Friction stir welding tool for circular seam of box bottom

Abstract

The invention relates to the technical field of welding, in particular to a box bottom circular seam friction stir welding tool which comprises a tool base, a circular ring mold tire is arranged on the inner wall of the tool base, a fork-shaped ring inner mold tire is arranged on the surface of the tool base, and a fork-shaped ring leveling assembly is arranged between the tool base and the fork-shaped ring inner mold tire. A large-end circular seam inner jacking mechanism is arranged on the surface of the tool base, a circular ring lifting mechanism is arranged on the inner wall of the tool base, a small-end circular seam inner jacking mechanism is arranged on the circular ring mold, and a fork-shaped ring small-end outer pressing mechanism is arranged on the surface of the tool base. By means of the technical scheme, the whole welding process is in a stable state, the positions of the parts can be accurately controlled no matter in the milling or welding process, process fluctuation caused by movement or deformation of the parts is reduced, and the repeatability and stability of the process are improved.

Description

Technical Field

[0001] The invention relates to the technical field of welding, in particular to a box bottom annular seam friction stir welding tool. Background Art

[0002] Box bottom annular seam friction stir welding is an advanced solid-state welding technology used to connect the annular weld of the box bottom. The basic principle is to use a specially shaped stirring head, which is usually composed of a shoulder and a stirring needle. During the welding process, the stirring head rotates at high speed and moves along the annular weld. The shoulder of the stirring head is in close contact with the surface of the workpiece, generating friction, so that the material around the stirring head is heated to a temperature close to but lower than the melting point of the material, and the material is in a thermoplastic state.

[0003] In daily work, it was found that there was no effective positioning tooling during the existing box bottom annular seam stir welding, which made it difficult to maintain a stable state during the friction welding process, causing the weld to shift to one side, and then causing the weld width to be uneven on both sides. This undesirable condition greatly reduced the overall welding effect and had a negative impact on the subsequent processing technology and assembly links. Summary of the invention

[0004] The purpose of the invention is to solve the disadvantage of poor stability of friction stir welding in the prior art and to propose a box bottom annular seam friction stir welding tool.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a box bottom annular seam stir friction welding tool, comprising a tool base, the inner wall of the tool base is provided with a circular ring mold, the surface of the tool base is provided with a fork-shaped ring inner mold, a fork-shaped ring leveling assembly is provided between the tool base and the fork-shaped ring inner mold, the surface of the tool base is provided with a large-end annular seam inner tightening mechanism, the inner wall of the tool base is provided with a circular ring lifting mechanism, the circular ring mold is provided with a small-end annular seam inner tightening mechanism, the surface of the tool base is provided with a fork-shaped ring small-end outer clamping mechanism, a circular ring outer clamping mechanism is provided above the circular ring mold, a top cover large-end outer clamping mechanism is provided above the circular ring outer clamping mechanism, and a lock bottom welding outer clamping mechanism is provided above the circular ring outer clamping mechanism.

[0006] Preferably, the circular lifting mechanism includes a motor reduction assembly installed on a tooling base, a screw elevator is installed on the surface of the tooling base, the output end of the motor reduction assembly is fixedly connected to the input end of the screw elevator, and a plurality of guide assemblies are arranged on the surface of the tooling base.

[0007] Preferably, the tightening mechanism in the large end annular seam includes a slewing support gear group assembly installed on a tooling base, two motor reduction assemblies 2 are installed on the surface of the tooling base, the output ends of the motor reduction assemblies 2 are meshed and connected with the slewing support gear group assembly, and a plurality of slider assemblies are arranged on the surface of the tooling base, and the slider assemblies are connected to the slewing support gear group assembly through a crank.

[0008] Preferably, the tightening mechanism in the small end annular seam includes a plurality of spiral elevators 2 installed on the circular ring mold, a motor reduction assembly 3 is installed on the surface of the circular ring mold, and a welding pad is arranged above the plurality of spiral elevators 2.

