A friction stir welding assembly method for large-diameter common-bottom storage tanks in a vertical configuration.

Abstract

This invention provides a friction stir welding method for assembling large-diameter common-bottom tanks in a vertical configuration. The method includes the following steps: determining whether the tank is a single-layer or double-layer common-bottom tank; if so, assembling and welding the single-layer common-bottom tank using a vertical assembly and welding method; otherwise, assembling and welding the double-layer common-bottom tank using a vertical assembly and welding method. The beneficial effects of this invention are: it enables friction stir welding of the circumferential seams of large-diameter single-layer and double-layer common-bottom tanks for launch vehicles in a vertical configuration, making high-reliability, high-quality, and high-efficiency welding of the common-bottom tank circumferential seams possible. This has significant practical implications and substantial economic value for the engineering application of aerospace products.

Description

Technical Field

[0001] This invention belongs to the field of rocket equipment technology, and in particular relates to a friction stir welding assembly method for a large-diameter common-bottom propellant tank in a vertical configuration. Background Technology

[0002] With the development and application of friction stir welding technology in the aerospace field, in the production of fuel tanks for spacecraft with a diameter of 3.35m, friction stir welding has been implemented for the longitudinal seams of the cylinder section, the main weld seam of the tank bottom, and the circumferential seam of the tank body. Furthermore, the circumferential seams of the tank body are all welded using a horizontal assembly welding method. In the production of fuel tanks for 5m large-diameter spacecraft, while the longitudinal seams of the cylinder section and the main weld seam of the tank bottom have also been produced using friction stir welding, the circumferential seams of the tank body still employ fusion welding. However, due to the characteristics of my country's new generation of launch vehicle fuel tanks—large diameter, long length, thickness, and new structure—fusion welding can no longer meet the welding requirements of the products, and friction stir welding is now necessary for the production of the circumferential seams of the tank body.

[0003] Due to the influence of the 5m diameter, ultra-long and thick common bottom structure of my country's new generation of carrier rockets and the corresponding equipment structure, the horizontal welding mode requires special measures to ensure the precision requirements of the assembly gap and misalignment of the tank circumferential seams. High-precision assembly and welding is extremely difficult to achieve. The vertical assembly and welding mode alleviates the impact of the tank and tooling weight on the assembly precision to a certain extent.

[0004] Disadvantages of existing technology:

[0005] (1) When assembling horizontally, the product is prone to deformation under the action of gravity, which affects the roundness and needs to be gradually adjusted through tooling assembly.

[0006] (2) The rigid internal support mechanism is heavy, which will cause the head or foot box to bear a lot of load under the action of gravity, and is prone to bending deformation, which is not conducive to ensuring the shape and size of the product.

[0007] (3) The horizontal design is difficult to assemble, and due to the length of the spindle, it is difficult to assemble and weld the long cylinder section, resulting in a large number of circumferential seams and a long production cycle. Summary of the Invention

[0008] In view of this, the present invention aims to propose a friction stir welding assembly method for large-diameter common-bottom tanks in a vertical configuration, in order to overcome the shortcomings of the prior art.

[0009] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0010] A friction stir welding assembly method for a large-diameter common-bottom storage tank in a vertical configuration includes the following steps:

[0011] S1. Determine whether the tank is a single-layer common-bottom tank or a double-layer common-bottom tank. If yes, proceed to step S2; otherwise, proceed to step S3.

[0012] S2. Assemble and weld the single-layer common-bottom tank using a vertical assembly and welding method.

[0013] S3. Assemble and weld the double-layer common-bottom tank using a vertical assembly and welding method.

[0014] The vertical assembly and welding method for a single-layer common-bottom tank in step S2 includes the following steps:

[0015] S21. Fuel tank assembly and welding;

[0016] S22. After the fuel tank assembly and welding are completed, single-layer common bottom assembly and welding shall be carried out.

[0017] S23. Oxygen box assembly and welding;

[0018] The vertical assembly and welding method for the double-layer common-bottom tank in step S3 includes the following steps:

[0019] S31, double-layer common bottom assembly and oxygen tank rear bottom frame assembly;

[0020] S32, Oxygen box sealing welding;

[0021] S33. After the oxygen box sealing fixture is removed, it is taken off the shelf and flipped over so that the double-layer common bottom assembly and the oxygen box face upwards. Then it is flipped over again and put back on the shelf.

[0022] S34, Hydrogen tank section is mounted and assembled;

[0023] S35, circumferential weld of hydrogen tank section;

[0024] S36, Hydrogen tank front bottom frame assembly;

[0025] S37. Hydrogen tank sealing completed.

[0026] Furthermore, the fuel tank assembly welding in step S21 includes the following steps:

[0027] A1. Connect the fuel tank bottom assembly to the lifting rings and hoist it into the equipment;

[0028] A2. The moving ring drives the bottom assembly of the fuel tank into the upper ring assembly position;

[0029] A3. Make the upper ring clamping mechanism clamp the transition ring of the fuel tank bottom assembly, smooth the mating surface of the transition ring, and grind and clean it.

[0030] A4. Replace the fixed inner support pad on the cylinder section feeding mechanism with an arc-shaped pad;

[0031] A5. Hoist the first cylindrical section of the rear box to the cylindrical section feeding mechanism and support the lower end of the first cylindrical section. The feeding mechanism will send the first cylindrical section into the equipment feeding position.

[0032] A6. The cylinder section feeding mechanism pushes the first cylinder section to the lower retaining ring;

[0033] A7. Make the lower clamping ring clamping mechanism clamp the first cylinder section, smooth the mating surface of the first cylinder section, and grind and clean it.

[0034] A8. The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the feeding mechanism cylinder section support rotates to align the quadrants, and then the fuel tank bottom assembly and the first cylinder section circumferential seam are joined.

[0035] A9. The cylinder section feeding mechanism pushes the fixed inner support to the weld position;

[0036] A10. Tighten and fix the internal support;

[0037] A11. Inspect, measure, and adjust the quality of weld assembly;

[0038] A12. The welding actuator rotates around the housing to complete the friction stir welding;

[0039] A13. Loosen the upper and lower clamping rings, the upper clamping ring clamping mechanism moves upward, and clean the front side of the weld.

[0040] A14. In-situ detection of ultrasonic phased array;

[0041] A15. Loosen the fixed inner support, lower the inner support by 300mm, and clean the back of the weld.

[0042] A16. Ultrasonic phased array testing;

[0043] A17. Loosen the support at the lower end of the feeding mechanism cylinder section;

[0044] A18. The moving ring drives the already welded half-box assembly to rise, so that the lower end of the first cylinder section enters the upper retaining ring;

[0045] A19. Make the upper clamping ring clamping mechanism clamp the first cylinder section, smooth the lower end mating surface of the first cylinder section, and grind and clean it.

[0046] A20. The cylindrical section feeding mechanism is moved out of the equipment's feeding position;

[0047] A21. Replace the fixed internal support plate with a flat plate;

[0048] A22. Hoist the second cylinder section of the fuel tank to the cylinder section feeding mechanism and support the lower end of the second cylinder section. The feeding mechanism will send the second cylinder section into the equipment feeding position.

[0049] A23. The cylinder section feeding mechanism pushes the second cylinder section to the lower retaining ring;

[0050] A24. Make the lower clamping ring clamping mechanism clamp the second cylinder section, smooth the mating surface of the second cylinder section, and grind and clean it.

[0051] A25. The upper ring clamping mechanism moves downward synchronously with the moving ring. Before the engagement, the feeding mechanism cylinder section support rotates to align the quadrants, and then the first cylinder section and the second cylinder section are engaged in the circumferential seam.

[0052] A26. The cylinder section feeding mechanism pushes the fixed inner support to the weld position;

[0053] A27. Tighten and fix the internal support;

[0054] A28. Inspect, measure, and adjust the quality of weld assembly;

[0055] A29. The welding actuator rotates around the housing to complete the positioning and formal welding;

[0056] A30. Loosen the upper and lower clamping rings. The upper clamping ring clamping mechanism moves upward. Clean the front side of the weld.

[0057] A31. In-situ detection of ultrasonic phased array;

[0058] A32. Loosen the fixed inner support, lower the inner support by 300mm, and clean the back of the weld.

[0059] A33. Ultrasonic phased array detection;

[0060] A34. Perform assembly and welding of the remaining cylinder sections of the fuel tank according to steps A17 to A33.

[0061] A35. The moving ring drives the already welded half-box assembly to rise, so that the lower end of the cylinder section enters the upper retaining ring;

[0062] A36. Measure the length of the half-box of the fuel tank so that the upper clamping ring clamping mechanism clamps the cylinder section;

[0063] A37. The cylindrical section feeding mechanism is moved out of the feeding position of the equipment.

