Magnetic suction type pipeline welding back gas protection device and method

Abstract

The invention relates to the technical field of gas protection equipment for welding, in particular to a magnetic suction type pipeline welding back gas protection device and method.The magnetic suction type pipeline welding back gas protection device comprises a pipe fitting, an internal walking mechanism and a rotating mechanism can be arranged on the pipe fitting, and the rotating mechanism is arranged on the outer wall of the pipe fitting; the internal walking mechanism is arranged on the inner wall of the pipe fitting; the magnetic attraction assembly is connected with the rotating mechanism and the internal walking mechanism, the rotating mechanism can drive the internal walking mechanism to rotate in the pipe fitting through the magnetic attraction assembly, and synchronous coupling of the internal walking mechanism and the external rotating mechanism is achieved through the arrangement of the internal walking mechanism and the external rotating mechanism and the utilization of the magnetic attraction assembly; the problem that a traditional pipeline welding back gas protection device is difficult to flexibly move and position in a pipe fitting is solved, it is ensured that a gas protection cover accurately reaches the target position of the welding back, and meanwhile an external rotating mechanism is driven to move through a magnetic attraction assembly.

Description

Technical Field

[0001] This invention relates to the field of gas protection equipment for welding, and more specifically, to a magnetic suction type back gas protection device and method for pipeline welding. Background Technology

[0002] In welding of oil, chemical, nuclear power, and pressure pipelines, back gas shielding is essential for the root welds of reactive metals such as stainless steel, nickel-based alloys, and titanium alloys, as well as high-alloy steels. The core purpose is to prevent the back of the weld from being oxidized and nitrided by air (mainly oxygen and nitrogen) at high temperatures, thus avoiding defects such as oxide scale formation, loss of alloying elements, porosity, and reduced corrosion resistance and mechanical properties. Current processes primarily involve sealing the pipe ends on both sides of the weld using water-soluble paper, high-temperature resistant tape, or mechanical methods (such as rubber plugs or metal baffles). The core of existing back gas shielding technology lies in forming a gas chamber through physical sealing and replacing the air with a high-purity inert gas, following the principles of "low inlet, high outlet" (suitable for shielding gases denser than air) or "high inlet, low outlet" (suitable for shielding gases less dense than air).

[0003] A pipeline welding gas protection device (announcement number WO2018176856A1) is described, comprising a main body with side sealing plates on both sides. The main body and side sealing plates cooperate to form a welding space. The side sealing plates have through holes for the pipeline to be welded to pass through. The main body has an operating port communicating with the welding space and an inlet for inputting welding shielding gas. An open sealing plate is installed at the operating port. The main body, side sealing plates, open sealing plates, and pipeline form a welding space. Shielding gas is introduced into the welding space through the inlet, filling the welding space and flowing through the gap between the open sealing plate and the pipeline to the operating port. The pipeline to be welded is placed within the aforementioned pipeline welding gas protection device. The welding operator can rotate the pipeline while simultaneously welding it at the operating port using tungsten inert gas (TIG) welding, enabling continuous operation.

[0004] While the above-mentioned technical solutions can provide gas protection for the welding position, they consume a large amount of protective gas. For large-diameter pipes, the internal argon purging method consumes a huge amount of gas, which not only wastes resources but also significantly increases production costs. For small-diameter pipes, the narrow internal space makes it difficult for personnel to enter and perform effective back protection operations, resulting in difficulty in guaranteeing welding quality.

[0005] A search revealed that Chinese invention patent CN109693059B discloses a back-side air-filled protective device for pipe welding, comprising a blocking component and blocking airbags. The blocking component includes a connector and a support component. The support component is symmetrically arranged at both ends of the connector. The blocking airbags are configured as two, each sleeved at both ends of the connector. The blocking component is axially perforated with an airflow pipe extending out of the support components at both ends. The airflow pipe is provided with a plurality of radially arranged first and second diversion pipes. The first and second diversion pipes are respectively connected to the blocking airbags at both ends of the connector.

[0006] The above technical solution fixes the blocking airbag at a certain position inside the pipe to form a static air chamber. The air chamber formed by the two blocking airbags is fixed. When the welding torch moves around the pipe, the airbags and air chambers do not rotate with it. Since the air chamber covers the weld seam of the entire pipe, gas will continuously flow out from a circle of weld seam, and the amount of shielding gas consumed is still relatively large. Moreover, when the two sections of pipe to be welded are long, it is difficult for the blocking airbags to reach the location of the weld seam, making positioning inconvenient. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a magnetic suction type back gas protection device and method for pipeline welding. The present invention solves the problem that traditional pipeline welding back gas protection devices are difficult to move and position flexibly inside the pipe fitting by setting an internal walking mechanism and an external rotating mechanism, and using a magnetic suction component 104 to achieve synchronous coupling between the two. The internal walking mechanism adopts a step-by-step movement method in which two outer covers alternately clamp the inner wall of the pipe fitting. With the extension and retraction of the first electric push rod, it can move stably and reliably along the axis of the pipe fitting, ensuring that the gas protection cover accurately reaches the target position on the back of the weld. At the same time, the magnetic suction component drives the external rotating mechanism to move.

[0008] A magnetic suction type pipeline welding back gas protection device includes a pipe fitting, on which an internal traveling mechanism and a rotating mechanism can be provided. The rotating mechanism is located on the outer wall of the pipe fitting, and the internal traveling mechanism is located on the inner wall of the pipe fitting.

[0009] A magnetic suction assembly connects the rotating mechanism and the internal traveling mechanism respectively. The rotating mechanism can drive the internal traveling mechanism to rotate inside the tube through the magnetic suction assembly.

[0010] The internal traveling mechanism is capable of moving within the pipe fitting along the pipe fitting axis.

[0011] The internal walking mechanism includes an outer cover, and there are two outer covers. The centers of the two outer covers are respectively fixedly connected to the two ends of the first electric push rod. A clamping assembly is provided inside the outer cover. The clamping assembly is connected to a second universal wheel. The clamping assembly can drive the second universal wheel to press against or move away from the inner wall of the pipe.

