Welding protection device and method for thin-walled pipe

Abstract

The present invention discloses a welding protection device for thin-walled tubes, comprising: a fastening sleeve, the first end of which penetrates into the interior of the thin-walled tube, the second end of which clamps the second end of the thin-walled tube, and the outer wall thereof matches the inner wall of the thin-walled tube, the inner wall of which is provided with a first groove along its axial direction, and the second end of the first groove is connected with the air pipe; a second groove is provided on the outer wall of the fastening sleeve along its circumference; a plurality of through holes are evenly distributed at the bottom end of the second groove, connecting the first groove and the second groove; a top cover, which is detachably connected to the first end of the fastening sleeve, and the outer diameter of the top cover is larger than the inner diameter of the fastening sleeve, sealing the first groove. This invention solves the problems of limited welding space and low welding efficiency of thin-walled tubes, by expanding the thin-walled tube through the fastening sleeve and the fastening pin, the protective gas is evenly distributed into the second groove directly through the first groove, thereby preventing the welding deformation of the thin-walled tube, making up for the defect of limited welding space, and improving the welding efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power thin-wall pipe welding, and in particular to a welding protection device and method for thin-wall pipes. Background Art

[0002] In the manufacturing of new reactor vessels and internal components of the fourth-generation nuclear power plant, thin-walled tube butt welds and thin-walled tube and flange butt welds are involved. Due to the small size of the tube, the back side cannot be cleaned, and the base welding needs to achieve single-sided welding and double-sided forming.

[0003] In the prior art, in order to ensure single-sided welding and double-sided forming of thin-walled tubes, the inner wall of the entire tube is filled with inert gas (such as Ar), and a U-shaped puller or a circular clamp is used on the external front to fix the two sides of the weld to prevent deformation.

[0004] However, when the tube thickness is ≤10mm, deformation will occur around the corner weld of the puller and the test plate, affecting the straightness of the tube, and the external anti-deformation device will also take up a large space. For the new small pile type, the front tooling may cause the welding space to be limited. At this time, only part of the weld can be welded first, and then the anti-deformation tooling can be removed before welding the other part.

[0005] This operation will increase the degree of local deformation, consume a large amount of inert gas, increase the number of welded joints, affect product quality, and reduce welding efficiency. Moreover, the process of disassembling the tooling may cause the shielding gas to leak or even mix with air. Summary of the invention

[0006] The purpose of the present invention is to provide a welding protection device and method for thin-walled pipes. The device and method are intended to solve the problems of limited welding space and low welding efficiency of traditional thin-walled pipe welding tools. The thin-walled pipe is expanded by a fastening sleeve and a fastening pin, and a first groove, a second groove and evenly distributed through holes are provided, so that the protective gas is evenly distributed directly into the second groove through the first groove, thereby preventing welding deformation of the thin-walled pipe, compensating for the defect of limited welding space, and improving welding efficiency.

[0007] To achieve the above-mentioned purpose, the present invention provides a welding protection device for a thin-walled tube, comprising a fastening sleeve, a first groove, a second groove, a plurality of through holes and a top cover; the first end of the fastening sleeve penetrates into the interior of the thin-walled tube, the second end clamps the second end of the thin-walled tube, and the outer wall of the fastening sleeve matches the inner wall of the thin-walled tube; a first groove is arranged on the inner wall of the fastening sleeve along its axial direction, and the second end of the first groove is connected to the external air pipe; a second groove is arranged on the outer wall of the fastening sleeve along its circumference; a plurality of through holes are evenly distributed at the bottom end of the second groove, which are used to connect the first groove and the second groove; the top cover is detachably connected to the first end of the fastening sleeve, and the outer diameter of the top cover is larger than the inner diameter of the fastening sleeve, and is used to seal the first groove on the inner wall of the fastening sleeve;

[0008] The external air pipe passes the shielding gas into the first groove of the fastening sleeve, and under the action of the air pressure inside the first groove, the shielding gas is evenly passed into the second groove on the outer wall of the fastening sleeve through a plurality of through holes to form a uniform shielding gas flow, which fills the back weld between the thin-walled tube and the fastening sleeve, and creates a protective atmosphere at the back weld of the thin-walled tube; during the welding process, the uniform shielding gas flow at the back weld of the thin-walled tube can protect the molten liquid metal from reacting with the oxidizing gas in the air, thereby affecting the weld formation and performance of the back weld of the thin-walled tube, and completing the welding protection of the back weld of the thin-walled tube.

