Anti-deformation adaptive welding tool system for large pressure vessel

Abstract

The present application belongs to the technical field of pressure vessel welding tooling, and particularly relates to a deformation-preventing self-adaptive welding tooling system for large pressure vessels, which comprises a base, a welding controller, a wire feeding controller, a mechanical arm and a welding head. The mechanical arm is fixed above the base, and the welding head is assembled at the end of the mechanical arm and electrically connected with the welding controller. The side of the mechanical arm is provided with a welding wire reel and a wire feeder. The wire feeder is composed of a cap and a mounting cylinder. The inside of the mounting cylinder is assembled with multiple groups of wire guide blocks, wire guide holes and three groups of linkage shafts. The present application realizes pulse intermittent wire feeding through a multi-gear meshing linkage structure, and realizes self-adaptive wire pressing, intermittent feeding and precise retraction through spring return, ball sliding groove displacement and hydraulic buffer structure, thereby solving the problems of traditional welding tooling, such as wire feeding slip, uneven feeding and unstable arc. At the same time, the present application reduces the heat accumulation of the base material through intermittent heat input, and effectively inhibits the welding deformation of large pressure vessels.

Description

Technical Field

[0001] This invention belongs to the field of pressure vessel welding fixture technology, specifically relating to an anti-deformation adaptive welding fixture system for large pressure vessels. Background Technology

[0002] Large pressure vessels are widely used in critical fields such as petrochemicals, energy equipment, nuclear power, and special equipment. The welding quality of their cylinders, heads, and circumferential seams directly determines the operational safety, pressure resistance stability, and service life of the equipment. Large pressure vessels are characterized by thick walls, large volumes, long weld seams, and wide heat-affected zones. During the welding process, the continuous and concentrated welding heat input can easily cause localized overheating and thermal stress concentration in the base material, leading to defects such as welding deformation, coarse weld grains, porosity, slag inclusions, and arc spatter. In severe cases, this can result in the pressure vessel failing to meet pressure resistance standards, posing significant safety hazards. Therefore, the stability of wire feeding, the precision of arc control, and the ability to suppress welding deformation in welding fixtures are crucial for ensuring the welding quality of large pressure vessels.

[0003] Currently, most existing welding fixtures for large pressure vessels employ traditional constant-speed wire feeding structures with a single wire feeding mode. During the feeding of fine or soft welding wires (aluminum wire, flux-cored wire), problems such as wire slippage, dragging and bending, wire jamming, and wire retraction easily occur, making them unsuitable for all-position welding conditions. Traditional welding equipment operates at a constant wire feeding speed, resulting in continuous accumulation of welding heat input. This makes it difficult to accurately control the droplet transition, leading to poor smooth transitions, large amounts of welding spatter, significant arc length fluctuations, and susceptibility to short circuits and arc interruptions. Consequently, welds exhibit uneven width and penetration, significantly reducing weld quality and mechanical properties.

[0004] Meanwhile, existing welding fixtures mostly use fixed, rigid clamping structures for wire feeding, which cannot achieve adaptive pulse-type clamping and loosening adjustment, and cannot meet the process requirements of pulse welding and frequent spot welding starts and stops. Under conditions where the wire feeding hose is too long, the pipeline is bent, or there is scale buildup on the inner wall, the wire feeding resistance fluctuates significantly. Conventional rigid clamping structures cannot dynamically compensate for friction, easily leading to problems such as inconsistent wire feeding speed and uneven feed rate. This not only causes unstable welding arcs but also leads to welding defects due to wire stretching deformation and feed deviations. Furthermore, continuous rigid clamping of the welding wire can easily cause soft welding wires to be flattened and bent, preventing the release of residual stress inside the pipeline, further exacerbating problems such as wire jamming, wire sticking, and nozzle burning, significantly reducing welding efficiency.