[0012] When one of the outer covers is connected to a universal wheel that is pressed against the inner wall of the pipe fitting, and the other outer cover is connected to a universal wheel that is moved away from the inner wall of the pipe fitting, the extension rod of the first electric push rod extends and can drive one outer cover to move, while the other outer cover does not move. At this time, the universal wheel connected to the outer cover that does not move moves away from the inner wall of the pipe fitting, while the universal wheel connected to the other outer cover that has moved moves against the inner wall of the pipe fitting. The extension rod of the first electric push rod retracts, driving the outer cover that does not move to move, thus realizing the movement of the two outer covers.

[0013] It also includes a gas protection mechanism, the internal traveling mechanism being connected to the gas protection mechanism, the gas protection mechanism being used for gas protection during welding, and the gas protection mechanism being used for delivering protective gas.

[0014] Furthermore, the clamping assembly includes a fixed plate, which is fixed inside the outer cover. The fixed plate has several evenly arranged sliding grooves, each of which is slidably connected to a slider. Each slider is rotatably connected to a crank arm, and the other end of all the crank arms is rotatably connected to the apex of a rotating block. The rotating block is a rhomboid block, and the center of the rotating block is rotatably connected to the center of the fixed plate. Each slider is fixedly connected to a round rod, and each round rod passes through the outer cover. The outer end of each round rod is fixedly connected to a second universal wheel. Two oppositely arranged sliders are fixedly connected to the two ends of a second electric push rod.

[0015] Furthermore, the gas protection mechanism includes a gas delivery detection component and a gas protection cover. The gas protection cover is connected to the first electric push rod and the gas delivery detection component. One end of the gas protection cover is open, and a gas screen is provided inside the open end of the gas protection cover.

[0016] Furthermore, it also includes a rubber pad. A rubber pad receiving frame is fixedly provided at the open end of the gas protective cover. A rubber pad is provided inside the rubber pad receiving frame. The rubber pad is adapted to the shape of the rubber pad receiving frame. A number of evenly arranged set screws are screwed onto the rubber pad receiving frame. The set screws can hold the rubber pad in place.

[0017] It also includes a sensor and a pressure relief valve. The pressure relief valve is located on one side of the gas protection shroud, and the sensor is located inside the gas protection shroud to monitor the gas pressure inside the gas protection shroud. When the gas pressure exceeds a set threshold, the pressure relief valve opens to release the pressure.

[0018] Furthermore, the gas delivery detection assembly includes an oxygen analyzer, an endoscope, and a gas delivery hose. One end of the gas delivery hose is fixedly connected to a gas cylinder. The probe of the endoscope is disposed inside the gas protective cover, and the working end of the probe of the oxygen analyzer is disposed inside the gas protective cover.

[0019] Furthermore, the gas protective cover is connected to the first electric push rod via an elastic positioning mechanism. The elastic positioning mechanism includes a support block, which is fixedly connected to the gas protective cover. A pair of guide posts are fixed to the lower side of the support block. Each guide post passes through both ends of the crossbeam and is fixedly connected to a baffle at its end. The baffle is fixedly connected to the crossbeam via a spring. The guide post passes through the spring. The crossbeam is fixedly connected to the telescopic rod of the third electric push rod. The outer shell of the third electric push rod is fixed to the first electric push rod.

[0020] Furthermore, the rotating mechanism includes a bracket with a welding port at the center, a handle fixed on the bracket, and the bracket is magnetically connected to the internal walking mechanism via a magnetic attraction component. A universal wheel is installed at each of the four corners of the bracket.

[0021] Furthermore, the magnetic suction assembly includes a first magnet and a second magnet, with the first magnet fixed to the upper sides of both ends of the bracket and the second magnet fixed to the outer end of the outer cover.

[0022] A method for using a magnetic suction type back gas protection device for pipeline welding includes the following steps:

[0023] Step 1: The operator first assembles the two pipe fittings to be welded. After the weld joint is assembled, the entire weld joint is completely sealed from the outside with masking tape.

[0024] Step 2: Along the pipe wall, simultaneously place the rotating mechanism and the external traveling mechanism on the inside and outside of the top of the pipe, respectively. The rotating mechanism and the external traveling mechanism remain relatively fixed under the action of magnetic force. At this time, the first magnet on the support and the second magnet on the outer cover of the internal traveling mechanism on the inner wall of the pipe achieve the initial coupling of the inner and outer mechanisms through magnetic attraction.

[0025] Step 3: When movement is required, the controller controls the clamping component of one of the outer covers in the internal walking mechanism to work, so that all the corresponding sliders drive the round rod and the second universal wheel to extend outward and press against the inner wall of the pipe fitting, fixing the outer cover as a fulcrum; at the same time, the clamping component of the other outer cover is in a relaxed state, the second universal wheel is away from the inner wall, and then the controller starts the first electric push rod, its telescopic rod extends, driving the relaxed outer cover to move along the axis of the pipe fitting to the vicinity of the welding area;

[0026] Step 4: After the movement is in place, the controller controls the clamping component of the outer cover to move, so that the second universal wheel abuts against the inner wall to become the new fixed fulcrum. The clamping component of the outer cover at the original fixed fulcrum is released, and the second universal wheel disengages from the inner wall. Then, the first electric push rod retracts, driving the outer cover at the original fixed fulcrum to move to a position close to the new fulcrum, completing one step movement. This cycle continues until the gas protection cover of the gas protection mechanism moves to the target protection position on the back of the weld.

[0027] During the movement of the internal walking mechanism, the external rotating mechanism moves along with it due to the presence of the magnetic attraction component until the welding joint is aligned with the welding position.