[0064] Furthermore, the single-layer common-bottom assembly welding in step S22 includes the following steps:

[0065] B1. Hoist the common bottom to the bottom loading mechanism, level the common bottom locking mating surface, and grind and clean the welding area;

[0066] B2. Based on the half-box length of the fuel tank, calculate the side milling amount of the fuel tank section, and mill, grind and clean the mating surface at the lower end of the section;

[0067] B3. The bottom feeding mechanism pushes the common bottom to the lower layer clamping ring and clamps the common bottom transition ring tightly;

[0068] B4. The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be aligned, the bottom feeding mechanism rotates to align the quadrants. The upper ring clamping mechanism and the moving ring press down synchronously to lock the bottom assembly. Check, measure and adjust the assembly seam quality.

[0069] B5. The bottom loading mechanism pushes the bottom locking inner support to the welding position and tightens the bottom locking welding area. Check, measure and adjust the assembly quality of the inner support.

[0070] B6. The welding actuator rotates around the housing to complete the friction stir welding;

[0071] B7. Loosen the upper and lower clamping rings, the upper clamping ring clamping mechanism moves upward, and clean the front side of the weld;

[0072] B8. Ultrasonic phased array testing;

[0073] B9. Loosen the inner support at the bottom of the lock;

[0074] B10, the moving ring drives the half-box of the fuel tank to rise, so that the common bottom transition ring enters the upper retaining ring;

[0075] B11. Make the upper ring clamping mechanism clamp the common bottom transition ring, smooth the mating surface of the lower end of the common bottom transition ring, and grind and clean it.

[0076] B12. The bottom loading mechanism moves out of the loading position of the equipment;

[0077] B13. Replace the inner support pad of the cylindrical feeding mechanism with an arc-shaped pad.

[0078] Furthermore, the oxygen box assembly welding in step S23 includes the following steps:

[0079] C1. Hoist the first section of the oxygen tank to the section feeding mechanism, and level the lower support of the first section of the oxygen tank. The feeding mechanism will then send the first section of the oxygen tank into the equipment feeding position.

[0080] C2. Perform assembly welding of the first section of the oxygen tank and the common bottom butt joint circumferential seam according to steps A23 to A33;

[0081] C3. Replace the inner support pad of the cylindrical feeding mechanism with a flat pad.

[0082] C4. Perform assembly and welding of the remaining oxygen tank cylinder sections' butt joint circumferential seams according to steps A17 to A33;

[0083] C5. The moving ring drives the already welded box assembly to rise, so that the lower end of the last cylinder section of the oxygen box enters the upper retaining ring.

[0084] C6. Measure the sum of the lengths of the fuel box and the oxygen box half-box to make the upper clamping ring clamping mechanism clamp the cylinder section;

[0085] C7. The cylindrical section feeding mechanism is moved out of the equipment's feeding position;

[0086] C8. Hoist the oxygen tank bottom assembly to the bottom feeding mechanism, and fix the short shell connection to the end frame connecting ring of the feeding mechanism. Grind and clean the welding area.

[0087] C9. Hoist the detachable inner support and support mandrel to the bottom loading mechanism of the box, and the loading mechanism will send the front bottom assembly into the loading position of the equipment.

[0088] C10, The bottom feeding mechanism pushes the oxygen tank bottom assembly to the lower retaining ring;

[0089] C11. Make the lower clamping ring clamping mechanism clamp the oxygen tank bottom assembly tightly, and make the transition ring mating surface of the oxygen tank bottom assembly smooth.

[0090] C12. Based on the height of the oxygen tank bottom assembly and the length of the fuel tank + oxygen tank half tank, calculate the side milling amount of the oxygen tank sealing ring section, mill the lower end of the section's mating surface, and grind and clean it.

[0091] C13. The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the bottom feeding mechanism rotates to align the front and rear quadrants of the whole box, and then joins the bottom assembly of the oxygen box with the cylindrical section circumferential seam.

[0092] C14. The bottom feeding mechanism pushes the detachable internal support to the weld position;

[0093] C15. Tighten the removable internal support;

[0094] C16. Inspect, measure, and adjust the quality of weld assembly;

[0095] C17. The welding actuator rotates around the housing to complete friction stir welding;

[0096] C18. Loosen the upper and lower clamping rings, the upper clamping ring clamping mechanism moves upward, and clean the front side of the weld.

[0097] C19. In-situ detection of ultrasonic phased array;

[0098] C20. Loosen the removable inner support, raise it 300mm, and clean the back of the weld.

[0099] C21. Ultrasonic phased array detection;

[0100] C22. Remove the detachable internal support and transport the box out through the manhole at the bottom of the box;

[0101] C23. Disassemble the connecting ring of the end frame of the bottom loading mechanism and the connecting bolt of the short shell;

[0102] C24. The rotating ring drives the box to rise and enter the unloading position;

[0103] C25. The bottom loading mechanism is moved out of the loading position of the equipment;

[0104] C26. Remove the container from the shelf and carry out X-ray inspection, compensator, delivery pipe, parts installation, hydraulic, airtight, helium mass spectrometry leak detection, retain the process, and clean up the excess materials;

[0105] C27. Container delivery.

[0106] Furthermore, the assembly of the double-layer common-bottom assembly and the oxygen tank rear bottom upper frame in step S31 includes the following steps:

[0107] D1. With the convex spherical surface of the common bottom assembly facing upwards, connect the common bottom cylinder section to the lifting ring, and hoist it into the equipment. The lifting ring and the moving ring are connected to form a whole.

[0108] D2. The moving ring drives the common bottom assembly into the upper retaining ring;

[0109] D3. Make the upper ring clamping mechanism clamp the common bottom assembly transition ring tightly, and smooth the mating surface of the transition ring.

[0110] D4. Replace the fixed inner support pad on the cylinder section feeding mechanism with an arc-shaped pad;

[0111] D5. Hoist the oxygen tank section to the section feeding mechanism and support the lower end of the section. The feeding mechanism will then send the section into the equipment feeding position.

[0112] D6. The feeding mechanism pushes the cylinder section to the lower retaining ring;

[0113] D7. Make the lower clamping ring clamping mechanism clamp the cylinder section, smooth the mating surface of the cylinder section, and grind and clean it.

[0114] D8. The upper ring clamping mechanism moves downward synchronously with the moving ring. Before the engagement, the feeding mechanism cylinder section support rotates to align the quadrants, and then the common bottom assembly and the cylinder section circumferential seam are engaged.

[0115] Furthermore, the oxygen box sealing welding in step S32 includes the following steps:

[0116] E1. The cylinder section feeding mechanism pushes the fixed inner support to the weld position;

[0117] E2. Tighten and fix the internal support;

[0118] E3. Inspect, measure, and adjust the quality of the weld assembly;

[0119] E4. The welding actuator rotates around the housing to complete the friction stir welding;

[0120] E5. Loosen the upper and lower clamping rings. The upper clamping ring clamping mechanism moves upward. Clean the front side of the weld.

[0121] E6. In-situ detection of ultrasonic phased array;

[0122] E7. Loosen the fixed inner support, lower the inner support by 300mm, and clean the back of the weld.

[0123] E8. Ultrasonic phased array detection.

[0124] Furthermore, after the oxygen tank sealing fixture is removed in step S33, the assembly is flipped over so that the double-layer common-bottom assembly and the oxygen tank face upwards, and then flipped over again and put back on the rack, including the following steps:

[0125] F1. Loosen the support at the lower end of the feeding mechanism cylinder section;

[0126] F2. The moving ring drives the already welded oxygen box half-box assembly to rise, so that the lower end of the cylinder section enters the upper retaining ring;

[0127] F3. Measure the length of half of the oxygen tank to ensure that the upper clamping ring clamping mechanism clamps the cylinder section;

[0128] F4. The cylindrical section feeding mechanism moves out of the equipment's feeding position;

[0129] F5. Hoist the oxygen tank bottom assembly to the bottom feeding mechanism, and fix the short shell connection to the end frame connecting ring of the feeding mechanism. Grind and clean the welding area.

[0130] F6. Hoist the detachable inner support and support mandrel to the bottom loading mechanism of the oxygen tank. The loading mechanism will send the oxygen tank bottom assembly into the loading position of the equipment.

[0131] F7. The bottom feeding mechanism pushes the oxygen tank bottom assembly to the lower retaining ring.

[0132] F8. Make the lower clamping ring clamping mechanism clamp the oxygen tank bottom assembly, and mill the mating surface of the transition ring of the oxygen tank bottom assembly until it is smooth.

