A kind of ultra-narrow gap laser wire filling welding device for nuclear-grade austenitic stainless steel pipeline

Abstract

The present application relates to a kind of ultra-narrow gap laser wire filling welding device of nuclear-grade austenitic stainless steel pipeline, including mounting seat and laser welding gun, laser welding gun is fixed in the side of mounting seat by hoop seat;Mounting seat is equipped with wire guide hole, and the bottom of mounting seat is fixed with the wire guide hole The wire feeding tube communicated with;Welding wire is stretched from the end of wire feeding tube, and the laser beam emitted by laser welding gun falls on the free section of welding wire stretch;Mounting seat is equipped with side hole on both sides, and both side holes are equipped with support disc;Mounting seat is equipped with gas blowing module for blowing gas to protect welding position.The present application drives two support discs to be synchronized and be in contact with the sidewall of groove by pneumatic linkage mechanism, can automatically calibrate mounting seat and wire feeding tube to the center position of groove, in combination with the design that the free section length of welding wire is shorter, effectively avoids the contact and collision of welding wire and groove sidewall from two aspects of spatial positioning and physical constraint, improves the precision of welding wire alignment molten pool center, reduces the generation of welding defects.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, specifically to an ultra-narrow gap laser filler wire welding device for nuclear-grade austenitic stainless steel pipes. Background Technology

[0002] Nuclear-grade austenitic stainless steel pipes are core pressure-bearing components in critical loops of nuclear power plant coolant and steam systems. Ultra-narrow gap laser filler wire welding technology is widely used in the welding of such thick-walled pipes. Currently, this process generally adopts an ultra-narrow gap bevel with a wider outer edge and a narrower inner edge. The maximum outer width is usually 15-30mm, and the narrowest part inside is only 5-10mm, with a bevel depth of over 100mm.

[0003] Existing ultra-narrow gap laser wire feeding welding devices generally adopt a side-feed structure. The wire feed nozzle is fixedly installed on one side of the laser welding gun. After the welding wire extends from the wire feed nozzle, there is a 10-20mm exposed free section. It needs to pass through the narrow bevel space and be fed into the laser molten pool at the bottom of the bevel. The limited space of the ultra-narrow gap restricts the feeding path of the welding wire. The free end of the welding wire is very likely to touch the two side walls of the bevel, which can lead to the welding wire bending, jamming, or even deflecting the wire feed nozzle, causing unexpected interruption of the welding process.

[0004] Furthermore, in actual pipeline welding, the strong reflection of laser light from the bevel sidewall significantly heats the internal environment of the bevel, which can easily cause the free end of the welding wire to soften and bend due to heat. At the same time, mechanical vibration during the welding process can also cause the free end of the welding wire to wobble. Both of these factors together cause the welding wire to fail to accurately align with the center of the molten pool, resulting in fatal weld defects such as incomplete fusion and undercut. Summary of the Invention

[0005] Based on this, this application provides an ultra-narrow gap laser filler wire welding device for nuclear-grade austenitic stainless steel pipes to solve the technical problems in the prior art where the free section of the welding wire is prone to collision with the sidewall of the bevel, resulting in welding interruption, and the free section of the welding wire is prone to thermal softening and bending. It achieves precise guidance, stable support and effective cooling of the welding wire.

[0006] This application provides an ultra-narrow gap laser filler wire welding device for nuclear-grade austenitic stainless steel pipes, including a mounting base and a laser welding gun, wherein the laser welding gun is fixed to the side of the mounting base by a clamp.

[0007] The mounting base is provided with a wire guide channel, and a wire feeding tube communicating with the wire guide channel is fixed at the bottom of the mounting base;

[0008] The welding wire extends from the end of the wire feeding tube, and the laser beam emitted by the laser welding gun falls on the free section of the welding wire.

[0009] The mounting base has side holes on both sides, and a support plate is installed in each of the side holes;

[0010] The mounting base is equipped with an air blowing module that blows air onto the welding position for protection;

[0011] The air blowing module includes an air inlet channel opened at the top of the mounting base and extending vertically downward, an air blowing pipe fixed at the bottom of the mounting base, and a pneumatic linkage mechanism located inside the mounting base.

[0012] The pneumatic linkage mechanism is configured such that when the protective gas enters the blowing pipe from the air inlet, it drives the two support plates to move away from each other, so that the two support plates abut against the two side walls of the bevel respectively.

[0013] When the air blowing protection stops, the two support plates can be reset and hidden in the corresponding side holes.