[0028] Step 5: When the gas protection cover is moved to the appropriate position, adjust the position of the crossbeam by the third electric push rod of the elastic positioning mechanism, so that the support block moves the gas protection cover to initially approach the pipeline. When the rubber pad is about to contact the pipe fitting, the guide column slides in the crossbeam hole, the baffle compresses the spring, and uses the spring force to make the rubber pad tightly fit the outer wall of the pipe fitting. Then tighten the set screw on the rubber pad receiving frame to further ensure the seal between the rubber pad and the pipe fitting.

[0029] Step Six: Before welding begins, the protective gas in the gas cylinder is delivered to the gas protective hood through the gas delivery hose via the gas screen. The oxygen analyzer monitors the oxygen concentration inside the hood in real time. When the concentration drops below the set value and the endoscope shows a clear view of the welding area, the operator can proceed with the welding operation. During the welding process, the sensor monitors the gas pressure inside the hood. If the pressure exceeds the threshold, the pressure relief valve will automatically open to release the pressure.

[0030] Step 7: If the axial protection position needs to be adjusted, repeat "Steps 3-4" above. If the circumferential protection position needs to be adjusted, pull the handle to drive the rotating mechanism to rotate. Through the magnetic force of the first magnet and the second magnet, the internal walking mechanism and the gas protection cover will rotate synchronously inside the pipe.

[0031] Compared with the prior art, the advantages and positive effects of the present invention are:

[0032] This invention solves the problem that traditional gas protection devices for pipeline welding back side are difficult to move and position flexibly inside the pipe fitting by setting up an internal walking mechanism and an external rotating mechanism and using a magnetic suction component to achieve synchronous coupling between the two. The internal walking mechanism adopts a step-by-step movement method in which two outer covers alternately clamp the inner wall of the pipe fitting. With the extension and retraction of the first electric push rod, it can move stably and reliably along the axis of the pipe fitting, ensuring that the gas protection cover accurately reaches the target position on the welding back side. At the same time, the magnetic suction component drives the external rotating mechanism to move.

[0033] The rotating mechanism can drive the internal traveling mechanism and the gas protection cover to rotate synchronously inside the pipe by operating the handle, thus realizing the adjustment of the protection position in the circumferential direction.

[0034] The gas protection cover in the gas protection mechanism is designed with a rubber pad receiving frame and an adjustable top screw, and is equipped with an elastic positioning mechanism to ensure that the rubber pad fits tightly against the outer wall of the pipe, effectively preventing the leakage of protective gas and improving the protection effect.

[0035] The clamping assembly drives the diamond-shaped rotating block through the second electric push rod, which drives multiple sliders and universal wheels to extend or retract simultaneously, thus achieving stable clamping of the inner wall of pipe fittings of different diameters.

[0036] The gas delivery detection component integrates an oxygen analyzer, endoscope, and sensors, enabling real-time monitoring of oxygen concentration inside the protective cover, the field of view in the welding area, and gas pressure. When the gas pressure exceeds a set threshold, the pressure relief valve automatically opens to release pressure, ensuring welding quality and operational safety. Compared to traditional back gas protection devices, it can significantly reduce the amount of back protective gas used. In addition to back gas protection, it also has functions for monitoring the oxygen content of the protective gas and inspecting the weld root, facilitating the inspection of the oxidation color at the weld root. Attached Figure Description

[0037] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0038] Figure 1 This is the three-dimensional representation of the present invention. Figure 1 ;

[0039] Figure 2 This is a perspective view of the pipe fitting of the present invention when cut open;

[0040] Figure 3 This is a partial perspective view illustrating the rotating mechanism of the present invention;

[0041] Figure 4 This is a partial perspective view of the internal walking mechanism and gas protection mechanism of the present invention;

[0042] Figure 5 This is a partial perspective view of the clamping components of the present invention;

[0043] Figure 6 This is a partial cross-sectional view of the internal walking mechanism and other components of the present invention.

[0044] Figure 7 This is a perspective view of the present invention.

[0045] In the diagram: 1. Rotating mechanism; 101. Bracket; 102. Weld joint; 103. Handle; 104. Magnetic suction assembly; 1041. First magnet; 1042. Second magnet; 105. Caster wheel one; 2. Pipe fitting; 3. Internal walking mechanism; 301. Outer cover; 303. Caster wheel two; 304. Clamping assembly; 3041. Fixed plate; 3042. Round rod; 3043. Slider; 3044. Second electric push rod; 3045. Crank arm; 3046. Slide groove; 305. First electric push rod 4. Gas protection mechanism; 401. Gas delivery detection assembly; 4011. Oxygen analyzer; 4012. Endoscope; 4013. Gas delivery hose; 404. Gas protection cover; 405. Sensor; 406. Pressure relief valve; 407. Rubber pad housing frame; 408. Gas screen; 409. Rubber pad; 4091. Top screw; 5. Elastic positioning mechanism; 501. Support block; 502. Guide column; 503. Crossbeam; 504. Spring; 505. Third electric push rod; 506. Baffle. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the accompanying drawings:

[0047] Example 1:

[0048] Combination Figures 1 to 7 A magnetic suction type pipeline welding back gas protection device includes a pipe fitting 2. An internal traveling mechanism 3, a gas protection mechanism 4 and a rotating mechanism 1 can be installed on the pipe fitting 2. The rotating mechanism 1 is installed on the outer wall of the pipe fitting 2, and the internal traveling mechanism 3 is installed on the inner wall of the pipe fitting 2. The internal traveling mechanism 3 is connected to the gas protection mechanism 4. The gas protection mechanism 4 is used to deliver protective gas to protect the weld joint of the pipe fitting 2 during welding.

[0049] The magnetic suction assembly 104 is connected to the rotating mechanism 1 and the internal walking mechanism 3 respectively. The rotating mechanism 1 can drive the internal walking mechanism 3 to rotate inside the tube 2 through the magnetic suction assembly 104.

