A pipe hole gas shield welding chuck and a pipe hole gas shield welding method

Abstract

The present invention discloses a pipe inner hole gas shielded welding chuck and a pipe inner hole gas shielded welding method, comprising a base member, a clamp seat, a flat bushing, an airway bushing, and an air inlet pipe. The base member is threadedly connected with a stud. A clamp seat is fixedly connected to the base member, and another clamp seat is used to abut against the stud. Two flat bushings are respectively connected to the two clamp seats. Two airway bushings are respectively connected to the two clamp seats. Each airway bushing and the clamp seat enclose an airway to form a gas channel. The airway is connected to the inner side of the airway bushing. The air inlet pipe is connected to the airway. The air inlet pipe is used to input inert gas. When the stud is pressed until the two clamp seats are closed, a first pipe member inserted between the two flat bushings and a second pipe member inserted between the two airway bushings are aligned. The welding process can perform single-sided welding and double-sided forming of pipe orifice butt inner hole welding, reduces the labor intensity of construction workers, and changes the previous manual outer hole welding construction to automatic machine inner hole welding construction, effectively improving work efficiency and shortening the operation cycle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of protective welding, in particular to a pipe hole gas shielded welding chuck and a pipe hole gas shielded welding method. BACKGROUND

[0002] The inner hole welding process has a wide range of application scenarios. For example, 24 inlet and outlet water pipes of a certain product main heat exchanger should be welded with corresponding pipe openings on the side wall of the pressure container to complete the on-site installation of the main heat exchanger. However, due to space limitations, the welding torch can only be inserted from the pipe openings on one side of the outer wall of the pressure container, and the 24 connecting pipes are welded one by one to form 24 on-site butt welds of the main heat exchanger. The inner hole welding of the main heat exchanger is deep hole, all-position, full blind, and non-groove helium-argon mixed gas shielded non-melting electrode arc welding.

[0003] The wall thickness difference, misalignment and gap of the pipe joint will affect the quality of the inner hole welding. The weld of the inner hole welding workpiece is concave upward and convex downward, which exceeds the appearance inspection requirement in some cases, and it is difficult to pass the X-ray inspection. Therefore, after the inner hole welding process parameters are optimized and determined, the main difficulty in the implementation of the inner hole welding on site is the quality control of the butt joint installation of the main heat exchanger pipe opening and the pressure container pipe opening. When the pipe openings are butt jointed, the welding process is carried out in the pipe, and a special protective gas cover is designed on the outside of the pipe opening for back protection.

[0004] Therefore, it is necessary to design a chuck tool that can meet the requirements of the pipe opening butt joint assembly adjustment accuracy and provide reliable inert gas protection for the single-sided welding and double-sided forming process of the pipe opening weld. SUMMARY

[0005] To solve the above problems, the present application provides a pipe hole gas shielded welding chuck and a pipe hole gas shielded welding method.

[0006] The present application provides a pipe hole gas shielded welding chuck, which comprises a base piece, a clamping seat, a flat bushing, a gas channel bushing and an air inlet pipe. The base piece is threadedly connected with a stud. Two clamping seats are oppositely arranged, one of which is fixedly connected with the base piece, and the other is used to abut against the stud. The flat bushing has two halves, and the two halves of the flat bushing are connected with the two clamping seats respectively. The gas channel bushing has two halves, and the two halves of the gas channel bushing are connected with the two clamping seats respectively. The gas channel bushing is spaced apart from the flat bushing, and each half of the gas channel bushing and the clamping seat form a gas channel. The gas channel is communicated with the inner side of the gas channel bushing. The air inlet pipe is provided with at least two air inlet pipes, which are connected with one side of the clamping seat away from the gas channel bushing and communicated with the gas channel. The air inlet pipe is used to input inert gas. Under the condition that the stud is pressed to close the two clamping seats, the first pipe arranged between the two halves of the flat bushing is opposite to the second pipe arranged between the two halves of the gas channel bushing.

[0007] In some embodiments, the air passage is formed on the inner side of the air passage liner, and the first pipe penetrating between the two halves of the flat liner is in alignment with the second pipe penetrating between the two halves of the air passage liner when the stud is pressed against the two clamping seats to be closed, and the gap of the pipe formed by the first pipe and the second pipe is in alignment with the air port.