[0009] Most preferably, the welding protection device also includes a fastening pin, which is detachably arranged at the second end of the fastening sleeve, and is used to resist and expand the fastening sleeve and the thin-walled tube to ensure the straightness of the thin-walled tube during the welding process, prevent the thin-walled tube from welding deformation, and complete the welding deformation protection of the thin-walled tube.

[0010] Most preferably, the welding protection device further comprises a screw rod, a first end of which is sequentially penetrated by a fastening pin and a fastening sleeve for fixing the fastening pin and the fastening sleeve.

[0011] Most preferably, the top cover is disposed at the first end of the screw rod and is detachably connected to the first end of the fastening sleeve, and is used for sealing the first groove on the inner wall of the fastening sleeve.

[0012] Most preferably, the welding protection device also includes a fixing piece, which is arranged at the second end of the screw rod and is used to fix the screw rod after the first end of the screw rod is penetrated with a fastening pin and a fastening sleeve in sequence; the fixing piece includes a nut and a washer.

[0013] Most preferably, the fastening sleeve further comprises:

[0014] A cylindrical sleeve, the first end of which penetrates into the interior of the thin-walled tube and is detachably connected to the top cover; the outer wall of the cylindrical sleeve matches the inner wall of the thin-walled tube;

[0015] The disc sleeve is coaxially connected to the second end of the cylindrical sleeve, and its outer diameter is larger than the inner diameter of the thin-walled tube, and is used to clamp the second end of the thin-walled tube.

[0016] Most preferably, a protrusion is provided on the top cover; a mounting groove is provided on the first end of the fastening sleeve; and the protrusion is matched and connected with the first end of the fastening sleeve through the mounting groove.

[0017] Most preferably, the top cover is also provided with a plurality of symmetrically distributed air outlet holes, which are connected to the second groove and are used to discharge the protective gas in the second groove out of the back weld to prevent the gas pressure inside the welding protection device from being too high.

[0018] Most preferably, the second end of the first groove is connected to an external air pipe through an air inlet pipe, so as to pass the protective gas in the external air pipe into the first groove through the air inlet pipe.

[0019] The present invention also provides a welding protection device method for thin-walled tubes. The welding protection method is implemented based on the above-mentioned welding protection device for thin-walled tubes. The welding protection method comprises the following steps:

[0020] Step 1: insert the first end of the fastening sleeve into the thin-walled tube to be welded, clamp the second end of the thin-walled tube with the second end of the fastening sleeve, fix the thin-walled tube to be welded, ensure that the thin-walled tube expands due to heat during welding, resist and expand the first end of the fastening sleeve and the fastening pin, ensure the straightness of the thin-walled tube during welding, so that the thin-walled tube will not be deformed by welding, so as to complete the welding deformation protection of the thin-walled tube;

[0021] Step 2: Pass a fastening pin and a fastening sleeve through the first end of the screw rod in sequence, and fix the top cover to the first end of the fastening sleeve to seal the first groove;

[0022] Step 3: Start welding the thin-walled tube, and pass the protective gas in the external air pipe into the first groove through the air inlet pipe;

[0023] Step 4: Under the action of gas pressure, the shielding gas in the first groove enters the second groove through a plurality of through holes to form a uniform shielding gas flow, evenly filling the back weld of the thin-walled tube, and creating a protective atmosphere in the back weld of the thin-walled tube. During the welding process, the shielding gas flow protects the back weld from reacting with the oxidizing gas and affecting the weld forming of the back weld of the thin-walled tube, so as to complete the welding protection of the back weld of the thin-walled tube.

