Laser welding device and process for machining large-diameter thin-wall low-thermal-expansion alloy pipe

Abstract

The invention relates to the technical field of pipe fitting laser welding, and discloses a laser welding device and process for machining a large-diameter thin-wall low-thermal-expansion alloy pipe, and the laser welding device for machining the large-diameter thin-wall low-thermal-expansion alloy pipe comprises a machine body, a welding table arranged on one side of the machine body, and a supporting assembly arranged on the welding table and used for supporting. The two alloy pipes are arranged at the top of the supporting assembly and used for welding, the laser welding gun is arranged on the welding table and located on one sides of the alloy pipes, the rotating motor is arranged on one side of the machine body, the clamping base is arranged on one side of an output shaft of the rotating motor, and the clamping unit is arranged on the clamping base. Local stress concentration is avoided through cooperation of air bag clamping and a moving plate, an air bag cavity of the clamping assembly is matched with the moving plate of the auxiliary assembly to form a two-way pressure control structure, when the air bag is inflated and expanded, directional expansion can be achieved, the clamping contact area can be enlarged, and thin wall sinking caused by point contact or line contact is avoided.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology for pipe fittings, and in particular to a laser welding device and process for processing large-diameter, thin-walled, low-thermal-expansion alloy pipes. Background Technology

[0002] Large-diameter, thin-walled, low-thermal-expansion alloy tubes are widely used in high-end fields such as aerospace and energy equipment due to their lightweight and low coefficient of thermal expansion. Their welding quality directly affects the operational safety of the equipment. However, these tubes present processing challenges due to their thin walls being prone to deformation and their large diameters being difficult to position. Existing clamping and support designs for large-diameter alloy tube laser welding equipment have three major drawbacks when adapting to thin-walled, low-thermal-expansion tubes:

[0003] Firstly, there is a limitation in the adaptability of rigid clamping blocks. Existing devices often use several independent rigid clamping blocks to clamp the pipe body. While this structure is suitable for thick-walled, high-hardness pipes, it is ineffective for large-diameter, thin-walled pipes. The contact between the clamping blocks and the pipe body is often localized, with point or line contact. The clamping stress per unit area far exceeds the load-bearing limit of the thin-walled pipe, easily causing indentation and wrinkling at the clamping point, and even leading to micro-cracks in low-thermal-expansion alloy pipes due to stress concentration. Secondly, the load-bearing capacity of the bottom support is insufficient. Large-diameter, thin-walled pipes not only have a large size span but also a high overall weight (especially long pipe sections). Existing support structures are mostly single-sided support plates or simple two-point supports, lacking... The method of forming a uniform multi-point support system makes the pipe body prone to sagging and shifting due to its own weight. During the rotation welding process, the center of gravity becomes unbalanced, further aggravating the deformation of the thin wall at the clamping point. Thirdly, the adaptability of clamping scenarios is limited. Most clamping devices are only designed for single clamping scenarios of the outer or inner wall of the pipe. For example, the outer wall clamping device cannot reach into the inside of the large-diameter pipe to achieve inner wall positioning, and the inner wall clamping device is difficult to adapt to the outer wall requirements of small-diameter pipes. When facing different diameters or clamping scenarios, the entire set of clamping components needs to be disassembled and replaced. The adjustment cycle is long and the operation is cumbersome, which seriously restricts the efficiency of batch processing. Moreover, frequent changes of fixtures can easily introduce positioning errors and affect welding accuracy. Summary of the Invention

[0004] In view of the problems of easy deformation of thin-walled large-diameter alloy tubes and difficulty in positioning large-diameter tubes in the existing technology, a laser welding device for processing large-diameter thin-walled low thermal expansion alloy tubes is proposed.

[0005] Its purpose is to solve the problems of rigid clamping being prone to deformation, large diameter being difficult to position, and poor adaptability by using bidirectional pressure control of airbag and arc-shaped moving plate, uniform support of multi-support plate with rollers, and bidirectional clamping switching of trigger rod and arc-shaped push bar, so as to achieve high-precision and high-efficiency laser welding of this type of pipe to meet the needs of high-end fields.

[0006] The technical solution of the present invention is a laser welding device for processing large-diameter thin-walled low thermal expansion alloy tubes, including a machine body, a welding table disposed on one side of the machine body, a support assembly disposed on the welding table for support, two alloy tubes disposed on the top of the support assembly for welding, a laser welding gun disposed on the welding table and located on one side of the alloy tubes, a rotary motor disposed on one side of the machine body, a clamping seat disposed on one side of the output shaft of the rotary motor, and a clamping unit disposed on the clamping seat;

[0007] The clamping unit includes several movable slots evenly opened on one side of the clamping seat, clamping components respectively disposed in the movable slots, and a driving component disposed inside the clamping seat for driving the clamping components to move and clamp.

[0008] The clamping component includes a clamping assembly disposed on the driving component and an auxiliary assembly disposed inside the clamping assembly; the clamping assembly includes a moving block disposed in the moving slot, a clamping block disposed on the top of the moving block, air bladder cavities symmetrically opened on both sides of the clamping block, an air bladder disposed on the inner wall of one side of the air bladder cavity, and an inflation channel opened inside the moving block for connecting the air bladder.