[0133] F9. Based on the milling amount of the transition ring of the oxygen box bottom assembly and the half box length, calculate the side milling amount of the oxygen box sealing ring section, mill the lower end of the section, and grind and clean it.

[0134] F10. The upper ring clamping mechanism moves downward synchronously with the moving ring. Before the engagement, the bottom feeding mechanism rotates to align the quadrants, and then the bottom assembly of the oxygen tank and the circumferential seam of the oxygen tank cylinder are engaged.

[0135] F11, The bottom loading mechanism pushes the detachable internal support to the weld position;

[0136] F12, tighten the removable inner support;

[0137] F13. Inspect, measure, and adjust the quality of the weld assembly;

[0138] F14. The welding actuator rotates around the housing to complete the friction stir welding;

[0139] F15. Loosen the upper and lower clamping rings. The upper clamping ring clamping mechanism moves upward. Clean the front side of the weld.

[0140] F16, In-situ detection of ultrasonic phased array;

[0141] F17. Loosen the removable inner support, rise approximately 300mm, and clean the back of the weld.

[0142] F18, Ultrasonic phased array testing;

[0143] F19. Remove the detachable inner support and transport the box out through the manhole at the bottom of the box. Then, assemble the detachable inner support outside the box for later use.

[0144] F20, Disassemble the bolts connecting the bottom loading mechanism and the short shell;

[0145] F21. The rotating ring drives the housing to rise and enter the unloading position;

[0146] F22, The bottom loading mechanism moves out of the loading position of the equipment;

[0147] F23. Flip the oxygen tank off the frame so that the bottom assembly of the oxygen tank faces upward, and disassemble the process end frame;

[0148] F24. Connect and fix the short shell end frame of the oxygen tank bottom to the lifting ring and place it on the frame.

[0149] Furthermore, the hydrogen tank section mounting assembly in step S34 includes the following steps:

[0150] G1, the moving ring drives the oxygen tank to descend, so that the lower end of the common bottom section enters the upper ring;

[0151] G2. Make the upper ring clamping mechanism clamp the common bottom cylinder section, and mill the remaining material at the lower end of the common bottom cylinder section to make it smooth.

[0152] G3. Hoist the hydrogen tank section to the section feeding mechanism and support the lower end of the hydrogen tank section. The feeding mechanism will then send the hydrogen tank section into the equipment feeding position.

[0153] G4, the cylinder section feeding mechanism pushes the cylinder section to the lower retaining ring;

[0154] G5. Make the lower clamping ring clamping mechanism clamp the cylinder section, smooth the mating surface of the cylinder section, and grind and clean it.

[0155] G6. The upper ring clamping mechanism moves downward synchronously with the moving ring. Before the engagement, the feeding mechanism cylinder section support rotates to align the quadrants, and then the common bottom assembly and the cylinder section circumferential seam are engaged.

[0156] Furthermore, the circumferential weld of the hydrogen tank section in step S35 includes the following steps:

[0157] H1, The cylinder section feeding mechanism pushes the fixed inner support to the weld position;

[0158] H2, tighten and fix the internal support;

[0159] H3. Inspect, measure, and adjust the quality of weld assembly;

[0160] H4. The welding actuator rotates around the housing to complete the friction stir welding;

[0161] H5. Loosen the upper and lower clamping rings. The upper clamping ring clamping mechanism moves upward, and the front of the weld is cleaned.

[0162] H6. In-situ detection of ultrasonic phased array;

[0163] H7. Loosen the fixed inner support, lower the inner support by 300mm, and clean the back of the weld.

[0164] H8, Ultrasonic phased array detection;

[0165] H9. Loosen the support at the lower end of the feeding mechanism cylinder section;

[0166] H10, the moving ring drives the already welded half-box assembly to rise, so that the lower end of the cylinder section enters the upper retaining ring;

[0167] H11, The cylindrical section feeding mechanism moves out of the equipment's feeding position;

[0168] H12. Perform assembly welding of the circumferential seams of other hydrogen tank sections according to steps G3 to H11;

[0169] H13. Measure the length of half of the oxygen tank + hydrogen tank to ensure that the upper clamping ring clamping mechanism clamps the cylinder section.

[0170] H14, the cylinder section feeding mechanism moves out of the feeding position of the equipment.

[0171] Furthermore, the assembly of the hydrogen tank front bottom frame in step S36 includes the following steps:

[0172] I1. Hoist the hydrogen tank bottom assembly to the tank bottom feeding mechanism, and fix the short shell connection to the end frame connecting ring of the feeding mechanism. Grind and clean the welding area.

[0173] I2. Hoist the detachable inner support and support mandrel to the bottom feeding mechanism of the tank, and the feeding mechanism will send the hydrogen tank bottom assembly into the equipment feeding position.

[0174] I3. The bottom feeding mechanism pushes the hydrogen tank bottom assembly to the lower retaining ring.

[0175] I4. Make the lower clamping ring clamping mechanism clamp the hydrogen tank bottom assembly tightly, and smooth and clean the transition ring mating surface of the hydrogen tank bottom assembly.

[0176] I5. Based on the milling amount of the transition ring of the hydrogen tank bottom assembly and the sum of the lengths of the oxygen tank and the hydrogen tank half-tank, calculate the side milling amount of the hydrogen tank sealing ring section, and mill the lower end mating surface of the section.

[0177] I6. The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the bottom feeding mechanism rotates to align the front and rear quadrants of the whole tank, and then joins the bottom assembly of the hydrogen tank and the circumferential seam of the hydrogen tank cylinder section.

[0178] I7. The bottom loading mechanism pushes the detachable internal support to the weld position;

[0179] I8. Tighten the removable inner support;

[0180] 19. Inspect, measure, and adjust the quality of the weld assembly;

[0181] I10. The welding actuator rotates around the housing to complete the friction stir welding;

[0182] I11. Loosen the upper and lower clamping rings. The upper clamping ring clamping mechanism moves upward. Clean the front side of the weld.

[0183] I12. In-situ detection of ultrasonic phased array;

[0184] I13. Loosen the removable inner support, raise it 300mm, and clean the back of the weld.

[0185] I14. Ultrasonic phased array detection.

[0186] Compared with existing technologies, the friction stir welding assembly method for large-diameter common-bottom tanks in a vertical configuration described in this invention has the following advantages:

[0187] (1) The present invention describes a vertical assembly method for friction stir welding of a large-diameter common-bottom tank. Vertical assembly eliminates the influence of gravity on the roundness and flexural deformation of the cylinder section and tank bottom. Gravity can also be used to improve the assembly clearance, which is beneficial to ensuring the product's dimensional form and position. The tooling can be made relatively strong and will not flexurally deform due to gravity, which is beneficial to ensuring the product's dimensional form and position. The vertical structure is not affected by gravity, making assembly less difficult. At the same time, the cylinder section can be extended into a long cylinder section, which can significantly reduce the number of circumferential seams and improve production efficiency.

[0188] (2) The present invention describes a friction stir welding assembly method for a large-diameter common-bottom tank in a vertical mode, which realizes friction stir welding of the circumferential seam of a large-diameter single-layer common-bottom tank and a double-layer common-bottom tank of a launch vehicle in a vertical mode, making it possible to weld the circumferential seam of the common-bottom tank with high reliability, high quality and high efficiency. It has important practical significance and huge economic value for the engineering application of aerospace products. Attached Figure Description

[0189] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0190] Figure 1 This is a schematic diagram of the vertical assembly and welding method for a single-layer common-bottom storage tank according to an embodiment of the present invention;

[0191] Figure 2 This is a detailed flowchart illustrating the vertical assembly and welding method for a single-layer common-bottom storage tank according to an embodiment of the present invention.

[0192] Figure 3 This is a schematic diagram of the vertical assembly and welding method for a double-layer common-bottom storage tank according to an embodiment of the present invention;

[0193] Figure 4 This is a detailed flowchart illustrating the vertical assembly and welding method for a double-layer common-bottom storage tank according to an embodiment of the present invention. Detailed Implementation

[0194] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0195] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0196] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0197] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0198] like Figure 1 As shown in the figure, a friction stir welding assembly method for a large-diameter common-bottom storage tank in a vertical configuration includes the following steps:

[0199] S1. Determine whether the tank is a single-layer common-bottom tank or a double-layer common-bottom tank. If yes, proceed to step S2; otherwise, proceed to step S3.

[0200] S2. Assemble and weld the single-layer common-bottom tank using a vertical assembly and welding method.

[0201] S3. Assemble and weld the double-layer common-bottom tank using a vertical assembly and welding method.

