A laser welding device and method for a frequency converter sheet metal case

Abstract

The application discloses a frequency converter sheet metal case laser welding device and method, and relates to the technical field of laser welding. The frequency converter sheet metal case laser welding device and method comprises a machine tool, a laser emitter for emitting laser for welding, a displacement sensor for measuring the distance between a workpiece and the laser emitter, a camera for shooting a weld, and a nozzle for spraying protective gas to a welding position. The machine tool is internally provided with a clamping assembly for changing the inclination angle of the machine case, a backflow assembly for recycling the protective gas, and an adjusting assembly for changing the gas flow angle of the backflow assembly. The backflow assembly comprises an air guide block located above the side of the machine case and collecting the protective gas sprayed by the nozzle, and an air outlet sleeve fixed on the air guide block and recycling the collected protective gas to the machine case, so that the cooling speed of the molten pool is slowed down, the formation of pores is reduced, the shrinkage stress caused by rapid cooling is reduced, and the risk of thermal cracks is lowered.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, specifically to a laser welding device and method for a frequency converter sheet metal chassis. Background Technology

[0002] A frequency converter is a power control device that uses frequency conversion technology and microelectronics to control an AC motor by changing the frequency of the motor's power supply. The chassis is an indispensable component of the frequency converter, mainly protecting the electrical components inside the frequency converter. Existing frequency converter chassis are mainly sheet metal chassis. The frequency converter chassis is manufactured by bending a whole piece of metal sheet into the shape of the chassis and welding the joints of the metal sheets together. In the process of welding sheet metal chassis, laser welding equipment is mainly used. However, during welding, because the molten pool of laser welding is deep and narrow and the cooling rate is very fast, the gas in the liquid molten pool does not have enough time to escape, which makes the weld surface prone to porosity and cracks.

[0003] For example, the laser welding device for inverter sheet metal chassis disclosed in CN219402797U, although it uses an electric telescopic rod to drive a pressure plate and a U-shaped rod to fix the chassis body, does not use effective means to process the workpiece. As a result, the weld will still have pores and cracks due to the fast cooling rate of the molten pool. The laser composite welding emission device disclosed in CN107052580B, although it uses a semiconductor laser to preheat the workpiece to reduce the probability of pores and cracks, does not change the cooling rate of the weld, so pores and cracks are still relatively easy to occur.

[0004] Therefore, a laser welding device and method for inverter sheet metal chassis are proposed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a laser welding device and method for inverter sheet metal chassis, solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a laser welding device for a frequency converter sheet metal chassis, comprising a machine tool, a laser emitter for welding, a displacement sensor for measuring the distance between the workpiece and the laser emitter, a camera for capturing the weld seam, and a nozzle for spraying protective gas onto the weld. The machine tool is equipped with a clamping assembly for changing the chassis tilt angle, a recirculation assembly for reusing the protective gas, and an adjustment assembly for changing the angle of the airflow from the recirculation assembly. The recirculation assembly includes: a guide block located on the upper side of the chassis, which collects the protective gas sprayed from the nozzle; and an outlet sleeve fixed to the guide block, which blows the collected protective gas onto the chassis a second time.

[0007] Preferably, the recirculation assembly further includes: an air guide groove, which is formed on the air guide block to guide the collected protective gas to the air outlet sleeve.

[0008] Preferably, the adjusting assembly includes: a fixing rod, one end of which is installed at the bottom of the air guide block to provide support for the air guide block; a limiting rod, the top of which is fixed to the bottom of the fixing rod to provide support for the fixing rod; and a support rod, which is slidably sleeved on the limiting rod to limit the movement direction of the limiting rod.

[0009] Preferably, the adjustment assembly further includes: a fixing block, one end of which is fixed to the side wall of the fixing rod; and a telescopic rod, one end of which is fixed to the fixing block to change the position of the fixing rod.

[0010] Preferably, the adjustment assembly further includes: a fixed magnet, one end of which is fixed to a fixed rod; a movable magnet, located above the fixed magnet and magnetically engaged with it; a guide rod, one end of which is fixed to the fixed rod and the other end of which slides through the movable magnet to restrict the movement direction of the movable magnet; a power rod, one end of which is fixed to the top of the movable magnet and the other end of which is fixed to the top of the air outlet sleeve; an adjustment shaft, one end of which is fixed to the bottom of the air guide block; and an adjustment motor, the output end of which is fixed to the other end of the adjustment shaft to provide power for changing the angle of the air guide block.

