Pipeline welding protection device and pipeline welding protection method thereof

Abstract

The invention relates to the field of pipeline welding, in particular to a pipeline welding protection device and a pipeline welding protection method thereof.The protection device comprises a mounting cylinder, a fixing cylinder, a mounting plate, a sealing gasket, a sealing assembly, a first locking piece and a second locking piece; the sealing gasket comprises a round gasket part fixedly connected to the mounting plate and protruding edge parts integrally formed on the side, facing the mounting cylinder, of the round gasket part, the protruding edge parts are arranged on the plate face of the mounting plate and the open end of the mounting cylinder in a spaced mode, and the sealing assembly comprises a first driving piece and a second driving piece which are arranged in a sliding mode; and the multiple sealing blocks are hinged to the ends, close to the convex edge part, of the first driving piece and the second driving piece correspondingly, the multiple sealing blocks can form an annular sealing piece, can slide to the position between the convex edge part and the open end and can abut against the convex edge part, and the effects that the pipeline welding quality is guaranteed, and the welding machining safety is improved are achieved.

Description

Technical Field

[0001] The present application relates to the field of pipeline welding, and in particular to a pipeline welding protection device and a pipeline welding protection method thereof. Background Art

[0002] At present, during the pipeline laying and maintenance and rectification stage, it is often necessary to weld stainless steel pipes and stainless steel flanges. Due to the great affinity between stainless steel and oxygen medium, the weld metal of the stainless steel pipe is easily oxidized during the welding process. Therefore, effective weld protection measures need to be taken during welding, otherwise the mechanical properties and corrosion resistance of the weld metal will be reduced.

[0003] Under the current circumstances, in the maintenance work of chemical plants, since welding is a high-temperature hot work, when welding the welds of flammable and explosive medium pipelines and flanges, if there is flammable and explosive medium leakage in the upstream pipeline of the welding point.

[0004] The above-mentioned existing technical solutions have the following defects: during the welding process of the pipeline and the flange, the flammable and explosive medium leaking from the pipeline overflows and contacts the high-temperature weld or the sparks generated by the welding, posing a safety hazard of explosion, which is not conducive to the welding work of the pipeline. Summary of the Invention

[0005] In order to ensure the quality of pipeline welding and improve the safety of welding processing, the present application provides a pipeline welding protection device and a pipeline welding protection method.

[0006] On the one hand, the above technical objectives of this application are achieved through the following technical solutions:

[0007] A pipeline welding protection device and pipeline welding protection method thereof, comprising a mounting cylinder having an open end and a closed end at its two ends, a fixed cylinder having one end fixedly connected to the inner wall of the closed end of the mounting cylinder and arranged coaxially, a mounting plate in the form of a circular plate, one plate surface of which is coaxially fixedly connected to the fixed cylinder near the open end and spaced apart from the open end, a sealing gasket provided on the plate surface of the mounting plate on a side facing away from the fixed cylinder, a sealing assembly slidably provided on the outer wall of the fixed cylinder and having one end slidably provided outside the closed end, a first locking member provided on the outer wall of the closed end, and a second locking member provided on one end of the sealing assembly located outside the closed end;

[0008] The sealing gasket includes a circular pad portion fixed to the mounting plate and a convex edge portion integrally formed on the side of the circular pad portion facing the mounting tube, wherein the convex edge portion is spaced apart from the plate surface of the mounting plate and the open end of the mounting tube;

[0009] The sealing assembly includes a first driving member and a second driving member that are slidably arranged, and a plurality of sealing blocks that are respectively hinged to the first driving member and the second driving member near one end of the flange portion. The plurality of sealing blocks can form a circular ring seal and can slide between the flange portion and the open end and can be tightly pressed against the flange portion.

[0010] By adopting the above technical solution, before welding the pipeline, the end of the protective device provided with the sealing gasket is first placed into the interior of the pipeline from the pipe mouth, and the end of the sealing assembly away from the sealing gasket is located at the pipe mouth. When the sealing gasket is placed in the pipeline to be welded, the outer peripheral wall of the flange portion is pressed against the inner wall of the pipeline to be welded and the flange portion is squeezed. Then, the locking of the first locking member on the first driving member and the locking of the second locking member on the second driving member are respectively released, and the first driving member and the second driving member are pushed toward the flange portion in turn. Then, the first driving member and the second driving member are locked by the first locking member and the second locking member in turn, so that the multiple sealing blocks can be stably pressed against the flange portion and squeeze the flange portion in the horizontal direction. Combined with the squeezing of the inner wall of the pipeline to be welded on the radial direction of the flange portion, the sealing performance of the flange portion and the inner wall of the pipeline to be welded can be effectively improved, and the possibility of gas leakage upstream of the pipeline to be welded can be reduced. Finally, inert gas is filled from the pipe mouth to the direction of the sealing block, and then the flange is welded to the pipe mouth of the pipeline to be welded, thereby ensuring the quality of pipeline welding and improving the safety of the connection work.