[0008] In some embodiments, each half of the flat liner is provided with at least two first protrusions on the inner side and distributed along the circumferential direction of the flat liner, and each half of the air passage liner is provided with at least two second protrusions on the inner side and distributed along the circumferential direction of the air passage liner, and the first protrusions are in contact with the first pipe and the second protrusions are in contact with the second pipe when the stud is pressed against the two clamping seats to be closed.

[0009] In some embodiments, the air passage liner is spaced apart from the clamping seat near the axial end of the flat liner.

[0010] The air passage is distributed along the circumferential direction of the air passage liner, and the sealing plates are installed at both ends of the air passage in the circumferential direction and are sealingly connected with the air passage liner and the support.

[0011] A filter screen is arranged in the air passage, and the filter screen is spread between the air port and the air inlet pipe.

[0012] In some embodiments, the clamping seat is an arc structure, and the central angle of the arc structure is less than 180°.

[0013] In some embodiments, the base member is a C-shaped clamp, which includes a first arc segment, a straight segment, and a second arc segment, the arc end of the first arc segment is connected with one end of the straight segment, and the other end of the straight segment is connected with the arc end of the second arc segment.

[0014] The two clamping seats are a first clamping seat and a second clamping seat, the first clamping seat is connected to the inner side of the first arc segment, and the first clamping seat is connected with one end of the straight segment, the stud is threadedly installed on the second arc segment, and the stud is used to press the second clamping seat against the first clamping seat to be closed.

[0015] In some embodiments, the second clamping seat is connected with a top block on the outer side, the top block is distributed along the axial direction of the second clamping seat, and the top block is used to contact the stud.

[0016] In some embodiments, the top block is provided with an alignment hole, the alignment hole is arranged on the side of the top block away from the second clamping seat, and the alignment hole is used for the stud to pass through so that the axial ends of the two clamping seats are aligned when the stud is pressed against the two clamping seats to be closed.

[0017] In some embodiments, the pipe inner hole gas shielded welding electrode holder is further provided with a gas cylinder filled with inert gas, and the gas cylinder is in communication with the air inlet pipe through a hose.

[0018] A method for pipe bore gas shielded welding, using the pipe bore gas shielded welding chuck as described above, the method comprising:

[0019] Fixing and mounting the first pipe on the chuck of the pipe bore welding machine;

[0020] Aligning the first pipe mounted on the chuck with the second pipe to be connected and aligning the pipe ends;

[0021] Sleeving the two clamping seats on the first pipe and the second pipe and tightening the studs until the pipe is clamped;

[0022] After the gas passage is filled with inert gas, the gun head of the pipe bore welding machine rotates one round inside the first pipe, completing the welding of the connecting seam between the first pipe and the second pipe.

[0023] The application has the following beneficial effects: a pipe hole gas shielded welding chuck is provided, which comprises a base, a clamping seat, a flat sleeve, a gas channel sleeve and an air inlet pipe. The clamping seat is divided into two parts distributed on the upper and lower parts. The first clamping seat is installed on the base, and the second clamping seat is pressed on the first clamping seat through the stud on the base. A pair of flat sleeves are installed on the inner side of the two clamping seats. The first pipe to be welded is spatially positioned by the pair of flat sleeves. A pair of gas channel sleeves are installed on the inner side of the two clamping seats. The second pipe to be welded is spatially positioned by the pair of gas channel sleeves. The first pipe passing through the two flat sleeves is opposite to the second pipe passing through the two gas channel sleeves. Each gas channel sleeve and the clamping seat form a gas channel. The gas channel is communicated with the inner side of the gas channel sleeve. The air inlet pipe is connected to the side of the clamping seat away from the gas channel sleeve and is communicated with the gas channel. Inert gas is input into the gas channel through the air inlet pipe. Inert gas is provided as a protective gas for the pipe joint welding seam when the first pipe and the second pipe are welded. The pipe hole gas shielded welding chuck is applied. The two pipe joints to be welded are accurately fixed by manually installing and locking the upper and lower clamping seats. The purpose of accurately assembling the concentricity, straightness and pipe wall offset is achieved. The circumferential gas protection is formed at the joint welding seam. The high-precision welding of pipe joint welding is achieved. The welding process of single-sided welding and double-sided forming of pipe joint welding is achieved. The welding process includes but is not limited to the application of helium-argon mixed gas shielded non-melting electrode arc welding for deep hole, all-position, full-blind and non-groove pipe joint welding. The welding process of single-sided welding and double-sided forming of pipe joint welding is achieved by using the pipe hole gas shielded welding chuck. The labor intensity of the construction personnel is reduced. The manual outside welding construction is changed to automatic inner hole welding construction. The work efficiency is effectively improved. The operation cycle is shortened. In addition, the application has the characteristics of simple structure, small manufacturing difficulty, saving of human resources, low cost and small investment. It is very suitable for the welding process of single-sided welding and double-sided forming of pipe joint welding. It provides a strong reference for safe and precise welding process and automatic welding technology. It is convenient for wide application. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application.

