A laser welding apparatus and method for tube plugging of a steam generator

Abstract

The present application belongs to the technical field of welding device, especially relates to a laser welding device and method for steam generator pipe blockage, the welding device comprises a welding device and a steam generator, the welding device is applied to the welding of the steam generator, and the welding device comprises a laser welding gun, a fixing ring, a fixing rod, a protection plate, a connecting rod, a preheating plate, a telescopic rod and a close-fitting assembly. Through the preheating plate, in the welding process, the telescopic rod can be close to the edge position of the runner plate under the action of the reset spring, so that along with the welding operation, the laser welding gun can be guided by the telescopic rod and welded along the edge of the runner plate, and in the welding process, the preheating plate can be preheated under the driving of the laser welding gun, so that the temperature difference during welding can be reduced, and the thermal stress generated during welding can be reduced, and the welding quality is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of welding equipment technology, and particularly relates to a laser welding device and method for plugging pipes in steam generators. Background Technology

[0002] As people's living standards continue to improve, steam products are increasingly used in daily life, such as steam irons and steam cleaners. Currently, the mainstream product on the market is the electric heating element instant steam module. The biggest drawbacks of this type of product are low heating efficiency, large power attenuation, short lifespan, and relatively bulky size.

[0003] To address this issue, an instantaneous thick-film steam generator was developed. Utilizing the high thermal efficiency of the thick-film heating plate, water can vaporize more quickly and is more energy-efficient. However, during the production of the instantaneous thick-film steam generator, the flow channel plate needs to be welded to the thick-film heating plate. Because the thick-film heating plate is thicker than the flow channel plate, a temperature difference exists between the two plates during laser welding. This results in significant thermal stress at the weld joint after welding, potentially causing deformation or even cracking during subsequent use, leading to steam leakage. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a laser welding apparatus and method for plugging pipes in steam generators, thereby resolving the issues raised in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A laser welding device for plugging a steam generator includes a welding device and a steam generator. The welding device is used for welding the steam generator and includes a laser welding gun, a fixing ring, a fixing rod, a protective plate, a connecting rod, a preheating plate, a telescopic rod, and a bonding assembly.

[0007] The fixing ring is detachably sleeved on the front end of the laser welding gun. The protective plate is located at the bottom of the fixing ring, and the fixing rod is fixedly connected between the fixing ring and the protective plate. The connecting rod is fixedly connected to the bottom of the protective plate. The preheating plate is located at the bottom of the connecting rod. The telescopic rod is inserted through the preheating plate, and the top end of the telescopic rod is hinged to the bottom end of the connecting rod. The fastening assembly is connected between the top end of the telescopic rod and the bottom end of the connecting rod. An electric heating wire is provided inside the preheating plate.

[0008] Furthermore, the steam generator includes a flow channel plate, a pressure plate, an inlet pipe, an outlet pipe, a stud, a thick film heating plate, a positive power supply, a negative power supply, an inlet NTC, an outlet NTC, a nut, a mica gasket, a sleeve, insulation cotton, and a temperature controller.

[0009] The flow channel plate is fixed to the back of the thick film heating plate by laser welding, and the flow channel on the flow channel plate is S-shaped. Inlet pipe and outlet pipe are welded to both ends of the flow channel, and both the inlet pipe and outlet pipe are connected to the flow channel. The side of the thick film heating plate that is separated from the flow channel plate is covered with heat insulation cotton with adhesive backing. Pressure plates are set on the side of the two heat insulation cotton that are separated. There are multiple studs, nuts, mica washers and sleeves. Multiple studs are vertically inserted into the edges of the two pressure plates. Multiple nuts, multiple sleeves and multiple mica washers are all fitted onto multiple studs. A thermostat for monitoring the temperature of the thick film heating plate is installed at the bottom of the pressure plate. Inlet NTC and outlet NTC are respectively provided at both ends of the flow channel. The thick film heating plate is connected to the positive and negative terminals of the power supply.

