A device for inflation welding of a natural gas tank head

Abstract

The application discloses a kind of natural gas tank head inflation welding device, it is related to the technical field of transport tank production equipment, it includes first section rod;First umbrella rod, for multiple, rotationally connected in first section rod;Second umbrella rod, for multiple, rotationally connected in first section rod;Umbrella cloth is connected between first umbrella rod and second umbrella rod, gas cannot pass through;Baffle is fixed on first section rod;First umbrella rod and second umbrella rod inside are provided with elastic block to make itself fixed in the position of opening state;Second section rod, rotationally connected in first section rod end;Third section rod, rotationally connected in second section rod end;First section rod is provided with the unlocking assembly of making first umbrella rod and second umbrella rod fold, first section rod is provided with the fixing plate of the position of first section rod, second section rod and third section rod is fixed, and is unlocked by unlocking assembly in third section rod;Ventilation pipe is used to the ventilation of umbrella cloth.The application has the effect of improving the last head welding efficiency and quality of tank.

Description

A gas filling and welding device for natural gas tank head Technical Field

[0001] This application relates to the technical field of transport tank production equipment, and in particular to a gas filling and welding device for natural gas tank heads. Background Technology

[0002] Natural gas storage tanks and transport tanks are generally large in volume. As volumetric tanks, they are usually produced in two parts: the tank cylinder and the end caps. Finally, they are welded together to form a complete tank.

[0003] When welding the tank cylinder and the end cap, the tank cylinder is generally placed on a rotatable base, and the end cap is moved to the end of the tank cylinder by a frame. Then, a rotating tank end cap internal ring welding device, as disclosed in patent application number CN201310426209.X, is placed at the required welding point on the tank cylinder, so that the top cover covers the area to be welded. Finally, protective gas is introduced into the cover, and deep penetration welding is performed on the top of the tank. The base drives the tank cylinder and end cap to rotate, thereby completing the installation of one of the end caps.

[0004] Because it is impossible to install an inflation protection device inside the tank when welding the other end cap, and the pipe hole on the end cap is set off-center, the external direct welding method is generally used for welding. However, this welding method has lower welding efficiency and poorer welding quality compared to deep penetration welding, but there is no more effective method. Summary of the Invention

[0005] In order to improve the defect that the final end cap of a natural gas tank cannot be welded with deep penetration welding, resulting in poor welding efficiency and quality, this application provides a gas filling and welding device for the end cap of a natural gas tank.

[0006] The gas filling and welding device for a natural gas tank head provided in this application adopts the following technical solution:

[0007] A gas filling and welding device for a natural gas tank head, comprising:

[0008] First section of the pole;

[0009] The first umbrella pole, consisting of multiple poles, is rotatably connected to the outer circumferential wall of the first pole with the axis of the first pole as the center.

[0010] There are multiple second umbrella poles, which are rotatably connected to the outer circumferential wall of the first section pole about the axis of the first section pole. The second umbrella pole is closer to the end cap than the first umbrella pole. Both the first and second umbrella poles are provided with torsion springs at their rotation axes. The torsion springs cause the first and second umbrella poles to rotate away from the end cap.

[0011] The canopy, connected between the first and second umbrella rods, prevents gas from passing through and covers the weld seam at the connection between the canister and the end cap;

[0012] A baffle is fixed to the outer circumferential wall of the first section of the pole and located on the side of the first and second umbrella poles near the end cap;

[0013] A spring groove is provided at the end of the first and second umbrella shafts. A spring block is slidably connected in the spring groove. A spring is fixedly provided on the inner wall of the spring groove. The other end of the spring is fixedly connected to the spring block.

[0014] The first section of the pole has an unlocking cavity inside, and a locking hole is provided on the outer circumferential wall of the first section of the pole so that the spring can be inserted into the unlocking cavity. An unlocking pin is rotatably connected inside the unlocking cavity. An arc-shaped unlocking groove is provided on the unlocking pin opposite the locking hole. When the spring abuts against the unlocking pin, the torsion spring can drive the first umbrella pole and the second umbrella pole to rotate.