[0025] Figure 1 A radial section view of a pipe hole gas shielded welding chuck provided by the application is shown in the figure.

[0026] Figure 2 Figure 1 is a schematic view of an axial section of a pipe hole gas shielded welding chuck provided in the present application.

[0027] Fig. 10 is a schematic view of an axial section of a pipe hole gas shielded welding chuck provided in the present application. DETAILED DESCRIPTION

[0028] The 24 inlet and outlet water pipes of a main heat exchanger should be welded with the corresponding pipe openings on the side wall of the pressure vessel to complete the field installation of the main heat exchanger. However, due to space limitations, the 24 field butt welds of the main heat exchanger can only be inserted into the welding gun from the pipe openings on one side of the pressure vessel outer wall, and then welded one by one in the 24 pipe connections. This process is called the main heat exchanger pipe hole welding process. To solve the pipe welding process technical problem, mainly for new materials such as safety level pipe, copper alloy pipe, stainless steel and duplex stainless steel pipe, around safety, precision welding process, automatic welding technology and process improvement, etc. Welding process research is carried out to form applicable welding technology and improve the technical level and efficiency of pipe welding.

[0029] The stainless steel safety level pipe full position and horizontal rolling automatic welding process research is based on a certain product. It serves the product construction, solves the product pipe construction welding problem, improves and upgrades the pipe welding process, develops new pipe welding process, and makes the factory's pipe welding develop towards high efficiency and high quality automation. It is the purpose of this patent.

[0030] The main heat exchanger hole welding is a deep hole, full position, full blind and non-groove helium-argon mixed gas protection non-melting electrode arc welding (TIG). The main workpiece welding parameters of the product are: φ57*3.8 stainless steel pipe (or duplex stainless steel pipe), welding pipe opening wall thickness 3.8mm, depth 260mm.

[0031] The difficulties of hole welding are that the wall thickness difference, misalignment and gap of the hole welding pipe joint will affect the quality of the hole welding. The hole welding workpiece welds often have the phenomenon of concave up and convex down, and some exceed the appearance inspection requirements, and it is difficult to pass the film inspection. After many scientific research tests, the inventor suggests that the pipe opening size and butt assembly parameters should be controlled as follows: wall thickness 3.8±0.1mm, misalignment less than 0.5mm and gap less than 0.5mm.

[0032] After optimizing and finalizing the internal hole welding process parameters, the main challenge in on-site internal hole welding lies in quality control of the butt joint installation between the main heat exchanger and pressure vessel nozzles. During butt jointing, welding takes place inside the pipes, requiring a dedicated gas shield to protect the back of the nozzles.

[0033] The protective gas hood should have the characteristics of good protection effect and easy installation. Therefore, it is necessary to design a pipe hole gas shielded welding chuck that can not only meet the requirements of pipe nozzle butt assembly adjustment accuracy, but also provide reliable inert gas protection for the single-sided welding and double-sided forming process of the pipe nozzle weld.

[0034] In order to achieve the above purpose, the present application discloses a pipe inner hole gas shielded welding chuck, hereinafter referred to as the chuck, please refer to Figure 1 and Figure 2 The chuck includes a base 10, a clamping seat 20, a flat bushing 30, an airway bushing 40 and an air inlet pipe 50, which is mainly divided into two halves, the clamping seat 20 is provided with two relatively, the flat bushing 30 is provided with two petals, the airway bushing 40 is provided with two petals, and the air inlet pipe 50 is provided with at least two. Figure 1 and Figure 2 The two components are distributed in upper and lower parts.