[0050] The internal traveling mechanism 3 is capable of moving within the pipe fitting 2 along its axial direction. The internal traveling mechanism 3 includes two outer covers 301, the centers of which are respectively fixedly connected to the two ends of a first electric push rod 305. A clamping assembly 304 is provided inside each outer cover 301, and the clamping assembly 304 is connected to a second universal wheel 303. The clamping assembly 304 can drive the second universal wheel 303 to press against or move away from the inner wall of the pipe fitting 2.

[0051] The rotating mechanism 1 includes a bracket 101, a welding port 102 is provided in the center of the bracket 101, a handle 103 is fixed on the bracket 101, the bracket 101 is magnetically connected to the internal walking mechanism 3 through a magnetic suction assembly 104, and universal wheels 105 are respectively installed at the four corners of the bracket 101.

[0052] The magnetic assembly 104 includes a first magnet 1041 and a second magnet 1042. The first magnet 1041 is fixed to the upper sides of both ends of the bracket 101, and the second magnet 1042 is fixed to the outer end of the outer cover 301.

[0053] Example 2, based on the above examples, further discloses the following:

[0054] When one of the outer covers 301 is connected to a universal wheel 303 that is pressed against the inner wall of the pipe fitting 2, and the other outer cover 301 is connected to a universal wheel 303 that is moved away from the inner wall of the pipe fitting 2, the extension rod of the first electric push rod 305 extends and can drive one outer cover 301 to move, while the other outer cover 301 does not move. At this time, the universal wheel 303 connected to the one outer cover 301 that does not move moves away from the inner wall of the pipe fitting 2, while the universal wheel 303 connected to the other outer cover 301 that has moved moves against the inner wall of the pipe fitting 2. The extension rod of the first electric push rod 305 retracts, driving the one outer cover 301 that does not move to move, thus realizing the movement of the two outer covers 301.

[0055] In this embodiment, the gas protection mechanism 4 is used to deliver protective gas to the welding point of the pipe fitting 2 during welding. The non-contact synchronous rotation of the inner and outer mechanisms of the pipe fitting 2 is achieved through the magnetic suction component 104. When the operator holds the handle 103 on the bracket 101 and rotates it, the bracket 101 drives the inner walking mechanism 3 to rotate synchronously inside the pipe fitting 2 through the magnetic attraction between the first magnet 1041 and the second magnet 1042 on the outer cover 301 of the inner walking mechanism 3. This ensures that the gas protection mechanism 4 is always facing the welding area, achieving precise following of the back gas protection during the welding process. The movement of the inner walking mechanism 3 adopts a step-by-step design of "alternating clamping-movement".

[0056] Specifically, when the clamping assembly 304 of one outer cover 301 drives the universal wheel 303 to press against the inner wall of the pipe fitting 2, the outer cover 301 becomes a fixed fulcrum. At this time, the telescopic rod of the first electric push rod 305 extends, driving the other outer cover 301, which is in a relaxed state and whose universal wheel 303 is away from the inner wall, to move a certain distance along the axial direction of the pipe fitting 2. Subsequently, the moved outer cover 301, through the clamping assembly 304, makes the universal wheel 303 press against the inner wall to become a new fixed fulcrum. The clamping assembly 304 of the outer cover 301 at the original fixed fulcrum is released, the universal wheel 303 moves away from the inner wall, and the telescopic rod of the first electric push rod 305 retracts, driving the outer cover 301 at the original fixed fulcrum to move to a new position. This cycle repeats, realizing the stable axial movement of the internal walking mechanism 3 within the pipe fitting 2, thereby driving the gas protection mechanism 4 to adjust the protection position as needed to meet the back protection requirements of welding pipelines of different lengths.

[0057] Example 3: Based on the above examples, this example further discloses the following:

[0058] The clamping assembly 304 includes a fixed disk 3041, which is fixed inside the outer cover 301. The fixed disk 3041 has several evenly arranged sliding grooves 3046. Each sliding groove 3046 is slidably connected to a slider 3043. Each slider 3043 is rotatably connected to a crank arm 3045. The other end of all crank arms 3045 is rotatably connected to the apex of a rotating block. The rotating block is a rhomboid block, and its center is rotatably connected to the center of the fixed disk 3041. Each slider 3043 is fixedly connected to a round rod 3042, which passes through the outer cover 301. The outer end of each round rod 3042 is fixedly connected to a universal wheel 303. Two opposing sliders 3043 are fixedly connected to the two ends of a second electric push rod 3044.

[0059] In this embodiment, the extension and retraction of the telescopic rod of the second electric push rod 3044 can drive two oppositely arranged sliders 3043 to slide synchronously in opposite directions within the groove 3046 of the fixed disk 3041. When the telescopic rod of the second electric push rod 3044 extends, the two sliders 3043 will slide towards the two ends of the groove 3046 respectively, and then push the rhomboid rotating block to rotate around its center on the fixed disk 3041 through the crank arm 3045 rotatably connected to it. As the rotating block rotates, the other crank arms 3045 connected to the top of the rotating block will also be driven, so that all sliders 3043 slide outward along their respective grooves 3046. The sliders 3043 drive the round rod 3042 to extend outward from the outer cover 301, so that the universal wheels 303 at the outer end of the round rod 3042 simultaneously press against the inner wall of the pipe 2, realizing the clamping and fixing of the internal walking mechanism 3 at the outer cover 301.

[0060] When the telescopic rod of the second electric push rod 3044 retracts, the two opposing sliders 3043 slide towards the center of the groove 3046. Similarly, the crank arm 3045 pulls the rotating block to rotate in the opposite direction, causing all sliders 3043 to slide inward along the groove 3046. The round rod 3042 then retracts into the outer cover 301, and the universal wheel 303 moves away from the inner wall of the pipe 2, releasing the clamping state at the outer cover 301. Through this telescopic action of the second electric push rod 3044, the tightness between the universal wheel 303 in the clamping assembly 304 and the inner wall of the pipe 2 is controlled, providing clamping and releasing function switching for the "alternating clamping-movement" step-like movement of the internal walking mechanism 3. When the internal walking mechanism 3 moves, due to the presence of the magnetic suction assembly 104, the external rotating mechanism 1 follows.