[0009] Preferably, the external clamping mechanism at the small end of the fork-shaped ring includes a cylinder mounting seat 1 fixedly connected to the surface of the tooling base, the surface of the cylinder mounting seat 1 is rotatably connected to a cylinder 1, the output end of the cylinder 1 is rotatably connected to a rocker arm 1, the surface of the tooling base is fixedly connected to a rocker arm mounting seat 1, the rocker arm 1 is rotatably connected to the rocker arm mounting seat 1, and the surface of the rocker arm 1 is fixedly connected to a clamping block 1.

[0010] Preferably, the annular outer clamping mechanism comprises an annular outer pressure ring frame mounted on a tooling base, the surface of the annular outer pressure ring frame is fixedly connected to a frame body, the surface of the annular outer pressure ring frame is provided with an annular small end clamping assembly and an annular large end outer clamping assembly, the annular small end clamping assembly comprises a cylinder mounting seat 2 and a rocker arm mounting seat 2 fixedly connected to the surface of the annular outer pressure ring frame, the surfaces of the cylinder mounting seat 2 and the rocker arm mounting seat 2 respectively rotate the cylinder 2 and the rocker arm 2, the output end of the cylinder 2 is rotatably connected to the rocker arm 2, the surface of the rocker arm 2 is fixedly connected to a clamping block 2, the annular large end outer clamping assembly comprises a cylinder mounting seat 3 and a rocker arm mounting seat 3 fixedly connected to the surface of the annular outer pressure ring frame, the surfaces of the cylinder mounting seat 3 and the rocker arm mounting seat 3 respectively rotate the cylinder 3 and the rocker arm 3, the output end of the cylinder 3 is rotatably connected to the rocker arm 3, and the surface of the rocker arm 3 is fixedly connected to a clamping block 3.

[0011] Preferably, the external clamping mechanism at the large end of the top cover includes an external pressure ring frame of the top cover, and the surfaces of the external pressure ring frame of the top cover are respectively fixedly connected with multiple cylinder mounting seats four and rocker arm mounting seats four, and the surfaces of the cylinder mounting seats four and rocker arm mounting seats four respectively rotate the cylinder four and the rocker arm four, the output end of the cylinder four is rotationally connected to the rocker arm four, and the surface of the rocker arm four is fixedly connected to a clamping block four.

[0012] Preferably, the lock bottom welding external clamping mechanism comprises a lock bottom external pressure ring frame, and a plurality of groups of short shell external clamping components are arranged on the surface of the lock bottom external pressure ring frame.

[0013] Compared with the prior art, the advantages and positive effects of the present invention are: In the present invention, through this scheme, the circular ring lifting mechanism cooperates with the circular ring mold to avoid the milling cutter space when milling the circular ring big end before welding. The inner tightening mechanism of the large end circular seam is used for tightening the inner surface of the welding edge of the circular ring big end and the small end of the fork-shaped ring when welding the circular ring big end. The inner tightening mechanism of the small end circular seam is used for tightening the inner surface of the welding edge of the circular ring small end and the large end of the top cover when welding the circular ring small end. The outer pressing mechanism of the fork-shaped ring small end is used for pressing the outer surface of the welding edge of the fork-shaped ring small end when welding the circular ring big end. The outer pressing mechanism of the circular ring is used for tightening the outer surface of the welding edge of the circular ring big end when welding the circular ring big end. The outer surface pressing and the outer surface pressing of the welding edge of the small end of the circular ring during the annular seam welding of the small end of the circular ring; the outer pressing mechanism of the large end of the top cover is used for the outer surface pressing of the welding edge of the large end of the top cover during the annular seam welding of the small end of the circular ring; the outer pressing mechanism of the lock bottom welding is used for the outer mounting plane pressing of the short shell during the lock bottom annular seam welding of the box bottom and the short shell. The welding parts are fixed and positioned from all directions, so that the whole welding process is in a stable state. Whether in milling or welding, the position of the parts can be precisely controlled, reducing the process fluctuations caused by the movement or deformation of the parts, and improving the repeatability and stability of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention provides a schematic cross-sectional structure diagram of a box bottom annular seam friction stir welding tool; Figure 2 A partial structural schematic diagram of a box bottom annular seam friction stir welding tooling proposed by the present invention; Figure 3 Another structural schematic diagram of a box bottom annular seam friction stir welding tooling provided by the present invention; Figure 4 The invention proposes a box bottom annular seam stir friction welding tool Figure 3 Schematic diagram of some structures; Figure 5 The present invention provides a schematic cross-sectional structural diagram of a tool base for a box bottom annular seam stir friction welding tool.