[0035] The base 10 is the installation base of the chuck. The two clamping seats 20 are the first clamping seat 21 and the second clamping seat 22. The first clamping seat 21 is fixedly connected to the base 10. The stud 11 is threadedly connected to the base 10. The relative position of the stud 11 on the base 10 can be adjusted. The second clamping seat 22 is used to abut against the stud 11. The second clamping seat 22 is pressed against the first clamping seat 21 through the stud 11 on the base 10. When the stud 11 presses the second clamping seat 22 against the first clamping seat 21, the second clamping seat 22 and the first clamping seat 21 are in a closed state. Please refer to Figure 1 , Figure 1 There is a clamping seat closing gap L1, which is controlled to be about 0.3 mm, for example, 0.3 mm ± 0.05 mm, so the central angle between the first clamping seat 21 and the second clamping seat 22 is less than and close to 180°.

[0036] Please refer to Figure 1 and Figure 2 Two flat bushings 30 are installed in pairs inside the two clamping seats 20. The two flat bushings 30 are connected to the two clamping seats 20 respectively. The flat bushings 30 are used to directly contact the first pipe to be welded. The first pipe to be welded is spatially positioned by the two flat bushings 30. Since the flat bushings 30 are components that directly contact the first pipe, the inner diameter of the flat bushings 30 is equal to the outer diameter of the first pipe. Figure 1 The clamp seat shown closes the gap L1, so the central angle of the single-petal flat bushing 30 is less than and close to 180°.

[0037] Please refer to Figure 1 and Figure 2 A pair of distributed two-limb airway bushings 40 are installed inside the two clamps 20, and the two-limb airway bushings 40 are connected with the two clamps 20 respectively. The airway bushings 40 are spaced from the flat bushings 30, and the flat bushings 30 are located on one side of the axial direction of the clamp 20, and the airway bushings 40 are located on the other side of the axial direction of the clamp 20. The airway bushings 40 are used to directly contact the second pipe to be welded, and the space positioning of the second pipe to be welded is realized through the pair of distributed two-limb airway bushings 40. Since the airway bushings 40 are the components directly contacting the second pipe, the inner diameter of the airway bushings 40 is equal to the outer diameter of the second pipe. Since there is a clamp closing gap L1 as shown in Figure 1 , the central angle of the airway bushing 40 is less than and close to 180°.

[0038] The particularity of the airway bushing 40 is that, please refer to Figure 1 and Figure 2 Each limb of the airway bushing 40 forms an airway 41 with the clamp 20, and the airway 41 is communicated to the inside of the airway bushing 40, and the airway 41 forms an air port 411 on the inside of the airway bushing 40, Figure 2 The air port span L2 is shown in the figure, which refers to the size of the air port 411 along the axial direction of the clamp 20, and the air port span L2 is controlled at about 1mm, for example, 1mm±0.5mm. The inlet pipe 50 is connected to the side of the clamp 20 away from the airway bushing 40, and the inlet pipe 50 is communicated with the airway 41. The inert gas is input into the airway 41 through the inlet pipe 50, and the inert gas is communicated to the outer circumferential side of the first pipe and the second pipe through the air port 411, which provides the inert gas for the back of the butt joint during the pipe orifice butt joint inner hole welding, and provides necessary inert gas protection for the outer side of the pipe during the welding process.

[0039] In the scheme of the present application, the two pipe orifices to be welded are accurately fixed by manually installing and locking the upper and lower clamps 20. When the studs 11 are pressed against the two clamps 20 as shown in Figure 1 , the first pipe inserted between the two flat bushings 30 is opposite to the second pipe inserted between the two airway bushings 40, which realizes the purpose of accurately assembling the concentricity, straightness and pipe wall misalignment of the first pipe and the second pipe, and forms a circumferential accurate gas protection at the joint weld, so as to realize the high-precision welding of pipe butt joint, and realize the welding process of single-sided welding and double-sided forming of pipe orifice butt joint inner hole welding, including but not limited to the realization of helium-argon mixed gas protection non-melting electrode arc welding for deep hole, all-position, full-blind and non-grooving of main heat exchanger inner hole welding.

[0040] The pipe orifice butt joint inner hole welding single-sided welding double-sided forming welding process is carried out by using the pipe inner hole gas shield welding clamp of the application, the labor intensity of the construction personnel is reduced, the manual outside welding construction is changed into the machine automatic inner hole welding construction, the work efficiency is effectively improved, and the operation cycle is shortened.

[0041] In addition, the scheme has the characteristics of simple structure, small manufacturing difficulty, saving of human resources, low cost and small investment, and is very suitable for application in the pipe orifice butt joint inner hole welding single-sided welding double-sided forming welding process. For the pipe orifice butt joint welding of new varieties and new specifications of materials such as medium and small diameter safety level pipelines, copper alloy pipelines, stainless steel and duplex stainless steel pipelines, safe and precise welding process and automatic welding technology are provided, and wide application and use are facilitated.