[0011] Optionally, the convex edge portion is processed from its outer diameter to the direction of its inner diameter to form a slope;

[0012] The sealing block is processed with a first arc-shaped surface which can be fitted with the inclined surface of the convex edge portion.

[0013] By adopting the above technical solution, the inclined surface can effectively increase the release area between the sealing block and the flange, while also reducing the thickness of the flange. After the sealing block is pressed against the flange, the flange is more likely to deform, which can further improve the sealing performance of the flange to the inner wall of the pipe.

[0014] Optionally, the inner diameter of the flange portion is consistent with the outer diameter of the mounting plate.

[0015] By adopting the above technical solution, the inner wall of the convex edge is in contact with the outer peripheral surface of the mounting plate, so that the mounting plate forms support for the convex edge in the direction of the inner wall of the pipe to be welded, and is conducive to the convex edge and the inner wall of the pipe to be welded to be tightly pressed, which is conducive to improving the sealing of the convex edge against the inner wall of the pipe to be welded.

[0016] Optionally, the first driving member includes a connecting plate arranged outside the closed end and in a circular ring shape, and a first sliding rod with one end fixed to the connecting plate and slidably arranged on the outer wall of the fixed cylinder. There are at least two first sliding rods, and the sealing block is hinged to one end of the first sliding rod close to the flange and can be received in the mounting cylinder.

[0017] By adopting the above technical solution, within the limited space of the installation tube, the first slide rod can be pushed from the space outside the closed end of the installation tube, which is beneficial for the first slide rod to drive the sealing block to press against the convex edge.

[0018] Optionally, the first driving member includes a connecting tube fixed to the outer wall of the closed end and sleeved on the outer wall of the first sliding rod, a driving rod rotatably arranged in the connecting tube, an insertion rod fixed to one end of the driving rod and located in the connecting tube, and a spring fixed to the driving rod and the other end of which abuts against the inner wall of the connecting tube, the spring and the insertion rod are respectively located on opposite sides of the same end of the driving rod, and the end of the insertion rod away from the spring can be plugged into the first sliding rod.

[0019] By adopting the above technical solution, the spring can rely on its own elastic force to stably insert the insertion rod into the socket, thereby locking the first sliding rod. When the locking relationship needs to be released, the driving rod is pressed away from one end of the insertion rod, so that the driving rod compresses the spring, thereby facilitating the insertion rod to disengage from the socket.

[0020] Optionally, two insertion holes are provided on the first sliding rod. When the sealing block is pressed against the convex edge, the insertion rod is inserted into one of the insertion holes. When the sealing block is located in the installation tube, the insertion rod is inserted into the other insertion hole.

[0021] By adopting the above technical solution, the effective working state and the idle state of the first sliding rod are locked respectively.

[0022] Optionally, the second driving member includes a telescopic rod slidably inserted on the connecting plate, and a second sliding rod fixed to the telescopic rod and spaced apart from the telescopic rod. There are at least two second sliding rods and they are spaced apart from the first sliding rod in sequence. The sealing block is hinged to one end of the second sliding rod close to the flange and can be received in the mounting tube.

[0023] By adopting the above technical solution, the second sliding rod can accommodate the sealing block in the installation cylinder, and is also conducive to forming a circular ring-shaped sealing member with multiple sealing blocks.

[0024] Optionally, the second locking member includes a mounting tube fixedly connected to the outer wall of the connecting plate facing away from the closed end of the mounting tube, a rotating rod eccentrically arranged on the outer wall of the mounting tube, and a locking block movably arranged in the mounting tube and abutting against the outer peripheral surface of the rotating rod. The telescopic rod is slidably arranged in the mounting tube, and the locking block can be tightly pressed against the telescopic rod.

[0025] By adopting the above technical solution, while not hindering the telescopic rod from driving the sealing block to move, it is also convenient to lock the position of the telescopic rod and the connecting plate. The overall structure of the second locking piece is simple and easy to operate, and it can also form a stable locking connection between the connecting plate and the telescopic rod.