[0015] Figure 6 The present invention provides a schematic structural diagram of a circular ring lifting mechanism and a large-end ring seam inner tightening mechanism of a box bottom ring seam stir friction welding tooling; Figure 7 The present invention provides a schematic cross-sectional structure diagram of a small end annular seam inner tightening mechanism of a box bottom annular seam stir friction welding tool; Figure 8 The present invention provides a schematic diagram of the internal tightening mechanism of the small end annular seam of the box bottom annular seam stir friction welding tooling; Fig. 9 The present invention provides a schematic diagram of the structure of the outer clamping mechanism of the fork-shaped ring small end of the box bottom annular seam stir friction welding tooling; Fig.10The present invention provides a schematic diagram of the structure of the outer ring clamping mechanism of the box bottom annular seam friction stir welding tooling; Fig.11 A partial structural schematic diagram of the outer ring clamping mechanism of the box bottom annular seam friction stir welding tooling provided by the present invention; Fig.12 The present invention provides a schematic diagram of the structure of the outer clamping mechanism of the top cover large end of the box bottom annular seam stir friction welding tooling; Fig.13 A schematic diagram of the partial structure of the outer clamping mechanism of the top cover large end of the box bottom annular seam stir friction welding tooling proposed by the present invention; Fig.14 The present invention provides a schematic structural diagram of a bottom locking welding external clamping mechanism of a box bottom annular seam stir friction welding tooling.

[0016] Legend: 1. Tooling base; 2. Circular ring mold; 3. Circular ring lifting mechanism; 31. Motor reduction assembly 1; 32. Screw lift 1; 33. Guide assembly; 4. Large end ring gap internal tightening mechanism; 41. Slider assembly; 42. Slewing support gear assembly; 43. Motor reduction assembly 2; 44. Crank; 5. Small end ring gap internal tightening mechanism; 51. Screw lift 2; 52. Motor reduction assembly 3; 53. Welding pad; 6. Fork ring small end external clamping mechanism; 61. Cylinder 1; 62. Rocker 1; 63. Clamping block 1; 64. Rocker mounting seat 1; 65. Cylinder mounting seat 1; 7. Circular ring external clamping mechanism; 71. Circular ring external pressure ring frame; 72. Frame; 73. Circular ring small End clamping assembly; 731, cylinder two; 732, rocker arm two; 733, clamping block two; 734, rocker arm mounting seat two; 735, cylinder mounting seat two; 74, external clamping assembly of the large end of the ring; 741, cylinder three; 742, rocker arm three; 743, rocker arm mounting seat three; 744, clamping block three; 745, cylinder mounting seat three; 8, external clamping mechanism of the large end of the top cover; 81, cylinder mounting seat four; 82, cylinder four; 83, rocker arm four; 84, rocker arm mounting seat four; 85, clamping block four; 86, external pressure ring frame of the top cover; 9, external clamping mechanism of the bottom lock welding; 91, external pressure ring frame of the bottom lock; 92, external clamping assembly of the short shell; 10, fork-shaped ring leveling assembly; 11, fork-shaped ring inner mold tire. DETAILED DESCRIPTION