[0009] The auxiliary component includes symmetrically opened limiting grooves inside the moving block near the side, two symmetrically distributed moving plates arranged in the limiting grooves, the moving plates being arc-shaped, a pressing block arranged on one side of the moving plate, a sliding hole extending through the middle of the entire moving plate, and a trigger rod arranged in the sliding hole.

[0010] Furthermore, the auxiliary component also includes a sealing ring disposed in the middle of the trigger rod, a return spring disposed on one side of the sealing ring, a push ring disposed on one side of the return spring, and the push ring is sleeved on the trigger rod. Push bars are symmetrically disposed on both sides of one end of the push ring, and one end of the push bars is respectively hinged to the middle of the moving plate. A movable groove is symmetrically opened inside the push ring. A drive block is disposed in the sliding groove, and the drive block abuts against the side of the sliding groove away from the spring.

[0011] Furthermore, the push bar is arc-shaped, and the trigger rod has an arc-shaped groove that fits and abuts against one side of the push bar.

[0012] Furthermore, the clamping block and the trigger rod are slidably connected at both ends.

[0013] Furthermore, a sealing component is provided in the middle of the sliding hole. In the initial state, the sealing ring abuts against the sealing component. The sealing component includes a closed hole opened in the middle of the sliding hole and connected to the air passage, a sealing rod set in the closed hole, a baffle set at one end of the sealing rod, a connecting spring set on one side of the baffle, and a mounting groove opened on one side of the closed hole. One end of the connecting spring is fixedly connected to one side of the mounting groove, and the connecting spring is sleeved on the sealing rod.

[0014] Furthermore, the middle of both sides of the air bladder cavity is convex, and one side of the air bladder cavity is W-shaped.

[0015] Furthermore, the driving component includes a small motor disposed inside the clamping seat, a rotating shaft disposed on one side of the output shaft of the small motor, a driving bevel gear disposed at one end of the rotating shaft, a plurality of driven bevel gears disposed on one side of the driving bevel gear, a lead screw disposed at one end of the driven bevel gear, a moving block being threadedly connected to the lead screw, and the lead screw being limited in the moving groove, and an anti-detachment plate being provided at the outer end of the lead screw to prevent the moving block from falling off.

[0016] Furthermore, the inflation port of the inflation channel is located on one side of the moving block, and an inflation pipe is provided at the inflation port. A strip groove for the inflation pipe to move is opened on one side of the top of the moving groove, and an air pump connected to the inflation pipe is provided inside the clamping seat.

[0017] Another objective of this invention is to provide a laser welding process for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes. The purpose is to avoid the problems of thin-walled deformation and docking misalignment in existing processes by adapting the aforementioned device structure and its bidirectional pressure-controlled clamping, uniform rotation support, and bidirectional clamping switching functions; to achieve automated connection between the process and the device to reduce manual labor and improve efficiency; and to ensure consistent welding quality for tubes of different diameters through standardized control (such as directional expansion of airbags and uniform rotation of the tube body), thus meeting the precision and stability requirements of high-end fields.

[0018] To achieve the above objectives, the present invention provides the following technical solution: a laser welding process for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes, comprising the following steps:

[0019] S1: First, spot weld the two alloy tubes together to position them, then place the two alloy tubes to be welded on top of the support assembly and adjust the welding torch to the appropriate welding operation range.

[0020] S2: Start the clamping drive, turn on the small motor in the clamping seat, and drive the bevel gear and driven bevel gear to make the screw rotate, which drives the moving block to move along the moving groove until the clamping block is close to the inner wall or outer wall of the alloy tube.

[0021] S3: The inner or outer wall of the alloy tube pushes the trigger rod to slide, the sealing ring disengages from the squeezing and sealing rod, at which point the inflation channel is opened, the air pump inflates the airbag through the inflation channel, and at the same time pushes the ring to compress the reset spring, causing the arc-shaped push bar on the corresponding side to move the moving plate to squeeze and seal one side of the airbag.

[0022] S4: The airbag on the other side can be quickly inflated and expanded towards the alloy tube in the airbag cavity, clamping the inner or outer wall of the alloy tube.

[0023] S5: Start the rotating motor to drive the clamping seat and alloy tube to rotate at a constant speed, and simultaneously turn on the laser welding gun to continuously weld the joint until the whole circle is completed.

[0024] S6: Reset and remove parts, turn off the laser welding gun and rotating motor, release air from the air pump to cause the airbag to contract, reverse the small motor to drive the clamping parts to reset, the extrusion block separates from the inner or outer wall, and the welded alloy tube is removed.