[0061] Example 4: Based on the above examples, this example further discloses the following:

[0062] The gas protection mechanism 4 includes a gas delivery and detection component 401, a gas protection cover 404, a sensor 405, a rubber pad 409, and a pressure relief valve 406. The gas protection cover 404 is connected to the first electric push rod 305 and the gas delivery and detection component 401. One end of the gas protection cover 404 is open, and a gas screen 408 is provided inside the open end of the gas protection cover 404. A rubber pad receiving frame 407 is fixedly provided at the open end of the gas protection cover 404. A rubber pad 409 is provided inside the pad receiving frame 407. The rubber pad 409 is adapted to the shape of the rubber pad receiving frame 407. The rubber pad receiving frame 407 is screwed with several evenly arranged set screws 4091, which can hold the rubber pad 409 in place. The pressure relief valve 406 is located on one side of the gas protection cover 404. The sensor 405 is located inside the gas protection cover 404 to monitor the gas pressure inside the gas protection cover 404. When the gas pressure exceeds a set threshold, the pressure relief valve 406 opens to release pressure.

[0063] In this embodiment, the gas screen 408 is a mesh screen plate with air holes, fixedly installed inside the gas protection cover 404. Protective gas is supplied to the gas protection cover 404 through the gas delivery and detection component 401. The gas diffuses evenly throughout the entire internal space of the protection cover via the gas screen 408, creating a stable protective atmosphere for the pipeline welding back area. The rubber pad 409 inside the rubber pad receiving frame 407, under the action of the set screw 4091, can be adaptively adjusted according to pipelines of different diameters, ensuring that the rubber pad 409 can tightly fit the outer wall of the pipeline, effectively preventing damage to the protective layer. Gas leaks from the gap between the open end of the gas protective cover 404 and the pipeline. The rubber gasket 409 is replaceable and removable, making it easy to use. The sensor 405 is a pressure sensor that can monitor the gas pressure inside the gas protective cover 404 in real time. When the protective gas is continuously input and the gas pressure inside the cover exceeds the set threshold, the pressure relief valve 406 automatically opens to discharge the excess gas, so that the gas pressure inside the cover is maintained within a suitable welding protection range. This ensures the protection effect required for welding quality and avoids the adverse effects that excessive gas pressure may have on the equipment or welding area.

[0064] The gas delivery detection assembly 401 includes an oxygen analyzer 4011, an endoscope 4012, and a gas delivery hose 4013. One end of the gas delivery hose 4013 is fixedly connected to a gas cylinder. The probe of the endoscope 4012 is disposed inside the gas protection cover 404, and the working end of the probe of the oxygen analyzer 4011 is disposed inside the gas protection cover 404.

[0065] Example 5: Based on the above examples, this example further discloses the following:

[0066] In this embodiment, the other end of the gas delivery hose 4013 passes through and is connected to the side wall of the gas protective cover 404, and is used to stably deliver the protective gas in the gas cylinder to the gas screen 408. The probe working end of the oxygen analyzer 4011 extends into the gas protective cover 404, and can monitor the oxygen concentration inside the cover in real time and accurately. When the oxygen concentration is higher than the set allowable value, it can promptly remind the operator to adjust the delivery volume of the protective gas or check the sealing condition to ensure that the oxygen concentration in the welding area is within the ideal inert gas protection range, and avoid the oxidation of the weld due to excessive oxygen residue. The probe of the endoscope 4012 is installed inside the gas protective cover 404 near the welding area. It is connected to an external display device through a cable. The operator can clearly observe the real-time status of the pipeline welding back through the display device during the welding process, including the molten pool shape, weld formation and the coverage of the protective gas, etc., which facilitates timely detection and adjustment of possible problems during the welding process, and greatly improves the accuracy and reliability of the welding operation.

[0067] The gas protective cover 404 is connected to the first electric push rod 305 through an elastic positioning mechanism 5. The elastic positioning mechanism 5 includes a support block 501, which is fixedly connected to the gas protective cover 404. A pair of guide posts 502 are fixed to the lower side of the support block 501. Each guide post 502 passes through both ends of the crossbeam 503 and is fixedly connected to a baffle 506 at its end. The baffle 506 is fixedly connected to the crossbeam 503 through a spring 504. The guide post 502 passes through the spring 504. The crossbeam 503 is fixedly connected to the telescopic rod of the third electric push rod 505. The outer shell of the third electric push rod 505 fixes the first electric push rod 305.

[0068] In this embodiment, when the first electric push rod 305 drives the gas protective cover 404 closer to the pipeline surface, the crossbeam 503, under the action of the third electric push rod 505, can drive the support block 501 and the gas protective cover 404 to perform initial positioning. When the gas protective cover 404 is about to contact the pipeline, the guide post 502 will slide in the hole of the crossbeam 503, and the baffle 506 will compress the spring 504. The elastic force of the spring 504 will enable the gas protective cover 404 to adaptively conform to the pipeline surface with different curvatures or with slight unevenness, ensuring that a good pre-seal is formed between the protective cover and the pipeline, and avoiding damage to the protective cover or poor sealing caused by rigid contact.

[0069] The present invention also includes a controller, which is electrically connected to the first electric push rod 305, the second electric push rod 3044 and the third electric push rod 505. The controller transmits data with the sensor 405 and controls the oxygen analyzer 4011 and the endoscope 4012. The invention also includes a display screen for displaying the real-time status of the back of the pipeline weld detected by the endoscope 4012.