[0017] See also Figure 1-Figure 14The present invention provides a technical solution: a box bottom annular seam friction stir welding tool, comprising a tool base 1, a circular ring mold 2 is arranged on the inner wall of the tool base 1, a fork-shaped ring inner mold 11 is arranged on the surface of the tool base 1, a fork-shaped ring leveling component 10 is arranged between the tool base 1 and the fork-shaped ring inner mold 11, a large-end annular seam inner tightening mechanism 4 is arranged on the surface of the tool base 1, a circular ring lifting mechanism 3 is arranged on the inner wall of the tool base 1, a small-end annular seam inner tightening mechanism 5 is arranged on the circular ring mold 2, a fork-shaped ring small-end external clamping mechanism 6 is arranged on the surface of the tool base 1, a circular ring external clamping mechanism 7 is arranged above the circular ring mold 2, a top cover large-end external clamping mechanism 8 is arranged above the circular ring external clamping mechanism 7, and a bottom lock welding external clamping mechanism 9 is arranged above the circular ring external clamping mechanism 7.

[0018] Specifically, the ring lifting mechanism 3 includes a motor reduction assembly 31 installed on the tooling base 1, a spiral elevator 32 is installed on the surface of the tooling base 1, the output end of the motor reduction assembly 31 is fixedly connected to the input end of the spiral elevator 32, and a plurality of guide assemblies 33 are arranged on the surface of the tooling base 1.

[0019] Specifically, the large-end annular seam inner tightening mechanism 4 includes a slewing support gear set assembly 42 installed on the tooling base 1, two motor reduction assemblies 43 are installed on the surface of the tooling base 1, and the output end of the motor reduction assembly 43 is meshed and connected with the slewing support gear set assembly 42. A plurality of slider assemblies 41 are arranged on the surface of the tooling base 1, and the slider assembly 41 is connected to the slewing support gear set assembly 42 through a crank 44.

[0020] Specifically, the small end annular seam inner tightening mechanism 5 includes a plurality of spiral elevators 2 51 installed on the circular ring mold 2, a motor reduction assembly 3 52 is installed on the surface of the circular ring mold 2, and a welding pad 53 is arranged above the plurality of spiral elevators 2 51.

[0021] Specifically, the outer clamping mechanism 6 at the small end of the fork-shaped ring includes a cylinder mounting seat 65 fixedly connected to the surface of the tooling base 1, the surface of the cylinder mounting seat 65 is rotatably connected to a cylinder 61, the output end of the cylinder 61 is rotatably connected to a rocker arm 62, the surface of the tooling base 1 is fixedly connected to a rocker arm mounting seat 64, the rocker arm 62 is rotatably connected to the rocker arm mounting seat 64, and the surface of the rocker arm 62 is fixedly connected to a clamping block 63.

[0022] Specifically, the outer ring pressing mechanism 7 includes an outer ring pressing ring frame 71 installed on the tooling base 1, the surface of the outer ring pressing ring frame 71 is fixedly connected with a frame body 72, the surface of the outer ring pressing ring frame 71 is provided with an outer ring small end pressing assembly 73 and an outer ring large end pressing assembly 74, the outer ring small end pressing assembly 73 includes a cylinder mounting seat 2 735 and a swing rod mounting seat 2 734 fixedly connected to the surface of the outer ring pressing ring frame 71, the surfaces of the cylinder mounting seat 2 735 and the swing rod mounting seat 2 734 rotate the cylinder 2 731 and the swing rod 2 734 respectively 2. The output end of the cylinder 2 731 is rotatably connected to the rocker rod 2 732, and the surface of the rocker rod 2 732 is fixedly connected to the clamping block 2 733. The outer clamping assembly 74 at the large end of the circular ring includes a cylinder mounting seat 3 745 and a rocker rod mounting seat 3 743 fixedly connected to the surface of the outer ring pressure ring frame 71. The surfaces of the cylinder mounting seat 3 745 and the rocker rod mounting seat 3 743 rotate the cylinder 3 741 and the rocker rod 3 742 respectively. The output end of the cylinder 3 741 is rotatably connected to the rocker rod 3 742, and the surface of the rocker rod 3 742 is fixedly connected to the clamping block 3 744.