[0011] Preferably, the clamping assembly includes: a power motor, which is installed inside the machine tool through a motor housing to provide power for changing the tilt angle of the machine housing; a rotating shaft, one end of which is fixed to the output end of the power motor; a winding wheel, the side wall of which is fixed to the other end of the rotating shaft; a traction rope, one end of which is fixed to the winding wheel; and guide wheels one and two, the side walls of which abut against the traction rope to restrict the movement direction of the traction rope.

[0012] Preferably, the clamping assembly further includes: a rotary motor connected to the other end of the traction rope via a motor housing; a rotary shaft, one end of which is fixed to the output end of the rotary motor; a sliding seat movably sleeved outside the rotary shaft via a bearing; a support plate, the side wall of which is fixed to the other end of the rotary shaft; a clamping plate mounted on the support plate to fix the machine housing to be welded; a limiting block, one end of which is fixed to the side wall of the clamping plate; a sliding rod, one end of which slides through the limiting block; an upper magnet, the side wall of which is fixed to the clamping plate; a lower magnet, located below the upper magnet and magnetically engaged with the upper magnet; and a guide rail fixed inside the machine tool and slidingly engaged with the sliding seat to restrict the movement direction of the sliding seat.

[0013] Preferably, the nozzle is connected to a heating box via a gas supply pipe. The heating box is used to heat the protective gas. A gas storage tank for storing the protective gas is connected to the heating box. The gas storage tank is installed inside the machine tool.

[0014] The present invention also provides an operating method for a laser welding device for a frequency converter sheet metal chassis, comprising the following steps:

[0015] S1. Fix the chassis to be welded using the clamping assembly, start the laser emitter using the control panel, spray protective gas into the welding area using the nozzle, and determine the flow rate of the protective gas by measuring the distance using the displacement sensor.

[0016] S2. Use the control panel to start the laser emitter to perform welding, while the camera takes a picture of the weld and transmits it to the image recognition system built into the control panel.

[0017] S3. Utilize the reflux assembly to reuse the protective gas;

[0018] S4. The image recognition system identifies the received photo and determines the timing of adjustment of the adjustment component and clamping component.

[0019] S5. After welding is completed, replace with the next chassis.

[0020] Preferably, the clamping assembly changes the chassis angle within a range of 35°-55°.

[0021] This invention provides a laser welding device and method for inverter sheet metal chassis. Compared with the prior art, it has the following advantages:

[0022] (1) The laser welding device and method for the inverter sheet metal chassis, by heating the protective gas and then blowing it to the welding point, can slow down the cooling rate of the molten pool, allowing the gas dissolved in the molten pool to escape for more time, which helps to reduce the formation of pores, reduce the shrinkage stress caused by rapid cooling, thereby reducing the risk of hot cracks, and also reduce the hardening phenomenon caused by uneven cooling, thereby reducing the possibility of cold cracks, thus avoiding the appearance of pores and cracks at the weld of the inverter sheet metal chassis, improving the welding quality, and thus improving the product quality.

[0023] (2) The laser welding device and method for the inverter sheet metal chassis can make the protective gas cover the molten pool more effectively by adjusting the angle of the workpiece, ensuring that harmful gases (such as hydrogen, oxygen, etc.) can be discharged in time, preventing the gas from stagnating in the molten pool and forming pores after cooling, and allowing the protective gas sprayed from the nozzle to act more directly on the welding area, ensuring optimal gas coverage, helping to better remove harmful gases generated during the welding process, reducing the formation of defects such as pores, improving welding quality and yield, reducing rework caused by welding defects, thereby reducing material costs and production time, and also changing the welding angle to a certain extent, reducing transverse shrinkage stress and improving welding quality.