[0014] In one implementation, the air blowing tube is sleeved outside the wire feeding tube, and the two are aligned.

[0015] The end of the wire feeding tube extends outside the air blowing tube, and an annular air guiding cavity is formed between the air blowing tube and the wire feeding tube;

[0016] An air inlet is formed between the end of the air blowing tube and the outer wall of the wire feeding tube;

[0017] The air nozzle should be aligned with the welding position.

[0018] In one implementation, the pneumatic linkage mechanism includes a piston body and a guide rod;

[0019] A horizontally extending transverse hole is provided inside the mounting base and below the air intake channel;

[0020] The bottom of the air intake channel is connected to the center of the horizontal hole;

[0021] Piston bodies are slidably installed on both sides of the intake channel inside the transverse hole;

[0022] Guide rods are coaxially fixed on the opposite end faces of the two piston bodies;

[0023] Both guide rods extend axially along the transverse hole and slide through into the corresponding side hole;

[0024] The ends of the two guide rods located inside the side holes are connected to the support plates on the corresponding sides;

[0025] Both piston bodies are provided with L-shaped holes;

[0026] The first port of the L-shaped hole penetrates the end face of the piston body away from the guide rod, and the second port of the L-shaped hole faces downward and penetrates the outer peripheral wall of the piston body.

[0027] A second flow guide channel is provided symmetrically inside the mounting base and below the horizontal hole, and the two second flow guide channels are respectively connected to the two ends of the horizontal hole;

[0028] After the protective gas enters the transverse hole from the intake channel and pushes the two pistons away from each other to their extreme positions, the second port aligns with and connects with the second guide channel on the same side.

[0029] In one implementation, a second spring is fitted around the outside of both guide rods;

[0030] One end of the second spring is fixed to the side of the piston body away from the first port, and the other end is fixed to the inner wall of the transverse hole.

[0031] When there is no air pressure in the air intake channel, the two second springs push the two piston bodies to move closer to each other and reset.

[0032] In one implementation, the air blowing module further includes a first flow channel and an annular cavity;

[0033] The first guide channel is horizontally disposed in the mounting base, and the ends of the two second guide channels away from the horizontal hole are connected to the first guide channel.

[0034] The annular cavity is located within the mounting base and is distributed around the guide wire channel;

[0035] The first guide channel is connected to the annular cavity;

[0036] Several connecting holes are arranged in a ring array around the guide wire channel on the bottom wall of the annular cavity;

[0037] Each connecting hole extends vertically downwards and is connected to the annular air guide cavity.

[0038] In one implementation, mounting holes extending along the axial direction of the guide rod are provided on the surfaces of the two support plates that are close to each other.

[0039] The end of the guide rod away from the piston body is slidably inserted into the mounting hole on the same side;

[0040] A first spring extending along the axial direction of the guide rod is fixed on the end faces of the two guide rods that are far apart from each other;

[0041] The other ends of the two first springs are fixedly connected to the inner end walls of the corresponding mounting holes.

[0042] In one implementation, racks extending axially along the transverse hole are fixed to the ends of the two piston bodies on the side that are close to each other.

[0043] A shaft is rotatably mounted in the middle of the transverse hole and below the air intake channel, and the shaft passes between the two racks.

[0044] A gear is fixedly mounted on the shaft, and the gear meshes with both racks.

[0045] The ends of the rack are in contact with and resist the end face of the opposite piston body.

[0046] In one implementation, the surfaces of the two support disks facing away from each other are each fitted with a number of balls in a circular array.

[0047] In one implementation, a wire inlet nozzle communicating with the wire guide channel is fixed on the top of the mounting base;

[0048] The top of the mounting base is fixed with a pipe interface that communicates with the air intake channel.

[0049] In one implementation, a vertically extending fixing rod is also fixed to the top of the mounting base, and a connecting block for connecting to the movable end of an external lifting unit is fixed to the top of the fixing rod.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0051] The pneumatic linkage mechanism drives two support plates to extend synchronously and abut against the side walls of the bevel. This allows the mounting base and wire feed tube to be automatically aligned to the center of the bevel. Combined with the design of a short free section for the welding wire, this effectively avoids contact and collision between the welding wire and the side walls of the bevel from both spatial positioning and physical constraints. This improves the accuracy of the welding wire aligning with the center of the molten pool and reduces the generation of welding defects.