[0026] Optionally, the outer wall of the locking block is processed into an arc-shaped convex surface, and a locking groove is opened on the outer wall of the telescopic rod along its length direction. The notch of the locking groove is an arc-shaped concave surface and can be tightly pressed against the arc-shaped convex surface of the locking block.

[0027] By adopting the above technical solution, the arcuate surface can increase the contact area between the two, thereby increasing the static friction between the two, thereby improving the locking stability of the locking block on the telescopic rod.

[0028] On the other hand, this application also provides the following technical solutions:

[0029] A pipeline welding protection method includes the following steps:

[0030] Step 1: Place the protective device as a whole into the pipe to be welded from the pipe opening of the pipe to be welded;

[0031] Step 2: Release the lock of the telescopic rod by the second locking assembly;

[0032] Step 3: Push the connecting plate until the sealing block is pressed against the convex edge;

[0033] Step 4: After the sealing block is pressed against the convex edge, insert the insertion rod into the insertion hole away from the sealing block;

[0034] Step 5: Push the telescopic rod until the sealing block touches the convex edge;

[0035] Step 6: Move the operating panel so that the locking block locks the telescopic rod and the connecting plate;

[0036] Step 7: Blow inert gas into the sealing block from the pipe mouth of the pipe to be welded.

[0037] In summary, this application has the following technical effects:

[0038] 1. By providing an installation cylinder, a fixing cylinder, a mounting plate, a sealing gasket, a sealing assembly, a first locking piece, and a second locking piece, when the sealing gasket is placed in the pipe to be welded, the outer peripheral wall of the convex edge portion is pressed against the inner wall of the pipe to be welded and the convex edge portion is squeezed, and then the locking piece is released from the locking piece to the driving piece, and the first driving piece and the second driving piece are pushed toward the convex edge portion in sequence, and then the driving piece is locked by the locking piece in sequence, so that the multiple sealing blocks can be stably pressed against the convex edge portion and squeeze the convex edge portion in the horizontal direction, and cooperate with the squeezing of the inner wall of the pipe to be welded on the radial direction of the convex edge portion, which can effectively improve the sealing performance of the convex edge portion and the inner wall of the pipe to be welded, and reduce the possibility of gas leakage in the upstream of the pipe to be welded, and finally fill in inert gas from the pipe orifice to the pipe to be welded in the direction of the sealing block, and then start welding the flange to the pipe orifice to be welded, thereby ensuring the quality of pipeline welding and improving the safety of the joint work;

[0039] 2. By providing a beveled surface on the convex edge, the release area between the sealing block and the convex edge can be effectively increased while reducing the thickness of the convex edge. When the sealing block is pressed against the convex edge, the convex edge is more likely to deform, which can further improve the sealing performance of the convex edge against the inner wall of the pipe.

[0040] 3. By setting the inner diameter of the flange to be consistent with the outer diameter of the mounting plate, the inner wall of the flange is in contact with the outer peripheral surface of the mounting plate, so that the mounting plate can support the flange in the direction of the inner wall of the pipe to be welded, and facilitate the flange to be tightly pressed against the inner wall of the pipe to be welded, thereby improving the sealing performance of the flange against the inner wall of the pipe to be welded. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is the appearance structure diagram of this application;

[0042] Figure 2 This is a structural diagram of the application from another angle;

[0043] Figure 3 It is a cross-sectional structural diagram of the installation cylinder;

[0044] Figure 4 This is the assembly structure diagram of the fixed cylinder, mounting plate and sealing gasket;

[0045] Figure 5 It is a structural diagram of the sealing component;

[0046] Figure 6 is a structural diagram of the first driving member;

[0047] Figure 7 is a structural diagram of the second driving member;

[0048] Figure 8 is a cross-sectional structural diagram of the first locking member;

[0049] Figure 9 It is an exploded structural diagram of the second locking member.