[0015] The second rod is rotatably connected to the end of the first rod, and a second rotating rod is rotatably connected inside it.

[0016] The third rod is rotatably connected to the end of the second rod, and a third rotating rod is rotatably connected inside it.

[0017] The second rotating rod is fixed with a second helical tooth at both ends, and the third rod is fixed with a third helical tooth. When the third helical tooth meshes with the second helical tooth, the second rod and the third rod are at 90°. One end of the unlocking pin extends out of the first rod and is fixed with a first helical tooth. When the first helical tooth meshes with the second helical tooth, the first rod and the second rod are at 90°. The third rod extends out of the pipe hole of the end cap.

[0018] The first section of the rod is rotatably connected to a fixed rod on its outer circumference, and the other end of the fixed rod is a hook. The third section of the rod is equipped with a fixed block that can retract into the third section of the rod on its outer circumference, and the hook is hung on the fixed block. The second section of the rod is fixed with a first stop block and a second stop block on its outer circumference.

[0019] When the hook is hung on the fixed block, the first section of the rod is located at the central axis of the tank, the third section of the rod extends out from the end cap tube hole, the second section of the rod is perpendicular to both the first and third sections of the rod, the first stop block abuts against the first section of the rod, and the second stop block abuts against the third section of the rod;

[0020] The first, second, and third sections of the rod can all pass through the end cap tube hole;

[0021] The vent pipe is connected to the umbrella fabric at one end and extends out of the end cap tube hole to connect to the device for filling protective gas at the other end.

[0022] Optionally, the umbrella fabric is connected together with the first and second umbrella poles, and the cross-section of the umbrella fabric is "U" shaped when it is opened.

[0023] Optionally, the first and second umbrella poles are staggered.

[0024] Optionally, an opening cylinder can be fitted onto the end of the first section of the pole away from the second section of the pole. Multiple first push plates and second push plates are fixed at the end of the opening cylinder. The first push plate is positioned opposite to the first umbrella pole, and the second push plate is positioned opposite to the second umbrella pole. When the first push plate abuts against the first umbrella pole and drives the first umbrella pole to rotate and open, the second push plate abuts against the second umbrella pole and opens the second umbrella pole.

[0025] Optionally, the ends of the first and second umbrella rods are fixed with arc plates that can fit against the inner wall of the tank, and the arc plates can pass through the pipe holes of the end cap.

[0026] Optionally, a sponge layer is fixed between the two first umbrella poles and between the two second umbrella poles of the umbrella fabric, the sponge layer being used to press against the inner wall of the can.

[0027] Optionally, a fixing hole is provided on the outer circumferential wall of the third section rod, and a push groove communicating with the fixing hole is provided inside the third section rod. One end of the push groove is connected to the outside. A push rod is slidably connected in the push groove. A placement groove for the fixing block is provided at the position of the push rod opposite the fixing hole. The fixing block is rotatably connected in the placement groove. A torsion spring is provided at the rotation shaft of the fixing block to allow the fixing block to extend out of the fixing hole. During the process of the push rod pushing inward, the fixing block will completely rotate into the placement groove.

[0028] In summary, this application includes at least one of the following beneficial technical effects:

[0029] After the first and second umbrella rods are opened, the spring block is inserted into the unlocking groove, and the first umbrella rod is abutted against the tank port. Then, the corresponding helical gears are engaged and the hook is hung on the fixing block. During the installation of the end cap, the third rod and the vent pipe extend from the end cap pipe opening. After the end cap is pre-installed, the space enclosed by the umbrella cloth covers the connection between the tank and the end cap, which allows the weld to be filled with protective gas, improving the efficiency and quality of the welding between the tank and the end cap.