[0052] Through the integrated pneumatic linkage mechanism design, the protective gas pressure is used as the power source to drive the support plate to extend. There is no need to set up additional electrical or hydraulic drive components. This not only greatly simplifies the overall structure of the device and reduces the failure rate and maintenance cost of the equipment, but also ensures the synchronization of the support positioning action and the protective gas injection action, thus ensuring the safety and stability of the welding process.

[0053] The shielding gas ejected from the gas nozzle blows onto the weld pool, effectively isolating it from air and preventing the weld metal from oxidizing. At the same time, as the gas flows in the annular gas guide cavity, it is distributed around the wire feed tube, and when it is ejected from the gas nozzle, it is also distributed around the free end of the welding wire. With the continuous supply of shielding gas, the welding wire, wire feed tube, and gas blowing tube near the welding position can be continuously and forcibly cooled, further preventing the welding wire, wire feed tube, and gas blowing tube from softening and deforming due to laser reflection heat.

[0054] The automatic reset mechanism driven by the second spring allows the support plate to retract automatically and be hidden in the side hole when a power failure or gas supply interruption occurs during welding. This effectively avoids the safety hazard of the device getting stuck in the bevel due to the support plate extending out, and significantly improves the emergency safety and reliability of welding operations. Attached Figure Description

[0055] Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention;

[0056] Figure 2 for Figure 1A partial structural diagram of the structure shown;

[0057] Figure 3 This is a schematic diagram showing the structural distribution of the wire feeding tube and the air blowing tube in this invention;

[0058] Figure 4 for Figure 2 One of the schematic diagrams of a partial cross-section of the structure shown;

[0059] Figure 5 for Figure 4 Enlarged schematic diagram of the structure at point A in the middle;

[0060] Figure 6 for Figure 2 The second schematic diagram of a partial cross-section of the structure shown;

[0061] Figure 7 for Figure 6 Enlarged schematic diagram of the structure at point B;

[0062] Figure 8 This is a schematic diagram showing the distribution of the laser filler wire welding device within the bevel during operation.

[0063] Figure 9 This is a schematic diagram of the structure when the two side support plates are in contact with the inner walls of the bevel.

[0064] In the diagram: 01. Nuclear-grade austenitic stainless steel tube; 02. Bevel; 03. Circular joint; 04. Welding wire; 05. Laser beam; 1. Mounting base; 101. Wire guide channel; 102. Wire inlet nozzle; 103. Side hole; 11. Clamp seat; 12. Fixing rod; 121. Connecting block; 2. Laser welding torch; 3. Wire feed tube; 31. Air blowing tube; 32. Circular air guiding chamber; 33. Air blowing port; 4. Support plate. ; 41. Mounting hole; 42. First spring; 43. Ball bearing; 5. Air inlet channel; 51. First guide channel; 52. Annular cavity; 53. Connecting hole; 54. Pipe interface; 55. Horizontal hole; 56. Second guide channel; 6. Piston body; 61. L-shaped hole; 611. First port; 612. Second port; 7. Guide rod; 71. Second spring; 8. Shaft; 81. Gear; 82. Rack. Detailed Implementation

[0065] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments.

[0066] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0067] Before describing the specific structure and working process of this welding device in detail, it is necessary to first explain the application scenarios of this device, such as... Figure 8 As shown, during the welding operation, the two nuclear-grade austenitic stainless steel tubes 01 to be welded are first precisely joined together using the corresponding tooling fixtures. The joint of the two nuclear-grade austenitic stainless steel tubes 01 forms an annular joint 03, which is the welding position where the laser beam 05 and the welding wire 04 work together. A narrow gap bevel 02 with a wider outer edge and a narrower inner edge is formed between the ends of the two nuclear-grade austenitic stainless steel tubes 01. The inner walls on both sides of the bevel 02 refer to the end faces of the corresponding nuclear-grade austenitic stainless steel tubes 01. After welding is completed, an annular weld zone that meets the welding requirements is formed at the annular joint 03.

[0068] Please see Figures 1 to 7 This application provides an ultra-narrow gap laser filler wire welding device for nuclear-grade austenitic stainless steel pipes, including a mounting base 1 and a laser welding gun 2. The mounting base 1 serves as the main body of the device and is generally wider at the top and narrower at the bottom to adapt to the outer width and inner narrowness of the bevel 02. A vertically upward extending fixing rod 12 is fixed to the top of the mounting base 1, and a connecting block 121 is fixed to the top of the fixing rod 12. The connecting block 121 is used to connect with an external lifting unit (not shown in the figure).

[0069] Specifically, the lifting unit can be an existing linear drive structure such as a cylinder or an electric push rod, with its moving end fixed to the connecting block 121 to realize the overall lifting movement of the device so that the corresponding components can descend into the narrow gap during welding work.