[0042] When the stud 11 is pressed against the two clamping seats 20, the first pipe is opposite the second pipe, the first pipe is opposite the second pipe, and the first pipe is opposite the second pipe. Figure 2 The gas port 411 and the gas port span L2 are shown, and in some embodiments, the first pipe and the second pipe are opposite the gas port 411, so that the inert gas from the gas port 411 is directly conducted to the pipe orifice gap of the first pipe and the second pipe, improving the protection effect of the inert gas during welding.

[0043] In some embodiments, please refer to Figure 2 Each flat sleeve 30 is provided with at least two first protrusions 31, the first protrusions 31 are located on the inner side of the flat sleeve 30, and the first protrusions 31 are distributed along the ring direction of the flat sleeve 30, each gas channel sleeve 40 is provided with at least two second protrusions 42, the second protrusions 42 are located on the inner side of the gas channel sleeve 40, and the second protrusions 42 are distributed along the ring direction of the gas channel sleeve 40, by setting the first protrusions 31 in direct contact with the first pipe and the second protrusions 42 in direct contact with the second pipe, the area of the contact surface between the flat sleeve 30 and the first pipe is reduced, the area of the contact surface between the gas channel sleeve 40 and the second pipe is reduced, thereby reducing the influence of the manufacturing process on the positioning of the pipe, and improving the positioning effect of the flat sleeve 30 on the first pipe and the gas channel sleeve 40 on the second pipe.

[0044] In some embodiments, please refer to Figure 1 The axial end of the gas channel sleeve 40 close to the flat sleeve 30 is spaced apart from the clamping seat 20, and the gas port 411 formed by the gas channel 41 on the inner side of the gas channel sleeve 40 is smoothly formed. Please refer to Figure 1 and Figure 2, the air channel 41 is distributed along the annular direction of the air channel liner 40, and the air channel 41 is provided with sealing plates 43 at both ends in the annular direction, the sealing plates 43 are in sealing connection with the air channel liner 40 and the support, and the air channel 41 is provided with a filter screen 412, the filter screen 412 is arranged between the air inlet 411 and the air inlet pipe 50, and after the filter screen 412 is arranged in the air channel 41, the air channel 41 is sealed by the sealing plates 43, and only the air inlet 411 is left as the outlet of the inert gas. By additionally arranging the filter screen 412 in the air channel 41, the filter screen 412 includes but is not limited to a copper wire filter screen 412, the inert gas is filtered through the filter screen 412, and the service life of the chuck is improved.

[0045] In some embodiments, referring to Figure 1 and Figure 2 , the clamping seat 20 is in an arc structure, mainly referring to that the outer circumferential side of the clamping seat 20 is in an arc surface, and Figure 1 corresponding to the clamping seat overlap gap L1 shown in , the central angle of the arc structure is less than and close to 180°.

[0046] In some embodiments, referring to Figure 1 , the base piece 10 is specifically designed as a C-shaped clamp, the C-shaped clamp includes a first arc segment 121, a straight segment 122 and a second arc segment 123, one end of the first arc segment 121 in the arc direction is connected with one end of the straight segment 122, and the other end of the straight segment 122 is connected with one end of the second arc segment 123 in the arc direction. The two clamping seats 20 are respectively a first clamping seat 21 and a second clamping seat 22, the first clamping seat 21 is attached to the inner side of the first arc segment 121, and one end of the first clamping seat 21 is connected with the straight segment 122, and the stud 11 is threadedly installed on the second arc segment 123, and the stud 11 is used to press the second clamping seat 22 to be overlapped with the first clamping seat 21. By designing the straight segment 122 in the base piece 10, the second clamping seat 22 is always pressed against the straight segment 122 during the process that the stud 11 presses the second clamping seat 22 to be overlapped with the first clamping seat 21, so that the second clamping seat 22 and the first clamping seat 21 can be accurately overlapped.

[0047] It should be noted that, during the process that the stud 11 presses the second clamping seat 22 to be overlapped with the first clamping seat 21, the first pipe and the second pipe located between the two clamping seats 20 also have a guiding effect on the overlapping process of the first clamping seat 21 and the second clamping seat 22, so that the first clamping seat 21 and the second clamping seat 22 can be accurately overlapped.