[0010] Furthermore, the fastening assembly includes a fixed block, a fixed screw, a fixed shaft, a movable block, a return spring, a limiting block, and a stop block. The fixed block is rotatably sleeved on the bottom end of the connecting rod. The fixed screw is threaded into the rear side of the fixed block, and one end of the fixed screw inserted into the inner side of the fixed block can contact the surface of the connecting rod. The fixed shaft is horizontally and vertically fixedly connected to the front side of the fixed block. The movable block and the return spring are detachably sleeved on the fixed shaft, and the movable block is located in front of the return spring. The two ends of the return spring are respectively kept in close contact with the movable block and the fixed block. The bottom end of the movable block is hinged to the top end of the telescopic rod. The telescopic rod can only deflect along the plane where the laser welding gun is located, and the angle of deflection of the telescopic rod is less than five degrees. There are two stop blocks, which are fixedly connected to the front and rear sides of the bottom end of the connecting rod, respectively. The limiting block is fixedly connected to the side of the fixed block near the protective plate, and the limiting block can contact both stop blocks.

[0011] Furthermore, a clearance assembly is provided at the connection between the telescopic rod and the preheating plate. The clearance assembly includes a counterweight, a rectangular protrusion, and a slider. A strip-shaped through hole is provided through the preheating plate, and the telescopic rod is inserted through the through hole. The length direction of the through hole is parallel to the length direction of the fixed shaft. The rectangular protrusion is fixedly connected to the top edge of the through hole. The slider is fixedly sleeved on the telescopic rod and slidably installed on the inner side of the rectangular protrusion. The counterweight is slidably sleeved on the telescopic rod. The front and rear sides of the counterweight are both designed with bevels. The length of the top surface of the counterweight is greater than the length of its bottom surface, and the length of the top surface of the counterweight is greater than the length of the rectangular protrusion.

[0012] Furthermore, notches are provided at the top positions of the front and rear sides of the rectangular protrusion, and rollers are rotatably installed between the inner walls of the two sides of the notches, and the rollers can contact the inclined surface of the counterweight.

[0013] Furthermore, the diameter of the telescopic rod at the bottom of the preheating plate is smaller than its diameter at the top of the preheating plate, and a ball bearing is installed at the bottom end of the telescopic rod.

[0014] Furthermore, a guide tube is provided between the laser welding gun and the protective plate. The guide tube is installed at the bottom of the laser welding gun, and welding wire for welding is inserted in the guide tube.

[0015] Furthermore, the weight of the counterweight is greater than the weight of the preheating plate, and the counterweight is always able to keep one of its inclined surfaces in contact with the roller on the corresponding side.

[0016] The present invention also provides a method for using a laser welding device for plugging pipes in a steam generator, the method comprising the following steps:

[0017] Step 1: First, clamp and fix the thick film heating plate on the welding platform, with the welding surface of the thick film heating plate facing upwards. Then, place the flow channel plate to be welded on top of the thick film heating plate and adjust its position.

[0018] Step 2: Hold the laser welding gun in one hand and press down on the flow channel plate with the other hand. Then, spot weld the edge of the flow channel plate to simply fix the flow channel plate to the thick film heating plate.

[0019] Step 3: After spot welding is completed, place the laser welding gun on top of the flow channel plate and adjust the position of the laser welding gun so that the bottom end of the telescopic rod can be kept close to the edge of the flow channel plate, while the preheating plate is suspended above the edge of the flow channel plate.

[0020] Step 4: Use a laser welding gun to weld along the edge of the flow channel plate step by step. During the welding process, the preheating plate can be activated to preheat the area of ​​the flow channel plate to be welded, thereby reducing the welding temperature difference and reducing the generation of thermal stress.

[0021] The technical effects and advantages of this invention are as follows:

[0022] 1. The present invention incorporates a preheating plate. During the welding process, the telescopic rod can be pressed tightly against the edge of the flow channel plate under the action of the return spring. As the welding operation proceeds, the laser welding gun can perform welding operations along the edge of the flow channel plate under the guidance of the telescopic rod. Furthermore, during the welding process, the preheating plate can preheat the position to be welded under the action of the laser welding gun, thereby reducing the temperature difference during welding, thus reducing the thermal stress generated during welding and ensuring welding quality.