[0050] Explanation of reference numerals: 1. mounting cylinder; 11. cylinder body; 12. bottom plate; 2. fixing cylinder; 21. slide groove; 22. fixing block; 3. mounting plate; 4. sealing gasket; 41. round pad portion; 42. flange portion; 43. embedding groove; 5. sealing assembly; 51. first driving member; 511. connecting plate; 512. first sliding rod; 5121. insertion hole; 513. first fixing plate; 52. second driving member; 521. telescopic rod; 5211. locking groove; 522. support rod; 523. second sliding rod; 524. second fixing plate; 53. hinged rod; 54. sealing block; 541. fixing groove; 542 , first arcuate surface; 543, second arcuate surface; 6, first locking piece; 61, connecting tube; 611, operating notch; 612, connecting part; 62, mounting shaft; 63, driving rod; 631, operating section; 632, mounting section; 633, plug-in section; 634, pressing column; 64, plug-in rod; 65, spring; 7, second locking piece; 71, mounting tube; 711, thickened portion; 712, mounting hole; 713, support; 714, limiting hole; 72, fixed shaft; 73, rotating rod; 74, operating panel; 75, locking block; 751, locking block; 752, connecting block; 753, limiting rod. DETAILED DESCRIPTION

[0051] The present application is further described in detail below with reference to the accompanying drawings.

[0052] Example 1

[0053] The present application discloses a pipeline welding protection device, combined with Figure 1-Figure 5 The protective device includes a mounting tube 1 with an open end and a closed end at both ends respectively, a fixing tube 2 coaxially arranged in the mounting tube 1 and fixed at one end to the inner wall of the closed end of the mounting tube 1, a mounting plate 3 coaxially fixed to the fixing tube 2 away from the closed end of the mounting tube 1 and spaced apart from the open end of the mounting tube 1, a sealing gasket 4 detachably connected to the mounting plate 3 on the side away from the fixing tube 2 by screws, a sealing assembly 5 slidably arranged on the mounting tube 1 and one end of which can slide in a direction away from the open end of the mounting tube 1, a first locking piece 6 fixedly arranged on the outer wall of the closed end of the mounting tube 1, and a second locking piece 7 arranged at the sliding end of the sealing assembly 5 and located outside the closed end of the mounting tube 1.

[0054] Combine Figure 3 and Figure 4The mounting tube 1 includes a body 11 and a bottom plate 12 integrally formed on one end of the body 11. The end of the body 11 away from the bottom plate 12 is an open end, and a circular hole is coaxially provided on the bottom plate 12. One end of the fixed tube 2 is fixedly connected to the bottom plate 12 and arranged corresponding to the circular hole. The outer diameter of the fixed tube 2 is larger than the diameter of the circular hole. The length of the fixed tube 2 is larger than the depth of the mounting tube 1, and the other end of the fixed tube 2 is located outside the body 11. A plurality of slide grooves 21 are provided on the outer wall of the fixed tube 2 along its axis and at equal angles. In this embodiment, there are eight slide grooves 21, and the two ends of the slide grooves 21 are respectively connected to the two end faces of the fixed tube 2. A fixing block 22 is integrally formed on the outer wall of the fixed tube 2 and located between two adjacent slide grooves 21. The fixing block 22 is provided with a through hole whose axis is parallel to the axis of the fixed tube 2. After the bolt is inserted into the through hole, the fixed tube 2 can be fixed to the inner plate surface of the bottom plate 12.

[0055] Reference Figure 4 The mounting plate 3 is a circular plate and is coaxially fixed to the end face of the fixing tube 2 located outside the open end of the mounting tube 1 by bolts. The outer diameter of the mounting plate 3 is larger than the outer diameter of the cylinder 11. The sealing gasket 4 includes a circular pad portion 41 having an outer diameter larger than the diameter of the mounting plate 3, and an annular flange portion 42 integrally formed and provided on the circular surface of one side of the circular pad portion 41. The outer diameter of the flange portion 42 is the same as the outer diameter of the circular pad portion 41 and both are larger than the outer diameter of the cylinder 11. The inner diameter of the flange portion 42 is the same as the outer diameter of the mounting plate 3. The side of the flange portion 42 facing away from the circular pad portion 41 is formed with an inclined surface, which slopes from the outer wall of the flange portion 42 to its inner wall. The annular flange portion 42 and the circular pad portion 41 form a groove 43. The mounting plate 3 is disposed in the groove 43, and the surface of the mounting plate 3 facing away from the circular pad portion 41 is spaced apart from the inclined surface, creating a space for the flange portion 42.