[0048] In some embodiments, referring to Figure 1 and Figure 2 , the second clamping seat 22 is connected with a top block 23 located on the outer side, the top block 23 is distributed along the axial direction of the second clamping seat 22, the top block 23 is used to contact the stud 11, and the stud 11 can tightly overlap the second clamping seat 22 by pressing the top block 23.

[0049] In some embodiments, the top block 23 is provided with an alignment hole, which is formed in the side of the top block 23 away from the second clamp seat 22, and is used for the threaded stud 11 to pass through so as to align the axial ends of the two clamp seats 20 when the threaded stud 11 is pressed against the two clamp seats 20. When the threaded stud 11 is in abutment with the top block 23, the threaded stud 11 is located in the alignment hole, and the axial ends of the two clamp seats 20 are automatically aligned.

[0050] It should be further noted that in the scheme without the alignment hole of the top block 23, the axial ends of the two clamp seats 20 can also be aligned by operation, and the slight misalignment of the axial ends of the two clamp seats 20 does not affect the smooth use of the chuck.

[0051] In some embodiments, the pipe inner hole gas shield welding chuck is further provided with a gas cylinder filled with inert gas, which is communicated with the gas inlet pipe 50 through a hose, and the connection between the hose and the gas inlet pipe 50 is fastened to improve the defect of gas leakage.

[0052] The application also provides a pipe inner hole gas shield welding method based on the above-mentioned pipe inner hole gas shield welding chuck, which realizes the welding process of single-sided welding and double-sided forming of pipe joint butt inner hole welding, including but not limited to the realization of helium-argon mixed gas shield non-melting electrode arc welding applied to deep hole, all-position, full-blind and non-grooving inner hole welding of main heat exchanger.

[0053] First, the first pipe fitting is fixedly installed on the head of the inner hole welding machine, the axial center of the first pipe fitting is adjusted until the axial center of the first pipe fitting is kept concentric with the head of the inner hole welding machine, the perpendicularity of the first pipe fitting and the rotating surface of the head of the inner hole welding machine is adjusted, and the extension length of the head of the inner hole welding machine is adjusted, so that the welding point is aligned with the joint position of the pipe end when the head rotates.

[0054] Then, the pre-prepared gas cylinder filled with inert gas is connected to the gas inlet pipe 50 of the chuck through a hose, and the mutual connection between the gas cylinder, the hose and the gas inlet pipe 50 is fastened to prevent the inert gas from leaking.

[0055] Then, the first pipe fitting is brought close to the pipe end of the second pipe fitting which needs to be butt-jointed, and the up-down and left-right positions of the welding machine head are adjusted to make the pipe ends of the two pipe fittings as much as possible to be aligned and to make the two pipe fittings to be distributed on the same straight line.

[0056] Next, the assembly work of the chuck is carried out, the first clamp seat 21 and the second clamp seat 22 are clamped and locked to the two pipe fittings by adjusting the threaded stud 11, at this time, the flat sleeve 30 and the gas passage sleeve 40 will accurately adjust the pipe end of the two pipe fittings to be concentric and keep the two pipe fittings to be distributed on the same straight line through precise fitting, and at the same time, the wall misalignment of the two pipe fittings is also adjusted, so that the pipe ends are accurately assembled to ensure the accurate welding of the pipe ends.

[0057] Finally, in the case of filling inert gas in the inner air channel 41 of the clamp, the inner hole welding machine gun head rotates one circle inside the pipe opening, and the inner hole gas protection welding of the pipe butt joint of the first pipe and the second pipe can be completed by applying appropriate welding specifications.

[0058] In the pipe inner hole gas protection welding method of the present application, the upper and lower clamping seats 20 are fastened together by the stud 11, and the assembly precision requirement of the pipe opening butt joint is met by the flat bush 30 and the air channel bush 40, so that the high-precision and convenient assembly of the pipe opening butt joint is realized, the full-range inert gas protection of the entire circumference of the pipe opening butt joint is provided, and the safe and precise welding process and automatic welding technology are realized for the pipe opening butt joint welding of new varieties and new specifications of materials such as medium and small diameter safety level pipes, copper alloy pipes, stainless steel and duplex stainless steel pipes, which provides a strong reference for the safe and precise welding process and automatic welding technology, and is convenient for wide range of popularization and application.