[0202] This invention primarily addresses friction stir welding of the circumferential seam in the vertical configuration of a common-bottom propellant tank for a 5m large-diameter launch vehicle. The propellant tanks include two types: single-layer and double-layer common-bottom tanks. Existing propellant tanks mainly consist of a front bottom, a front short shell, a front cylindrical section, a single / double-layer common bottom, a rear cylindrical section, a rear bottom, and a rear end shell. The single-layer common bottom has a central outflow hole structure, while the double-layer common bottom consists of two stacked bottom sections with an insulating interlayer in between, and lacks a central outflow hole.

[0203] like Figures 1-2 As shown, the assembly and welding method for a single-layer common-bottom vertical tank is as follows:

[0204] For single-layer common-bottom tanks, the vertical welding scheme minimizes the impact of gravity on structural components such as cylinder sections and the tank bottom, ensuring better roundness. This allows for the assembly and welding of longer cylinder sections. Furthermore, gravity facilitates vertical assembly, enabling the welding of single-layer common-bottom and convex-bottom side cylinder sections on the tank welding frame. This allows for sequential welding of different tank sections without the need for repositioning, shortening the process flow, reducing manufacturing time, and lowering lifting risks. Additionally, welding single-layer common-bottom and convex-bottom side cylinder sections on the circumferential joint frame allows for single-bottom insulation, significantly improving the openness of the single-layer common-bottom insulation and reducing the difficulty of insulation construction for the single-layer common-bottom assembly.

[0205] The vertical assembly and welding of the single-layer common-bottom tank body begins with the fuel tank bottom assembly and proceeds sequentially to the oxygen tank bottom assembly. No secondary assembly on the frame is performed during the welding process. The fitting of the common-bottom assembly and the fuel tank section's locking circumferential seam is completed in a vertical position on the frame. This method eliminates the need for sealing welding of the fuel tank; during the entire tank assembly and welding process, only the sealing welding of the circumferential seam between the oxygen tank bottom assembly and the section is performed. To ensure welding quality and achieve efficient production, after each circumferential seam is welded, defects that cannot be determined by ultrasonic phased array testing are supplemented by on-site X-ray radiography. Figure 1 As shown, in this embodiment, the fuel tank is a kerosene tank.

[0206] The specific assembly and welding method for a single-layer common-bottom storage tank in vertical assembly is as follows:

[0207] (1) Connect the fuel tank bottom assembly to the lifting ring, hoist it into the equipment, and connect the lifting ring and the moving ring to form a whole;

[0208] (2) The moving ring drives the bottom assembly of the fuel tank into the upper ring assembly position;

[0209] (3) Make the upper ring clamping mechanism clamp the transition ring of the fuel tank bottom assembly, smooth the mating surface of the transition ring, and grind and clean it.

[0210] (4) Replace the fixed inner support pad on the cylinder section feeding mechanism with an arc-shaped pad;

[0211] (5) Hoist the first cylinder section of the rear box to the cylinder section feeding mechanism and support the lower end of the first cylinder section. The feeding mechanism will send the first cylinder section into the equipment feeding position.

[0212] (6) The cylinder section feeding mechanism pushes the first cylinder section to the lower layer of the retaining ring;

[0213] (7) Make the lower ring clamping mechanism clamp the first cylinder section, smooth the mating surface of the first cylinder section, and grind and clean it;

[0214] (8) The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the feeding mechanism cylinder section support rotates to align the quadrants, and then the fuel box bottom assembly and the first cylinder section circumferential seam are joined.

[0215] (9) The cylinder section feeding mechanism pushes the fixed inner support to the weld position;

[0216] (10) Tighten and fix the internal support;

[0217] (11) Inspect, measure and adjust the quality of weld assembly (including roundness, butt gap, misalignment, and fit between the product and the backing plate);

[0218] (12) The welding actuator rotates around the housing to complete the friction stir welding;

[0219] (13) Loosen the upper and lower clamping rings, the upper clamping ring pressing mechanism moves upward, and clean the front of the weld;

[0220] (14) In-situ detection of ultrasonic phased array;

[0221] (15) Loosen the fixed inner support, the inner support will drop about 300mm, and clean the back of the weld;

[0222] (16) Ultrasonic phased array detection;

[0223] (17) Loosen the support at the lower end of the feeding mechanism cylinder section;

[0224] (18) The moving ring drives the already welded half-box assembly to rise, so that the lower end of the first cylinder section enters the upper ring;

[0225] (19) Make the upper ring clamping mechanism clamp the first cylinder section, smooth the lower end mating surface of the first cylinder section, and grind and clean it.

[0226] (20) The cylindrical section feeding mechanism moves out of the equipment feeding position;

[0227] (21) Replace the fixed inner support plate with a flat plate;

[0228] (22) The second cylinder section of the fuel tank is hoisted to the cylinder section feeding mechanism and the lower end of the second cylinder section is supported. The feeding mechanism sends the second cylinder section into the equipment feeding position.

[0229] (23) The cylinder section feeding mechanism pushes the second cylinder section to the lower ring;

[0230] (24) Make the lower ring clamping mechanism clamp the second cylinder section, smooth the mating surface of the second cylinder section, and grind and clean it;

[0231] (25) The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the feeding mechanism cylinder section support rotates to align the quadrants, and then the first cylinder section and the second cylinder section are joined together.

[0232] (26) The cylinder section feeding mechanism pushes the fixed inner support to the weld position;

[0233] (27) Tighten and fix the internal support;

[0234] (28) Inspect, measure and adjust the quality of weld assembly (including roundness, butt gap, misalignment, and fit between the product and the backing plate);

[0235] (29) The welding actuator rotates around the housing to complete the positioning and formal welding;

[0236] (30) Loosen the upper and lower clamping rings, the upper clamping ring pressing mechanism moves upward, and clean the front of the weld;

[0237] (31) In-situ detection of ultrasonic phased array;

[0238] (32) Loosen the fixed inner support, the inner support will drop about 300mm, and clean the back of the weld;

[0239] (33) Ultrasonic phased array detection;

[0240] (34) Perform assembly and welding of the remaining cylinder section of the fuel tank according to steps 17 to 33;

[0241] (35) The moving ring drives the already welded half-box assembly to rise, so that the lower end of the cylinder section enters the upper ring;

[0242] (36) Measure the length of the half-box of the fuel tank so that the upper clamping ring clamping mechanism clamps the cylinder section;

[0243] (37) The cylindrical section feeding mechanism moves out of the equipment feeding position;

[0244] (38) Hoist the common bottom to the bottom loading mechanism, level the common bottom locking mating surface, and grind and clean the welding area;

[0245] (39) Calculate the side milling amount of the fuel box section based on the half length of the fuel box, and mill and grind the lower end of the section to ensure the length of the fuel box;

[0246] (40) The bottom feeding mechanism pushes the common bottom to the lower layer of the clamping ring and clamps the common bottom transition ring;

[0247] (41) The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the bottom feeding mechanism rotates to align the quadrants. The upper ring clamping mechanism and the moving ring press down synchronously to lock the bottom assembly. Check, measure and adjust the assembly seam quality (including butt gap and misalignment).

[0248] (42) The bottom loading mechanism pushes the bottom support to the welding position and tightens the bottom welding area. Check, measure and adjust the assembly quality of the inner support (including the fit between the product and the pad).

[0249] (43) The welding actuator rotates around the housing to complete the friction stir welding;

[0250] (44) Loosen the upper and lower clamping rings, the upper clamping ring pressing mechanism moves upward, and clean the front of the weld;

[0251] (45) Ultrasonic phased array detection;

[0252] (46) Loosen the inner support of the lock bottom;

[0253] (47) The moving ring drives the half-box of the fuel box to rise, so that the common bottom transition ring enters the upper ring;

[0254] (48) Make the upper ring clamping mechanism clamp the common bottom transition ring, smooth the mating surface of the lower end of the common bottom transition ring, and grind and clean it.

[0255] (49) The bottom loading mechanism moves out of the loading position of the equipment;

[0256] (50) Replace the inner support pad of the cylindrical section feeding mechanism with an arc-shaped pad;

[0257] (51) Hoist the first section of the oxygen tank to the section feeding mechanism, and level the lower end support of the first section of the oxygen tank. The feeding mechanism then sends the first section of the oxygen tank into the equipment feeding position.

[0258] (52) Perform assembly welding of the first section of the oxygen tank and the common bottom butt joint circumferential seam according to steps 23 to 33;

[0259] (53) Replace the inner support pad of the cylindrical feeding mechanism with a flat pad;

[0260] (54) Perform assembly and welding of the remaining oxygen tank cylinder sections' butt joints according to steps 17 to 33;

[0261] (55) The moving ring drives the already welded box assembly to rise, so that the lower end of the last cylinder section of the oxygen box enters the upper ring.