[0056] Combine Figure 5-Figure 7 The sealing assembly 5 includes a first driving member 51 and a second driving member 52 that are slidably disposed in the slide groove 21 and can extend out of the circular hole, a pair of hinged rods 53 that are spaced apart and have one end hinged to the driving member and are located between the mounting plate 3 and the bottom plate 12, and a sealing block 54 that is hinged to the end of the hinged rod 53 away from the driving member. The outer wall of the sealing block 54 can extend out of the gap between the open end of the cylinder 11 and the mounting plate 3 and can be tightly pressed against the inclined surface of the flange 42. After the sealing gasket 4 is inserted into the inner wall of the pipe to be welded, the outer wall of the flange 42 is in contact with the inner wall of the pipe to form a preliminary seal. When the sealing block 54 is pressed against the inclined surface of the flange 42, it squeezes the flange 42, further enhancing the sealing between the flange 42 and the inner wall of the pipe to be welded.

[0057] Reference Figure 6The first driving member 51 slides within the circular hole at one end away from the mounting plate 3. The first driving member 51 comprises a connecting plate 511, a first sliding rod 512 whose length is perpendicular to the surface of the connecting plate 511 and one end is fixed to the connecting plate 511, and a pair of first fixing plates 513 fixed to the outer wall of the first sliding rod 512 at the end away from the connecting plate 511. The connecting plate 511 is a circular plate with coaxial circular holes formed therein. Four first sliding rods 512 are provided and are evenly arranged at equal angles on the same surface of the connecting plate 511. The four first sliding rods 512 slide within four mutually spaced slots 21, respectively. The outer walls of the first sliding rods 512 are flush with the outer circumferential walls of the connecting plate 511 and the outer circumferential walls of the fixing tube 2. Two insertion holes 5121 are formed on the outer wall of one of the first sliding rods 512, spaced apart along its length, into which the locking end of the first locking member 6 can be inserted. The first fixing plate 513 is a strip-shaped plate and its length direction is parallel to the length direction of the first sliding rod 512 . One end of the hinge rod 53 is hinged between a pair of first fixing plates 513 .

[0058] Reference Figure 7 The second driving member 52 slides within the circular hole at its end away from the mounting plate 3. The second driving member 52 includes a telescopic rod 521 that slides within the circular hole; a support rod 522 with one end fixed to the telescopic rod 521 and positioned between two adjacent first sliding rods 512; a second sliding rod 523 fixed to the end of the support rod 522 away from the telescopic rod 521 and slidingly positioned within the slide groove 21; and a second fixing plate 524 fixed to the outer wall of the end of the second sliding rod 523 away from the support rod 522. The telescopic rod 521 is a round rod, and the end of the telescopic rod 521 away from the support rod 522 is located outside the connecting plate 511, facing away from the base plate 12. A locking groove 5211 is defined on the outer circumference of the telescopic rod 521 along its axis. The wall of the locking groove 5211 is an arc-shaped concave surface. The locking end of the second locking member 7 can be snapped into the locking groove 5211. The length of the support rods 522 is perpendicular to the axis of the telescopic rod 521. There are four support rods 522, each located between two adjacent first slide rods 512. Four second slide rods 523 are provided, each slidably positioned within the slide slots 21 between two first slide rods 512. The four second slide rods 523 and the four first slide rods 512 are alternately positioned within the eight slide slots 21. The outer walls of the second slide rods 523 are flush with the outer circumferential wall of the fixed cylinder 2. The second fixed plate 524 is a strip-shaped plate with its length parallel to the length of the second slide rods 523. One end of the hinged rod 53 is hinged between the two second fixed plates 524.

[0059] Reference Figure 5The sealing blocks 54 are comprised of eight pieces, each hinged to eight pairs of hinged rods 53. The sealing blocks 54 are generally fan-shaped, and the sidewalls of the eight sealing blocks 54 fit together to form a circular seal. A fixing groove 541 is integrally formed on one sidewall of the sealing block 54, and the end of the hinged rod 53, facing away from the fixing plate, is hingedly connected to the fixing groove 541. On the side of the sealing block 54 facing away from the fixing groove 541, a first curved surface 542 and a second curved surface 543 are formed from opposite edges of the sealing block 54 in the middle. The first curved surface 542 is capable of fitting against the inclined surface of the convex edge, while the second curved surface 543 is capable of abutting against the open end of the cylinder 11.

[0060] Combine Figure 7 and Figure 8 The first locking member 6 includes a connecting tube 61 with one end fixedly provided on the outer surface of the base plate 12 and coaxially arranged with the circular hole, a mounting shaft 62 fixedly provided on the connecting tube 61 and perpendicular to the axis of the connecting tube 61, a driving rod 63 rotatably provided on the mounting shaft 62, an insert rod 64 fixedly connected to the driving end of the driving rod 63, and a spring 65 with one end fixedly connected to the driving end of the driving rod 63, and the end of the spring 65 away from the driving rod 63 abuts against the inner wall of the connecting tube 61.