[0059] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all the preferred embodiments and all the changes and modifications falling within the scope of the present application.

[0060] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A gas shielded welding chuck for inner hole of pipe, characterized in that: include: A base part, threaded with studs; Two clamping seats are provided opposite to each other, one of which is fixedly connected to the base member, and the other is used to abut against the stud; A flat bushing is provided with two lobes, and the two lobes of the flat bushing are respectively connected to the two clamping seats; An airway bushing is provided with two petals, the two petals of the airway bushing are connected to the two clamping seats respectively, the airway bushing is spaced apart from the flat bushing, and each petal of the airway bushing and the clamping seat enclose an airway, and the airway is connected to the inner side of the airway bushing; There are at least two air inlet pipes, each of which is connected to a side of the clamping seat away from the airway bushing and communicates with the airway, and is used to input inert gas; Wherein, under the condition that the stud is pressed until the two clamp seats are closed, the first pipe member passing through the two halves of the flat bushing is directly opposite to the second pipe member passing through the two halves of the airway bushing; The air duct is connected to the inner side of the air duct bushing to form an air port. When the stud is pressed until the two clamp seats are closed, the first pipe member inserted between the two halves of the flat bushing is directly opposite to the second pipe member inserted between the two halves of the air duct bushing, and the pipe port gap formed by the first pipe member and the second pipe member is directly opposite to the air port. Each petal of the flat bushing is provided with at least two first protrusions located on the inner side and distributed along the circumferential direction of the flat bushing, and each petal of the airway bushing is provided with at least two second protrusions located on the inner side and distributed along the circumferential direction of the airway bushing. When the stud is pressed to close the two clamp seats, the first protrusion contacts the first pipe fitting and the second protrusion contacts the second pipe fitting.

2. The gas shielded welding chuck for inner hole of pipe according to claim 1, characterized in that: An axial end of the airway bushing close to the flat bushing is spaced apart from the clamping seat; The air duct is distributed along the circumferential direction of the air duct bushing, and sealing plates are installed at both ends of the circumferential direction of the air duct. The sealing plates are sealed and connected to the air duct bushing and the clamping seat. A filter is provided in the air passage, and the filter is spread between the air port and the air inlet pipe.

3. The gas shielded welding chuck for inner hole in pipe according to claim 1 or 2, characterized in that: The clamping seat is an arc-shaped structure, and the central angle of the arc-shaped structure is less than 180°.

4. The gas shielded welding chuck for inner hole of pipe according to claim 3, characterized in that: The base member is a C-shaped clamp, which includes a first arc segment, a straight segment, and a second arc segment, wherein an arcuate end of the first arc segment is connected to one end of the straight segment, and the other end of the straight segment is connected to an arcuate end of the second arc segment; The two clamping seats are respectively a first clamping seat and a second clamping seat, the first clamping seat is fittedly connected to the inner side of the first arc segment, and the first clamping seat is connected to one end of the straight segment, the stud is threadedly installed on the second arc segment, and the stud is used to press the second clamping seat to fit together with the first clamping seat.

5. The gas shielded welding chuck for inner hole of pipe according to claim 4, characterized in that: The second clamping seat is connected to a top block located on the outside. The top block is distributed along the axial direction of the second clamping seat and is used to contact the stud.

6. The chuck for gas shielded welding of inner holes in pipes according to claim 5, characterized in that: The top block is provided with an alignment hole, which is provided on a side of the top block away from the second clamp seat. The alignment hole is used for the stud to pass through so as to align the axial ends of the two clamp seats when the stud is pressed to close the two clamp seats.

7. The chuck for gas shielded welding of inner holes in pipes according to claim 1 or 2, characterized in that: The pipe inner hole gas shielded welding chuck is also provided with a gas cylinder filled with inert gas, and the gas cylinder is connected to the air inlet pipe through a hose.

8. A method for gas shielded welding of inner holes in a pipe, characterized in that: The method using the pipe hole gas shielded welding chuck according to any one of claims 1 to 7 comprises: The first pipe is fixedly mounted on the head of the internal hole welding machine; Place the first pipe installed on the machine head close to the second pipe to be docked and align the pipe ends; Put the two clamps on the first pipe and the second pipe and tighten the studs until the pipe openings are clamped; After the air passage is filled with inert gas, the gun head of the inner hole welding machine rotates once inside the first pipe to complete the welding of the butt joint between the first pipe and the second pipe.

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