[0262] (56) Measure the length of half of the fuel box + oxygen box so that the upper clamping ring clamping mechanism clamps the cylinder section;

[0263] (57) The cylindrical section feeding mechanism moves out of the equipment feeding position;

[0264] (58) Hoist the oxygen tank bottom assembly to the bottom feeding mechanism, and fix the short shell connection to the end frame connecting ring of the feeding mechanism. Grind and clean the welding area.

[0265] (59) Hoist the detachable inner support and support mandrel to the bottom loading mechanism of the box, and the loading mechanism will send the front bottom assembly into the loading position of the equipment.

[0266] (60) The bottom feeding mechanism pushes the oxygen tank bottom assembly to the lower ring;

[0267] (61) Make the lower ring clamping mechanism clamp the oxygen tank bottom assembly, and make the transition ring mating surface of the oxygen tank bottom assembly smooth.

[0268] (62) Calculate the side milling amount of the oxygen box sealing ring section based on the height of the oxygen box bottom assembly and the length of the fuel box + oxygen box half box, mill the lower end of the section, and grind and clean it.

[0269] (63) The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the bottom feeding mechanism rotates to align the front and rear quadrants of the whole box, and then joins the bottom assembly of the oxygen box and the ring seam of the cylinder section.

[0270] (64) The bottom feeding mechanism pushes the detachable inner support to the weld position;

[0271] (65) Tighten the removable internal support;

[0272] (66) Inspect, measure and adjust the quality of weld assembly (including roundness, butt gap, misalignment, and fit between the product and the backing plate);

[0273] (67) The welding actuator rotates around the housing to complete the friction stir welding;

[0274] (68) Loosen the upper and lower clamping rings, the upper clamping ring clamping mechanism moves upward, and clean the front side of the weld;

[0275] (69) In-situ detection of ultrasonic phased array;

[0276] (70) Loosen the removable inner support, rise about 300mm, and clean the back of the weld;

[0277] (71) Ultrasonic phased array detection;

[0278] (72) Remove the detachable inner support and transport the box out through the manhole at the bottom of the box. Then, assemble the detachable inner support outside the box for later use.

[0279] (73) Disassemble the connecting ring of the end frame of the bottom loading mechanism and the connecting bolt of the short shell;

[0280] (74) The moving ring drives the box to rise and enter the unloading position;

[0281] (75) The bottom loading mechanism moves out of the loading position of the equipment;

[0282] (76) Remove the box from the shelf and carry out X-ray inspection, compensator, delivery pipe, parts installation, hydraulic, airtight, helium mass spectrometry leak detection, retention process, and cleaning of excess materials;

[0283] (77) Delivery of the container.

[0284] like Figures 2-3 As shown, the assembly and welding method for a vertical double-layer common-bottom tank is as follows:

[0285] For double-layer common-bottom tanks, due to the lack of a central flange in the common bottom and the inability of the PMI interlayer in the middle of the double-layer common bottom to withstand the welding upsetting force, it is impossible to place the sealing weld on the circumferential seam between the common bottom assembly and the oxygen tank section. The welding method is as follows: with the convex spherical surface of the common bottom assembly facing upwards, first perform friction stir welding on the circumferential seam between the common bottom assembly and the oxygen tank section, then perform friction stir welding on the circumferential seam between the oxygen tank bottom assembly and the oxygen tank section, and use this circumferential seam as the sealing seam to complete the oxygen tank welding. The detachable internal support is then removed from the manhole flange on the bottom side of the oxygen tank. After the oxygen tank welding is completed, it needs to be removed from the frame, reversed, and then remounted so that the oxygen tank bottom assembly faces upwards. The hydrogen tank is then welded section by section, and the circumferential seam between the hydrogen tank bottom assembly and the hydrogen tank section is used as the second sealing seam to complete the welding production of the entire common-bottom tank. The detachable internal support is then removed from the manhole flange on the bottom side of the hydrogen tank. During the welding process, the end face of the common bottom section needs to be pre-set with allowance and transition end frame for the common bottom assembly to be mounted on the frame. The transition end frame is removed when the hydrogen tank is welded.

[0286] The specific assembly and welding method for the double-layered common-bottom storage tank is as follows:

[0287] (1) With the convex spherical surface of the common bottom assembly facing upward, connect the common bottom cylinder section (including the process end frame) to the lifting ring, hoist it into the equipment, and connect the lifting ring and the moving ring to form a whole;

[0288] (2) The moving ring drives the common bottom assembly into the upper retaining ring;

[0289] (3) Make the upper ring clamping mechanism clamp the common bottom assembly transition ring, and smooth the mating surface of the transition ring;

[0290] (4) Replace the fixed inner support pad on the cylinder section feeding mechanism with an arc-shaped pad;

[0291] (5) Hoist the oxygen tank section to the section feeding mechanism and support the lower end of the section. The feeding mechanism will send the section into the equipment feeding position.

[0292] (6) The feeding mechanism pushes the cylinder section to the lower ring;

[0293] (7) Make the lower ring clamping mechanism clamp the cylinder section, smooth the mating surface of the cylinder section, and grind and clean it;

[0294] (8) The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the feeding mechanism cylinder section support rotates to align the quadrants, and then joins the bottom assembly and the cylinder section ring seam.

[0295] (9) The cylinder section feeding mechanism pushes the fixed inner support to the weld position;

[0296] (10) Tighten and fix the internal support;

[0297] (11) Inspect, measure and adjust the quality of weld assembly (including roundness, butt gap, misalignment, and fit between the product and the backing plate);

[0298] (12) The welding actuator rotates around the housing to complete the friction stir welding;

[0299] (13) Loosen the upper and lower clamping rings, the upper clamping ring pressing mechanism moves upward, and clean the front of the weld;

[0300] (14) In-situ detection of ultrasonic phased array;

[0301] (15) Loosen the fixed inner support, the inner support will drop about 300mm, and clean the back of the weld;

[0302] (16) Ultrasonic phased array detection;

[0303] (17) Loosen the support at the lower end of the feeding mechanism cylinder section;

[0304] (18) The moving ring drives the already welded oxygen box half-box assembly to rise, so that the lower end of the cylinder section enters the upper ring;

[0305] (19) Measure the length of half of the oxygen box so that the upper clamping ring clamping mechanism clamps the cylinder section;

[0306] (20) The cylindrical section feeding mechanism moves out of the equipment feeding position;

[0307] (21) Hoist the oxygen tank bottom assembly to the bottom feeding mechanism, and fix the short shell connection to the end frame connecting ring of the feeding mechanism. Grind and clean the welding area.

[0308] (22) The detachable inner support and support mandrel are hoisted to the bottom loading mechanism of the oxygen tank, and the loading mechanism sends the oxygen tank bottom assembly into the loading position of the equipment.

[0309] (23) The bottom feeding mechanism pushes the oxygen tank bottom assembly to the lower ring;

[0310] (24) Make the lower ring clamping mechanism clamp the oxygen tank bottom assembly, and mill the transition ring mating surface of the oxygen tank bottom assembly until it is smooth.

[0311] (25) Based on the milling amount of the transition ring of the oxygen box bottom assembly and the half box length, calculate the side milling amount of the oxygen box sealing ring section, mill the butt joint surface of the lower end of the section, and grind and clean it.

[0312] (26) The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the bottom feeding mechanism rotates to align the quadrants, and then joins the bottom assembly of the oxygen box and the circumferential seam of the oxygen box cylinder.

[0313] (27) The bottom loading mechanism pushes the detachable inner support to the weld position;

[0314] (28) Tighten the removable internal support;

[0315] (29) Inspect, measure and adjust the quality of weld assembly (including roundness, butt gap, misalignment, and fit between the product and the backing plate);

[0316] (30) The welding actuator rotates around the housing to complete the friction stir welding;

[0317] (31) Loosen the upper and lower clamping rings, the upper clamping ring pressing mechanism moves upward, and clean the front of the weld;

[0318] (32) In-situ detection of ultrasonic phased array;

[0319] (33) Loosen the removable inner support, rise about 300mm, and clean the back of the weld;

[0320] (34) Ultrasonic phased array detection;

[0321] (35) Remove the detachable inner support and transport the box out through the manhole at the bottom of the box. Then, assemble the detachable inner support outside the box for later use.

[0322] (36) Disassemble the bolts connecting the bottom loading mechanism and the short shell;

[0323] (37) The moving ring drives the box to rise and enter the unloading position;

[0324] (38) The bottom feeding mechanism moves out of the equipment feeding position;

[0325] (39) Flip the oxygen box off the frame so that the bottom assembly of the oxygen box faces upward, and disassemble the process end frame;

[0326] (40) Connect and fix the short shell end frame of the oxygen tank bottom to the lifting ring and put it on the frame. The lifting ring and the moving ring are connected to form a whole.

