end of the air outlet sleeve 36 is fixedly installed on the side wall of the air guiding block 35. The air outlet sleeve 36 is used to blow the collected protective gas to the chassis for the second time. The air outlet sleeve 36 is made of flexible material and can also be set to be similar to a corrugated pipe shape. An air guiding groove 351 is opened on the air guiding block 35. The air guiding groove 351 is used to drain the collected protective gas to the air outlet sleeve 36. The air guiding groove 351 is a spiral groove, which spirally rises from both ends of the arc-shaped air guiding block 35 to the central position, and the part near both ends is in an open state communicating with the outside, while the part near the central position is only communicated with the air outlet sleeve 36 and not with the outside.

[0026] The adjusting assembly includes: a support rod 3, a limit rod 31, a fixing rod 32, a fixing block 33, a telescopic rod 34, a fixed magnet 37, a moving magnet 38, a guiding rod 39, a power rod 310, an adjusting motor 4, and an adjusting shaft 41. One end of the support rod 3 is fixedly installed on the side wall of the sliding seat 27. One end of the limit rod 31 is slidably inserted into the long side of the L-shaped support rod 3. The support rod 3 is used to limit the moving direction of the limit rod 31. The top of the limit rod 31 is fixedly installed at the bottom of the fixing rod 32. The limit rod 31 is used to provide support for the fixing rod 32. One end of the fixing rod 32 is fixedly installed at the bottom of the air guiding block 35. The fixing rod 32 is used to provide support for the air guiding block 35. One end of the fixing block 33 is fixedly installed on the side wall of the fixing rod 32. One end of the telescopic rod 34 is fixedly installed on the side wall of the fixing block 33. The telescopic rod 34 is used to change the position of the fixing rod 32. One end of the fixed magnet 37 is fixedly installed on the side wall of the fixing rod 32. The moving magnet 38 is located above the fixed magnet 37. The moving magnet 38 and the fixed magnet 37 are magnetically matched. One end of the guiding rod 39 is fixedly installed on the side wall of the fixing rod 32. The other end of the guiding rod 39 is slidably inserted through the moving magnet 38. The guiding rod 39 is used to limit the moving direction of the moving magnet 38. One end of the power rod 310 is fixedly installed on the top of the moving magnet 38. The other end of the power rod 310 is fixedly installed on the top of the air outlet sleeve 36.

[0027] During use, in the process of the protective gas being ejected from the nozzle 16, after the protective gas contacts the surface of the frequency converter sheet metal chassis, it spreads out in a fan shape on the surface of the frequency converter sheet metal chassis. By arranging an air guiding block 35 outside the welding joint and opening a spiral rising air guiding groove 351 inside the air guiding block 35, the fan-shaped diffused protective gas can spiral up and converge from both sides to the central position along the air guiding groove in the air guiding block 35, and be blown out through the air outlet sleeve 36, flowing to the just-completed welding joint. The still warm but cooled protective gas compared with that ejected from the nozzle 16 flows to the welding joint for the second time to keep the welding joint warm, thereby delaying the cooling rate of the molten pool. As the welding position changes, the magnetic force of the fixed magnet 37 after being energized is controlled by the control panel to be mutually exclusive with the magnetic force of the moving magnet 38, so that the moving magnet 38 moves to the side away from the fixed magnet 37 under the action of the repulsive force. While the moving magnet 38 moves, it drives the power lever 310 to move, and the power lever 310 drives the air outlet sleeve 36 to move, so that the angle between the air outlet sleeve 36 and the inverter sheet metal chassis is changed, so that the protective gas of the secondary flow can closely follow the change of the welding position, ensuring the welding quality.

[0028] Further, when the workpiece being welded is relatively long, the telescopic rod 34 can be controlled to start through the control panel. The telescopic rod 34 drives the fixed block 33 to move, and the fixed block 33 drives the fixed rod 32 to move synchronously. The fixed rod 32 drives the air guide block 35 to move synchronously through the moving magnet 38, the guide rod 39, the power lever 310, and the adjusting shaft 41, so as to shorten the distance between the air blown out by the air outlet sleeve 36 and the welding position, so that when the protective gas of the secondary flow contacts the workpiece, the temperature will not drop too low, and the rate of the molten pool cooling can be well delayed.