[0070] Example 6: Based on the above examples, this example further discloses the following:

[0071] The working process of this invention is as follows:

[0072] The operator first assembles the two pipe fittings 2 to be welded. After the weld joint is assembled, the entire weld joint is completely sealed from the outside with masking tape. Along the pipe wall, the rotating mechanism 1 and the external traveling mechanism are placed inside and outside the top of the pipe, respectively. The rotating mechanism 1 and the external traveling mechanism are kept relatively fixed under the action of magnetic force. At this time, the first magnet 1041 on the bracket 101 and the second magnet 1042 on the outer cover 301 of the inner traveling mechanism 3 of the inner wall of the pipe fitting 2 achieve the initial coupling of the inner and outer mechanisms through magnetic attraction. When movement is required, the controller controls the clamping component 304 of one of the outer covers 301 of the inner traveling mechanism 3 to work, that is, the second electric push rod 3044 extends, driving the relative slider 3043 to slide along the slide groove 3046 of the fixed plate 3041. The crank arm 3045 pushes the rhomboid rotating block to rotate, so that all sliders 3043 drive the round rod 3042 and the universal wheel 303 to extend outward synchronously and press against the inner wall of the pipe fitting 2, fixing the outer cover 301 as a fulcrum.

[0073] Meanwhile, the clamping assembly 304 of the other outer cover 301 is in a relaxed state, and the second universal wheel 303 is away from the inner wall. Then the controller activates the first electric push rod 305, whose telescopic rod extends, driving the relaxed outer cover 301 to move along the axis of the pipe 2 to the vicinity of the welding area. After moving into position, the controller controls the clamping assembly 304 of the outer cover 301 to move, so that the second universal wheel 303 presses against the inner wall to become a new fixed fulcrum. The clamping assembly 304 of the outer cover 301 at the original fixed fulcrum is released, and the second universal wheel 303 is disengaged from the inner wall. After that, the telescopic rod of the first electric push rod 305 retracts, driving the outer cover 301 at the original fixed fulcrum to move to a position close to the new fulcrum, completing one step movement. This cycle continues until the gas protection cover 404 of the gas protection mechanism 4 moves to the target protection position on the back of the weld. During the movement, the external rotating mechanism 1 moves along with the magnetic suction assembly 104 until the welding port 102 is aligned with the welding position.

[0074] When the gas shield 404 moves to the appropriate position, the position of the crossbeam 503 is adjusted by the third electric push rod 505 of the elastic positioning mechanism 5, so that the support block 501 drives the gas shield 404 to initially approach the pipeline. When the rubber pad 409 is about to contact the pipe fitting 2, the guide post 502 slides in the hole of the crossbeam 503, the baffle 506 compresses the spring 504, and the elastic force of the spring 504 makes the rubber pad 409 tightly fit the outer wall of the pipe fitting 2. Then, the set screw 4091 on the rubber pad receiving frame 407 is tightened to further ensure the seal between the rubber pad 409 and the pipe fitting 2.

[0075] Before welding begins, protective gas from the gas cylinder is delivered to the gas protective hood 404 via the gas delivery hose 4013 and the gas screen 408. The oxygen analyzer 4011 monitors the oxygen concentration inside the hood in real time. When the concentration drops below the set value and the endoscope 4012 displays a clear view of the welding area, the operator performs the welding operation. During the welding process, the sensor 405 monitors the gas pressure inside the hood. If the pressure exceeds the threshold, the pressure relief valve 406 automatically opens to release pressure.

[0076] If the axial protection position needs to be adjusted, repeat the above "alternating clamping-moving" steps. If the circumferential protection position needs to be adjusted, pull the handle 103 to drive the rotating mechanism 1 to rotate. Through the magnetic force of the first magnet 1041 and the second magnet 1042, the internal walking mechanism 3 will be driven to rotate. Throughout the process, the display screen shows the welding back condition detected by the endoscope 4012 and the monitoring data of the oxygen meter 4011 and the sensor 405 in real time, which makes it easy for the operator to monitor the welding quality and protection effect in real time.

[0077] Example 7: Based on the above examples, this example further discloses the following:

[0078] The present invention also provides a method for using a magnetic suction type back gas protection device for pipeline welding, comprising the following steps:

[0079] Step 1: The operator first assembles the two pipe fittings 2 that need to be welded. After the weld joint is assembled, the entire weld joint is completely sealed from the outside with masking tape.

[0080] Step 2: Along the pipe wall, simultaneously place the rotating mechanism 1 and the external traveling mechanism on the inside and outside of the top of the pipe, respectively. The rotating mechanism 1 and the external traveling mechanism remain relatively fixed under the action of magnetic force. At this time, the first magnet 1041 on the bracket 101 and the second magnet 1042 on the outer cover 301 of the inner wall of the pipe 2 travel mechanism 3 achieve the initial coupling of the inner and outer mechanisms through magnetic attraction.

[0081] Step 3: When movement is required, the controller controls the clamping component 304 of one of the outer covers 301 in the internal walking mechanism 3 to work, so that all the corresponding sliders 3043 drive the round rods 3042 and the second universal wheel 303 to extend outward synchronously and press against the inner wall of the pipe 2, fixing the outer cover 301 as a fulcrum; at the same time, the clamping component 304 of the other outer cover 301 is in a relaxed state, the second universal wheel 303 is away from the inner wall, and then the controller activates the first electric push rod 305, its telescopic rod extends, driving the relaxed outer cover 301 to move along the axis of the pipe 2 to the vicinity of the welding area;

[0082] Step 4: After the movement is in place, the controller controls the clamping component 304 of the outer cover 301 to move, so that the universal wheel 2 303 abuts against the inner wall to become a new fixed fulcrum. The clamping component 304 of the outer cover 301 at the original fixed fulcrum is released, and the universal wheel 2 303 is disengaged from the inner wall. Then, the first electric push rod 305 retracts, driving the outer cover 301 at the original fixed fulcrum to move to a position close to the new fulcrum, completing one step movement. This cycle continues until the gas protection cover 404 of the gas protection mechanism 4 moves to the target protection position on the back of the weld.

[0083] During the movement of the internal walking mechanism 3, the external rotating mechanism 1 moves along with it due to the presence of the magnetic suction component 104 until the welding joint 102 is aligned with the welding position.