[0023] 2. The steam generator in this invention utilizes an S-shaped flow channel on the flow plate to allow liquid to flow along the flow path, preventing water from reaching the steam outlet prematurely. By attaching insulation cotton to both sides of the thick-film heating plate, heat loss from the steam is effectively reduced. The design of the upper and lower pressure plates effectively isolates the thick-film heating plate, preventing burns. Simultaneously, the two pressure plates connected by studs prevent the insulation cotton's adhesive from failing due to heat and detaching. During use, the temperature controller regulates the surface temperature of the thick-film heating plate and the steam temperature. The NTC inlet and outlet water outlets of the flow channel prevent dry burning when there is no water, avoiding damage to the steam generator.

[0024] 3. By incorporating an obstacle avoidance component, during the welding process, when the preheating plate comes into contact with the protrusions, inlet pipe, or outlet pipe on the flow channel plate, the preheating plate can move away from the flow channel plate under the obstruction and push of the protrusions, inlet pipe, or outlet pipe, thereby ensuring that the preheating plate is not blocked by the protrusions, inlet pipe, or outlet pipe on the flow channel plate and guaranteeing the smooth progress of welding. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the first overall structure of the steam generator in this invention;

[0026] Figure 2 This is a schematic diagram of the second overall structure of the steam generator in this invention;

[0027] Figure 3 This is a three-dimensional schematic diagram of the thick film heating plate, flow channel plate, water inlet pipe and water outlet pipe in this invention;

[0028] Figure 4 This is a three-dimensional schematic diagram of the laser welding gun, protective plate, preheating plate, and telescopic rod in this invention;

[0029] Figure 5 This is a three-dimensional schematic diagram of the protective plate, connecting rod, fixing block, preheating plate and counterweight block in this invention;

[0030] Figure 6 This is a three-dimensional schematic diagram of the preheating plate, telescopic rod, counterweight, fixed shaft, and fixed block in this invention.

[0031] Figure 7 This is a three-dimensional schematic diagram of the preheating plate, telescopic rod, fixed shaft, return spring, and fixing block in this invention.

[0032] Figure 8 This is a three-dimensional schematic diagram of the preheating plate, rectangular protrusion, and roller shaft in this invention;

[0033] Figure 9This is a three-dimensional schematic diagram of the telescopic rod, movable block, counterweight block, slider, and ball bearings in this invention.

[0034] In the diagram: 1. Laser welding gun; 2. Fixing ring; 3. Fixing rod; 4. Protective plate; 5. Connecting rod; 6. Preheating plate; 7. Telescopic rod; 8. Flow channel plate; 9. Pressure plate; 10. Inlet pipe; 11. Outlet pipe; 12. Stud; 13. Thick film heating plate; 14. Power supply positive terminal; 15. Power supply negative terminal; 16. Inlet NTC; 17. Outlet NTC; 18. Nut; 19. Mica gasket; 20. Sleeve; 21. Insulation cotton; 22. Temperature controller; 23. Fixing block; 24. Fixing screw; 25. Fixing shaft; 26. Movable block; 27. Return spring; 28. Limiting block; 29. ​​Stop block; 30. Counterweight block; 31. Rectangular protrusion; 32. Slider; 33. Roller shaft; 34. Ball bearing; 35. Guide tube. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0036] This invention provides, for example Figures 1 to 9 The laser welding device for plugging a steam generator shown includes a welding device and a steam generator. The welding device is used for welding the steam generator. The welding device includes a laser welding gun 1, a fixing ring 2, a fixing rod 3, a protective plate 4, a connecting rod 5, a preheating plate 6, a telescopic rod 7, and a fastening assembly.