[0005] More importantly, the uninterrupted pulse wire feeding and adaptive pressure relief reset structure of traditional welding fixtures result in continuously high heat input to the base material during welding, leading to a significant heat accumulation effect. This fails to effectively suppress welding deformation in large pressure vessels. In complex all-position welding scenarios such as vertical and overhead welding, the molten pool is prone to flowing and sagging, easily generating defects such as weld beads, incomplete penetration, porosity, and slag inclusions. The weld grain refinement effect is poor, and the overall welding consistency and stability cannot meet the high-precision and high-reliability welding standards for large pressure vessels. Furthermore, traditional welding operations rely on manual operation, resulting in a high rate of human error and high labor intensity. They cannot achieve automated and precise adaptive welding operations and are ill-suited to the mass production and high-quality processing requirements of modern large pressure vessels.

[0006] Existing welding fixtures for large pressure vessels suffer from numerous technical defects, including poor wire feeding stability, lack of pulse adaptive adjustment function, uncontrollable welding heat input, weak anti-deformation ability, numerous welding defects, and poor adaptability. It is necessary to develop an automated welding fixture system that can achieve pulse adaptive wire feeding, precise arc stabilization, dynamic temperature control to prevent deformation, and adaptability to welding under all working conditions, in order to overcome the shortcomings of existing technologies. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a deformation-resistant adaptive welding fixture system for large pressure vessels.

[0008] The present invention discloses an anti-deformation adaptive welding fixture system for large pressure vessels, comprising a base, a welding controller, a wire feed controller, a robotic arm, and a welding head. The robotic arm is fixedly mounted above the base, and the welding head is mounted on the upper end of the robotic arm. The welding head is electrically connected to the welding controller. A wire spool and a wire feeder are fixedly mounted on one side of the robotic arm. The wire spool contains a coil of welding wire. The wire feeder includes a cap and a mounting cylinder, which are interlocked and fixedly connected. One side of the mounting cylinder is fixed... Two wire guide blocks are fixedly installed and arranged opposite each other. Each of the two wire guide blocks has a wire guide hole in the middle. A shaft 1, a shaft 2, and a shaft 3 are connected to one side of the mounting cylinder. A drive wheel is fixed to one end of shaft 1, a driven wheel is fixed to one end of shaft 2, and a pressure wheel 1 is rotatably connected to one end of shaft 3. A servo motor is fixedly installed on the inner wall of the cap, and shaft 1 is fixedly connected to the output end of the servo motor. The welding wire enters the welding head through the wire guide hole, and the wire feed controller is electrically connected to the servo motor.

[0009] Gear 1 is integrally formed on the outer side of shaft 1, gear 2 is integrally formed on the outer side of shaft 2, and gear 3 is integrally formed on the outer side of shaft 3; gear 1, gear 2, and gear 3 mesh with each other, gear 1 is fan-shaped, a sleeve plate is integrally formed on the outer side of shaft 3, and a pressure wheel 2 is rotatably connected to one end of the sleeve plate, the driving wheel and pressure wheel 2 are symmetrically arranged and in contact with the welding wire, and the driven wheel and pressure wheel 1 are symmetrically arranged and in contact with the welding wire.

[0010] The outer side of the shaft 2 is integrally formed with a limiting disk, and the outer side of the limiting disk is integrally formed with limiting block 1 and limiting block 2; the limiting block 1 and limiting block 2 are distributed at a 90-degree angle.

[0011] The inner wall of the mounting cylinder is integrally formed with a limiting block three, and a spring is provided between the limiting block two and the limiting block three.

[0012] A sleeve is fixedly installed on the inner wall of the cap, and a ball bearing is rotatably connected to the inner wall of the sleeve. A spiral groove, a return groove, and a connecting groove are provided on the outer wall of the second shaft.

[0013] The spiral groove, return groove, and connecting groove are interconnected, and the ball is rotatably connected within the spiral groove, return groove, and connecting groove.

[0014] Both the first and second clamping rollers are conical.

[0015] The spiral groove and the return groove have the same depth, and the connecting groove has a depth less than the depths of the spiral groove and the return groove.

[0016] The connection between the connecting groove and the return groove is rounded, and the connection between the connecting groove and the spiral groove is stepped; a gap is provided at the rolling connection between the ball and the sleeve.