[0084] Step 5: When the gas protection cover 404 is moved to the appropriate position, the position of the crossbeam 503 is adjusted by the third electric push rod 505 of the elastic positioning mechanism 5, so that the support block 501 drives the gas protection cover 404 to initially approach the pipeline. When the rubber pad 409 is about to contact the pipe fitting 2, the guide post 502 slides in the hole of the crossbeam 503, the baffle 506 compresses the spring 504, and the elastic force of the spring 504 makes the rubber pad 409 tightly fit the outer wall of the pipe fitting 2. Then, the set screw 4091 on the rubber pad receiving frame 407 is tightened to further ensure the seal between the rubber pad 409 and the pipe fitting 2.

[0085] Step Six: Before welding begins, the protective gas in the gas cylinder is delivered to the gas protective cover 404 through the gas delivery hose 4013 via the gas screen 408. The oxygen meter 4011 monitors the oxygen concentration inside the cover in real time. When the concentration drops below the set value and the endoscope 4012 shows a clear view of the welding area, the operator performs the welding operation. During the welding process, the sensor 405 monitors the gas pressure inside the cover. If the pressure exceeds the threshold, the pressure relief valve 406 automatically opens to release pressure.

[0086] Step 7: If the axial protection position needs to be adjusted, repeat the above "Steps 3-4". If the circumferential protection position needs to be adjusted, pull the handle 103 to drive the rotating mechanism 1 to rotate. Through the magnetic force of the first magnet 1041 and the second magnet 1042, the internal walking mechanism 3 and the gas protection cover 404 will rotate synchronously inside the pipe 2.

[0087] If the axial protection position needs to be adjusted, first stop the supply of protective gas, then move the gas protection cover 404 away from the inner wall of the pipe fitting 2, and repeat the above "steps 3-5".

[0088] Throughout the welding process, the display screen shows the welding back condition detected by the endoscope 4012 and the monitoring data of the oxygen analyzer 4011 and sensor 405 in real time, which makes it easy for operators to monitor the welding quality and protection effect in real time.

[0089] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A magnetic suction type pipeline welding back gas protection device, comprising a pipe fitting (2), characterized in that, An internal walking mechanism (3) and a rotating mechanism (1) can be provided on the pipe fitting (2). The rotating mechanism (1) is provided on the outer wall of the pipe fitting (2), and the internal walking mechanism (3) is provided on the inner wall of the pipe fitting (2). The magnetic suction assembly (104) is connected to the rotating mechanism (1) and the internal walking mechanism (3) respectively. The rotating mechanism (1) can drive the internal walking mechanism (3) to rotate inside the tube (2) through the magnetic suction assembly (104). The internal walking mechanism (3) is capable of moving within the pipe fitting (2) along the axis of the pipe fitting (2); The internal walking mechanism (3) includes an outer cover (301), there are two outer covers (301), the centers of the two outer covers (301) are respectively fixedly connected to the two ends of the first electric push rod (305), a clamping assembly (304) is provided inside the outer cover (301), the clamping assembly (304) is connected to the universal wheel (303), the clamping assembly (304) can drive the universal wheel (303) to press against or move away from the inner wall of the pipe (2); When one of the outer covers (301) is connected to the universal wheel (303) and it is pressed against the inner wall of the pipe fitting (2), and the other outer cover (301) is connected to the universal wheel (303) and it is away from the inner wall of the pipe fitting (2), the extension rod of the first electric push rod (305) extends and can drive one outer cover (301) to move, while the other outer cover (301) does not move. At this time, the universal wheel (303) connected to the one outer cover (301) that does not move moves away from the inner wall of the pipe fitting (2), while the universal wheel (303) connected to the other outer cover (301) that has moved moves against the inner wall of the pipe fitting (2). The extension rod of the first electric push rod (305) retracts and drives the one outer cover (301) that does not move to move, thereby realizing the movement of the two outer covers (301). It also includes a gas protection mechanism (4), the internal walking mechanism (3) is connected to the gas protection mechanism (4), the gas protection mechanism (4) is used to provide gas protection during welding, and the gas protection mechanism (4) is used to deliver protective gas.

2. The magnetic suction type pipeline welding back gas protection device according to claim 1, characterized in that, The clamping assembly (304) includes a fixed disk (3041) fixed inside the outer cover (301). The fixed disk (3041) has several evenly arranged sliding grooves (3046). Each sliding groove (3046) is slidably connected to a slider (3043). Each slider (3043) is rotatably connected to a crank arm (3045). The other end of all the crank arms (3045) is rotatably connected to the vertex of a rotating block. The rotating block is a rhomboid block. The center of the rotating block is rotatably connected to the center of the fixed disk (3041). The sliders (3043) are fixedly connected to round rods (3042). Each round rod (3042) passes through the outer cover (301). The outer end of each round rod (3042) is fixedly connected to the universal wheel (303). Two oppositely arranged sliders (3043) are fixedly connected to the two ends of a second electric push rod (3044).

3. A magnetic suction type pipeline welding back gas protection device according to claim 2, characterized in that, The gas protection mechanism (4) includes a gas delivery detection component (401) and a gas protection cover (404). The gas protection cover (404) is connected to the first electric push rod (305) and the gas delivery detection component (401). One end of the gas protection cover (404) is open, and a gas screen (408) is provided inside the open end of the gas protection cover (404).

4. A magnetic suction type pipeline welding back gas protection device according to claim 3, characterized in that, It also includes a rubber pad (409). A rubber pad receiving frame (407) is fixedly provided at the open end of the gas protective cover (404). A rubber pad (409) is provided inside the rubber pad receiving frame (407). The rubber pad (409) is adapted to the shape of the rubber pad receiving frame (407). The rubber pad receiving frame (407) is screwed with a number of evenly arranged set screws (4091). The set screws (4091) can hold the rubber pad (409). It also includes a sensor (405) and a pressure relief valve (406). The pressure relief valve (406) is located on one side of the gas protection shield (404), and the sensor (405) is located inside the gas protection shield (404) to monitor the gas pressure inside the gas protection shield (404). When the gas pressure exceeds a set threshold, the pressure relief valve (406) opens to release pressure.