[0061] The connecting tube 61 is sleeved around the four first slide bars 512. An operating notch 611 is defined on the end of the connecting tube 61 facing away from the base plate 12, toward the base plate 12. The operating notch 611 is spaced from the base plate 12 and includes a connecting portion 612. Two mounting notches (not shown) are defined on the outer wall of the connecting tube 61, located on opposite sides of the operating notch 611. The mounting shaft 62 is fixedly mounted within these two mounting notches. The end of the spring 65, away from the drive rod 63, abuts against the inner wall of the connecting portion 612.

[0062] The drive rod 63 includes an operating section 631 that rotates within the operating notch 611, a mounting section 632 integrally formed with the end of the operating section 631 facing away from the mounting notch, a plug-in section 633 integrally formed with the end of the mounting section 632 facing away from the operating section 631, and a pressing post 634 fixedly mounted on the operating section 631. The mounting section 632 is rotatably connected to the mounting shaft 62. The plug-in section 633 is located within the connecting tube 61, with the end of the plug-in section 633 facing away from the mounting section 632 located below the connecting portion 612. The pressing post 634 is located outside the connecting tube 61. The operating section 631, mounting section 632, and plug-in section 633 form a Z-shape overall, with the lengths of the operating section 631 and the plug-in section 633 parallel to each other.

[0063] The insertion rod 64 is inserted through and fixedly connected to the end of the insertion section 633 away from the mounting section 632. The length of the insertion rod 64 is perpendicular to the length of the insertion section 633. The two ends of the insertion rod 64 are located on opposite sides of the insertion section 633, and the end of the insertion rod 64 away from the connecting portion 612 can be inserted into the insertion hole 5121. One end of the spring 65 is sleeved over the end of the insertion rod 64 located between the insertion section 633 and the connecting portion 612 to enhance the installation stability of the spring 65. When the sealing block 54 is pressed against the flange 42, the insertion rod 64 can be inserted into the insertion hole 5121 away from the sealing block 54. When the sealing block 54 is stored in the barrel 11, the insertion rod 64 can be inserted into the insertion hole 5121 near the sealing block 54.

[0064] Combine Figure 7 and Figure 9 The second locking member 7 includes a mounting tube 71 with one end surface fixedly connected to the outer wall of the connecting plate 511 on the side facing away from the first sliding rod 512; a fixed shaft 72 inserted into and fixedly connected to the mounting tube 71; a rotating rod 73 sleeved and rotatably mounted on the fixed shaft 72; an operating plate 74 with one end fixedly connected to the outer wall of the rotating rod 73; and a locking block 75 movably mounted on the inner wall of the mounting tube 71. The outer diameter of the mounting tube 71 matches that of the connecting plate 511. The mounting tube 71 is sleeved onto the telescopic rod 521 and the telescopic rod 521 is slidably mounted within the mounting tube 71. The locking block 75 is capable of abutting against the locking groove 5211, thereby securing the telescopic rod 521 when the telescopic rod 521 is extended or retracted.

[0065] Reference Figure 9 The outer wall of one side of the mounting tube 71 is thickened to form a thickened portion 711. A mounting hole 712 is machined in the middle of the thickened portion 711, connecting the inner and outer walls of the mounting tube 71. The thickened portion 711 is formed with supports 713 on both sides of the mounting hole 712. The fixed shaft 72 passes through and is fixedly mounted on the two supports 713. The rotating rod 73 is rotatably mounted in the mounting hole 712 and located between the two supports 713. The rotating rod 73 is a round rod with an eccentric hole formed in the rotating rod 73, connecting the two end surfaces of the rotating rod 73 and with the axis parallel to the axis of the rotating rod 73. The eccentric hole is staggered with the axis of the rotating rod 73, and the fixed shaft 72 is inserted into the eccentric hole.