[0070] The mounting base 1 has a clamp seat 11 on its side. The laser welding gun 2 is installed in the clamp hole of the clamp seat 11. By tightening the screws on the clamp seat 11, the laser welding gun 2 can be firmly installed on the side of the mounting base 1.

[0071] The mounting base 1 is provided with a vertically extending wire guide channel 101. The top of the mounting base 1 is fixed with a wire inlet nozzle 102 communicating with the wire guide channel 101. The bottom of the mounting base 1 is fixed with a wire feeding tube 3 communicating with the wire guide channel 101. The welding wire 04 is supplied by an external wire feeding mechanism (using existing technology, the specific structure and principle of which will not be described in detail) and fed into the wire guide channel 101 through the wire inlet nozzle 102. Finally, it extends out through the end of the wire feeding tube 3. The length of the free section of the welding wire 04 extending from the end of the wire feeding tube 3 is limited to 5-8mm.

[0072] Specifically, the wire feeding tube 3 consists of a vertical part and an inclined part, with an included angle of 110°-160° between their axes. This angle transition ensures smooth wire feeding and avoids jamming.

[0073] In addition, such as Figure 1As shown, the laser beam 05 emitted by the laser welding gun 2 falls on the free section of the welding wire 04, so that the laser beam 05 can melt the free section of the welding wire 04.

[0074] The mounting base 1 has symmetrical side holes 103 on both sides, and a support plate 4 is installed in each of the two side holes 103. The two support plates 4 are symmetrically distributed. The mounting base 1 is equipped with an air blowing module for blowing air to the welding position for protection.

[0075] The air blowing module includes an air inlet duct 5 opened at the top of the mounting base 1 and extending vertically downward, an air blowing pipe 31 fixed at the bottom of the mounting base 1, and a pneumatic linkage mechanism provided in the mounting base 1.

[0076] The mounting base 1 has a pipe interface 54 fixed on its top. The pipe interface 54 is connected to the air inlet 5 and is used to connect to the external air supply pipeline (not shown in the figure).

[0077] The pneumatic linkage mechanism is configured such that when the protective gas enters the blowing pipe 31 from the air inlet 5, it drives the two support plates 4 to move away from each other, so that the two support plates 4 abut against the two side walls of the bevel 02 respectively; when the blowing protection stops, the two support plates 4 can be reset and hidden in the corresponding side hole 103.

[0078] According to the present invention, the pneumatic linkage mechanism is configured to utilize the pneumatic power of the protective gas as a power source for linkage. Specifically, when the protective gas enters from the air inlet 5 and eventually flows into the air blowing pipe 31, the pneumatic linkage mechanism can drive the two support plates 4 to move away from each other, so that the two support plates 4 abut against the two side walls of the bevel 02 respectively. Thus, after the welding wire 04 enters the bevel 02, the center positioning of the mounting base 1 and the wire feeding tube 3 is achieved, and the swing space of the free section of the welding wire 04 is physically constrained.

[0079] When the air blowing protection stops and the air pressure disappears, the reset element in the pneumatic linkage mechanism drives the two support plates 4 to move closer to each other and reset to be hidden in the corresponding side hole 103, so as to reduce the overall width of the device and facilitate the entry and exit of the bevel 02.

[0080] The above-mentioned air blowing module is illustrated by example, such as... Figure 2 and Figure 3 As shown, the air blowing pipe 31 is sleeved on the outside of the wire feeding pipe 3, and the two are aligned; the end of the wire feeding pipe 3 extends to the outside of the air blowing pipe 31, and an annular air guiding cavity 32 is formed between the air blowing pipe 31 and the wire feeding pipe 3; an annular air blowing port 33 is formed between the end of the air blowing pipe 31 and the outer wall of the wire feeding pipe 3, and is distributed around the end of the wire feeding pipe 3; the air blowing port 33 is aligned with the welding position.

[0081] As a specific implementation, the wire feeding tube 3 and the air blowing tube 31 adopt this coaxial sleeve structure, which allows the protective gas to be sent out around the welding wire 04 to form a uniform protective air curtain, and to circulate and cool the welding wire 04, the wire feeding tube 3 and the air blowing tube 31 during the gas flow process.