[0023] Specifically, the top cover large end external clamping mechanism 8 includes a top cover external pressure ring frame 86, and the surfaces of the top cover external pressure ring frame 86 are respectively fixedly connected with multiple cylinder mounting seats four 81 and rocker arm mounting seats four 84, and the surfaces of the cylinder mounting seats four 81 and the rocker arm mounting seats four 84 respectively rotate the cylinder four 82 and the rocker arm four 83, and the output end of the cylinder four 82 is rotationally connected to the rocker arm four 83, and the surface of the rocker arm four 83 is fixedly connected to the clamping block four 85.

[0024] Specifically, the lock bottom welding external clamping mechanism 9 comprises a lock bottom external clamping ring frame 91 , and a plurality of groups of short shell external clamping components 92 are arranged on the surface of the lock bottom external clamping ring frame 91 .

[0025] Working principle: When using it, you only need to operate the tooling base 1, the circular ring mold 2, the circular ring lifting mechanism 3, the large end ring seam inner tightening mechanism 4, the small end ring seam inner tightening mechanism 5, the fork ring small end outer tightening mechanism 6, the circular ring outer tightening mechanism 7, and the top cover large end outer tightening mechanism 8 to achieve the positioning operation; The circular ring mold 2 is lifted and lowered by a circular ring lifting mechanism 3, and the spiral lifter 32 is controlled by a motor reduction assembly 31 to move, thereby driving the circular ring mold 2 to move in the guide assembly 33, so as to avoid the milling cutter space when the large end of the circular ring is milled before the annular seam is welded. The spiral lifter 32 is at any lifting height position, and the lifting position is self-locked by the motor power-off self-locking; The large end annular seam inner tightening mechanism 4 is used for the annular seam welding of the large end of the circular ring. The inner surface of the welding edge of the large end of the circular ring and the small end of the fork-shaped ring is tightened. The welding pads 53 are arranged continuously in the circumferential direction of the weld. The rotary support gear assembly 42 can be controlled to rotate by the motor reduction assembly 2 43. The rotary support gear assembly 42 drives multiple sets of slider assemblies 41 and the crank 44 to move, so as to realize the secure tightening of the workpiece of the large end annular seam of the circular ring. The length of the crank 44 can be adjusted to ensure that the crank 44 slider assembly 41 and the corresponding matching welding pad 53 cannot be stuck with the workpiece when tightened, that is, the angle between the axis of the crank 44 and the center of the welding pad 53 is less than 90°; The small end annular seam inner tightening mechanism 5 is used for the annular seam welding of the small end of the circular ring. The inner surface of the welding edge of the small end of the circular ring and the large end of the top cover is tightened. The motor reduction assembly 52 controls the spiral elevator 2 51 to rise, ensuring that the welding pad 53 can achieve the tight tightening of the annular seam workpiece of the small end of the circular ring. The small end annular seam inner tightening mechanism 5 is in operation, ensuring that the tooling can ensure the stability of the milling and stir friction welding process without vibration, and the end jump accuracy is better than 0.2mm and the diameter jump accuracy is better than 0.15mm. The outer pressing mechanism 6 of the small end of the fork-shaped ring is used to press the outer surface of the welding edge of the small end of the fork-shaped ring when the annular seam of the large end of the circular ring is welded. When in use, the cylinder 61 drives the swing rod 62 to rotate on the swing rod mounting seat 64, so that the swing rod 62 can drive the pressing block 63 to press the outer surface of the welding edge of the small end of the fork-shaped ring; The outer clamping mechanism 7 of the circular ring is used for clamping the outer surface of the welding edge of the large end of the circular ring when the circular ring large end is welded and for clamping the outer surface of the welding edge of the small end of the circular ring when the circular ring small end is welded. When in use, the clamping process can be performed by the circular ring small end clamping assembly 73 and the circular ring large end outer clamping assembly 74 respectively. When the circular ring small end clamping assembly 73 is working, the cylinder 2 731 is opened, the cylinder 2 731 controls the swing rod 2 732 to rotate on the swing rod mounting seat 2 734, and drives the clamping block 2 733 to clamp the outer surface of the welding edge of the small end of the circular ring. When the outer clamping assembly 74 of the large end of the circular ring is working, the cylinder 3 741 is opened, the cylinder 3 741 controls the swing rod 3 742 to rotate on the swing rod mounting seat 3 743, and drives the clamping block 3 744 to clamp the outer surface of the welding edge of the large end of the circular ring; The top cover big end outer clamping mechanism 8 is used to clamp the outer surface of the top cover big end welding edge when the circular ring small end annular seam is welded. The top cover big end outer clamping mechanism 8 is installed on the top cover upper pressure ring in the tooling gantry, and is lifted and lowered with the lifting mechanism in the tooling gantry. When the workpiece is clamped, the top cover big end outer clamping mechanism 8 is lifted and lowered to a set height position with the lifting mechanism in the tooling gantry, and then the top cover big end outer clamping mechanism 8 is controlled to realize the clamping of the outer surface of the top cover big end welding edge, and the cylinder 482 is turned on. The cylinder 482 controls the swing rod 483 to rotate on the swing rod mounting seat 484, and drives the clamping block 485 to clamp the outer surface of the top cover big end welding edge; The lock bottom welding external clamping mechanism 9 is used to clamp the outer installation plane of the short shell when the box bottom and the short shell lock bottom ring seam are welded. The short shell outer clamping assembly 92 is installed on the lock bottom outer pressure ring frame 91. The lock bottom welding external clamping mechanism 9 is installed on the top cover upper pressure ring in the tooling gantry, and can be raised and lowered with the lifting mechanism in the tooling gantry. The lock bottom welding external clamping mechanism 9 adopts a double clamping scheme, and the lifting mechanism in the tooling gantry realizes the clamping of the lower plane of the lock bottom outer pressure ring frame 91 and the upper short shell plane of the short shell.