[0024] (3) The laser welding device and method for the inverter sheet metal chassis can slow down the cooling rate of the weld and its surrounding area by blowing out protective gas twice, thereby reducing the risk of cracking. The slower cooling rate helps to form a more uniform and stable metal microstructure, reducing the brittle phase (such as martensite) generated by rapid cooling, thereby improving the mechanical properties of the weld. Through the heat preservation measures, the weld area can be kept at a higher temperature for a longer time, thus providing more opportunities for residual gas to escape, further reducing the probability of porosity. The heat preservation process can help the weld area solidify more uniformly, 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 be ensured that the gas always accurately covers the cooling weld area, providing the best protection effect. It can be used not only for straight welding, but also for circumferential welding, fillet weld and other welding scenarios, and has wide applicability.

[0025] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is another perspective view of the overall structure of the present invention;

[0028] Figure 3 This is a cross-sectional view of the machine tool of the present invention;

[0029] Figure 4 This is a structural diagram showing the location of the gas storage cylinder of the present invention;

[0030] Figure 5 This is a structural diagram of the position of the power motor of the present invention;

[0031] Figure 6 This is a schematic diagram of the clamping plate holding the sheet metal chassis of the frequency converter according to the present invention;

[0032] Figure 7 This is a schematic diagram showing the position of the clamping plate of the present invention;

[0033] Figure 8 This is a schematic diagram showing the position of the guide rail of the present invention;

[0034] Figure 9 This is a schematic diagram showing the position of the telescopic rod of the present invention;

[0035] Figure 10This is a schematic diagram showing the exploded state of the support rod of the present invention;

[0036] Figure 11 This is a schematic diagram illustrating the position adjustment of the motor according to the present invention;

[0037] Figure 12 This is a cross-sectional view of the air guide block of the present invention;

[0038] Figure 13 This is a cross-sectional view of the air guide block of the present invention from another perspective.

[0039] In the diagram: 1. Machine tool; 11. Laser emitter; 12. Displacement sensor; 13. Camera; 14. Air tank; 15. Heating box; 16. Nozzle; 2. Power motor; 21. Rotating shaft; 22. Winding wheel; 23. Traction rope; 24. Guide wheel one; 241. Guide wheel two; 25. Rotary 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 guide block; 351. Air guide groove; 36. Air outlet sleeve; 37. Fixed magnet; 38. Moving magnet; 39. Guide rod; 310. Power rod; 4. Adjusting motor; 41. Adjusting shaft. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Please see Figures 1 to 13 The present invention provides the following technical solutions:

[0042] Example 1: A laser welding device for a frequency converter sheet metal chassis includes a machine tool 1, a laser emitter 11 mounted on the machine tool 1 via 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 capturing the weld seam, and a nozzle 16 for spraying protective gas onto the weld. The nozzle 16 is connected to a heating box 15 via a gas supply pipe. The heating box 15 is fixedly mounted on the base of the laser emitter 11 and is used to heat 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 inside the machine tool 1. The angle between the protective gas blown out by the nozzle 16 and the chassis is between 30° and 50°.

[0043] In use, the inverter sheet metal chassis to be welded is placed at the welding position, and then the laser emitter 11, displacement sensor 12, camera 13 and pneumatic components are activated through the control panel. The laser emitter 11 emits a laser to perform welding operations on the inverter sheet metal chassis. The displacement sensor 12 measures the distance between the inverter sheet metal chassis being welded and the laser emitter 11 to adjust the flow rate of the protective gas. At the same time, the protective gas stored in the gas tank 14 is delivered to the nozzle 16 through the gas pipe using the pneumatic components. The protective gas sprayed from the nozzle 16 covers the surface of the workpiece at the welding point, thereby effectively preventing oxidation at the welding point.

[0044] The gas supplied from the gas tank 14 to the nozzle 16 is temporarily stored and heated by the heating box 15. After the protective gas is heated, it is then supplied to the nozzle 16 through the gas supply pipe and sprayed out. The heated protective gas can preheat and keep the welded area and surrounding area of ​​the workpiece warm, thereby reducing the temperature difference between the workpiece surface and the surrounding environment and reducing the temperature gradient between the welded area and the unheated area. After the welding is completed, the welded inverter sheet metal chassis can be removed and replaced with the next one.