[0037] The fixing ring 2 is detachably sleeved on the front end of the laser welding gun 1. The protective plate 4 is located at the bottom of the fixing ring 2, and the fixing rod 3 is fixedly connected between the fixing ring 2 and the protective plate 4. The connecting rod 5 is fixedly connected to the bottom of the protective plate 4. The preheating plate 6 is located at the bottom of the connecting rod 5. The telescopic rod 7 is inserted through the preheating plate 6, and the top end of the telescopic rod 7 is hinged to the bottom end of the connecting rod 5. The fastening assembly is connected between the top end of the telescopic rod 7 and the bottom end of the connecting rod 5. An electric heating wire is provided inside the preheating plate 6. A guide tube 35 is provided between the laser welding gun 1 and the protective plate 4. The guide tube 35 is installed at the bottom of the laser welding gun 1, and welding wire for welding is inserted in the guide tube 35.

[0038] When welding the steam generator, the bottom end of the telescopic rod 7 can be kept close to the edge of the weld by being close to the component, so that the laser welding gun 1 can be kept on the same welding path as the edge of the weld. During the welding of the steam generator with the laser welding gun 1, the preheating plate 6 can be preheated by the laser welding gun 1 to be welded, thereby reducing the temperature difference during welding, reducing the thermal stress generated during welding, ensuring welding quality, and preventing the weld of the steam generator from deforming and cracking during subsequent use, thus ensuring the normal use of the steam generator.

[0039] like Figures 1 to 3 As shown, the steam generator includes a flow channel plate 8, a pressure plate 9, a water inlet pipe 10, a water outlet pipe 11, a stud 12, a thick film heating plate 13, a power supply positive terminal 14, a power supply negative terminal 15, a water inlet NTC 16, a water outlet NTC 17, a nut 18, a mica gasket 19, a sleeve 20, insulation cotton 21, and a temperature controller 22;

[0040] The flow channel plate 8 is fixed to the back of the thick film heating plate 13 by laser welding. The flow channel on the flow channel plate 8 is S-shaped. A water inlet pipe 10 and a water outlet pipe 11 are welded to both ends of the flow channel, and both the water inlet pipe 10 and the water outlet pipe 11 are connected to the flow channel. Insulation cotton 21 is glued to the side of the thick film heating plate 13 that is separated from the flow channel plate 8 using adhesive. A pressure plate 9 is provided on the side of each of the two insulation cotton pieces that are separated. The stud 12, nut 18, mica washer 19, and sleeve 20 are also included. The number of each is multiple, and multiple studs 12 are vertically inserted through and inserted into the edge of the two pressure plates 9. Multiple nuts 18, multiple sleeves 20 and multiple mica gaskets 19 are all sleeved on multiple studs 12. A thermostat 22 for monitoring the temperature of the thick film heating plate 13 is installed at the bottom of the pressure plate 9. The two ends of the flow channel are respectively provided with an inlet NTC16 and an outlet NTC17. The thick film heating plate 13 is connected to a positive power supply 14 and a negative power supply 15.

[0041] The S-shaped flow channel on the flow plate 8 allows the liquid to flow along the flow path, preventing water from reaching the steam port in advance. By attaching insulation cotton 21 to both sides of the thick film heating plate 13, the loss of steam heat can be effectively reduced. The design of the upper and lower pressure plates 9 can effectively isolate the thick film heating plate 13 to prevent personnel from being burned. At the same time, the two pressure plates 9 connected together by the studs 12 can prevent the adhesive on the insulation cotton 21 from failing due to heat and falling off.

[0042] During use, the thermostat 22 can control the surface temperature of the thick film heating plate 13 and the steam temperature. The inlet NTC16 and outlet NTC17 of the flow channel are respectively set to prevent dry burning when there is no water, thus avoiding damage to the steam generator in this invention.