5. A magnetic suction type pipeline welding back gas protection device according to claim 4, characterized in that, The gas delivery detection assembly (401) includes an oxygen meter (4011), an endoscope (4012), and a gas delivery hose (4013). One end of the gas delivery hose (4013) is fixedly connected to a gas cylinder. The probe of the endoscope (4012) is located inside the gas protection cover (404), and the working end of the probe of the oxygen meter (4011) is located inside the gas protection cover (404).

6. A magnetic suction type pipeline welding back gas protection device according to claim 5, characterized in that, The gas shield (404) is connected to the first electric push rod (305) through an elastic positioning mechanism (5). The elastic positioning mechanism (5) includes a support block (501). The support block (501) is fixedly connected to the gas shield (404). A pair of guide posts (502) are fixed on the lower side of the support block (501). Each guide post (502) passes through both ends of the crossbeam (503) and is fixedly connected to a baffle (506) at its end. The baffle (506) is fixedly connected to the crossbeam (503) through a spring (504). The guide post (502) passes through the spring (504). The crossbeam (503) is fixedly connected to the telescopic rod of the third electric push rod (505). The outer shell of the third electric push rod (505) is fixed to the first electric push rod (305).

7. A magnetic suction type pipeline welding back gas protection device according to claim 5, characterized in that, The rotating mechanism (1) includes a bracket (101), a welding port (102) is provided in the center of the bracket (101), a handle (103) is fixed on the bracket (101), the bracket (101) is magnetically connected to the internal walking mechanism (3) through a magnetic suction component (104), and a universal wheel (105) is installed at each of the four corners of the bracket (101).

8. A magnetic suction type pipeline welding back gas protection device according to claim 7, characterized in that, The magnetic suction assembly (104) includes a first magnet (1041) and a second magnet (1042). The first magnet (1041) is fixed to the upper side of both ends of the bracket (101), and the second magnet (1042) is fixed to the outer end of the outer cover (301).

9. The method of using a magnetic suction type pipeline welding back gas protection device according to claim 8, characterized in that, Includes the following steps: Step 1: The operator first assembles the two pipe fittings (2) that need to be welded. After the weld joint is assembled, the entire weld joint is completely sealed from the outside with paper tape. Step 2: Along the pipe wall, simultaneously place the rotating mechanism (1) and the external traveling mechanism on the inside and outside of the top of the pipe, respectively. The rotating mechanism (1) and the external traveling mechanism remain relatively fixed under the action of magnetic force. At this time, the first magnet (1041) on the bracket (101) and the second magnet (1042) on the outer cover (301) of the inner wall of the pipe fitting (2) achieve the initial coupling of the inner and outer mechanisms through magnetic attraction. Step 3: When movement is required, the controller controls the clamping component (304) of one of the outer covers (301) in the internal walking mechanism (3) to work, so that all the corresponding sliders (3043) drive the round rod (3042) and the universal wheel (303) to extend outward and press against the inner wall of the pipe (2) simultaneously, fixing the outer cover (301) as a fulcrum; at the same time, the clamping component (304) of the other outer cover (301) is in a relaxed state, the universal wheel (303) moves away from the inner wall, and then the controller starts the first electric push rod (305), its telescopic rod extends, and drives the relaxed outer cover (301) to move along the axis of the pipe (2) to the vicinity of the welding area; Step 4: After the movement is in place, the controller controls the clamping component (304) of the outer cover (301) to move, so that the universal wheel (303) abuts against the inner wall to become a new fixed fulcrum. The clamping component (304) of the outer cover (301) at the original fixed fulcrum is released, and the universal wheel (303) is disengaged from the inner wall. Then, the first electric push rod (305) retracts, driving the outer cover (301) at the original fixed fulcrum to move to a position close to the new fulcrum, completing one step movement. This cycle continues until the gas protection cover (404) of the gas protection mechanism (4) moves to the target protection position on the back of the weld. Step 5: When the gas shield (404) moves to the appropriate position, the position of the crossbeam (503) is adjusted by the third electric push rod (505) of the elastic positioning mechanism (5), so that the support block (501) drives the gas shield (404) to initially approach the pipeline. When the rubber pad (409) is about to contact the pipe fitting (2), the guide column (502) slides in the hole of the crossbeam (503), the baffle (506) compresses the spring (504), and the elastic force of the spring (504) makes the rubber pad (409) fit tightly against the outer wall of the pipe fitting (2). Then, the set screw (4091) on the rubber pad receiving frame (407) is tightened to further ensure the seal between the rubber pad (409) and the pipe fitting (2). Step 6: Before welding begins, the protective gas in the gas cylinder is delivered to the gas protective cover (404) through the gas delivery hose (4013) via the gas screen (408). The oxygen meter (4011) monitors the oxygen concentration inside the cover in real time. When the concentration drops below the set value and the endoscope (4012) shows a clear view of the welding area, the operator performs the welding operation. During the welding process, the sensor (405) monitors the gas pressure inside the cover. If the pressure exceeds the threshold, the pressure relief valve (406) automatically opens to release pressure. Step 7: If the axial protection position needs to be adjusted, repeat the above "Step 3-4". If the circumferential protection position needs to be adjusted, pull the handle (103) to drive the rotating mechanism (1) to rotate. Through the magnetic force of the first magnet (1041) and the second magnet (1042), the internal walking mechanism (3) and the gas protection cover (404) will rotate synchronously in the pipe (2).

10. The method of using a magnetic suction type pipeline welding back gas protection device according to claim 9, characterized in that, in, During the movement of the internal walking mechanism (3), the external rotating mechanism (1) moves along with it due to the presence of the magnetic suction component (104) until the welding joint (102) is aligned with the welding position.

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