Claims

1. A box bottom annular seam friction stir welding tool, comprising a tool base (1), characterized in that: The inner wall of the tooling base (1) is provided with a circular mold (2), the surface of the tooling base (1) is provided with a fork-shaped inner mold (11), a fork-shaped ring leveling assembly (10) is provided between the tooling base (1) and the fork-shaped inner mold (11), the surface of the tooling base (1) is provided with a large-end ring seam inner tightening mechanism (4), the inner wall of the tooling base (1) is provided with a circular ring lifting mechanism (3), the circular ring mold (2) is provided with a small-end ring seam inner tightening mechanism (5), the surface of the tooling base (1) is provided with a fork-shaped small-end outer clamping mechanism (6), the upper part of the circular ring mold (2) is provided with a circular ring outer clamping mechanism (7), the upper part of the circular ring outer clamping mechanism (7) is provided with a top cover large-end outer clamping mechanism (8), and the upper part of the circular ring outer clamping mechanism (7) is provided with a bottom lock welding outer clamping mechanism (9).

2. The box bottom annular seam friction stir welding tool according to claim 1, characterized in that: The annular lifting mechanism (3) comprises a motor reduction assembly (31) mounted on a tooling base (1); a screw lift (32) is mounted on the surface of the tooling base (1); an output end of the motor reduction assembly (31) is fixedly connected to an input end of the screw lift (32); and a plurality of guide assemblies (33) are arranged on the surface of the tooling base (1).