[0043] like Figures 4 to 7 As shown, the fastening assembly includes a fixing block 23, a fixing screw 24, a fixing shaft 25, a movable block 26, a return spring 27, a limiting block 28, and a stop block 29. The fixing block 23 is rotatably sleeved on the bottom end of the connecting rod 5. The fixing screw 24 is threaded into the rear side of the fixing block 23, and one end of the fixing screw 24 inserted into the inner side of the fixing block 23 can contact the surface of the connecting rod 5. The fixing shaft 25 is horizontally and vertically fixedly connected to the front side of the fixing block 23. The movable block 26 and the return spring 27 are detachably sleeved on the fixing shaft 25, and the movable block 26 is located at the bottom end of the connecting rod 5. The front side of the return spring 27, the two ends of the return spring 27 are kept close to the movable block 26 and the fixed block 23 respectively. The bottom end of the movable block 26 is hinged to the top end of the telescopic rod 7. The telescopic rod 7 can only deflect along the plane where the laser welding gun 1 is located, and the angle of deflection of the telescopic rod 7 is less than five degrees. There are two stops 29. The two stops 29 are fixedly connected to the front and rear sides of the bottom end of the connecting rod 5 respectively. The limiting block 28 is fixedly connected to the side of the fixed block 23 near the protective plate 4, and the limiting block 28 can contact both stops 29.

[0044] When welding the thick film heating plate 13 and the flow channel plate 8, the laser welding gun 1 is first used to spot weld the connection between the two, thereby achieving simple fixation of the thick film heating plate 13 and the flow channel plate 8. Then, the laser welding gun 1 is placed on top of the welding point between the thick film heating plate 13 and the flow channel plate 8, while the telescopic rod 7 is positioned on the side of the connecting column near the welding position of the flow channel plate 8. Then, the bottom end of the telescopic rod 7 is kept in contact with the edge of the flow channel plate 8. Since the welding head of the laser welding gun 1 is not in the same vertical plane as the telescopic rod 7 at this time, the hand holding the laser welding gun 1 is moved closer to the flow channel plate. The direction of 8 is moved, so that the flow channel plate 8 can squeeze the bottom end of the telescopic rod 7 through its edge. As the telescopic rod 7 is squeezed, the telescopic rod 7 can drive the movable block 26 at its top to squeeze the return spring 27. As the return spring 27 is continuously squeezed, the welding head of the laser welding gun 1 can gradually move closer to the flow channel plate 8. When the welding head of the laser welding gun 1 is flush with the edge of the flow channel plate 8, the laser welding gun 1 is also in the same plane as the telescopic rod 7. At this time, as the laser welding gun 1 is dragged backward, its welding head gradually completes the welding operation of the flow channel plate 8 and the thick film heating plate 13.

[0045] During the process of dragging the laser welding gun 1 backward to weld the flow channel plate 8 and the thick film heating plate 13, the preheating plate 6 can be suspended at the top edge of the flow channel plate 8, so as to complete the preheating operation of the flow channel plate 8 to be welded before the laser welding gun 1 welds the flow channel plate 8. This can reduce the temperature difference during subsequent welding, thereby reducing the thermal stress generated during welding, ensuring welding quality, preventing deformation and cracking of the welded part of the steam generator during subsequent use, and ensuring the normal use of the steam generator.

[0046] Furthermore, by providing a return spring 27, during the welding process, when the telescopic rod 7 moves with the laser welding gun 1 to the corner position of the flow channel plate 8, the return spring 27 can extend, thereby pushing the telescopic rod 7 along the chamfer position of the flow channel plate 8 towards the next edge to be welded through the movable block 26, thereby preheating the chamfer position of the flow channel plate 8. In addition, due to the reset effect of the return spring 27, the pushing force of the return spring 27 on the hand is reduced, which can also serve as a reminder to the welding personnel to avoid mis-welding of the non-welding area of ​​the thick film heating plate 13 due to excessive welding speed;

[0047] In addition, the position of the telescopic rod 7 can be adjusted for welders with different hand habits. To adjust, first remove the movable block 26, then loosen the fixing screw 24, and then move the fixing block 23, thereby driving the fixing shaft 25 to rotate to the other side of the connecting rod 5. During the rotation of the fixing block 23, when the limiting block 28 on the fixing block 23 contacts the stop block 29 on the side where the fixed shaft 25 is located after rotation, tighten the fixing screw 24 to lock the fixing block 23. Finally, the removed movable block 26 can be reinstalled on the fixing shaft 25. With the adjustment of the position of the telescopic rod 7, the welding needs of welders with different hand habits can be met.