[0030] After welding is completed, the second rotating rod and the unlocking column are rotated by rotating the third rotating rod. During the rotation of the unlocking column, the spring block is pushed out through the unlocking groove, which causes the first umbrella rod and the second umbrella rod to close under the action of the torsion spring. Then, the push rod is pushed to make the fixing block retract and disengage from the hook, releasing the position fixation between the first section rod, the second section rod and the third section rod. Finally, the third section rod, the second section rod and the first section rod are pulled out in sequence from the end cap tube hole.

[0031] The staggered design of the first and second umbrella poles can effectively increase the space occupied when the umbrella is closed. At the same time, the design of the umbrella fabric allows the first and second umbrella poles to be opened together through the opening tube, which improves the operating efficiency.

[0032] The arc plate design effectively improves the firmness of the contact with the inner wall of the tank, and also enhances the sealing of the space enclosed by the umbrella cloth in conjunction with the sponge layer. Attached Figure Description

[0033] Figure 1 is a structural schematic diagram of an embodiment of this application;

[0034] Figure 2 is a partial cross-sectional view showing the unlocking cavity;

[0035] Figure 3 is an enlarged view of the spring groove shown in part A of Figure 2;

[0036] Figure 4 is a partial cross-sectional view showing the unlocking components;

[0037] Figure 5 is a partial cross-sectional view showing the release component;

[0038] Figure 6 is a partial schematic diagram showing the usage state of the extended component.

[0039] In the diagram, 1. First section rod; 11. Baffle; 12. Locking hole; 13. Unlocking cavity; 14. Fixing rod; 141. Hook; 2. Second section rod; 21. First stop block; 22. Second stop block; 3. Third section rod; 31. Fixing hole; 32. Push groove; 4. Unlocking assembly; 41. Unlocking post; 411. Unlocking groove; 412. First helical tooth; 42. Second rotating rod; 421. Second helical tooth; 43. Third rotating rod; 431. Third helical tooth; 5. Release assembly; 51. Push rod; 511. Placement groove; 52. Fixing block; 6. First umbrella pole; 61. Arc plate; 62. Umbrella fabric; 621. Sponge layer; 63. Spring groove; 631. Spring; 632. Spring block; 7. Second umbrella pole; 8. Opening assembly; 81. Opening tube; 82. First push plate; 83. Second push plate; 9. Ventilation pipe. Detailed Implementation

[0040] The present application will be further described in detail below with reference to Figures 1-6.

[0041] This application discloses a gas filling and welding device for natural gas tank head.

[0042] Referring to Figures 1 and 2, the gas filling and welding device for the natural gas tank head includes a first rod 1, a second rod 2, a third rod 3, a first umbrella rod 6, and a second umbrella rod 7. The first rod 1 and the second rod 2 are rotatably connected to each other, and the second rod 2 and the third rod 3 are also rotatably connected to each other. Multiple first umbrella rods 6 are rotatably connected to the circumferential outer wall of the first rod 1 about its axis. Multiple second umbrella rods 7 are rotatably connected to the circumferential outer wall of the first rod 1 about its axis. The second umbrella rods 7 are closer to the head than the first umbrella rods 6. Torsion springs are installed at the rotation axes of both the first umbrella rods 6 and 7, causing them to rotate away from the head and adhere to the circumferential outer wall of the first rod 1. A baffle 11 is fixed to the circumferential outer wall of the first rod 1 on the side near the head at the rotation axes of the first umbrella rods 6 and 7. The first umbrella rods 6 and 7 are staggered.

[0043] Referring to Figures 2 and 3, spring grooves 63 are provided at the ends of the first umbrella rod 6 and the second umbrella rod 7 at their rotating shafts. A spring block 632 is slidably connected within the spring groove 63, and a spring 631 is fixedly mounted on the inner wall of the spring groove 63. The other end of the spring 631 is fixedly connected to the spring block 632. An unlocking cavity 13 is provided inside the first rod section 1, and a locking hole 12 is provided on the outer circumferential wall of the first rod section 1, allowing the spring block 632 to extend into the unlocking cavity 13. Arc plates 61 that fit against the inner wall of the tank are fixedly mounted at the ends of both the first umbrella rod 6 and the second umbrella rod 7. A canopy 62 connects the first umbrella rod 6 and the second umbrella rod 7, preventing gas from passing through the canopy 62. After the first umbrella rod 6 and the second umbrella rod 7 are opened, the canopy 62 has a U-shaped cross-section and covers the weld seam of the tank.