3. The box bottom annular seam friction stir welding tool according to claim 1, characterized in that: The large-end annular seam inner tightening mechanism (4) comprises a slewing support gear assembly (42) mounted on a tooling base (1); two motor reduction assemblies (43) are mounted on the surface of the tooling base (1); the output end of the motor reduction assembly (43) is meshedly connected to the slewing support gear assembly (42); a plurality of slider assemblies (41) are arranged on the surface of the tooling base (1); the slider assemblies (41) are connected to the slewing support gear assembly (42) via a crank (44).

4. The box bottom annular seam friction stir welding tool according to claim 1, characterized in that: The small end annular seam inner tightening mechanism (5) comprises a plurality of spiral elevators (51) mounted on the annular mold (2), a motor reduction assembly (52) is mounted on the surface of the annular mold (2), and a welding pad (53) is arranged above the plurality of spiral elevators (51).

5. The box bottom annular seam friction stir welding tool according to claim 1, characterized in that: The fork-shaped ring small end external clamping mechanism (6) comprises a cylinder mounting seat (65) fixedly connected to the surface of the tooling base (1); the surface of the cylinder mounting seat (65) is rotatably connected to a cylinder (61); the output end of the cylinder (61) is rotatably connected to a swing rod (62); the surface of the tooling base (1) is fixedly connected to a swing rod mounting seat (64); the swing rod (62) is rotatably connected to the swing rod mounting seat (64); and the surface of the swing rod (62) is fixedly connected to a clamping block (63).

6. The box bottom annular seam friction stir welding tool according to claim 1, characterized in that: The annular outer pressing mechanism (7) comprises an annular outer pressing ring frame (71) mounted on a tooling base (1); a frame body (72) is fixedly connected to the surface of the annular outer pressing ring frame (71); an annular small end pressing assembly (73) and an annular large end outer pressing assembly (74) are arranged on the surface of the annular outer pressing ring frame (71); the annular small end pressing assembly (73) comprises a cylinder mounting seat 2 (735) and a swing rod mounting seat 2 (734) fixedly connected to the surface of the annular outer pressing ring frame (71); the surfaces of the cylinder mounting seat 2 (735) and the swing rod mounting seat 2 (734) respectively rotate the cylinder 2 (731) and the swing rod 2 (732); The output end of the cylinder 2 (731) is rotationally connected to the rocker rod 2 (732), and the surface of the rocker rod 2 (732) is fixedly connected to the clamping block 2 (733). The outer clamping assembly (74) at the large end of the circular ring includes a cylinder mounting seat 3 (745) and a rocker rod mounting seat 3 (743) which are fixedly connected to the surface of the outer ring pressure ring frame (71). The surfaces of the cylinder mounting seat 3 (745) and the rocker rod mounting seat 3 (743) rotate the cylinder 3 (741) and the rocker rod 3 (742) respectively. The output end of the cylinder 3 (741) is rotationally connected to the rocker rod 3 (742), and the surface of the rocker rod 3 (742) is fixedly connected to the clamping block 3 (744).

7. The box bottom annular seam friction stir welding tool according to claim 1, characterized in that: The top cover large end external clamping mechanism (8) comprises a top cover external clamping ring frame (86), the surface of the top cover external clamping ring frame (86) is respectively fixedly connected with a plurality of cylinder mounting seats four (81) and rocker arm mounting seats four (84), the surfaces of the cylinder mounting seats four (81) and rocker arm mounting seats four (84) respectively rotate the cylinder four (82) and the rocker arm four (83), the output end of the cylinder four (82) is rotationally connected with the rocker arm four (83), and the surface of the rocker arm four (83) is fixedly connected with a clamping block four (85).

8. The box bottom annular seam friction stir welding tool according to claim 1, characterized in that: The bottom-locking welding external pressing mechanism (9) comprises a bottom-locking external pressing ring frame (91), and a plurality of groups of short shell external pressing components (92) are arranged on the surface of the bottom-locking external pressing ring frame (91).

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