[0024] The use of this invention solves the problems of limited welding space and low welding efficiency of traditional thin-walled tube welding tooling. The thin-walled tube is expanded by tightening the sleeve and the tightening pin, and a first groove, a second groove and evenly distributed through holes are set, so that the shielding gas is directly evenly distributed into the second groove through the first groove, thereby preventing welding deformation of the thin-walled tube, compensating for the defect of limited welding space, and improving welding efficiency.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The welding protection device provided by the present invention is provided with a fastening sleeve having a first groove, a second groove and evenly distributed through holes, so that the protective gas of the external air pipe is directly and evenly introduced into the back weld of the thin-walled tube, which plays a protective role during the single-sided welding and double-sided forming base welding, thereby improving the welding efficiency.

[0027] 2. The welding protection device provided by the present invention is provided with a fastening pin, which supports and expands the thin-walled tube during the welding process of the thin-walled tube to ensure that the thin-walled tube will not be deformed by welding.

[0028] 3. The welding protection device provided by the present invention is provided with a first groove and a vent pipe, which is convenient for direct connection with an external air pipe and will not affect welding installation, thereby making up for the defect of limited space in traditional welding and improving welding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of a welding protection device provided by the present invention;

[0030] Figure 2 A schematic diagram of the cross-sectional structure of the fastening sleeve provided by the present invention;

[0031] Figure 3 This is a schematic diagram of the side cross-sectional structure of the fastening sleeve provided by the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention and are not intended to limit the protection scope of the present invention.

[0033] The present invention is a welding protection device for a thin-walled tube 1, such as Figure 1 As shown, it includes a fastening sleeve 2, a top cover 3, a fastening pin 4, a screw 5, a fixing part 6 and an air intake pipe 7; in this embodiment, the material of the welding protection device is selected from any one or more of carbon steel, low alloy steel or stainless steel.

[0034] like Figure 1 As shown, the first end of the fastening sleeve 2 passes through the first end of the thin-walled tube 1 to be welded and enters the interior of the thin-walled tube 1, and the second end clamps the second end of the thin-walled tube 1; and the outer wall of the fastening sleeve 2 matches the inner wall of the thin-walled tube 1.

[0035] like Figure 2 and Figure 3As shown, a first groove 201 is arranged on the inner wall of the fastening sleeve 2 along its axial direction, and the second end of the first groove 201 is connected to the external air pipe K; a second groove 202 is arranged on the outer wall of the fastening sleeve 2 along its circumference; a plurality of through holes 203 are evenly distributed at the bottom end of the second groove 202 for connecting the first groove 201 and the second groove 202.

[0036] The small and uniform through holes 203 can ensure the uniformity of the shielding gas flow, ensuring that the shielding gas flows smoothly without affecting the molten pool at the center of the weld on the back of the thin-walled tube 1; in this embodiment, the number of the through holes 203 is 10 to 20, and the diameter of the through holes 203 is 1 to 2 mm.

[0037] like Figure 1 As shown, the top cover 3 is detachably connected to the first end of the fastening sleeve 2 , and the outer diameter of the top cover 3 is larger than the inner diameter of the fastening sleeve 2 , and is used to seal the first groove 201 on the inner wall of the fastening sleeve 2 .

[0038] The external air pipe K passes the shielding gas into the first groove 201 of the fastening sleeve 2, which plays a buffering role for the shielding gas. Under the action of the internal air pressure of the first groove 201, the shielding gas is evenly passed into the second groove 202 on the outer wall of the fastening sleeve 2 through a plurality of through holes 203 connected to the first groove 201, forming a uniform shielding gas flow, filling the back weld between the thin-walled tube 1 and the fastening sleeve 2, and creating a protective atmosphere at the back weld of the thin-walled tube 1; during the welding process, the liquid metal zone formed by the melting of the metal is more sensitive to the gas flow intensity, and the uniform shielding gas flow at the back weld of the thin-walled tube 1 can protect the molten liquid metal from reacting with oxygen or other oxidizing gases in the air to form an oxide film, thereby affecting the weld formation and performance of the back weld of the thin-walled tube 1, and completing the welding protection of the back weld of the thin-walled tube 1.

[0039] In this embodiment, the protective gas introduced through the external air pipe K is argon.