[0045] Example 2, the technical solution of which differs from Example 1 includes: the machine tool 1 is provided with a clamping assembly for changing the tilt angle of the machine box, the clamping assembly includes: a power motor 2, a rotating shaft 21, a winding wheel 22, a traction rope 23, a guide wheel 1 24, a guide wheel 241, a rotary 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;

[0046] The side wall of the power motor 2 is fixedly installed inside the machine tool 1 through the motor box. The power motor 2 is used to provide power for changing the tilt angle of the machine box. One end of the rotating shaft 21 is fixedly installed on the output end of the power motor 2 through the coupling. The side wall of the winding wheel 22 is fixedly installed on the other end of the rotating shaft 21. There are two traction ropes 23. One end of each of the two traction ropes 23 is 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 slides against the traction rope 23 located below the winding wheel 22. The side wall of the second guide wheel 241 also slides against the traction rope 23 located below the winding wheel 22. The movement direction of the traction rope 23 is restricted by the first guide wheel 24 and the second guide wheel 241.

[0047] The side wall of the rotary motor 25 is fixedly mounted on the motor housing. The top of the motor housing is fixedly connected to the other end of the traction rope 23 located below the winding wheel 22, and the bottom of the motor housing 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 mounted on the output end of the rotary motor 25 through a coupling. The inner wall of the sliding seat 27 is movably sleeved on the outside of the rotating shaft 26 through a bearing. One end of the rotating shaft 26 passes through the sliding seat 27. The side wall of the support plate 28 is fixedly connected to the other end of the rotating shaft 26. There are two sets of clamping plates 29. There are two clamping plates 29 in each set. One end of the clamping plate 29 in each set is fixedly mounted on the side wall of the support plate 28. The other clamping plate 29 in each set is slidably set outside the support plate 28. The machine housing to be welded is fixed by the cooperation of the two sets of clamping plates 29.

[0048] One end of the limiting block 210 is fixed to the side wall of the clamp 29 which is fixedly connected to the support plate 28. The lower magnet 213 is located below the upper magnet 212 and is magnetically engaged with the upper magnet 212. One end of the lower magnet 213 is also fixedly installed on the side wall of this clamp 29.

[0049] One end of the sliding rod 211 slides through the limiting block 210, and the other end of the sliding rod 211 is fixedly installed on the side wall of the clamp 29 which is slidably set outside the support plate 28. The side wall of the upper magnet 212 is also fixedly installed on the side wall of this clamp 29.

[0050] One end of the guide rail 214 is fixedly installed inside the machine tool 1. The guide rail 214 and the slide seat 27 are in sliding fit. The guide rail 214 is used to limit the movement direction of the slide seat 27.

[0051] When in use, when the nozzle 16 blows the protective gas to the welding area, the camera 13 takes an image of the weld after welding, and the image recognition system built into the control panel recognizes the image taken by the camera 13 to determine the porosity and cracks at the weld.

[0052] If there are few or no pores or cracks, maintain the status quo;

[0053] If the number of pores and cracks increases, the power motor 2 will be started via the control panel.

[0054] The power motor 2 drives the rotating shaft 21 to rotate, and 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 traction rope 23 is wound onto the winding wheel 22, and one end of the other traction rope 23 is released from the winding wheel 22. Initially, there are two traction ropes 23. One end of each traction rope 23 is fixed on the winding wheel 22 and the winding direction is opposite. 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.

[0055] When the traction rope 23 located above the winding wheel 22 is wound onto the winding wheel 22, the traction rope 23 drives the rotary motor 25 to move, the rotary motor 25 drives the rotary shaft 26 to move, the rotary shaft 26 drives the sliding seat 27 to move synchronously, the sliding seat 27 slides with the guide rail 214, so that the sliding seat 27 slides along the guide rail 214 under the drive of the traction rope 23, the sliding seat 27 drives the support plate 28 to move, the support plate 28 drives the clamping plate 29 to move, thereby driving the inverter sheet metal chassis held by the clamping plate 29 to move, so that the angle between the inverter sheet metal chassis and the protective gas blown out by the nozzle 16 changes, thereby reducing the probability of the occurrence of air holes and cracks;

[0056] By placing the two side plates of the inverter sheet metal chassis to be welded together between the clamping plates 29, the magnetic properties of the upper magnet 212 are changed after being energized by the control panel, so that the upper magnet 212 and the lower magnet 213 are magnetically attracted to each other. The attraction force drives the upper magnet 212 to move downward, which in turn drives one of the clamping plates 29 in the same group to move. When the clamping plate 29 moves, it drives the sliding rod 211 to move synchronously. The sliding rod 211 slides with the limit block 210, so that the sliding rod 211 can move linearly only along the limit block 210 under the action of external force. By bringing the two clamping plates 29 in the same group closer to each other, the clamping of the inverter sheet metal chassis is completed.