[0017] The sleeve is filled with hydraulic oil.

[0018] Compared with the prior art, the beneficial effects of the present invention are: This invention employs a symmetrical wheel set with a conical wheel structure to increase the contact friction of the welding wire, effectively overcoming the wire feeding resistance caused by pipe bends and scale buildup, and eliminating slippage and vibration. Combined with an adaptive displacement straightening and limiting structure, it prevents the welding wire from deviating or bending, significantly reducing faults such as wire jamming, nozzle blockage, and wire sticking. It is particularly suitable for the stable feeding of soft, fine welding wires such as aluminum welding wire and flux-cored welding wire, ensuring a constant and uniform wire feeding speed throughout the entire process. This invention utilizes intermittent meshing of sector teeth to achieve pulsed feed with one-time feeding and one-time stopping. Combined with rapid spring reset and small-amplitude retraction, it can precisely achieve a smooth droplet transfer with one pulse, significantly reducing welding spatter, stabilizing arc length, and effectively avoiding arc interruption and short circuit problems. Combined with a hydraulic buffer speed regulation structure, it can be matched with frequent spot welding and pulse welding start-stop conditions, ensuring consistent wire feed each time and high accuracy in welding parameter matching. This invention achieves intermittent heat input through pulsed intermittent wire feeding, reducing heat accumulation in the base material per unit time, lowering welding thermal stress, and fundamentally suppressing welding deformation of large pressure vessels, thus preventing burn-through of the base material. Simultaneously, it can stabilize the weld pool in all positions, including vertical and overhead welding, eliminating defects such as weld pool sagging, flowing, weld beads, and incomplete penetration, resulting in excellent weld formation quality for complex welds. Stable wire feeding and arc ensure uniform weld width and penetration depth. Pulsed wire feeding can break up the oxide film on the weld surface, reducing internal defects such as porosity and slag inclusions. Intermittent low heat input mode can refine the weld grain structure, improve weld strength, toughness, and pressure resistance, and significantly improve the welding reliability and service life of pressure vessels. This invention uses a controller to precisely regulate the wire feeding speed and pulse cycle, automatically matching welding current and voltage parameters. This eliminates the need for frequent manual adjustments, resulting in low labor intensity and a high degree of automation. The equipment's adaptive operation can effectively avoid human operation deviations, ensuring good welding consistency, high finished product qualification rate, and significantly reducing welding rework costs. This invention employs rounded corner transitions, stepped grooves, and gap ball bearing structures to ensure smooth and uninterrupted linkage reset. Combined with a hydraulic oil buffer structure, it can flexibly control the clamping feed speed, avoid damage from welding wire extrusion, and buffer mechanical impacts, reduce structural wear, ensure stable equipment operation, low failure rate, suitability for long-term continuous industrial production, and low maintenance costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is an overall plan view of the present invention; Figure 3 This is a schematic diagram of the wire feeder of the present invention; Figure 4 This is a schematic diagram of the internal structure of the wire feeder of the present invention; Figure 5 This is an exploded view of the wire feeder of the present invention; Figure 6 This is a schematic diagram of the shaft structure of the present invention; Figure 7 This is a schematic diagram showing the positional relationship between gear one, gear two, and gear three of the present invention; Figure 8 This is a plan view showing the positional relationship between the spiral groove, return groove, and connecting groove of the present invention.

[0020] In the picture: 1. Base; 2. Welding controller; 3. Wire feed controller; 4. Robotic arm; 5. Welding joint; 6. Welding wire spool; 7. Wire feeder; 71. Cap; 72. Mounting cylinder; 721. Shaft 1; 7211. Gear 1; 722. Shaft 2; 7221. Gear 2; 7222. Limiting disc; 7223. Limiting block 1; 7224. Limiting block 2; 7225. Limiting block 3; 7226. Spring; 7227. Spiral groove; 7228. Return groove; 7229. Connecting groove; 723. Shaft 3; 7231. Gear 3; 724. Sleeve plate; 73. Guide wire block; 731. Guide wire hole; 74. Driving wheel; 75. Driven wheel; 76. Pressure wheel one; 77. Servo motor; 78. Pressure roller two; 79. Sleeve; 791. Ball bearing. Detailed Implementation