[0040] Among them, Figure 2 and Figure 3 As shown, the fastening sleeve 2 also includes a cylindrical sleeve 204 and a disc sleeve 205; the first end of the cylindrical sleeve 204 passes through the first end of the thin-walled tube 1 and is detachably connected to the top cover 3; the outer wall of the cylindrical sleeve 204 matches the inner wall of the thin-walled tube 1; the disc sleeve 205 is coaxially connected to the second end of the cylindrical sleeve 204; and the outer diameter of the disc sleeve 205 is larger than the inner diameter of the thin-walled tube 1, and is used to clamp the second end of the thin-walled tube 1; the first end of the cylindrical sleeve 204 of the fastening sleeve 2 is provided with an assembly groove 206.

[0041] The fastening sleeve 2 is assembled from four-petal tooling parts, and the outer diameter of one of the four petals of the disc sleeve 205 is smaller than the inner diameter of the cylindrical sleeve 204, so that the fastening sleeve 2 can be pushed to the center of the diameter of the thin-walled tube 1 to be welded, tightened and loosened, and then the fastening sleeve 2 is taken out for easy assembly and installation. In this embodiment, the total length of the fastening sleeve 2 is 60-80 mm, the outer diameter of the disc sleeve 205 is 60-100 mm, and the outer diameter of the cylindrical sleeve 204 is 40-50 mm; the inner diameter of the fastening sleeve 2 is 15-18 mm.

[0042] like Figure 1 As shown, the welding protection device also includes a fastening pin 4, which is detachably arranged on the disc sleeve 205 at the second end of the fastening sleeve 2, and is used to resist and expand the fastening sleeve 2 and the thin-walled tube 1 to ensure the straightness of the thin-walled tube 1 during the welding process, prevent the thin-walled tube 1 from welding deformation, and complete the welding deformation protection of the thin-walled tube 1; during the assembly welding process, the outer wall of the fastening pin 4 is designed to have a certain slope. In this embodiment, the slope of the outer wall is 2 to 5°.

[0043] The welding protection device also includes a screw rod 5 ; the first end of the screw rod 5 is sequentially penetrated by a disc sleeve 205 and a cylindrical sleeve 204 of the fastening pin 4 and the fastening sleeve 2 , so as to fix the fastening pin 4 and the fastening sleeve 2 .

[0044] The top cover 3 is disposed at the first end of the screw rod 4 and is detachably connected to the first end of the cylindrical sleeve 204 of the fastening sleeve 2 to seal the first groove 201 on the inner wall of the fastening sleeve 2 .

[0045] The welding protection device also includes a fixing member 6, which is arranged at the second end of the screw rod 4 and is used to fix the screw rod 4 after the first end of the screw rod 4 is sequentially penetrated by the fastening pin 4 and the disc sleeve 205 and the cylindrical sleeve 204 of the fastening sleeve 2; in this embodiment, the fixing member 6 includes a nut and a washer.

[0046] A protrusion 301 is provided on the top cover 3; the protrusion 301 is matched and connected with the first end of the fastening sleeve 2 through the assembly groove 206 on the cylindrical sleeve 204; a plurality of symmetrically distributed air outlet holes 302 are also provided on the top cover 3, which are connected to the second groove 202 and are used to discharge the protective gas in the second groove 202 out of the back weld to prevent the gas pressure inside the welding protection device from being too high; in this embodiment, the number of the plurality of air outlet holes 302 is 2 or 4.

[0047] The second end of the first groove 202 inside the fastening sleeve 2 is connected to the external air pipe K through the air inlet pipe 7, so as to pass the protective gas in the external air pipe K into the first groove 202 through the air inlet pipe 7.

[0048] The present invention also provides a welding protection device method for a thin-walled tube 1. The welding protection method is implemented based on the above-mentioned welding protection device for a thin-walled tube 1. The welding protection method comprises the following steps:

[0049] Step 1: The first end of the cylindrical sleeve 204 in the fastening sleeve 2 is passed through the first end of the thin-walled tube 1 to be welded and enters the interior of the thin-walled tube 1, and the disc sleeve 205 at the second end of the fastening sleeve 2 clamps the second end of the thin-walled tube 1 to fix the thin-walled tube 1 to be welded, so that the thin-walled tube 1 expands due to heat during the welding process, and resists and expands the disc sleeve 205 of the fastening sleeve 2 and the first end of the fastening pin 4 to ensure the straightness of the thin-walled tube 1 during the welding process, so that the thin-walled tube 1 will not be deformed by welding, so as to complete the welding deformation protection of the thin-walled tube 1;