[0082] In one embodiment, the pneumatic linkage mechanism includes a piston body 6 and a guide rod 7. For example... Figure 6 and Figure 7 As shown, a horizontally extending transverse hole 55 is provided in the mounting base 1 and below the air intake channel 5; the bottom end of the air intake channel 5 communicates with the center of the transverse hole 55; piston bodies 6 are slidably installed in the transverse hole 55 on both sides of the air intake channel 5, and the two piston bodies 6 are symmetrically distributed; a guide rod 7 is coaxially fixed on the end face of the two piston bodies 6 on the side away from each other; the two guide rods 7 extend along the axial direction of the transverse hole 55 and slide through and extend into the side hole 103 on the corresponding side.

[0083] The ends of the two guide rods 7 located in the side holes 103 are connected to the support plate 4 on the corresponding side; both piston bodies 6 are provided with L-shaped holes 61; the first port 611 of the L-shaped hole 61 penetrates the end face of the piston body 6 away from the guide rods 7, and the second port 612 of the L-shaped hole 61 faces downward and penetrates the outer peripheral wall of the piston body 6; the mounting base 1 is provided with second guide channels 56 symmetrically below the transverse hole 55, and the two second guide channels 56 are respectively connected to the two ends of the transverse hole 55; after the protective gas enters the transverse hole 55 from the air inlet channel 5 and pushes the two piston bodies 6 away from each other to the extreme position, the second port 612 is aligned with and connected to the second guide channel 56 on the same side.

[0084] Furthermore, based on the above principles, this structure can achieve precise linkage between pneumatic drive and the opening and closing of the airflow path. Specifically, in the initial state, the second port 612 of the L-shaped hole 61 is misaligned with the second guide channel 56, and the airflow cannot pass through; when the pneumatic pressure pushes the piston body 6 to the position, the airflow path is just opened, realizing the timing coordination between the completion of positioning and the ejection of protective gas.

[0085] In a further embodiment, such as Figure 7 As shown, a second spring 71 is sleeved on the outside of both guide rods 7; one end of the second spring 71 is fixed to the side face of the piston body 6 away from the first port 611, and the other end is fixed to the inner end wall of the transverse hole 55; when there is no air pressure in the air inlet channel 5, the two second springs 71 push the two piston bodies 6 to move closer to each other and reset; this configuration makes the retraction action of the support plate 4 completely passive, without the need for an additional drive source, thus improving the reliability of the device.

[0086] In addition, such as Figure 5As shown, the air blowing module also includes a first guide channel 51 and an annular cavity 52; the first guide channel 51 is horizontally disposed in the mounting base 1, and the ends of the two second guide channels 56 away from the transverse hole 55 are connected to the first guide channel 51; the annular cavity 52 is disposed in the mounting base 1 and distributed around the guide wire channel 101; the first guide channel 51 is connected to the annular cavity 52; a number of connecting holes 53 are arranged in an annular array around the guide wire channel 101 on the bottom wall of the annular cavity 52; each connecting hole 53 extends vertically downward and is connected to the annular air guiding cavity 32.

[0087] By adopting the above-mentioned design of splitting and annular uniform distribution, the protective gas gathered from both sides can be evenly distributed into the annular gas guide cavity 32, ensuring that the airflow ejected from the gas blowing port 33 is more uniform and stable, and enhancing the welding protection and airflow cooling effect.

[0088] In one embodiment, such as Figure 6 and Figure 7 As shown, each of the two support plates 4 has a mounting hole 41 extending axially along the guide rod 7 on the side surface that is close to each other; the end of the guide rod 7 away from the piston body 6 is slidably inserted into the mounting hole 41 on the same side; a first spring 42 extending axially along the guide rod 7 is fixed on the end face of each of the two guide rods that is far from each other; the other end of the two first springs 42 is fixedly connected to the inner end wall of the mounting hole 41 on the corresponding side.

[0089] The guide rod 7 is movably connected to the support plate 4, and the elastic force of the first spring 42 is used to keep the support plate 4 in elastic contact with the two side walls of the bevel 02. During the welding process, when there is a slight deviation in the flatness of the side wall of the bevel 02 or a slight vibration, it can play an adaptive buffering role, maintain the effective contact between the support plate 4 and the side wall of the bevel 02, and avoid rigid impact that could cause the device to jam or misposition.

[0090] In one embodiment, such as Figure 7 As shown, racks 82 extending axially along the transverse hole 55 are fixed to the ends of the two piston bodies 6 that are close to each other; a shaft 8 is rotatably installed in the middle of the transverse hole 55 and below the air intake passage 5, and the shaft 8 passes between the two racks 82; a gear 81 is fixedly mounted on the shaft 8, and the gear 81 meshes with both racks 82; the ends of the racks 82 are in contact with and block the end face of the opposite piston body 6.