[0021] Example 1 like Figures 1 to 8 As shown, the anti-deformation adaptive welding fixture system for large pressure vessels includes a base 1, a welding controller 2, a wire feed controller 3, a robotic arm 4, and a welding head 5. The robotic arm 4 is fixedly installed above the base 1, and the welding head 5 is installed at the upper end of the robotic arm 4. The welding head 5 is electrically connected to the welding controller 2. A wire spool 6 and a wire feeder 7 are fixedly installed on one side of the robotic arm 4. The wire spool 6 contains a coil of welding wire. The wire feeder 7 includes a cap 71 and an mounting cylinder 72. The cap 71 and the mounting cylinder 72 are interlocked and fixed. Two wire guide blocks 73 are fixedly installed on one side of the mounting cylinder 72, and the two wire guide blocks 73 are arranged opposite each other. Each of the two wire guide blocks 73 has a wire guide hole 731 in the middle. A shaft rod 1 721, a shaft rod 2 722, and a shaft rod 3 723 are axially connected to one side of the mounting cylinder 72. Among them, one end of shaft 1 721 is fixed with a driving wheel 74, one end of shaft 2 722 is fixed with a driven wheel 75, one end of shaft 3 723 is rotatably connected with a pressure wheel 76, and a servo motor 77 is fixedly installed on the inner wall of cap 71. Shaft 1 721 is fixedly connected to the output end of servo motor 77. The welding wire enters the welding head 5 through the wire guide hole 731, and the wire feed controller 3 is electrically connected to the servo motor 77. The robotic arm 4 moves the welding head 5 to the welding position on the large pressure vessel. Then, the welding controller 2 starts the welding head 5 to perform the welding operation. During the welding process, the wire feed controller 3 starts the servo motor 77. The servo motor 77 drives the drive wheel 74 to rotate through the shaft 721. The surface of the drive wheel 74 rubs against the welding wire, thereby feeding the welding wire. At the same time, the friction drives the driven wheel 75 and the clamping wheel 76 to rotate synchronously for automatic wire feeding. The wire feed controller 3 controls the speed of the servo motor 77, thereby controlling the wire feeding speed. The wire feeding speed is uniform and stable, resulting in high welding quality consistency. The uniform speed drive ensures a constant arc length, consistent weld width and penetration depth, fewer defects, and significantly reduced labor intensity. It also accurately matches the welding current and voltage parameters, making it suitable for all-position welding. The difficulty is greatly reduced, human error is reduced, and spatter is less. It is especially reliable for feeding fine and soft welding wires, ensuring stable arc initiation, reducing wire sticking and burnout, and preventing deformation of large pressure vessels.