[0050] Step 2: The first end of the screw rod 5 is passed through the fastening pin 4 and the disc sleeve 205 and the cylindrical sleeve 204 of the fastening sleeve 2 in sequence, and the top cover 3 is fixed to the first end of the cylindrical sleeve 204 in the fastening sleeve 2 to seal the first end of the first groove 201 inside the fastening sleeve 2;

[0051] Step 3: Start welding the thin-walled tube 1, and let the protective gas in the external air pipe K pass through the air inlet pipe 7 into the first groove 201 inside the fastening sleeve 2, which plays a buffering role for the protective gas;

[0052] Step 4: Under the action of gas pressure, the shielding gas in the first groove 201 enters the second groove 202 on the outer wall of the fastening sleeve 2 through a plurality of through holes 203 connected to the first groove 201, forming a uniform shielding gas flow, evenly filling the back weld of the thin-walled tube 1, and creating a protective atmosphere in the back weld of the thin-walled tube 1. During the welding process, the uniform shielding gas flow protects the back weld of the thin-walled tube 1 from reacting with oxidizing gas, thereby affecting the weld formation and performance of the back weld of the thin-walled tube 1, so as to complete the welding protection of the back weld of the thin-walled tube 1.

[0053] Working principle of the present invention:

[0054] The first end of the cylindrical sleeve in the fastening sleeve is passed through the first end of the thin-walled tube to be welded and enters the inside of the thin-walled tube. The disc sleeve at the second end of the fastening sleeve clamps the second end of the thin-walled tube to fix the thin-walled tube to be welded, so that the thin-walled tube expands due to heat during the welding process, resists and expands the fastening sleeve and the fastening pin, and ensures the straightness of the thin-walled tube during the welding process, so that the thin-walled tube will not be deformed by welding, so as to complete the welding deformation protection of the thin-walled tube; the first end of the screw rod is passed through the fastening pin and the fastening sleeve in sequence, and the top cover is fixed to the first end of the fastening sleeve to seal the first end of the first groove inside the fastening sleeve; start When welding a thin-walled tube, the shielding gas in the external air pipe is passed through the air inlet pipe into the first groove inside the fastening sleeve, which plays a buffering role for the shielding gas; under the action of the air pressure, the shielding gas in the first groove enters the second groove through a plurality of through holes connected to the first groove, forming a uniform shielding gas flow, uniformly filling the back weld of the thin-walled tube, and creating a protective atmosphere in the back weld of the thin-walled tube. During the welding process, the shielding gas flow protects the back weld of the thin-walled tube from reacting with the oxidizing gas, which affects the weld formation and performance of the back weld of the thin-walled tube, so as to complete the welding protection of the back weld of the thin-walled tube.

[0055] In summary, the present invention provides a welding protection device and method for thin-walled tubes, which solve the problems of limited welding space and low welding efficiency of traditional thin-walled tube welding tooling. The thin-walled tube is expanded by a fastening sleeve and a fastening pin, and a first groove, a second groove and evenly distributed through holes are provided, so that the shielding gas is evenly distributed directly into the second groove through the first groove, thereby preventing welding deformation of the thin-walled tube, compensating for the defect of limited welding space, and improving welding efficiency.