[0066] Referring to the figure, the locking block 75 includes a locking block 751 disposed within the mounting tube 71, a connecting block 752 integrally formed with the locking block 751 and facing the inner wall of the mounting tube 71, and a limiting rod 753 fixedly disposed on the locking block 751 and spaced apart from the two end surfaces of the connecting block 752. The two ends of the connecting block 752 are spaced apart from the two ends of the locking block 751, and the length direction of the limiting rod 753 is perpendicular to the outer wall of the locking block 751. The outer wall of the locking block 751 facing away from the connecting block 752 is processed to form an arcuate convex surface. The arcuate convex surface and the connecting block 752 are located within the mounting hole 712, and the arcuate convex surface can be aligned with the arcuate concave surface of the locking groove 5211. The two supports 713 are respectively provided with a limiting hole 714 perpendicular to the fixed shaft 72, and the two limiting rods 753 are movably inserted into the two limiting holes 714.

[0067] After the operating plate 74 is bent, the rotating rod 73 rotates eccentrically on the fixed shaft 72, so that the outer wall of the rotating rod 73 that is farther away from the eccentric hole abuts against the surface of the connecting block 752 away from the locking block 751, thereby pressing the locking block 751 tightly into the locking groove 5211, and then locking the position of the telescopic rod 521 after it extends out of the mounting tube 71, so that the sealing block 54 is stably pressed against the flange portion 42 and seals the welded pipe.

[0068] Example 2

[0069] The present application discloses a pipeline welding protection method. Referring to the figure, the protection method includes the following steps:

[0070] Step 1: Place the protective device as a whole into the pipe to be welded from the pipe opening of the pipe to be welded;

[0071] Step 2: Release the lock of the telescopic rod 521 by the second locking assembly, so as to facilitate the first driving member 51 to push the sealing block 54 into the pipe to be welded;

[0072] Step 3: Push the connecting plate 511 until the sealing block 54 is pressed against the flange 42 to further improve the sealing performance of the flange 42;

[0073] Step 4: After the sealing block 54 is pressed against the flange 42 , the insertion rod 64 is inserted into the insertion hole 5121 away from the sealing block 54 , thereby positioning the first driving member 51 as a whole and ensuring that the sealing block 54 is stably pressed against the flange 42 ;

[0074] Step 5: Push the telescopic rod 521 until the sealing block 54 is pressed against the flange 42 , so that all the sealing blocks 54 form a seal, improving the sealing performance of the flange 42 as a whole.

[0075] Step 6: Move the operating plate 74 so that the locking block 75 locks the telescopic rod 521 and the connecting plate 511. After locking the telescopic rod 521, it is ensured that it is completely pressed against the flange 42, thereby achieving the purpose of improving the internal sealing of the pipe to be welded;

[0076] Step 7: Blow an inert gas, such as an inert gas or a mixed gas, into the sealing block 54 from the pipe mouth of the pipe to be welded. Argon or helium can be used as the inert gas, and argon carbon dioxide can be used as the mixed gas. Inert gases (argon and helium) do not chemically react with the metal during the welding process, can effectively isolate the air, and prevent oxidation of the molten pool. They are particularly suitable for welding metals such as stainless steel and titanium alloys. Because argon has a low boiling point (-186°C) and a density slightly higher than that of air, it can quickly vaporize to form a dense protective layer that covers the welding area and reduces deformation. Argon carbon dioxide mixtures can maintain the inert protection effect while adjusting the penetration depth and spatter control through binary or ternary ratios (such as Ar+He+CO2). For example, Ar+10%-20% CO2 mixtures are commonly used in carbon steel welding, which can not only improve arc stability but also reduce alloy element burnout.

[0077] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A pipeline welding protection device, characterized by: The invention comprises a mounting cylinder (1) having an open end and a closed end at both ends, a fixed cylinder (2) having one end fixedly connected to the inner wall of the closed end of the mounting cylinder (1) and arranged coaxially, a mounting plate (3) in the form of a circular plate and having one plate surface coaxially fixedly connected to the fixed cylinder (2) near the open end and spaced apart from the open end, a sealing gasket (4) arranged on the plate surface of the mounting plate (3) on the side facing away from the fixed cylinder (2), a sealing assembly (5) slidably arranged on the outer wall of the fixed cylinder (2) and having one end slidably arranged outside the closed end, a first locking member (6) arranged on the outer wall of the closed end, and a second locking member (7) arranged on one end of the sealing assembly (5) located outside the closed end; The sealing gasket (4) comprises a circular pad portion (41) fixedly connected to the mounting plate (3) and a convex edge portion (42) integrally formed on the side of the circular pad portion (41) facing the mounting tube (1), wherein the convex edge portion (42) is spaced apart from the plate surface of the mounting plate (3) and the open end of the mounting tube (1); The sealing assembly (5) comprises a first driving member (51) and a second driving member (52) which are slidably arranged, and a plurality of sealing blocks (54) which are respectively hinged to one end of the first driving member (51) and the second driving member (52) close to the flange (42). The plurality of sealing blocks (54) can form an annular sealing member and can slide between the flange (42) and the open end and can be tightly pressed against the flange (42).