[0029] In another embodiment different from the foregoing embodiment, the fixed rod 32 is no longer fixedly installed at the bottom of the air guide block 35. The adjusting assembly further includes: an adjusting motor 4 and an adjusting shaft 41. The output end of the adjusting motor 4 is fixedly connected to one end of the adjusting shaft 41 through a coupling. The adjusting motor 4 is used to provide power for changing the angle of the air guide block 35. One end of the adjusting shaft 41 is fixedly installed at the bottom of the air guide block 35. One end of the adjusting shaft 41 slides out of the mounting plate. The side wall of the adjusting shaft 41 is movably connected to the mounting plate through a bearing. One end of the mounting plate is fixedly installed on the side wall of the fixed rod 32; When the welding position is not linear, the adjusting motor 4 is controlled to start through the control panel. The adjusting motor 4 drives the adjusting shaft 41 to rotate, and the adjusting shaft 41 drives the air guide block 35 to rotate, so that the opening side of the air guide block 35 can deflect with the deflection of the welding position.

[0030] The embodiment of the present invention also provides an operation method applicable to a laser welding device for an inverter sheet metal chassis, including the following steps: S1. Fix the chassis to be welded by using the clamping assembly, control the laser emitter 11 to start welding by using the control panel, spray the protective gas to the welding position by using the nozzle 16, and determine the flow rate of the protective gas according to the distance measured by the displacement sensor 12; S2. Control the laser emitter 11 to start welding by using the control panel, and at the same time, the camera 13 takes a picture of the welding position and transmits it to the image recognition system carried in the control panel; S3. Reuse the protective gas by using the reflux assembly; S4. The image recognition system identifies the received photos and determines the adjustment timing of the adjustment component and the clamping component; S5. After welding is completed, replace with the next chassis.

[0031] Among them, the range of the chassis angle changed by the clamping component is between 35° and 55°.

[0032] In summary, the advantages of the present invention at least include: It can slow down the cooling rate of the molten pool, enabling the gas dissolved in the molten pool to have more time to escape, which helps to reduce the formation of pores.

[0033] It can reduce the shrinkage stress caused by rapid cooling, thereby reducing the risk of hot cracks.

[0034] It can slow down the cooling rate of the weld and its surrounding area, thus reducing the risk of cracks.

[0035] It can ensure that the gas always accurately covers the area of the weld being cooled, providing the best protection effect.

[0036] Meanwhile, the content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0037] It should be noted that in this article, relational terms such as first and second are only 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. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0038] Parallel: The parallel defined in this application is not limited to absolute parallel. This definition of parallel can be understood as substantially parallel, allowing for non-absolute parallel situations caused by factors such as assembly tolerances, design tolerances, and the influence of structural flatness, and allowing for errors within a small angle range. For example, within an assembly error range of 10 degrees or less, it can be understood as a parallel relationship.

[0039] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to 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 for a frequency converter sheet metal chassis, comprising a machine tool (1), a laser emitter (11) for emitting laser light for welding, a displacement sensor (12) for measuring the distance between a workpiece and the laser emitter (11), a camera (13) for photographing a weld, and a nozzle (16) for spraying a protective gas onto a weld, wherein: The machine tool (1) is provided with a clamping component for changing the tilt angle of the chassis, a reflux component for reusing the protective gas, and an adjusting component for changing the angle of the airflow ejected by the reflux component, wherein the reflux component comprises: An air guide block (35) is located on the upper side of the chassis and collects the protective gas sprayed by the nozzle (16); The air outlet sleeve (36) is fixed on the air guide block (35) and blows the collected protective gas to the chassis for a second time.

2. The inverter sheet metal chassis laser welding device according to claim 1 is characterized in that: The reflux assembly also includes: The air guide groove (351) is provided on the air guide block (35) and guides the collected protective gas toward the air outlet sleeve (36).