[0044] The central axis of the first rod 1 is collinear with the central axis of the can. A fixing rod 14 is rotatably connected to the outer wall of the first rod 1. The other end of the fixing rod 14 can be fixed to the third rod 3. At this time, the second rod 2 is perpendicular to both the first rod 1 and the third rod 3, and part of the third rod 3 extends out from the end cap tube hole. When the spring block 632 is located in the unlocking cavity 13, both the first umbrella rod 6 and the second umbrella rod 7 can remain open. When the spring block 632 is only located in the locking hole 12, the torsion spring can drive the first umbrella rod 6 and the second umbrella rod 7 to rotate and retract. The first rod 1, the second rod 2, and the third rod 3 are equipped with unlocking components 4 that can push the spring block 632 out of the unlocking cavity 13. The third rod 3 is equipped with a release component 5 to release the fixing rod 14 from the fixed state of the third rod 3. There is also an opening component 8 for opening the first umbrella rod 6 and the second umbrella rod 7 together. The umbrella fabric 62 is connected to a vent pipe 9, the other end of which extends out from the end cap tube hole and is connected to a device for charging protective gas. The first rod section 1, the second rod section 2, and the third rod section 3 can all pass through the end cap tube hole.

[0045] By expanding assembly 8, both the first umbrella rod 6 and the second umbrella rod 7 are rotated and opened, causing the spring block 632 to be located in the locking cavity, thus fixing the state of the first umbrella rod 6 and the second umbrella rod 7, thereby opening the umbrella cloth 62. Then, the arc plate 61 of the first umbrella rod 6 abuts against the inner wall of the tank. After rotating the second section rod 2 and the third section rod 3 to a mutually perpendicular state, they are fixed to the third section rod 3 by the fixing rod 14. Then, the end cap is moved, allowing the vent pipe 9 and the third section rod 3 to pass through the pipe hole of the end cap. The arc plate 61 of the second umbrella rod 7 abuts against the inner wall of the end cap, allowing the umbrella cloth 62 to cover the weld area. The arc plate 61 effectively improves the firmness of the fixed position of the first umbrella rod 6 and the second umbrella rod 7, and, together with the sponge layer 621, effectively improves the sealing of the space enclosed by the umbrella cloth 62. During subsequent welding, the vent pipe 9 continuously introduces protective gas into the space enclosed by the umbrella cloth 62, thereby improving the efficiency and quality of the tank end cap welding. After welding, the spring block 632 is pushed out of the unlocking cavity 13 by the unlocking component 4, and the torsion spring causes the first umbrella pole 6 and the second umbrella pole 7 to rotate and retract. Then, the fixing rod 14 is separated from the third section rod 3 by the release component 5, so that the third section rod 3, the second section rod 2 and the first section rod 1 can be pulled out from the end cap tube hole in sequence. The staggered arrangement of the first umbrella pole 6 and the second umbrella pole 7 can effectively reduce the space occupied by the first umbrella pole 6 and the second umbrella pole 7 when retracted.