[0057] Furthermore, the shape of the clamping plate 29 and the material of the contact surface can be adapted to different welded parts, thereby improving clamping stability and firmness.

[0058] After welding one side of the two side panels of the inverter sheet metal chassis is completed, the rotary motor 25 is started by controlling the control panel. The rotary motor 25 drives the rotary shaft 26 to rotate, and the rotary shaft 26 drives the support plate 28 to rotate. The support plate 28 drives the two sets 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 inverter sheet metal chassis is flipped to the direct under of the laser emitter 11, so that the welding operation can continue. After the welding is completed, the next inverter sheet metal chassis side panel to be welded can be replaced.

[0059] Example 3, the technical solution of this example that differs from Example 2 includes: the machine tool 1 is provided with a return component for secondary use of protective gas and an adjustment component for changing the angle of the airflow ejected from the return component. The return component includes: air guide block 35, air outlet sleeve 36, and air guide groove 351.

[0060] The air guide block 35 is located on the upper side of the chassis. The bottom plane of the air guide block 35 is parallel to the top plane of the chassis. The air guide block 35 is used to collect the protective gas sprayed from the nozzle 16. One end of the air outlet sleeve 36 is fixedly installed on the side wall of the air guide block 35. The air outlet sleeve 36 is used to blow the collected protective gas onto the chassis again. The air outlet sleeve 36 is made of flexible material and can also be set to be similar to a corrugated pipe. The air guide groove 351 is opened on the air guide block 35. The air guide groove 351 is used to guide the collected protective gas to the air outlet sleeve 36. The air guide groove 351 is a spiral groove that spirals upward from both ends of the arc-shaped air guide block 35 to the center position. Near the two ends, it is an opening that communicates with the outside. Near the center position, it only communicates with the air outlet sleeve 36 and does not communicate with the outside.

[0061] The adjustment 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 guide rod 39, a power rod 310, an adjustment motor 4, and an adjustment shaft 41.

[0062] One end of the support rod 3 is fixedly installed on the side wall of the sliding seat 27. One end of the limiting rod 31 slides through the long side of the L-shaped support rod 3. The support rod 3 is used to limit the movement direction of the limiting rod 31. The top of the limiting rod 31 is fixedly installed on the bottom of the fixed rod 32. The limiting rod 31 is used to provide support for the fixed rod 32. One end of the fixed rod 32 is fixedly installed on the bottom of the air guide block 35. The fixed rod 32 is used to provide support for the air guide block 35. One end of the fixed block 33 is fixedly installed on the side wall of the fixed rod 32. One end of the telescopic rod 34 is fixedly installed on the side wall of the fixed block 33. On the wall, the telescopic rod 34 is used to change the position of the fixed rod 32. One end of the fixed magnet 37 is fixedly installed on the side wall of the fixed rod 32. The movable magnet 38 is located above the fixed magnet 37. The movable magnet 38 and the fixed magnet 37 are magnetically engaged. One end of the guide rod 39 is fixedly installed on the side wall of the fixed rod 32. The other end of the guide rod 39 slides through the movable magnet 38. The guide rod 39 is used to limit the movement direction of the movable magnet 38. One end of the power rod 310 is fixedly installed on the top of the movable magnet 38. The other end of the power rod 310 is fixedly installed on the top of the air outlet sleeve 36.