[0048] like Figures 5 to 9 As shown, a clearance assembly is provided at the connection between the telescopic rod 7 and the preheating plate 6. The clearance assembly includes a counterweight 30, a rectangular protrusion 31, and a slider 32. A strip-shaped through hole is provided on the preheating plate 6, and the telescopic rod 7 is inserted through the through hole. The length direction of the through hole is parallel to the length direction of the fixed shaft 25. The rectangular protrusion 31 is fixedly connected to the top edge of the through hole. The slider 32 is fixedly sleeved on the telescopic rod 7, and the slider 32 is slidably installed on the inner side of the rectangular protrusion 31. The counterweight 30 is slidably sleeved on the telescopic rod 7. The front and rear sides of the counterweight 30 are both designed with slopes. The length of the top surface of the counterweight 30 is greater than the length of its bottom surface, and the length of the top surface of the counterweight 30 is greater than the length of the rectangular protrusion 31.

[0049] By incorporating a counterweight 30, during the welding process, as the telescopic rod 7 and the preheating plate 6 are progressively welded along the edge of the flow channel plate 8 under the drive of the laser welding gun 1, the preheating plate 6 moves with the laser welding gun 1. When the preheating plate 6 contacts the protrusions, inlet pipe 10, or outlet pipe 11 on the flow channel plate 8, the preheating plate 6 can move away from the flow channel plate 8 under the obstruction and push of these protrusions, inlet pipe 10, or outlet pipe 11. This prevents the preheating plate 6 from being blocked by these protrusions, inlet pipe 10, or outlet pipe 11. As the preheating plate 6 moves, the slider 32 can move along... The rectangular protrusion 31 moves within the through hole, and the side of the rectangular protrusion 31 near the flow channel plate 8 can squeeze the inclined surface of the counterweight 30, so that the counterweight 30 can move upward under the pressure of the edge of the rectangular protrusion 31. As the preheating plate 6 continues to move, when the preheating plate 6 is misaligned with the protrusion on the flow channel plate 8, the inlet pipe 10 or the outlet pipe 11, the counterweight 30 can move downward under its own weight. As the counterweight 30 moves downward, the inclined surface of the counterweight 30 near the flow channel plate 8 can squeeze the top edge of the corresponding side of the rectangular protrusion 31, so that the preheating plate 6 can return to its original position under the pushing force of the counterweight 30 on the rectangular protrusion 31.

[0050] like Figure 8 As shown, notches are provided at the top positions of the front and rear sides of the rectangular protrusion 31. A roller 33 is rotatably installed between the inner walls of the two sides of the notch, and the roller 33 can contact the inclined surface of the counterweight 30. The weight of the counterweight 30 is greater than the weight of the preheating plate 6, and the counterweight 30 can always keep one of its inclined surfaces in contact with the roller 33 on the corresponding side.

[0051] By providing a roller 33, when the rectangular protrusion 31 presses the counterweight 30 upward through its front or rear edge, the roller 33 can roll along the inclined part of the counterweight 30, thereby reducing the resistance encountered by the counterweight 30 when it moves upward, and thus enabling the counterweight 30 to move smoothly upward along the telescopic rod 7 under the pressing action of the rectangular protrusion.

[0052] like Figure 7 and Figure 9 As shown, the diameter of the telescopic rod 7 at the bottom of the preheating plate 6 is smaller than its diameter at the top of the preheating plate 6, and a ball bearing 34 is installed at the bottom end of the telescopic rod 7.

[0053] By incorporating ball bearings 34, when the bottom end of the telescopic rod 7 moves along the edge of the flow channel plate 8 on the thick film heating plate 13, the ball bearings 34 can reduce the frictional force on the bottom end of the telescopic rod 7, thereby enabling the telescopic rod 7 to move more smoothly.

[0054] The present invention also provides a method of using a laser welding device for plugging pipes with a steam generator, comprising the following steps:

[0055] Step 1: First, clamp and fix the thick film heating plate 13 on the welding platform, with the welding surface of the thick film heating plate 13 facing upwards. Then, place the flow channel plate 8 to be welded on top of the thick film heating plate 13 and adjust its position.