[0046] Referring to Figures 3 and 4, the unlocking assembly 4 includes an unlocking post 41, a second rotating rod 42, and a third rotating rod 43. The unlocking post 41 is rotatably connected within the unlocking cavity 13. One end of the unlocking post 41 extends from the end of the first rod 1 near the second rod 2 and is fixedly connected with a first helical tooth 412. The second rotating rod 42 is rotatably connected within the second rod 2, with second helical teeth 421 fixedly attached at both ends after extending out of the second rod 2. A first stop 21 and a second stop 22 are fixedly attached at both ends of the outer circumferential wall of the second rod 2. The third rotating rod 43 is rotatably connected within the third rod 3, with both ends extending out of the third rod 3, and a third helical tooth 431 fixedly attached at the end near the second rod 2. When the fixed rod 14 is fixedly connected to the third rod 3, the second rod 2 is perpendicular to both the first rod 1 and the third rod 3. At this time, the first helical tooth 412 meshes with the second helical tooth 421, and the first stop block 21 abuts against the outer wall of the first rod 1; the third helical tooth 431 meshes with the second helical tooth 421, and the second stop block 22 abuts against the outer wall of the third rod 3. An arc-shaped unlocking groove 411 is provided on the unlocking pin 41 opposite the locking hole 12. The spring block 632 can abut against the inner wall of the unlocking groove 411 and can abut against the circumferential outer wall of the unlocking pin 41 through the unlocking groove 411.

[0047] Before assembling the end cap, the first rod 1, the second rod 2, and the third rod 3 are pre-swung to a mutually perpendicular position, and the corresponding helical gears are engaged. Then, the fixing rod 14 is rotated to fix it to the third rod 3, ensuring that the third rod 3, the second rod 2, and the first rod 1 remain mutually perpendicular. The first push plate 82 and the second push plate 83 improve the stability of this position. When it is necessary to retract the first umbrella rod 6 and the second umbrella rod 7, the third rotating rod 43 is rotated. The third rotating rod 43, through its meshing relationship, drives the second rotating rod 42 to rotate. The second rotating rod 42 drives the unlocking pin 41 to rotate, thereby causing the spring block 632 to move from the unlocking groove 411 to the outer circumferential wall of the unlocking pin 41. Subsequently, under the action of the torsion spring, the first umbrella rod 6 and the second umbrella rod 7 rotate and retract.

[0048] Referring to Figure 5, the release assembly 5 includes a push rod 51 and a fixing block 52. A fixing hole 31 is formed on the outer circumference of the third rod 3, and a push groove 32 communicating with the fixing hole 31 is formed inside the third rod 3. One end of the push groove 32 is open to the outside. The push rod 51 is slidably connected within the push groove 32. A placement groove 511 is formed on the push rod 51 opposite the fixing hole 31, allowing the fixing block 52 to reside within it. The fixing block 52 is rotatably connected within the placement groove 511, and a torsion spring is provided at the rotation axis of the fixing block 52 to allow it to extend from the fixing hole 31. During the inward pushing of the push rod 51, the fixing block 52 will completely rotate into the placement groove 511. The end of the fixing rod 14 away from the rotation axis is a hook 141, which can be hung on the fixing block 52.

[0049] After the fixing block 52 extends from the fixing hole 31, the hook 141 is hung on the fixing block 52, thereby keeping the first section 1, the second section 2, and the third section 3 in a mutually perpendicular state. After the first umbrella rod 6 and the second umbrella rod 7 are retracted, the fixing block 52 is rotated into the placement groove 511 by pushing the push rod 51 inward. Finally, the hook 141 is disengaged from the fixing block 52, releasing the mutual fixation of the first section 1, the second section 2, and the third section 3, so that the third section 3, the second section 2, and the first section 1 can be removed from the end cap tube hole in sequence.

[0050] Referring to Figure 6, the opening assembly 8 includes an opening cylinder 81, a first push plate 82, and a second push plate 83. Both the first push plate 82 and the second push plate 83 are fixed to one end of the opening cylinder 81 and are spaced apart. The first push plate 82 is positioned opposite the first umbrella rod 6, and the second push plate 83 is positioned opposite the second umbrella rod 7. When the opening cylinder 81 is fitted onto the first section 1, the first push plate 82 abuts against and rotates the first umbrella rod 6 to open it, and the second push plate 83 abuts against and rotates the second umbrella rod 7 to open it. This allows the first umbrella rod 6 and the second umbrella rod 7 to open quickly together, effectively utilizing the staggered arrangement of the first and second umbrella rods 6 and the position of the umbrella fabric 62.