[0022] Gear 7211 is integrally formed on the outer side of shaft 1 721, gear 7221 is integrally formed on the outer side of shaft 2 722, and gear 7231 is integrally formed on the outer side of shaft 3 723. Gear 1 7211, gear 2 7221 and gear 3 7231 mesh with each other. Gear 1 7211 is fan-shaped. A sleeve plate 724 is integrally formed on the outer side of shaft 3 723. One end of the sleeve plate 724 is rotatably connected to a pressure wheel 2 78. The driving wheel 74 is symmetrically arranged with pressure wheel 2 78 and is in contact with the welding wire. The driven wheel 75 is symmetrically arranged with pressure wheel 1 76 and is in contact with the welding wire. When shaft 721 rotates, it drives gear 7211 to rotate. Gear 7211 meshes with gear 7221, driving shaft 722 to rotate. Gear 7221 then meshes with gear 7231, driving shaft 723 to rotate. When shaft 723 rotates, it drives clamping wheel 78 to rotate around the center of shaft 723 via sleeve plate 724. This causes clamping wheel 78 to automatically clamp the welding wire, providing appropriate clamping. The friction generated by the clamping allows the wire feeding wheel to stably drive the welding wire forward, effectively preventing the wire feeding wheel from slipping and ensuring... The wire feeding speed is constant and uniform, overcoming the conveying resistance caused by excessively long, bent, or internally dirty wire feeding hoses. This not only ensures a stable welding arc length and better weld formation quality, but also guarantees consistent wire feed during pulsed wire feeding and frequent spot welding starts and stops. It prevents the wire from being pulled back by the molten pool, which could lead to arc breakage. At the same time, it can limit the wire within the roller groove to prevent deviation and slightly straighten bent wires, reducing the probability of wire jamming and contact tip blockage, improving arc initiation smoothness, and reducing problems such as wire sticking to the workpiece and burnt contact tips. It can also prevent slippage during dragging for softer aluminum welding wires and flux-cored welding wires. Through the sector gear 7211, when it meshes with gear 7221, it is driven intermittently, causing the clamping wheel 78 to clamp and then release the welding wire, thus performing pulsed wire feeding. Pulsed wire feeding in welding achieves intermittent wire feeding and a stop-and-go feeding effect, enabling precise control of the molten droplets to achieve a smooth, continuous transition, significantly reducing welding spatter, effectively stabilizing the arc length, reducing arc interruption and short circuits, and reducing the heat input to the base material, preventing burn-through of large pressure vessels and welding deformation. This design not only solves the problem of non-ferrous metal molten pool flow and sag, but also breaks up the surface oxide film to reduce porosity and slag inclusions. It makes the molten pool easier to control and less prone to weld beads in all positions such as vertical and overhead welding. It can also refine the internal grains of the weld to improve the mechanical properties of the weld. In addition, it can reduce the probability of bending of the thin welding wire and reduce the probability of wire blockage and contact tip sticking. Pulse intermittent wire feeding achieves intermittent heat input by intermittently delivering the welding wire, reducing the total amount of heat received by the base material per unit time, thereby effectively controlling heat accumulation and preventing welding deformation caused by overheating.

[0023] The outer side of shaft 2 722 is integrally formed with a limiting disk 7222, and the outer side of the limiting disk 7222 is integrally formed with a limiting block 1 7223 and a limiting block 2 7224. Limiting block 1 7223 and limiting block 2 7224 are distributed at a 90-degree angle.

[0024] The inner wall of the mounting cylinder 72 is integrally formed with a limiting block 3 7225, and a spring 7226 is provided between the limiting block 2 7224 and the limiting block 3 7225. When shaft 2 722 rotates, it drives limit block 1 7223 and limit block 2 7224 to rotate. Spring 7226 is squeezed by limit block 2 7224 and limit block 3 7225, thus deforming. When gear 2 7221 disengages from gear 1 7211, the reaction force generated by spring 7226 can make shaft 2 722 quickly return to its original position, thereby making clamping wheel 2 78 quickly release the welding wire. This allows the welding wire to be released quickly within the pulse wire feeding cycle, which can release the rigid clamping constraint on the welding wire. With the small pullback of the mechanism, it helps the molten droplet to smoothly neck and fall off, achieving a one-drop-per-pulse transition. At the same time, it releases the residual stress of the welding wire inside the pipeline, prevents the soft welding wire from being rigidly pulled, bent and flattened, and allows the welding wire to float slightly with the arc during the pause phase to adapt to the arc length, further stabilizing the arc and reducing short-circuit spatter and wire blockage.

[0025] A sleeve 79 is fixedly installed on the inner wall of the cap 71, and a ball bearing 791 is rolledly connected to the inner wall of the sleeve 79. The outer wall of the shaft 722 is provided with a spiral groove 7227, a return groove 7228 and a connecting groove 7229.