[0327] (41) The moving ring drives the oxygen tank to descend, so that the lower end of the common bottom section enters the upper ring;

[0328] (42) Make the upper ring clamping mechanism clamp the common bottom cylinder section, and mill the remaining material at the lower end of the common bottom cylinder section to make it smooth;

[0329] (43) The hydrogen tank section is hoisted to the section feeding mechanism and the lower end of the hydrogen tank section is supported. The feeding mechanism sends the hydrogen tank section into the equipment feeding position.

[0330] (44) The cylinder section feeding mechanism pushes the cylinder section to the lower layer of the retaining ring;

[0331] (45) Make the lower ring clamping mechanism clamp the cylinder section, smooth the mating surface of the cylinder section, and grind and clean it;

[0332] (46) The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the feeding mechanism cylinder section support rotates to align the quadrants, and then joins the bottom assembly and the cylinder section ring seam.

[0333] (47) The cylinder section feeding mechanism pushes the fixed inner support to the weld position;

[0334] (48) Tighten and fix the internal support;

[0335] (49) Inspect, measure and adjust the quality of weld assembly (including roundness, butt gap, misalignment, and fit between the product and the backing plate);

[0336] (50) The welding actuator rotates around the housing to complete the friction stir welding;

[0337] (51) Loosen the upper and lower clamping rings, the upper clamping ring clamping mechanism moves upward, and clean the front of the weld;

[0338] (52) In-situ detection of ultrasonic phased array;

[0339] (53) Loosen the fixed inner support, the inner support will drop about 300mm, and clean the back of the weld;

[0340] (54) Ultrasonic phased array detection;

[0341] (55) Loosen the support at the lower end of the feeding mechanism cylinder section;

[0342] (56) The moving ring drives the already welded half-box assembly to rise, so that the lower end of the cylinder section enters the upper ring;

[0343] (57) The cylindrical section feeding mechanism moves out of the equipment feeding position;

[0344] (58) Perform assembly welding of the circumferential seams of other hydrogen tank sections according to steps 43 to 57;

[0345] (59) Measure the length of half of the oxygen tank + hydrogen tank so that the upper clamping ring clamping mechanism clamps the cylinder section;

[0346] (60) The cylindrical section feeding mechanism moves out of the equipment feeding position;

[0347] (61) Hoist the hydrogen tank bottom assembly to the tank bottom feeding mechanism, and fix the short shell connection to the end frame connecting ring of the feeding mechanism, and grind and clean the welding area;

[0348] (62) The detachable inner support and support mandrel are hoisted to the bottom feeding mechanism of the tank, and the feeding mechanism sends the hydrogen tank bottom assembly into the equipment feeding position.

[0349] (63) The bottom feeding mechanism pushes the hydrogen tank bottom assembly to the lower ring;

[0350] (64) Make the lower ring clamping mechanism clamp the hydrogen tank bottom assembly, smooth the transition ring mating surface of the hydrogen tank bottom assembly, and grind and clean it.

[0351] (65) Based on the milling amount of the transition ring of the hydrogen tank bottom assembly and the length of the oxygen tank + hydrogen tank half tank, calculate the side milling amount of the hydrogen tank sealing ring section and mill the lower end of the section.

[0352] (66) The upper ring clamping mechanism moves downward synchronously with the moving ring. Just before they are about to be joined, the bottom feeding mechanism rotates to align the front and rear quadrants of the whole tank, and then joins the bottom assembly of the hydrogen tank and the ring seam of the hydrogen tank cylinder section.

[0353] (67) The bottom loading mechanism pushes the detachable inner support to the weld position;

[0354] (68) Tighten the removable internal support;

[0355] (69) Inspect, measure and adjust the quality of weld assembly (including roundness, butt gap, misalignment, and fit between the product and the backing plate);

[0356] (70) The welding actuator rotates around the housing to complete the friction stir welding;

[0357] (71) Loosen the upper and lower clamping rings, the upper clamping ring clamping mechanism moves upward, and clean the front of the weld;

[0358] (72) In-situ detection of ultrasonic phased array;

[0359] (73) Loosen the removable inner support, rise about 300mm, and clean the back of the weld;

[0360] (74) Ultrasonic phased array detection;

[0361] (75) Remove the detachable inner support and transport the tank out of the tank through the manhole at the bottom of the hydrogen tank. Then, assemble the detachable inner support outside the tank for later use.

[0362] (76) Disassemble the connecting ring of the end frame of the bottom loading mechanism and the connecting bolt of the short shell;

[0363] (77) The moving ring drives the box to rise and enter the unloading position;

[0364] (78) The bottom loading mechanism moves out of the loading position of the equipment;

[0365] (79) Remove the box from the shelf and carry out X-ray inspection, parts installation, hydraulic, airtight, helium mass spectrometry leak detection, retention process, and cleaning of excess materials;

[0366] (80) Delivery of the container.

[0367] The purpose of this invention is: (1) This invention proposes a method for friction stir welding of the circumferential seam of a large-diameter single-layer common-bottom storage tank in a vertical mode. It adopts a sequential welding method from the bottom assembly of the fuel tank to the bottom assembly of the oxygen tank, and realizes the assembly of the common bottom and the cylinder section locking circumferential seam on the frame. This reduces the sealing weld of the double-cavity common-bottom storage tank to one, and improves the overall welding reliability and production efficiency.

[0368] (2) This invention proposes a vertical double-layer common bottom tank body circumferential seam stir friction welding method. Based on the special structure of double-layer common bottom without center flange, the whole project is divided into two major steps. Taking the bottom of the common bottom cylinder assembly as the welding starting point, the oxygen tank half is welded first. After the welding is completed, it is removed from the frame and flipped. Then, taking the cylinder section of the common bottom cylinder assembly as the starting point, the hydrogen tank half is welded, and finally the whole tank welding production is realized.

[0369] The advantages of using a vertical method for friction stir welding of the storage tank body in this invention are as follows:

[0370] (1) Vertical assembly eliminates the influence of gravity on the roundness and deflection of the cylindrical section and box bottom. Gravity can also be used to improve the assembly clearance, which helps to ensure the shape and position dimensions of the product;

[0371] (2) The tooling can be made strong and will not bend or deform due to gravity, which helps to ensure the shape and size of the product.

[0372] (3) The vertical structure is not affected by gravity, making assembly easier. At the same time, the cylinder section can be extended into a long cylinder section, which can greatly reduce the number of circumferential seams and improve production efficiency.