[0063] During use, as the protective gas is ejected from the nozzle 16, it comes into contact with the surface of the inverter sheet metal chassis and spreads out in a fan shape on the surface of the inverter sheet metal chassis. By setting an air guide block 35 outside the welding point and opening a spirally rising air guide groove 351 inside the air guide block 35, the fan-shaped diffused protective gas can spirally rise and converge from both sides to the center along the air guide groove inside the air guide block 35, and be blown out through the air outlet sleeve 36. It flows to the welding point that has just been welded and uses the protective gas, which still has a certain temperature but has cooled down compared to the nozzle 16, to flow to the welding point again to keep the welding point warm, thereby slowing down the rate of cooling of the molten pool.

[0064] As the welding position changes, the magnetic properties of the fixed magnet 37 after being energized, controlled by the control panel, repel the magnetic properties of the moving magnet 38. This causes the moving magnet 38 to move away from the fixed magnet 37 under the action of the repulsive force. As the moving magnet 38 moves, it drives the power rod 310 to move, which in turn drives the air outlet sleeve 36 to move. This changes the angle between the air outlet sleeve 36 and the inverter sheet metal chassis, allowing the secondary flow of protective gas to change in accordance with the welding position, thus ensuring welding quality.

[0065] Furthermore, when the workpiece being welded is long, the telescopic rod 34 can be activated via 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 via the moving magnet 38, guide rod 39, power rod 310, and adjusting shaft 41, thereby shortening the distance between the air blown out of the air outlet sleeve 36 and the welding point. This ensures that the temperature of the secondary flow of protective gas does not drop too low when it comes into contact with the workpiece, effectively slowing down the rate of cooling of the molten pool.

[0066] In another embodiment different from the aforementioned embodiments, the fixing rod 32 is no longer fixedly installed at the bottom of the air guide block 35, and the adjustment assembly also includes: an adjustment motor 4 and an adjustment shaft 41. The output end of the adjustment motor 4 is fixedly connected to one end of the adjustment shaft 41 through a coupling. The adjustment motor 4 is used to provide power for changing the angle of the air guide block 35. One end of the adjustment shaft 41 is fixedly installed at the bottom of the air guide block 35. One end of the adjustment shaft 41 slides out of the mounting plate. The side wall of the adjustment 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 fixing rod 32.

[0067] When the welding position is not linear, the control panel controls the start of the adjustment motor 4, which drives the adjustment shaft 41 to rotate. The adjustment 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.

[0068] This invention also provides an operating method for a laser welding device for a frequency converter sheet metal chassis, comprising the following steps:

[0069] S1. Fix the chassis to be welded using the clamping assembly, start the laser emitter 11 using the control panel, spray protective gas onto the welding area using the nozzle 16, and determine the flow rate of the protective gas by measuring the distance using the displacement sensor 12.

[0070] S2. The laser emitter 11 is started to weld using the control panel, and at the same time the camera 13 takes a picture of the weld and transmits it to the image recognition system built into the control panel.

[0071] S3. Utilize the reflux assembly to reuse the protective gas;

[0072] S4. The image recognition system identifies the received photo and determines the timing of adjustment of the adjustment component and clamping component.

[0073] S5. After welding is completed, replace with the next chassis.

[0074] The clamping components can change the chassis angle between 35° and 55°.

[0075] In summary, the advantages of the present invention include at least the following:

[0076] It can slow down the cooling rate of the molten pool, giving the dissolved gases more time to escape, which helps reduce porosity formation.

[0077] It can reduce shrinkage stress caused by rapid cooling, thereby reducing the risk of hot cracking.

[0078] It can slow down the cooling rate of the weld and its surrounding area, thereby reducing the risk of cracking.

[0079] This ensures that the gas always accurately covers the cooling weld area, providing optimal protection.

[0080] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0081] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0082] Parallelism: The parallelism defined in this application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism. It allows for situations where the parallelism is not absolute due to factors such as assembly tolerance, design tolerance, and structural flatness. It also allows for errors within a small angular range, such as within 10 degrees of assembly error. These can all be considered as parallel relationships.