2. A pipeline welding protection device according to claim 1, characterized in that: The convex edge portion (42) is processed from its outer diameter to the direction of its inner diameter to form a slope; The sealing block (54) is processed with a first arcuate surface (542) capable of fitting with the inclined surface of the convex edge portion (42).

3. A pipeline welding protection device according to claim 1 or 2, characterized in that: The inner diameter of the flange portion (42) is consistent with the outer diameter of the mounting plate (3).

4. The pipeline welding protection device according to claim 1, characterized in that: The first driving member (51) includes a connecting plate (511) arranged outside the closed end and in a circular ring shape, and a first sliding rod (512) with one end fixed to the connecting plate (511) and slidably arranged on the outer wall of the fixed cylinder (2). At least two first sliding rods (512) are provided. The sealing block (54) is hinged to one end of the first sliding rod (512) close to the flange portion (42) and can be received in the installation cylinder (1).

5. A pipeline welding protection device according to claim 4, characterized in that: The first driving member (51) includes a connecting tube (61) fixed to the outer wall of the closed end and sleeved on the outer wall of the first sliding rod (512), a driving rod (63) rotatably arranged in the connecting tube (61), an insertion rod (64) fixed to one end of the driving rod (63) and located in the connecting tube (61), and a spring (65) fixed to the driving rod (63) and with the other end abutting against the inner wall of the connecting tube (61), the spring (65) and the insertion rod (64) are respectively located on two opposite sides of the same end of the driving rod (63), and the end of the insertion rod (64) away from the spring (65) can be inserted into the first sliding rod (512).

6. The pipeline welding protection device according to claim 5, characterized in that: The first slide bar (512) is provided with two insertion holes (5121). When the sealing block (54) is pressed against the convex edge (42), the insertion rod (64) is inserted into one of the insertion holes (5121). When the sealing block (54) is located in the installation tube (1), the insertion rod (64) is inserted into the other insertion hole (5121).

7. The pipeline welding protection device according to claim 4, characterized in that: The second driving member (52) includes a telescopic rod (521) slidably inserted on the connecting plate (511), and a second sliding rod (523) fixed to the telescopic rod (521) and spaced apart from the telescopic rod (521). At least two second sliding rods (523) are provided and are spaced apart from the first sliding rod (512). The sealing block (54) is hinged to one end of the second sliding rod (523) close to the flange (42) and can be received in the mounting tube (1).

8. The pipeline welding protection device according to claim 7, characterized in that: The second locking member (7) comprises a mounting tube (71) fixedly connected to the outer wall of the closed end of the connecting plate (511) facing away from the mounting tube (1), a rotating rod (73) eccentrically arranged on the outer wall of the mounting tube (71), and a locking block (75) movably arranged in the mounting tube (71) and abutting against the outer peripheral surface of the rotating rod (73); the telescopic rod (521) is slidably arranged in the mounting tube (71), and the locking block (75) can be tightly abutted against the telescopic rod (521).

9. The pipeline welding protection device according to claim 8, characterized in that: The outer wall of the locking block (75) is processed into an arc-shaped convex surface, and a locking groove is opened on the outer wall of the telescopic rod (521) along its length direction. The notch of the locking groove is an arc-shaped concave surface and can be tightly pressed against the arc-shaped convex surface of the locking block (751).

10. A pipeline welding protection method, characterized by: The following steps are included: Step 1: Place the protective device as a whole into the pipe to be welded from the pipe opening of the pipe to be welded; Step 2: Unlocking the telescopic rod (521) by the second locking assembly; Step 3: Push the connecting plate (511) until the sealing block (54) is pressed against the flange (42); Step 4: After the sealing block (54) is pressed against the convex edge (42), the insertion rod (64) is inserted into the insertion hole (5121) away from the sealing block (54); Step 5: Push the telescopic rod (521) until the sealing block (54) is pressed against the flange (42); Step 6: Move the operating plate (74) so ​​that the locking block (75) locks the telescopic rod (521) and the connecting plate (511); Step 7: Blow inert gas into the sealing block (54) from the pipe opening of the pipe to be welded.

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