[0373] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for assembling and welding large diameter co-bucket containers in a vertical mode by friction stir welding, characterized in that: It comprises the following steps: S1, judging whether the storage tank is a single-layer common bottom storage tank or a double-layer common bottom storage tank, if it is a single-layer common bottom storage tank, then entering step S2, otherwise, entering step S3; S2, assembling and welding the single-layer common bottom storage tank by using a single-layer common bottom storage tank vertical assembly welding method; S3, assembling and welding the double-layer common bottom storage tank by using a double-layer common bottom storage tank vertical assembly welding method; The single-layer common bottom storage tank vertical assembly welding method in step S2 comprises the following steps: S21, fuel tank assembly welding; S22, after the fuel tank assembly welding is completed, single-layer common bottom assembly welding is performed; S23, oxygen tank assembly welding; The double-layer common bottom storage tank vertical assembly welding method in step S3 comprises the following steps: S31, double-layer common bottom assembly and oxygen tank rear bottom upper rack assembly; S32, oxygen tank sealing welding; S33, after the oxygen tank sealing tool is removed, the lower rack is turned over, the double-layer common bottom assembly and the oxygen tank are made upward, and then the lower rack is turned over again and reassembled; S34, hydrogen tank cylinder segment upper rack assembly; S35, hydrogen tank cylinder segment ring seam welding; S36, hydrogen tank front bottom upper rack assembly; S37, hydrogen tank sealing completion; The single-layer common bottom assembly welding in step S22 comprises the following steps: B1, the common bottom is hoisted to the tank bottom feeding mechanism, the common bottom lock bottom butt joint surface is leveled, and the welding area is polished and cleaned; B2, according to the length of the fuel tank half tank, the side milling amount of the fuel tank cylinder segment is calculated, the cylinder segment lower end butt joint surface is milled and polished; B3, the tank bottom feeding mechanism pushes the common bottom to the lower layer of the ring, and the common bottom transition ring is tightly held; B4, the upper layer of the ring pressing mechanism moves downward synchronously with the moving ring, before the butt joint is completed, the tank bottom feeding mechanism rotates to align the quadrant, the upper layer of the ring pressing mechanism moves downward synchronously with the moving ring to lock the bottom, the assembly quality of the butt joint is checked and measured, and the assembly quality is adjusted; B5, the tank bottom feeding mechanism pushes the lock bottom inner support to align the welding position and tightly supports the lock bottom welding area, the assembly quality of the inner support is checked and measured, and the assembly quality is adjusted; B6, the welding execution mechanism rotates around the tank body to complete the friction stir welding; B7, the upper and lower layers of the ring are loosened, the upper layer of the ring pressing mechanism is moved upward, and the welding seam front is cleaned; B8, ultrasonic phased array detection; B9, the lock bottom inner support is loosened; B10, the moving ring drives the fuel tank half tank to rise, so that the common bottom transition ring enters the upper layer of the ring; B11, the upper layer of the ring pressing mechanism tightly holds the common bottom transition ring, and the common bottom transition ring lower end butt joint surface is leveled and polished; B12, the tank bottom feeding mechanism moves out of the equipment feeding position; B13, the fixed inner support pad plate of the cylinder segment feeding mechanism is replaced by an arc pad plate; The double-layer common bottom assembly and oxygen tank rear bottom upper rack assembly in step S31 comprises the following steps: D1, the common bottom assembly convex spherical surface is upward, the common bottom cylinder segment is connected with the lifting ring, is hoisted into the equipment, and the lifting ring is connected with the moving ring to become an integral whole; D2, the moving ring drives the common bottom assembly to enter the upper layer of the ring; D3, the upper layer of the ring pressing mechanism tightly holds the common bottom assembly transition ring, and the transition ring butt joint surface is leveled; D4, the fixed inner support pad plate of the cylinder segment feeding mechanism is replaced by an arc pad plate; D5, the oxygen tank cylinder segment is hoisted to the cylinder segment feeding mechanism, and the cylinder segment lower end support is connected, and the feeding mechanism sends the cylinder segment into the equipment feeding position; D6, the feeding mechanism pushes the cylinder segment to the lower layer of the ring; D7, the lower layer of the ring compression mechanism holds the cylinder segment, and the cylinder segment joint surface is polished and cleaned; D8, the upper layer of the ring compression mechanism moves downward synchronously with the dynamic ring, before the joint, the feeding mechanism cylinder segment support rotates and aligns the quadrant, and then the joint combines the cylinder segment ring joint.

2. The method of claim 1, wherein the method is a vertical mode friction stir welding method for assembling and welding large diameter co-bucket containers. The fuel tank assembly welding in step S21 includes the following steps: A1, connect the fuel tank bottom assembly with the lifting ring, and hoist into the equipment; A2, the dynamic ring drives the fuel tank bottom assembly into the upper layer of the ring assembly position; A3, the upper layer of the ring compression mechanism holds the transition ring of the fuel tank bottom assembly, and the transition ring joint surface is polished and cleaned; A4, replace the fixed inner support pad plate on the cylinder segment feeding mechanism with an arc pad plate; A5, hoist the first cylinder segment of the rear tank to the cylinder segment feeding mechanism, support the lower end of the first cylinder segment, and send the first cylinder segment into the equipment feeding position by the feeding mechanism; A6, the cylinder segment feeding mechanism pushes the first cylinder segment to the lower layer of the ring; A7, the lower layer of the ring compression mechanism holds the first cylinder segment, and the first cylinder segment joint surface is polished and cleaned; A8, the upper layer of the ring compression mechanism moves downward synchronously with the dynamic ring, before the joint, the feeding mechanism cylinder segment support rotates and aligns the quadrant, and then the joint combines the cylinder segment ring joint; A9, the cylinder segment feeding mechanism pushes the fixed inner support to the welding position; A10, tighten the fixed inner support; A11, check, measure and adjust the welding assembly quality; A12, the welding execution mechanism rotates around the tank body, and completes the friction stir welding; A13, loosen the upper and lower layers of the ring, move the upper layer of the ring compression mechanism upward, and clean the front of the welding joint; A14, in-situ detection by ultrasonic phased array; A15, loosen the fixed inner support, lower the inner support by 300mm, and clean the back of the welding joint; A16, ultrasonic phased array detection; A17, loosen the support at the lower end of the cylinder segment of the feeding mechanism; A18, the dynamic ring drives the welded half-tank assembly to rise, and the lower end of the first cylinder segment enters the upper layer of the ring; A19, the upper layer of the ring compression mechanism holds the first cylinder segment, and the lower end of the first cylinder segment joint surface is polished and cleaned; A20, the cylinder segment feeding mechanism moves out of the equipment feeding position; A21, replace the fixed inner support pad plate with a flat pad plate; A22, hoist the second cylinder segment of the fuel tank to the cylinder segment feeding mechanism, support the lower end of the second cylinder segment, and send the second cylinder segment into the equipment feeding position by the feeding mechanism; A23, the cylinder segment feeding mechanism pushes the second cylinder segment to the lower layer of the ring; A24, the lower layer of the ring compression mechanism holds the second cylinder segment, and the second cylinder segment joint surface is polished and cleaned; A25, the upper layer of the ring compression mechanism moves downward synchronously with the dynamic ring, before the joint, the feeding mechanism cylinder segment support rotates and aligns the quadrant, and then the joint combines the first cylinder segment and the second cylinder segment ring joint; A26, the cylinder segment feeding mechanism pushes the fixed inner support to the welding position; A27, tighten the fixed inner support; A28, check, measure and adjust the welding assembly quality; A29, the welding execution mechanism rotates around the tank body, and completes the positioning and formal welding; A30, loosen the upper and lower layers of the ring, move the upper layer of the ring compression mechanism upward, and clean the front of the welding joint; A31, in-situ detection by ultrasonic phased array; A32, loosen the fixed inner support, lower the inner support by 300mm, clean the back of the weld; A33, detection by ultrasonic phased array; A34, perform assembly welding of the remaining cylinder segment of the fuel tank according to steps A17 to A33; A35, raise the half-tank assembly with the welded dynamic ring, and make the lower end of the cylinder segment enter the upper holding ring; A36, measure the length of the half-tank, and make the upper holding ring clamping mechanism hold the cylinder segment; A37, move the cylinder segment feeding mechanism out of the equipment feeding position.

3. The method of claim 1, wherein the method is a vertical mode large diameter co-bonded tank friction stir welding assembly method, characterized by: The oxygen tank assembly welding in step S23 includes the following steps: C1, hoist the first cylinder segment of the oxygen tank to the cylinder segment feeding mechanism, level the lower end support of the first cylinder segment of the oxygen tank, and send the first cylinder segment of the oxygen tank into the equipment feeding position by the feeding mechanism; C2, perform assembly welding of the first cylinder segment of the oxygen tank and the common bottom according to steps A23 to A33; C3, replace the fixed inner support pad plate of the cylinder segment feeding mechanism with a flat pad plate; C4, perform assembly welding of the remaining cylinder segments of the oxygen tank according to steps A17 to A33; C5, raise the tank assembly with the welded dynamic ring, and make the lower end of the last cylinder segment of the oxygen tank enter the upper holding ring; C6, measure the sum of the lengths of the fuel tank and the half-tank, and make the upper holding ring clamping mechanism hold the cylinder segment; C7, move the cylinder segment feeding mechanism out of the equipment feeding position; C8, hoist the oxygen tank bottom assembly to the bottom feeding mechanism, and fix the short shell connection on the end frame connection ring of the feeding mechanism, and polish the welding area; C9, hoist the detachable inner support and support core to the bottom feeding mechanism, and send the front bottom assembly into the equipment feeding position by the feeding mechanism; C10, push the oxygen tank bottom assembly to the lower holding ring by the bottom feeding mechanism; C11, make the lower holding ring clamping mechanism hold the oxygen tank bottom assembly, and make the transition ring joint surface of the oxygen tank bottom assembly smooth; C12, calculate the side milling amount of the cylinder segment of the oxygen tank sealing ring joint according to the height of the oxygen tank bottom assembly and the length of the fuel tank + oxygen tank half-tank, mill the lower end joint surface of the cylinder segment, and polish it; C13, move the upper holding ring clamping mechanism and the dynamic ring downward synchronously, and before the joint, rotate the bottom feeding mechanism to align the front and rear quadrants of the tank, and then joint the oxygen tank bottom assembly and the cylinder segment ring joint; C14, push the detachable inner support to the welding position by the bottom feeding mechanism; C15, tighten the detachable inner support; C16, check the assembly quality of the welding joint; C17, rotate the welding execution mechanism around the tank to complete the friction stir welding; C18, loosen the upper and lower holding rings, move the upper holding ring clamping mechanism upward, and clean the front of the welding joint; C19, in-situ detection by ultrasonic phased array; C20, loosen the detachable inner support, and raise the inner support by 300mm, and clean the back of the welding joint; C21, detection by ultrasonic phased array; C22, detach the detachable inner support and transport it out of the tank through the bottom manhole; C23, detach the end frame connection ring and the short shell connection bolt of the bottom feeding mechanism; C24, raise the tank by the dynamic ring, and enter the lower rack position; C25, move the bottom feeding mechanism out of the equipment feeding position; C26, box underframe, develop X-ray detection, compensator, conveying pipe, part installation, hydraulic, airtight, helium mass spectrometer leak detection, retention process, excess cleaning work; C27, box delivery.