[0056] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A welding protection device for thin-walled pipes, characterized in that: include: A fastening sleeve, the first end of which penetrates into the interior of the thin-walled tube, the second end of which clamps the second end of the thin-walled tube, and the outer wall of the fastening sleeve matches the inner wall of the thin-walled tube; A first groove is arranged on the inner wall of the fastening sleeve along its axial direction, and a second end of the first groove is connected to an external air pipe; A second groove is arranged on the outer wall of the fastening sleeve along its circumference; a plurality of through holes are evenly distributed at the bottom end of the second groove for connecting the first groove and the second groove; A top cover is detachably connected to the first end of the fastening sleeve, and the outer diameter of the top cover is larger than the inner diameter of the fastening sleeve, and is used to seal the first groove on the inner wall of the fastening sleeve; an external air pipe passes the protective gas into the first groove of the fastening sleeve, and under the action of the internal air pressure of the first groove, the protective gas is uniformly passed into the second groove on the outer wall of the fastening sleeve through the plurality of through holes to form a uniform protective gas flow, which fills the back weld between the thin-walled tube and the fastening sleeve, and creates a protective atmosphere at the back weld of the thin-walled tube; during the welding process, the uniform protective gas flow at the back weld of the thin-walled tube can protect the molten liquid metal from reacting with the oxidizing gas in the air, thereby affecting the weld formation and performance of the back weld of the thin-walled tube, and completing the welding protection of the back weld of the thin-walled tube; The welding protection device also includes a fastening pin, which is detachably arranged at the second end of the fastening sleeve and is used to resist and expand the fastening sleeve and the thin-walled tube to ensure the straightness of the thin-walled tube during welding, prevent the thin-walled tube from welding deformation, and complete the welding deformation protection of the thin-walled tube; The welding protection device also includes a screw, a first end of which is sequentially penetrated by the fastening pin and the fastening sleeve, and is used to fix the fastening pin and the fastening sleeve; The top cover is disposed at the first end of the screw rod and is detachably connected to the first end of the fastening sleeve, and is used to seal the first groove on the inner wall of the fastening sleeve; The welding protection device also includes a fixing piece, which is arranged at the second end of the screw rod and is used to fix the screw rod after the first end of the screw rod is sequentially penetrated by the fastening pin and the fastening sleeve; the fixing piece includes a nut and a washer.

2. The welding protection device for thin-walled pipe according to claim 1, characterized in that: The fastening sleeve also includes: A cylindrical sleeve, the first end of which penetrates into the interior of the thin-walled tube and is detachably connected to the top cover; the outer wall of the cylindrical sleeve matches the inner wall of the thin-walled tube; The disc sleeve is coaxially connected to the second end of the cylindrical sleeve and has an outer diameter larger than the inner diameter of the thin-walled tube, and is used to clamp the second end of the thin-walled tube.

3. The welding protection device for thin-walled pipe according to claim 1, characterized in that: The top cover is provided with a protrusion; the first end of the fastening sleeve is provided with an assembly groove; the protrusion is matched and connected with the first end of the fastening sleeve through the assembly groove.

4. The welding protection device for thin-walled pipe according to claim 1, characterized in that: The top cover is also provided with a plurality of symmetrically distributed air outlet holes which are connected to the second groove and are used to discharge the protective gas in the second groove out of the back weld to prevent the gas pressure inside the welding protection device from being too high.

5. The welding protection device for thin-walled pipe according to claim 1, characterized in that: The second end of the first groove is connected to an external air pipe through an air inlet pipe, and is used to pass the protective gas in the external air pipe into the first groove through the air inlet pipe.

6. A welding protection method for thin-walled pipes, characterized in that: The welding protection method is implemented based on the welding protection device for thin-walled pipes according to claim 5, and the welding protection method comprises the following steps: Step 1: insert the first end of the fastening sleeve into the thin-walled tube to be welded, clamp the second end of the fastening sleeve with the second end of the thin-walled tube, fix the thin-walled tube to be welded, and the fastening pin is used to resist and expand the fastening sleeve and the thin-walled tube to ensure that the thin-walled tube will not be deformed by welding, so as to complete the welding deformation protection of the thin-walled tube; Step 2: Pass the fastening pin and the fastening sleeve through the first end of the screw in sequence, and fix the top cover on the first end of the fastening sleeve to seal the first groove; Step 3: Start welding the thin-walled tube, and pass the protective gas in the external air pipe into the first groove through the air inlet pipe; Step 4: Under the action of gas pressure, the shielding gas in the first groove enters the second groove through a plurality of through holes to form a uniform shielding gas flow, uniformly filling the back weld of the thin-walled tube, and creating a protective atmosphere in the back weld of the thin-walled tube. During the welding process, the shielding gas flow protects the back weld from reacting with the oxidizing gas and affecting the weld forming of the back weld of the thin-walled tube, so as to complete the welding protection of the back weld of the thin-walled tube.

Images