[0056] Step 2: Hold the laser welding gun 1 in one hand and press down on the flow channel plate 8 with the other hand. Then, spot weld the edge of the flow channel plate 8 to simply fix the flow channel plate 8 to the thick film heating plate 13.

[0057] Step 3: After spot welding is completed, place the laser welding gun 1 on top of the flow channel plate 8, adjust the position of the laser welding gun 1 so that the bottom end of the telescopic rod 7 can be kept close to the edge of the flow channel plate 8, while the preheating plate 6 is suspended above the edge of the flow channel plate 8.

[0058] Step 4: Use laser welding gun 1 to gradually weld along the edge of flow channel plate 8. During the welding process, the preheating plate 6 can be activated to preheat the position of flow channel plate 8 to be welded, thereby reducing the welding temperature difference and reducing the generation of thermal stress.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A laser welding apparatus for plugging pipes in a steam generator, the welding apparatus being used for welding steam generators, characterized in that: The welding device includes a laser welding gun (1), a fixing ring (2), a fixing rod (3), a protective plate (4), a connecting rod (5), a preheating plate (6), a telescopic rod (7), and a fastening assembly; the fixing ring (2) is detachably sleeved on the front end of the laser welding gun (1), the protective plate (4) is located at the bottom of the fixing ring (2), and the fixing rod (3) is fixedly connected between the fixing ring (2) and the protective plate (4), the connecting rod (5) is fixedly connected to the bottom of the protective plate (4), and the preheating plate (6) is located at the bottom of the connecting rod (5). The telescopic rod (7) is inserted through the preheating plate (6), and the top end of the telescopic rod (7) is hinged to the bottom end of the connecting rod (5). The fastening assembly is connected between the top end of the telescopic rod (7) and the bottom end of the connecting rod (5). An electric heating wire is provided inside the preheating plate (6). The fastening assembly includes a fixing block (23), a fixing screw (24), a fixing shaft (25), a movable block (26), a return spring (27), a limiting block (28), and a stop block (29). The fixing block (23) is rotatably sleeved on the bottom end of the connecting rod (5). The fixing screw (24) is threaded into the rear side of the fixing block (23), and one end of the fixing screw (24) inserted into the inner side of the fixing block (23) can contact the surface of the connecting rod (5). The fixing shaft (25) is horizontally and vertically fixedly connected to the front side of the fixing block (23). The movable block (26) and the return spring (27) are detachably sleeved on the fixing shaft (25), and the movable block (26) is located in front of the return spring (27). The two ends of the return spring (27) are respectively connected to the movable block (26) and the fixing block (23). Keeping it close together, the bottom end of the movable block (26) is hinged to the top end of the telescopic rod (7). The telescopic rod (7) can only deflect along the plane where the laser welding gun (1) is located, and the angle of deflection of the telescopic rod (7) is less than five degrees. There are two stops (29). The two stops (29) are fixedly connected to the front and rear sides of the bottom end of the connecting rod (5). The limiting block (28) is fixedly connected to the side of the fixed block (23) near the protective plate (4), and the limiting block (28) can contact both stops (29).

2. The laser welding apparatus for plugging pipes in a steam generator according to claim 1, characterized in that: The steam generator includes a flow channel plate (8), a pressure plate (9), an inlet pipe (10), an outlet pipe (11), a stud (12), a thick film heating plate (13), a power supply positive terminal (14), a power supply negative terminal (15), an inlet NTC (16), an outlet NTC (17), a nut (18), a mica gasket (19), a sleeve (20), insulation cotton (21), and a thermostat (22). The flow channel plate (8) is fixed to the back of the thick film heating plate (13) by laser welding, and the flow channel on the flow channel plate (8) is S-shaped. The inlet pipe (10) and the outlet pipe (11) are welded to the two ends of the flow channel, respectively, and the inlet pipe (10) and the outlet pipe (11) are connected to the flow channel. The side of the thick film heating plate (13) that is separated from the flow channel plate (8) is covered with adhesive backing. The insulation cotton (21) is pasted on the side where the two insulation cotton (21) are separated, and a pressure plate (9) is provided on each side. There are multiple studs (12), nuts (18), mica gaskets (19) and sleeves (20). Multiple studs (12) are vertically inserted into the edge of the two pressure plates (9). Multiple nuts (18), multiple sleeves (20) and multiple mica gaskets (19) are all sleeved on multiple studs (12). A thermostat (22) for monitoring the temperature of the thick film heating plate (13) is installed at the bottom of the pressure plate (9). The two ends of the flow channel are respectively provided with an inlet NTC (16) and an outlet NTC (17). The thick film heating plate (13) is connected to a power supply positive terminal (14) and a power supply negative terminal (15).