[0091] When the two piston bodies 6 move closer to each other or further away from each other, the meshing transmission of the two racks 82 and the gear 81 ensures that the movement of the two piston bodies 6 is synchronized, thereby ensuring that the movement of the two support discs 4 is consistent, so that the welding wire 04 can be effectively aligned with the annular joint 03 in the bevel 02.

[0092] Furthermore, when the second spring 71 pushes the two piston bodies 6 to move closer to each other in a reset manner, the end of the rack 82 abuts against the end wall of the other piston body 6, which has a limiting and blocking effect, thereby limiting the extreme position of the two piston bodies 6 when they are reset, ensuring that there is enough air intake space between the two piston bodies 6, avoiding the end faces of the two piston bodies 6 from contacting and blocking the air intake path, and thus ensuring that the air pressure can smoothly push the two piston bodies 6 to move away from each other.

[0093] At the same time, by using the meshing of the two racks 82 and the gear 81, it is possible to avoid excessive deflection of the piston body 6 and the guide rod 7 around the axis, which would cause serious misalignment between the second port 612 and the second guide channel 56.

[0094] In one embodiment, such as Figure 6 As shown, the two support disks 4 are each embedded with a number of rolling balls 43 in a ring array on the opposite side surface. These rolling balls 43 serve as direct contact parts with the side wall of the bevel 02, which can convert sliding friction into rolling friction, reduce the resistance when the support disks 4 move, ensure the smoothness of the device when moving relative to the nuclear-grade austenitic stainless steel tube 01 during the welding process, and reduce scratches on the inner wall of the bevel 02.

[0095] Furthermore, it should be noted that in some optional embodiments, in order to ensure the sealing performance of the piston body 6 when it is driven by gas pressure in the transverse hole 55, at least one annular groove is provided on the outer peripheral wall of the piston body 6, and a high-temperature resistant fluororubber sealing ring is installed in the annular groove. The sealing ring slides and seals with the inner wall of the transverse hole 55.

[0096] The protective gas used in this application is usually pure argon or a mixture of argon and helium. On the one hand, it is used to form a protective atmosphere that isolates the air around the weld pool. On the other hand, it serves as a power medium to drive the pneumatic linkage mechanism. At the same time, when it flows through the annular gas guide cavity 32 and the gas blowing port 33, it can continuously remove the heat from the welding wire 04, the wire feeding tube 3 and the gas blowing pipe 31, thereby achieving forced cooling.

[0097] In addition, during welding operations, the external gas supply solenoid valve is opened 2-3 seconds in advance to allow the shielding gas to fill the pipeline and be ejected from the gas outlet 33. After the support plate 4 is positioned, the laser welding gun 2 and the wire feeding mechanism are started.

[0098] Based on the above structure, the working principle of this welding device is as follows:

[0099] The entire device is lowered by an external lifting unit, causing the bottom area of ​​the mounting base 1, the wire feeding tube 3, and the air blowing tube 31 to extend into the bevel 02. Adjustment is made so that the free section of the welding wire 04 extending from the end of the wire feeding tube 3 contacts the annular joint 03. Simultaneously, the laser beam 05 emitted by the laser welding gun 2 is precisely aligned with the annular joint 03. This state is as follows: Figure 8 As shown.

[0100] Then the external air supply system is activated, and protective gas is continuously supplied into the air inlet 5 through the pipe interface 54. The protective gas flows into the area between the two piston bodies 6 in the transverse hole 55 through the air inlet 5. Under the action of gas pressure, the two piston bodies 6 are pushed to move in a direction away from each other at the same time. At this time, the two second springs 71 are compressed and stored elastic potential energy.

[0101] When the two piston bodies 6 are far apart to their extreme positions, the second port 612 is completely aligned and connected with the upper end of the second guide channel 56 on the same side (at this time, the overlap rate between the second port 612 and the port of the second guide channel 56 is the largest, and the airflow is the largest). The protective gas flows into the second guide channel 56 through the L-shaped hole 61, and then flows into the annular air guide cavity 32 through the first guide channel 51, the annular cavity 52 and the connecting hole 53 in sequence. Finally, it is concentrated and sprayed out to the welding area through the blowing port 33.