[0051] The implementation principle of the gas filling and welding device for a natural gas tank head according to an embodiment of this application is as follows: After the first umbrella rod 6 and the second umbrella rod 7 are opened together by the opening cylinder 81, the arc plate 61 of the first umbrella rod 6 abuts against the edge of the inner wall of the tank. Then, the second section rod 2 and the third section rod 3 are rotated, so that the second helical tooth 421 meshes with the first helical tooth 412 and the second helical tooth 421. Then, the fixing rod 14 is rotated so that the hook 141 is hung on the fixing block 52. The head is moved so that the third section rod 3 and the vent pipe 9 extend from the head pipe hole. The arc plate 61 of the second umbrella rod 7 abuts against the inner wall of the head, so that the weld is located within the space enclosed by the umbrella cloth 62. Protective gas is introduced into the space enclosed by the umbrella cloth 62 through the vent pipe 9, and deep penetration welding is performed on the weld from the outside. The space enclosed by the umbrella cloth 62 effectively improves the welding quality between the head and the tank.

[0052] Finally, rotating the third rotating rod 43 causes the second rotating rod 42 to rotate the unlocking pin 41, thereby disengaging the spring block 632 from the unlocking slot 411. The first umbrella rod 6 and the second umbrella rod 7 then rotate and retract under the action of the torsion spring. Pushing the push rod 51 then disengages the hook 141 from the fixing block 52, releasing the mutual fixation between the first rod section 1, the second rod section 2, and the third rod section 3. Subsequently, the third rod section 3, the second rod section 2, and the first rod section 1 are sequentially removed from the end cap tube hole, achieving tool removal and improving the efficiency of tank end cap welding.

[0053] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A gas filling and welding device for a natural gas tank head, characterized in that: The system includes a first section rod (1); multiple first umbrella rods (6) that are rotatably connected to the outer circumferential wall of the first section rod (1) about the axis of the first section rod (1); multiple second umbrella rods (7) that are rotatably connected to the outer circumferential wall of the first section rod (1) about the axis of the first section rod (1), with the second umbrella rods (7) closer to the end cap than the first umbrella rods (6); torsion springs are provided at the rotation axes of both the first umbrella rods (6) and the second umbrella rods (7), causing the first umbrella rods (6) and the second umbrella rods (7) to rotate away from the end cap; and an umbrella cloth (62) that connects the first umbrella rods (6) and the second umbrella rods (7), preventing gas from passing through and allowing the weld at the connection between the tank and the end cap to be sealed. The first section of the rod (1) is covered with a baffle (11), which is fixed to the outer circumferential wall of the first section (1) and located on the side of the first umbrella rod (6) and the second umbrella rod (7) near the end cap. The ends of the first umbrella rod (6) and the second umbrella rod (7) are provided with spring grooves (63), and spring blocks (632) are slidably connected in the spring grooves (63). A spring (631) is fixed to the inner wall of the spring grooves (63), and the other end of the spring (631) is fixedly connected to the spring blocks (632). The first section of the rod (1) is provided with an unlocking cavity (13), and the outer circumferential wall of the first section of the rod (1) is provided with a locking hole (12) that allows the spring blocks (632) to extend into the unlocking cavity (13). An unlocking pin (41) is rotatably connected in the unlocking cavity (13). An arc-shaped unlocking groove (411) is provided at the position of the unlocking pin (41) opposite the locking hole (12). When the spring block (632) abuts against the unlocking pin (41), the torsion spring can drive the first umbrella rod (6) and the second umbrella rod (7) to rotate. The second section rod (2) is rotatably connected to the end of the first section rod (1), and the second rotating rod (42) is rotatably connected inside. The third section rod (3) is rotatably connected to the end of the second section rod (2), and the third rotating rod (43) is rotatably connected inside. The second rotating rod (42) is fixed with a second helical tooth (421) at both ends, and the third section rod (3) is fixed with a third helical tooth (431). When the third helical tooth (431) meshes with the second helical tooth (421), the second section rod (2) and the second section rod (7) rotate. The third rod (3) is at a 90° angle. One end of the unlocking pin (41) extends out of the first rod (1) and is fixed with a first helical tooth (412). When the first helical tooth (412) meshes with the second helical tooth (421), the first rod (1) and the second rod (2) are at a 90° angle. The third rod (3) extends out of the pipe hole of the end cap. The first rod (1) is rotatably connected to a fixed rod (14) on its circumferential outer wall. The other end of the fixed rod (14) is a hook (141). The third rod (3) is installed with a fixed block (52) that can retract into the third rod (3) on its circumferential outer wall. The hook (141) is hung on the fixed block (52). The second rod (2) is fixed with a first stop (21) and a second stop (22) on its circumferential outer wall.When the hook (141) is hung on the fixing block (52), the first rod (1) is located at the central axis of the tank, the third rod (3) extends out from the end cap tube hole, the second rod (2) is perpendicular to both the first rod (1) and the third rod (3), the first stop (21) abuts against the first rod (1), and the second stop (22) abuts against the third rod (3); the first rod (1), the second rod (2), and the third rod (3) can all pass through the end cap tube hole; the vent pipe (9) is connected at one end to the umbrella cloth (62), and the other end extends out from the end cap tube hole and is connected to the device for filling protective gas.