3. The inverter sheet metal chassis laser welding device according to claim 1, characterized in that: The regulating component includes: A fixing rod (32), one end of which is mounted on the bottom of the air guide block (35) to provide support for the air guide block (35); A limiting rod (31), the top of which is fixed to the bottom of the fixing rod (32) to provide support for the fixing rod (32); The support rod (3) is slidably sleeved on the limiting rod (31) to limit the moving direction of the limiting rod (31).

4. The inverter sheet metal chassis laser welding device according to claim 3 is characterized in that: The adjustment component also includes: A fixing block (33), one end of which is fixed to the side wall of the fixing rod (32); The telescopic rod (34) has one end fixed on the fixed block (33) to change the position of the fixed rod (32).

5. The inverter sheet metal chassis laser welding device according to claim 3 is characterized in that: The adjustment component also includes: A fixed magnet (37), one end of which is fixed to the fixed rod (32); A moving magnet (38) is located above the fixed magnet (37) and is magnetically matched with the fixed magnet (37); A guide rod (39), one end of which is fixed to the fixed rod (32), and the other end of which is slidably disposed on the moving magnet (38) to limit the moving direction of the moving magnet (38); A power rod (310), one end of which is fixed to the top of the moving magnet (38), and the other end of which is fixed to the top of the air outlet sleeve (36); An adjusting shaft (41), one end of which is fixed to the bottom of the air guide block (35); The output end of the regulating motor (4) is fixed to the other end of the regulating shaft (41) to provide power for changing the angle of the air guide block (35).

6. The inverter sheet metal chassis laser welding device according to claim 1, characterized in that: The clamping assembly comprises: A power motor (2) is installed in the machine tool (1) via a motor box to provide power for changing the tilt angle of the box; A rotating shaft (21), one end of which is fixed to the output end of the power motor (2); A winding wheel (22) having a side wall fixed to the other end of the rotating shaft (21); A traction rope (23), one end of which is fixed on the winding wheel (22); The side walls of the guide wheel 1 (24) and the guide wheel 2 (241) are both in contact with the traction rope (23), thereby limiting the moving direction of the traction rope (23).

7. The inverter sheet metal chassis laser welding device according to claim 6, characterized in that: The clamping assembly also includes: A rotating motor (25) connected to the other end of the traction rope (23) via a motor box; A rotating shaft (26), one end of which is fixed to the output end of the rotating motor (25); A sliding seat (27) is arranged outside the rotating shaft (26) through a bearing sleeve; A support plate (28) having a side wall fixed to the other end of the rotating shaft (26); A clamping plate (29) is mounted on the support plate (28) to fix the chassis to be welded; A limit block (210), one end of which is fixed on the side wall of the clamping plate (29); A sliding rod (211), one end of which is slidably inserted into the limiting block (210); An upper magnet (212) with side walls fixed on a clamping plate (29); The lower magnet (213) is located below the upper magnet (212) and is magnetically matched with the upper magnet (212); The guide rail (214) is fixed in the machine tool (1) and is slidably matched with the sliding seat (27) to limit the moving direction of the sliding seat (27).

8. The inverter sheet metal chassis laser welding device according to claim 1, characterized in that: The nozzle (16) is connected to a heating box (15) via a gas pipe. The heating box (15) is used to heat the protective gas. The heating box (15) is connected to a gas storage tank (14) for storing the protective gas. The gas storage tank (14) is installed in the machine tool (1).

9. An operating method for a frequency converter sheet metal chassis laser welding device applicable to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Fixing the chassis to be welded by using a clamping assembly, starting the welding by controlling the laser emitter (11) by using a control panel, spraying a protective gas to the welding position by using a nozzle (16), and determining the flow rate of the protective gas by the distance measured by the displacement sensor (12); S2, using the control panel to control the laser transmitter (11) to start welding, while the camera (13) takes a picture of the welding position and transmits it to the image recognition system installed in the control panel; S3, using the reflux component to recycle the protective gas; S4, the image recognition system recognizes the received photo and determines the adjustment timing of the adjustment component and the clamping component; S5. After welding is completed, replace the next chassis.

10. The operating method of the inverter sheet metal chassis laser welding device according to claim 9, characterized in that: The range of the chassis angle change by the clamping assembly is between 35° and 55°.

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