[0102] As the two piston bodies 6 move away from each other, through the connecting action of the guide rod 7, the piston bodies 6 push the support plate 4 on the same side to move outward along the axial direction of the transverse hole 55. Finally, both support plates 4 move to the outside of the side hole 103 and come into close contact with the side walls on both sides of the bevel 02. This state is as follows: Figure 9 As shown;

[0103] The above mechanism can automatically calibrate the mounting base 1 and the wire feeding tube 3 fixed on it to the position aligned with the center of the bevel 02, effectively ensuring the accuracy of the landing point of the welding wire 04. Combined with the design of this device that limits the length of the free section of the welding wire 04 extending from the end of the wire feeding tube 3 to 5-8mm, the exposed length of the welding wire 04 is greatly shortened, and the sway amplitude caused by laser reflection heat softening and mechanical vibration is reduced. From both spatial positioning and physical constraint aspects, the welding wire 04 is prevented from contacting and colliding with the side wall of the bevel 02.

[0104] During welding, the drive device on the tooling fixture drives the two nuclear-grade austenitic stainless steel tubes 01 to rotate simultaneously relative to the welding device, thereby achieving circumferential path welding.

[0105] The shielding gas ejected from the gas nozzle 33 blows onto the weld pool, effectively isolating it from air and preventing the weld metal from being oxidized, thus providing high-quality welding gas protection. At the same time, when the gas flows in the annular gas guide cavity 32, it will be distributed around the wire feed tube 3, and when it is ejected from the gas nozzle 33, it will also be distributed around the free end of the welding wire 04. With the continuous supply of shielding gas, the welding wire 04, the wire feed tube 3, and the parts of the gas nozzle 31 near the welding position can be continuously and forcibly cooled, further preventing the welding wire 04, the wire feed tube 3, and the gas nozzle 31 from softening and deforming due to laser reflection heat.

[0106] After the welding operation is completed and the protective gas supply is stopped, the gas pressure in the transverse hole 55 disappears rapidly. Under the elastic force of the second spring 71, the two piston bodies 6 are pushed to move closer to each other and reset. Then, the guide rod 7 drives the support plates 4 on both sides to reset and retract into the corresponding side holes 103, realizing the hidden storage of the support plates 4. This design can reduce the overall width of the structure formed by the mounting base 1 and the two support plates 4, making it convenient for the mounting base 1 to move down again into the bevel 02 and move up from the bevel 02 to detach.

[0107] In the above mechanism, the design of the pneumatic linkage mechanism, the corresponding gas channel in the mounting base 1 and the second spring 71 to push the piston body 6 to reset and move achieves precise timing coordination between the action of the support plate 4 and the supply of protective gas. No additional electrical or hydraulic drive components are required, which greatly simplifies the device structure and reduces the equipment failure rate. At the same time, it forms the operation logic of positioning and gas protection at the same time.

[0108] In addition, in the event of a sudden power outage or gas supply interruption, the elastic restoring force of the second spring 71 can automatically retract the support plate 4, avoiding the safety hazard of the device getting stuck in the bevel 02, and improving the reliability, accuracy and emergency safety of welding operations.

[0109] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

Claims

1. A laser filler wire welding device for ultra-narrow gap of nuclear-grade austenitic stainless steel pipe, comprising a mounting base (1) and a laser welding torch (2), wherein the laser welding torch (2) is disposed on the side of the mounting base (1), characterized in that: The mounting base (1) is provided with a vertical wire guide channel (101), and a wire feeding tube (3) communicating with the wire guide channel (101) is fixed at the bottom of the mounting base (1). The welding wire (04) extends from the end of the wire feeding tube (3), and the laser beam (05) emitted by the laser welding gun (2) falls on the free section of the welding wire (04) extending out. The mounting base (1) has side holes (103) on both sides, and a support plate (4) is installed in each of the side holes (103). The mounting base (1) is equipped with an air blowing module that blows air to the welding position for protection; The air blowing module includes an air inlet channel (5) opened on the mounting base (1), an air blowing pipe (31) fixed to the bottom of the mounting base (1), and a pneumatic linkage mechanism provided in the mounting base (1); The pneumatic linkage mechanism is configured such that when the protective gas enters the blowing pipe (31) from the air inlet (5), it drives the two support plates (4) to move away from each other, so that the two support plates (4) abut against the two side walls of the bevel (02); When the air blowing protection stops, the two support plates (4) can be reset and hidden in the corresponding side holes (103).

2. The laser wire filler welding apparatus according to claim 1, characterized in that: The air blowing tube (31) is sleeved on the outside of the wire feeding tube (3), and the two are aligned. The end of the wire feeding tube (3) extends to the outside of the air blowing tube (31), and an annular air guiding cavity (32) is formed between the air blowing tube (31) and the wire feeding tube (3). An air inlet (33) is formed between the end of the air blowing pipe (31) and the outer wall of the wire feeding pipe (3). The air inlet (33) is oriented toward the aligned welding position.