2. The gas filling and welding device for a natural gas tank head according to claim 1, characterized in that: The umbrella fabric (62) is connected together with the first umbrella pole (6) and the second umbrella pole (7). When the umbrella fabric (62) is opened, the cross section is "U".

3. The gas filling and welding device for a natural gas tank head according to claim 2, characterized in that: The first umbrella pole (6) and the second umbrella pole (7) are staggered.

4. The gas filling and welding device for a natural gas tank head according to claim 3, characterized in that: The end of the first section (1) away from the second section (2) can be fitted with an opening tube (81). The end of the opening tube (81) is fixed with a plurality of first push plates (82) and second push plates (83). The first push plate (82) is positioned opposite to the first umbrella rod (6), and the second push plate (83) is positioned opposite to the second umbrella rod (7). When the first push plate abuts against the first umbrella rod (6) and drives the first umbrella rod (6) to rotate and open, the second push plate (83) abuts against the second umbrella rod (7) and opens the second umbrella rod (7).

5. The gas filling and welding device for a natural gas tank head according to claim 1, characterized in that: The ends of the first umbrella rod (6) and the second umbrella rod (7) are fixed with arc plates (61) that can fit against the inner wall of the tank, and the arc plates (61) can pass through the pipe hole of the end cap.

6. The gas filling and welding device for a natural gas tank head according to claim 5, characterized in that: The umbrella fabric (62) has a sponge layer (621) fixed between the two first umbrella poles (6) and between the two second umbrella poles (7), and the sponge layer (621) is used to press against the inner wall of the can.

7. The gas filling and welding device for a natural gas tank head according to claim 1, characterized in that: The third rod (3) has a fixing hole (31) on its outer circumferential wall. The third rod (3) has a push groove (32) that communicates with the fixing hole (31) inside. One end of the push groove (32) is connected to the outside. A push rod (51) is slidably connected inside the push groove (32). A placement groove (511) is provided on the push rod (51) opposite to the fixing hole (31) for the fixing block (52) to be placed therein. The fixing block (52) is rotatably connected in the placement groove (511). A torsion spring is provided at the rotation axis of the fixing block (52) so that the fixing block (52) extends out of the fixing hole (31). During the process of pushing the push rod (51) inward, the fixing block (52) will be completely rotated into the placement groove (511).

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