[0026] The spiral groove 7227, the return groove 7228 and the connecting groove 7229 are interconnected, and the ball 791 is rotatably connected in the spiral groove 7227, the return groove 7228 and the connecting groove 7229; When shaft 722 rotates, ball bearings 791 roll within the spiral groove 7227. Axial force causes shaft 722 to move within sleeve 79, thereby driving clamping rollers 76 and 78 to move synchronously back and forth. This increases the friction between clamping rollers 76 and 78 and the welding wire, preventing slippage of the wire feed rollers and ensuring continuous and stable wire feeding speed. It also overcomes the resistance of the wire feeding pipeline to achieve uniform wire output and simultaneously limits and straightens the welding wire to prevent deviation and jamming. This improves arc initiation stability and reduces welding defects such as wire sticking and nozzle blockage. When the pressure roller 76 and pressure roller 78 rub against the welding wire, they drive the welding wire to rotate slightly. The wire feeding and slight retraction are completed in the pulse cycle, forcibly pulling off the molten droplet to achieve a one-drop-per-pulse transition. The arc length is automatically adjusted to prevent the welding wire from blocking the workpiece and causing a short circuit. The tension accumulated in the welding wire in the wire feeding hose is released to prevent soft welding wires such as aluminum from being bent and stuck under pressure. Ultimately, this reduces spatter, stabilizes the arc, and reduces wire blockage.

[0027] Both clamping roller 1 (76) and clamping roller 2 (78) are conical; Since both the first clamping wheel 76 and the second clamping wheel 78 are conical, when they squeeze and rub the welding wire, they further increase the friction force on the welding wire, increase the effective contact area with the welding wire, enhance the friction force to avoid slippage, and reduce problems such as welding wire flattening, tube jamming, and wire feeding vibration; the spiral groove 7227 and the return groove 7228 have the same depth, and the depth of the connecting groove 7229 is less than the depth of the spiral groove 7227 and the return groove 7228.

[0028] The connection between the connecting groove 7229 and the return groove 7228 is rounded, and the connection between the connecting groove 7229 and the spiral groove 7227 is stepped. A gap is provided at the rolling connection between the ball bearing 791 and the sleeve 79; When shaft 722 moves within sleeve 79, the medium between shaft 722 and the inner wall of sleeve 79 is compressed. Then, when ball 791 rolls to return groove 7228, the reaction force generated by the compressed medium causes shaft 722 to quickly return to its original position. Simultaneously, because the connection between connecting groove 7229 and return groove 7228 is rounded, and the connection between connecting groove 7229 and spiral groove 7227 is stepped, as ball 791 rolls along the inner wall of spiral groove 7227... When the ball is blocked by the step, it rolls smoothly in the spiral groove 7227. When the second shaft 722 returns to its original position, the reaction force generated by the spring 7226 causes the ball 791 to roll through the rounded corner into the connecting groove 7229. Since there is a gap at the rolling connection between the ball 791 and the sleeve 79, the ball 791 will not get stuck when rolling in the connecting groove 7229, so that the second shaft 722 can return to its original position smoothly and the operation between the structures is relatively smoother.

[0029] Sleeve 79 is filled with hydraulic oil; When shaft 2 722 moves within sleeve 79, the hydraulic oil is squeezed and generates a reaction force, which effectively controls the speed of shaft 2 722's rotation and displacement. This allows for gradual tightening of the welding wire and control of the longitudinal movement speed of clamping roller 1 76 and clamping roller 2 78. This avoids flattening or bending the welding wire due to excessive pressure, and precisely matches the feed and retraction rhythm of the pulse wire feeding. It also stably controls the amount of wire fed each time and the transition state of the molten droplets, effectively preventing wire slippage, wire jamming, and short circuit of the top wire, ensuring a continuous and stable arc, and significantly reducing welding spatter and welding defects in the workpiece.

[0030] The descriptions of the orientation and relative positional relationships of the structures in this invention, such as front, back, left, right, up, and down, do not constitute a limitation of this invention, but are merely for the convenience of description.