3. The laser wire-filling welding apparatus according to claim 2, characterized in that: The pneumatic linkage mechanism includes a piston body (6) and a guide rod (7). The mounting base (1) has a horizontally extending transverse hole (55) located inside and below the air intake channel (5). The bottom end of the air intake channel (5) is connected to the center of the transverse hole (55); The piston body (6) is slidably installed on both sides of the air inlet channel (5) inside the transverse hole (55); The guide rod (7) is coaxially fixed on the opposite end face of the two piston bodies (6). Both guide rods (7) extend axially along the transverse hole (55) and slide through into the corresponding side hole (103); The ends of the two guide rods (7) located in the side holes (103) are connected to the support plate (4) on the corresponding side; Both piston bodies (6) are provided with L-shaped holes (61); The first port (611) of the L-shaped hole (61) penetrates the end face of the piston body (6) away from the guide rod (7), and the second port (612) of the L-shaped hole (61) faces downward and penetrates the outer peripheral wall of the piston body (6). The mounting base (1) is provided with second guide channels (56) symmetrically below the transverse hole (55), and the two second guide channels (56) are respectively connected to the two ends of the transverse hole (55). After the protective gas enters the transverse hole (55) from the inlet channel (5) and pushes the two piston bodies (6) away from each other to the limit position, the second port (612) is aligned and connected with the second guide channel (56) on the same side.

4. The laser wire filler welding apparatus according to claim 3, characterized in that: Both guide rods (7) are fitted with a second spring (71) on their exterior. One end of the second spring (71) is fixed to the side face of the piston body (6) away from the first port (611), and the other end is fixed to the inner end wall of the transverse hole (55); When there is no air pressure in the air intake channel (5), the two second springs (71) push the two piston bodies (6) to move closer to each other and reset.

5. The laser wire filler welding apparatus according to claim 4, characterized in that: The air blowing module also includes a first flow channel (51) and an annular cavity (52); The first guide channel (51) is horizontally disposed in the mounting base (1), and the ends of the two second guide channels (56) away from the transverse hole (55) are connected to the first guide channel (51); The annular cavity (52) is located inside the mounting base (1) and is distributed around the guide wire channel (101); The first flow channel (51) is connected to the annular cavity (52); The bottom wall of the annular cavity (52) is provided with a plurality of connecting holes (53) arranged in an annular array around the guide wire channel (101). Each of the aforementioned connecting holes (53) extends vertically downward and is connected to the annular air guiding cavity (32).

6. The laser wire filler welding apparatus according to claim 3, characterized in that: The two support plates (4) are provided with mounting holes (41) extending axially along the guide rod (7) on the side surfaces that are close to each other. The end of the guide rod (7) away from the piston body (6) is slidably inserted into the mounting hole (41) on the same side; A first spring (42) extending along the axial direction of the guide rod (7) is fixed on the end faces of the two guide rods (7) that are far apart from each other. The other ends of the two first springs (42) are respectively fixedly connected to the inner end walls of the corresponding side mounting holes (41).

7. The laser wire filler welding apparatus according to claim 3, characterized in that: Both piston bodies (6) are fixed with racks (82) extending axially along the transverse hole (55) at their respective ends that are close to each other. A shaft (8) is rotatably mounted in the middle of the transverse hole (55) and below the air inlet channel (5), and the shaft (8) passes between the two racks (82); A gear (81) is fixedly mounted on the shaft (8), and the gear (81) meshes with both racks (82); The ends of the rack (82) all engage with the end face of the piston body (6) on the opposite side.

8. The laser wire-filling welding apparatus according to claim 1, characterized in that: The two support disks (4) are each arranged in a ring array on the opposite side surface, with several balls (43) embedded in each other.

9. The laser wire-filling welding apparatus according to claim 1, characterized in that: The mounting base (1) has a wire inlet (102) fixed on its top, which communicates with the wire guide channel (101). The mounting base (1) has a pipe interface (54) that communicates with the air inlet channel (5) fixed on its top.

10. The laser wire filler welding apparatus according to claim 1, characterized in that: The mounting base (1) is also fixed with a vertically upward extending fixing rod (12) at the top, and a connecting block (121) for connecting with the moving end of the external lifting unit is fixed at the top of the fixing rod (12).

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