4. The method of claim 1, wherein the method is a vertical mode large diameter co- base tank friction stir welding assembly method, characterized by: The oxygen tank sealing welding in step S32 includes the following steps: E1, the cylinder segment feeding mechanism pushes the fixed inner support to the weld position; E2, tighten the fixed inner support; E3, check and measure the weld assembly quality; E4, the welding execution mechanism rotates around the tank, completing friction stir welding; E5, loosen the upper and lower layer of the ring, the upper layer of the ring compression mechanism moves up, and the front of the weld is cleaned; E6, in-situ detection of ultrasonic phased array; E7, loosen the fixed inner support, the inner support is lowered by 300mm, and the back of the weld is cleaned; E8, ultrasonic phased array detection; 5. The method of claim 4, wherein the method is a vertical mode large diameter co- base tank friction stir welding assembly method, characterized by: After the oxygen tank sealing tool removal in step S33, the double-layer common bottom assembly and the oxygen tank are turned upside down, and then turned over again and reloaded, including the following steps: F1, loosen the support at the lower end of the cylinder segment of the feeding mechanism; F2, the moving ring drives the welded oxygen tank half-box assembly to rise, so that the lower end of the cylinder segment enters the upper layer of the ring; F3, measure the length of the oxygen tank half-box to make the upper layer of the ring compression mechanism hold the cylinder segment; F4, the cylinder segment feeding mechanism moves out of the equipment loading position; F5, hoist the oxygen tank bottom assembly to the tank bottom feeding mechanism, and fix the short shell connection on the end frame connection ring of the feeding mechanism. Polish the welding area; F6, hoist the detachable inner support and support shaft to the tank bottom feeding mechanism, and the feeding mechanism sends the oxygen tank bottom assembly into the equipment loading position; F7, the tank bottom feeding mechanism pushes the oxygen tank bottom assembly to the lower layer of the ring; F8, make the lower layer of the ring compression mechanism hold the oxygen tank bottom assembly, and mill the transition ring butt joint surface of the oxygen tank bottom assembly to be flat; F9, according to the milling amount of the transition ring of the oxygen tank bottom assembly and the length of the half-box, calculate the milling amount of the cylinder segment side of the oxygen tank sealing ring joint, mill the butt joint surface of the cylinder segment lower end, and polish and clean; F10, the upper layer of the ring compression mechanism moves downward synchronously with the moving ring. Before closing, the tank bottom feeding mechanism rotates to align the quadrant, and then the oxygen tank bottom assembly and the oxygen tank cylinder segment ring joint are closed; F11, the tank bottom feeding mechanism pushes the detachable inner support to the weld position; F12, tighten the detachable inner support; F13, check and measure the weld assembly quality; F14, the welding execution mechanism rotates around the tank, completing friction stir welding; F15, loosen the upper and lower layer of the ring, the upper layer of the ring compression mechanism moves up, and the front of the weld is cleaned; F16, in-situ detection of ultrasonic phased array; F17, loosen the detachable inner support, and the inner support is raised by about 300mm, and the back of the weld is cleaned; F18, ultrasonic phased array detection; F19, detach the detachable inner support and transport it out of the tank through the tank bottom manhole, and then assemble the detachable inner support outside the tank for use; F20, detach the tank bottom feeding mechanism and the short shell connection bolt; F21, the moving ring drives the tank to rise into the underframe position; F22, the tank bottom feeding mechanism moves out of the equipment loading position; F23, turn over the oxygen tank to make the oxygen tank bottom assembly face up, and detach the process end frame; F24, connect and fix the oxygen tank bottom short shell end frame with the lifting ring and load it.

6. The method of claim 5, wherein the method is a vertical mode large diameter co- base tank friction stir welding assembly method, characterized by: The assembling of the hydrogen tank cylinder segment in step S34 includes the following steps: G1. The movable ring drives the oxygen tank to descend, and the lower end of the common bottom cylinder segment enters the upper layer of the ring; G2. The upper layer of the ring tightens the mechanism and holds the common bottom cylinder segment, and the remaining amount of the lower end of the common bottom cylinder segment is milled and polished; G3. The hydrogen tank cylinder segment is hoisted to the cylinder segment loading mechanism, and the lower end of the hydrogen tank cylinder segment is supported, and the loading mechanism sends the hydrogen tank cylinder segment to the equipment loading position; G4. The cylinder segment loading mechanism pushes the cylinder segment to the lower layer of the ring; G5. The lower layer of the ring tightens the mechanism and holds the cylinder segment, and the butt joint surface of the cylinder segment is polished and cleaned; G6. The upper layer of the ring tightens the mechanism and moves downward synchronously with the movable ring, before the joint, the loading mechanism cylinder segment support rotates and aligns the quadrant, and then the common bottom assembly and the cylinder segment ring joint are jointed.

7. The method of claim 6, wherein the method is a vertical mode large diameter co- base tank friction stir welding assembly method, characterized by: The ring joint welding of the hydrogen tank cylinder segment in step S35 includes the following steps: H1. The cylinder segment loading mechanism pushes the fixed inner support to the welding position; H2. The fixed inner support is tightened; H3. The welding assembly quality is checked, measured and adjusted; H4. The welding execution mechanism rotates around the tank, and the friction stir welding is completed; H5. The upper and lower layers of the ring are loosened, the upper layer of the ring tightens the mechanism and moves upward, and the front of the welding joint is cleaned; H6. In-situ detection by ultrasonic phased array; H7. The fixed inner support is loosened, the inner support is lowered by 300 mm, and the back of the welding joint is cleaned; H8. Ultrasonic phased array detection; H9. The support at the lower end of the cylinder segment of the loading mechanism is loosened; H10. The movable ring drives the welded half tank assembly to ascend, and the lower end of the cylinder segment enters the upper layer of the ring; H11. The cylinder segment loading mechanism moves out of the equipment loading position; H12. The assembly and welding of the ring joint of other hydrogen tank cylinder segments are performed according to steps G3 to H11; H13. The length of the oxygen tank + hydrogen tank half tank is measured, and the upper layer of the ring tightens the mechanism and holds the cylinder segment; H14. The cylinder segment loading mechanism moves out of the equipment loading position.

8. The method of claim 7, wherein the method is a vertical mode large diameter co- base tank friction stir welding assembly method, characterized by: The front bottom of the hydrogen tank in step S36 includes the following steps: I1. The hydrogen tank bottom assembly is hoisted to the tank bottom loading mechanism, and the short shell is connected and fixed on the end frame connecting ring of the loading mechanism, and the welding area is polished and cleaned; I2. The detachable inner support and support core shaft are hoisted to the tank bottom loading mechanism, and the loading mechanism sends the hydrogen tank bottom assembly to the equipment loading position; I3. The tank bottom loading mechanism pushes the hydrogen tank bottom assembly to the lower layer of the ring; I4. The lower layer of the ring tightens the mechanism and holds the hydrogen tank bottom assembly, and the transition ring butt joint surface of the hydrogen tank bottom assembly is polished and cleaned; I5. According to the milling amount of the hydrogen tank bottom assembly transition ring and the sum of the oxygen tank and hydrogen tank half tank length, the milling amount of the hydrogen tank sealing ring joint cylinder segment side is calculated, and the lower end of the cylinder segment is milled; I6. The upper layer of the ring tightens the mechanism and moves downward synchronously with the movable ring, before the joint, the loading mechanism rotates and aligns the front and rear end quadrants of the whole tank, and then the hydrogen tank bottom assembly and the hydrogen tank cylinder segment ring joint are jointed; I7. The tank bottom loading mechanism pushes the detachable inner support to the welding position; I8. The detachable inner support is tightened; I9. The welding assembly quality is checked, measured and adjusted; I10. The welding execution mechanism rotates around the tank, and the friction stir welding is completed; I11. The upper and lower layers of the ring are loosened, the upper layer of the ring tightens the mechanism and moves upward, and the front of the welding joint is cleaned; I12, In-situ detection by ultrasonic phased array; I13, Loosen the detachable inner support, and the inner support is lifted by 300 mm, and the back of the weld is cleaned; I14, Detection by ultrasonic phased array.

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