Claims

1. A deformation-resistant adaptive welding fixture system for large pressure vessels, comprising a base (1), a welding controller (2), a wire feed controller (3), a robotic arm (4), and a welding head (5), characterized in that: The robotic arm (4) is fixedly installed above the base (1), and the welding head (5) is installed at the upper end of the robotic arm (4); The welding head (5) is electrically connected to the welding controller (2). A wire spool (6) and a wire feeder (7) are fixedly installed on one side of the robotic arm (4). The wire spool (6) contains a coil of welding wire. The wire feeder (7) includes a cap (71) and an mounting cylinder (72). The cap (71) and the mounting cylinder (72) are interlocked and fixed. Two wire guide blocks (73) are fixedly installed on one side of the mounting cylinder (72), and the two wire guide blocks (73) are arranged opposite each other. A wire guide hole (731) is provided in the middle of each of the two wire guide blocks (73). A shaft rod one (721), a shaft rod two (722), and a shaft rod three (723) are axially connected to one side of the mounting cylinder (72). Among them, one end of the first shaft (721) is fixed with a driving wheel (74), one end of the second shaft (722) is fixed with a driven wheel (75), one end of the third shaft (723) is rotatably connected with a pressure wheel (76), and a servo motor (77) is fixedly installed on the inner wall of the cap (71). The first shaft (721) is fixedly connected to the output end of the servo motor (77). The welding wire enters the welding head (5) through the wire guide hole (731), and the wire feed controller (3) is electrically connected to the servo motor (77).

2. The anti-deformation adaptive welding fixture system for large pressure vessels according to claim 1, characterized in that: Gear 1 (7211) is integrally formed on the outer side of shaft 1 (721), gear 2 (7221) is integrally formed on the outer side of shaft 2 (722), and gear 3 (7231) is integrally formed on the outer side of shaft 3 (723). The gears 1 (7211), 2 (7221) and 3 (7231) mesh with each other. The gear 1 (7211) is fan-shaped. The outer side of the shaft 3 (723) is integrally formed with a sleeve plate (724). One end of the sleeve plate (724) is rotatably connected to the pressure wheel 2 (78). The driving wheel (74) is symmetrically arranged with the pressure wheel 2 (78) and contacts the welding wire. The driven wheel (75) is symmetrically arranged with the pressure wheel 1 (76) and contacts the welding wire.

3. The anti-deformation adaptive welding fixture system for large pressure vessels according to claim 2, characterized in that: The outer side of the shaft two (722) is integrally formed with a limiting disk (7222), and the outer side of the limiting disk (7222) is integrally formed with a limiting block one (7223) and a limiting block two (7224). The limiting block one (7223) and the limiting block two (7224) are distributed at a 90-degree angle.

4. The anti-deformation adaptive welding fixture system for large pressure vessels according to claim 3, characterized in that: The inner wall of the mounting cylinder (72) is integrally formed with a limiting block three (7225), and a spring (7226) is provided between the limiting block two (7224) and the limiting block three (7225).

5. The anti-deformation adaptive welding fixture system for large pressure vessels according to claim 4, characterized in that: The inner wall of the cap (71) is fixedly installed with a sleeve (79), and the inner wall of the sleeve (79) is rotatably connected with a ball (791). The outer wall of the shaft (722) is provided with a spiral groove (7227), a return groove (7228) and a connecting groove (7229).

6. The anti-deformation adaptive welding fixture system for large pressure vessels according to claim 5, characterized in that: The spiral groove (7227), return groove (7228) and connecting groove (7229) are interconnected, and the ball (791) is rotatably connected within the spiral groove (7227), return groove (7228) and connecting groove (7229).

7. The anti-deformation adaptive welding fixture system for large pressure vessels according to claim 6, characterized in that: Both the first clamping wheel (76) and the second clamping wheel (78) are conical.

8. The anti-deformation adaptive welding fixture system for large pressure vessels according to claim 7, characterized in that: The spiral groove (7227) and the return groove (7228) have the same depth, and the connecting groove (7229) has a depth less than the depth of the spiral groove (7227) and the return groove (7228).

9. The anti-deformation adaptive welding fixture system for large pressure vessels according to claim 8, characterized in that: The connection between the connecting groove (7229) and the return groove (7228) is rounded, and the connection between the connecting groove (7229) and the spiral groove (7227) is stepped. A gap is provided at the rolling connection between the ball (791) and the sleeve (79).

10. The anti-deformation adaptive welding fixture system for large pressure vessels according to claim 9, characterized in that: The sleeve (79) is filled with hydraulic oil.

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