[0083] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which 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 the workpiece and the laser emitter (11), a camera (13) for capturing the weld seam, and a nozzle (16) for spraying protective gas onto the weld, characterized in that, The machine tool (1) is equipped with a clamping assembly for changing the tilt angle of the machine casing, a recirculation assembly for reusing protective gas, and an adjustment assembly for changing the angle of the airflow ejected from the recirculation assembly. The recirculation assembly includes: The air guide block (35) is located on the upper side of the chassis and collects the protective gas sprayed from the nozzle (16); The air outlet sleeve (36) is fixed on the air guide block (35) to blow the collected protective gas onto the chassis a second time; The adjustment component includes: A fixing rod (32) is installed at one end at the bottom of the air guide block (35) to provide support for the air guide block (35); The limiting rod (31) is fixed at 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 restrict the movement direction of the limiting rod (31); The fixing block (33) is fixed at one end to the side wall of the fixing rod (32); The telescopic rod (34) is fixed at one end to the fixed block (33) to change the position of the fixed rod (32); A fixed magnet (37) is fixed at one end to a fixed rod (32); The movable magnet (38) is located above the fixed magnet (37) and is magnetically coupled with the fixed magnet (37); The guide rod (39) is fixed at one end to the fixed rod (32) and slides through the moving magnet (38) at the other end, thus restricting the movement direction of the moving magnet (38). The power rod (310) is fixed at one end to the top of the moving magnet (38) and at the other end to the top of the air outlet sleeve (36); The adjusting shaft (41) is fixed at one end to the bottom of the air guide block (35); The output end of the motor (4) is fixed to the other end of the adjusting shaft (41), providing power to change the angle of the air guide block (35).

2. The laser welding device for a frequency converter sheet metal chassis according to claim 1, characterized in that, The reflow assembly also includes: The air guide duct (351) is opened on the air guide block (35) to guide the collected protective gas to the air outlet sleeve (36).

3. The laser welding device for a frequency converter sheet metal chassis according to claim 1, characterized in that, The clamping assembly includes: The power motor (2) is installed inside the machine tool (1) through the motor box, and provides power to change the tilt angle of the machine box; The rotating shaft (21) is fixed at one end to the output end of the power motor (2); The winding wheel (22) has its sidewall fixed to the other end of the rotating shaft (21); One end of the traction rope (23) is fixed to the winding wheel (22); Guide wheel one (24) and guide wheel two (241) both have their side walls abutting against the traction rope (23), restricting the direction of movement of the traction rope (23).

4. The laser welding device for a frequency converter sheet metal chassis according to claim 3, characterized in that, The clamping assembly also includes: A rotary motor (25) is connected to the other end of a traction rope (23) via a motor housing; The rotating shaft (26) is fixed at one end to the output end of the rotary motor (25); The sliding seat (27) is movably sleeved outside the rotating shaft (26) via a bearing; The support plate (28) has its side wall fixed to the other end of the rotating shaft (26); The clamping plate (29) is installed on the support plate (28) to fix the chassis to be welded; The limiting block (210) is fixed at one end to the side wall of the clamp (29); The sliding rod (211) has one end slidably inserted into the limiting block (210); The upper magnet (212) is fixed to the side wall of the clamp (29); The lower magnet (213) is located below the upper magnet (212) and is magnetically coupled with the upper magnet (212); The guide rail (214) is fixed inside the machine tool (1) and slides with the slide seat (27) to restrict the movement direction of the slide seat (27).

5. The laser welding device for a frequency converter sheet metal chassis according to claim 1, characterized in that, The nozzle (16) is connected to a heating box (15) via a gas supply pipe. The heating box (15) is used to heat 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 installed inside the machine tool (1).

6. An operating method applicable to the laser welding device for a frequency converter sheet metal chassis as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Fix the chassis to be welded using the clamping assembly, start the laser emitter (11) using the control panel, spray protective gas onto the welding area using the nozzle (16), and determine the flow rate of the protective gas by measuring the distance using the displacement sensor (12). S2. Use the control panel to control the laser emitter (11) to start welding, and at the same time the camera (13) takes a picture of the weld and transmits it to the image recognition system in the control panel; S3. Utilize the reflux assembly to reuse the protective gas; S4. The image recognition system identifies the received photo and determines the timing of adjustment of the adjustment component and clamping component. S5. After welding is completed, replace with the next chassis.

7. The operation method of the laser welding device for a frequency converter sheet metal chassis according to claim 6, characterized in that: The clamping assembly can change the angle of the chassis within the range of 35°-55°.

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