3. The laser welding apparatus for plugging pipes in a steam generator according to claim 1, characterized in that: An avoidance component is provided at the connection between the telescopic rod (7) and the preheating plate (6). The avoidance component includes a counterweight (30), a rectangular protrusion (31), and a slider (32). A strip-shaped through hole is provided on the preheating plate (6), and the telescopic rod (7) is inserted through the through hole. The length direction of the through hole is parallel to the length direction of the fixed shaft (25). The rectangular protrusion (31) is fixedly connected to the top edge of the through hole. The slider (32) is fixedly sleeved on the telescopic rod (7), and the slider (32) is slidably installed on the inner side of the rectangular protrusion (31). The counterweight (30) is slidably sleeved on the telescopic rod (7). The front and rear sides of the counterweight (30) are both designed with slopes. The length of the top surface of the counterweight (30) is greater than the length of its bottom surface, and the length of the top surface of the counterweight (30) is greater than the length of the rectangular protrusion (31).

4. The laser welding apparatus for plugging pipes in a steam generator according to claim 3, characterized in that: The rectangular protrusion (31) has notches at the top of both the front and rear sides. A roller (33) is rotatably installed between the inner walls of the two sides of the notch, and the roller (33) can contact the inclined surface of the counterweight (30).

5. The laser welding apparatus for plugging pipes in a steam generator according to claim 3, characterized in that: The diameter of the telescopic rod (7) at the bottom of the preheating plate (6) is smaller than the diameter at the top of the preheating plate (6), and a ball bearing (34) is installed at the bottom end of the telescopic rod (7).

6. The laser welding apparatus for plugging pipes in a steam generator according to claim 5, characterized in that: A guide tube (35) is provided between the laser welding gun (1) and the protective plate (4). The guide tube (35) is installed at the bottom of the laser welding gun (1), and welding wire for welding is inserted in the guide tube (35).

7. The laser welding apparatus for plugging pipes in a steam generator according to claim 4, characterized in that: The weight of the counterweight (30) is greater than that of the preheating plate (6), and the counterweight (30) is always able to keep one of its inclined surfaces in contact with the roller (33) on the corresponding side.

8. A welding method using the laser welding apparatus for plugging steam generator pipes as described in claim 7, characterized in that, Includes the following steps: Step 1: First, clamp and fix the thick film heating plate (13) on the welding platform, and make the welding surface of the thick film heating plate (13) face upward. Then, place the flow channel plate (8) to be welded on top of the thick film heating plate (13) and adjust its position. Step 2: Hold the laser welding gun (1) in one hand and press down on the flow channel plate (8) with the other hand. Then, spot weld the edge of the flow channel plate (8) to simply fix the flow channel plate (8) to the thick film heating plate (13). Step 3: After spot welding is completed, place the laser welding gun (1) on the top of the flow channel plate (8), adjust the position of the laser welding gun (1) so that the bottom end of the telescopic rod (7) can be kept close to the edge of the flow channel plate (8), while the preheating plate (6) is suspended at the top of the edge of the flow channel plate (8). Step 4: Use a laser welding gun (1) to gradually weld along the edge of the flow channel plate (8). During the welding process, the preheating plate (6) can be activated to preheat the position of the flow channel plate (8) to be welded, thereby reducing the welding temperature difference and reducing the generation of thermal stress.

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