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

[0026] 1. By using airbag clamping and moving plate in synergy, local stress concentration is avoided. The airbag cavity of the clamping component, together with the moving plate of the auxiliary component, forms a "two-way pressure control" structure. When the airbag is inflated, the moving plate can guide the airbag to expand directionally toward the alloy tube wall by blocking one side of the airbag cavity or squeezing the airbag, thereby expanding the clamping contact area (avoiding thin-walled depressions caused by point contact or line contact) and adapting to the material characteristics of the low thermal expansion alloy tube, which is "thin-walled and easily deformable".

[0027] 2. This device features a flexible clamping mode, adapting to the needs of tubes of different sizes. The auxiliary components achieve "bidirectional adaptation for clamping the inner or outer wall" through the linkage structure of the trigger rod, push bar, and moving plate. When clamping the inner wall, the trigger rod is squeezed and moves, and the push bar drives the moving plate to move in opposite directions, cooperating with the airbag to clamp the inner wall. If clamping the outer wall is required, the reverse drive of the clamping components can achieve the outer wall fit by limiting the moving plate and expanding the airbag. Without changing the fixture, it can adapt to the clamping needs of alloy tubes of different diameters (within the large diameter range), reducing tooling change time and improving processing versatility and efficiency. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the overall structure of the clamping unit and the alloy steel pipe to be welded according to the present invention;

[0030] Figure 3 This is a three-dimensional structural diagram of the clamping component of the present invention;

[0031] Figure 4 This is a cross-sectional view of the clamping component of the present invention;

[0032] Figure 5 For the present invention Figure 4 Enlarged structural diagram at point A in the middle;

[0033] Figure 6 This is a three-dimensional structural diagram of the clamping component and the driving component of the present invention;

[0034] Figure 7This is a schematic diagram of the overall structure of the moving block and clamping block of the present invention;

[0035] Figure 8 This is a cross-sectional view of the internal structure of the clamping block of the present invention;

[0036] Figure 9 For the present invention Figure 8 Enlarged structural diagram at point B;

[0037] Figure 10 This is a three-dimensional structural diagram of the auxiliary component of the present invention;

[0038] Figure 11 This is a three-dimensional structural diagram of the trigger rod of the present invention;

[0039] Figure 12 This is a cross-sectional view of the inflation channel of the present invention.

[0040] In the picture:

[0041] 1. Welding table; 11. Support assembly; 12. Rotary motor; 13. Clamping seat; 14. Moving groove; 2. Clamping assembly; 21. Moving block; 22. Clamping block; 23. Airbag cavity; 24. Inflation channel; 3. Auxiliary assembly; 301. Limiting groove; 302. Moving plate; 303. Extrusion block; 304. Sliding hole; 305. Trigger rod; 306. Sealing ring; 307. Return spring; 308. Pushing ring; 309. Pushing bar; 310. Movable groove; 311. Drive block; 312. Arc groove; 4. Sealing assembly; 41. Sealing hole; 42. Sealing rod; 43. Baffle; 44. Connecting spring; 5. Drive component; 51. Rotating shaft; 52. Lead screw; 53. Anti-detachment plate; 6. Strip groove. Detailed Implementation

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0043] Example 1, referring to Figures 1-12This invention provides a laser welding device for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes, comprising a body, a welding table 1 disposed on one side of the body, a support assembly 11 disposed on the welding table 1 for support, the support assembly 11 consisting of two support plates and several rollers disposed on the support plates to facilitate rotational support of the alloy tubes, two alloy tubes for welding placed on top of the support assembly 11, a laser welding gun disposed on the welding table 1 and located on one side of the alloy tubes, a rotary motor 12 mounted on one side of the body, a clamping seat 13 fixedly connected to one side of the output shaft of the rotary motor 12, and a clamping unit disposed on the clamping seat 13; the clamping unit includes several moving slots 1 evenly distributed on one side of the clamping seat 13. 4. Clamping components respectively disposed in the moving groove 14, and driving components 5 disposed inside the clamping seat 13 for driving the clamping components to move and clamp; the clamping components include clamping assembly 2 disposed on the driving component 5, and auxiliary components 3 disposed inside the clamping assembly 2; the clamping assembly 2 includes a moving block 21 slidably connected in the moving groove 14, a clamping block 22 fixedly connected to the top of the moving block 21, the clamping block 22 is elliptical in shape, air bladder cavities 23 are symmetrically opened on both sides of the clamping block 22, an air bladder (not shown in the figure, the air bladder is not made of pressure-resistant and wear-resistant material, and its whole body can be a T-shaped integral molding to facilitate inflation in the air bladder cavity 23) is installed on the inner wall of one side of the air bladder cavity 23, and an inflation channel 24 is opened inside the moving block 21 to connect the air bladder.

[0044] The auxiliary component 3 includes a limiting groove 301 symmetrically opened inside the movable block 21 near the side, two symmetrically distributed movable plates 302 slidably connected in the limiting groove 301, the movable plates 302 being arc-shaped, a pressing block 303 fixedly connected to one side of the movable plate 302, a sliding hole 304 penetrating through the middle of the entire movable plate 302, and a trigger rod 305 slidably connected in the sliding hole 304. The auxiliary component 3 also includes a sealing ring 306 fixedly connected to the middle of the trigger rod 305, a return spring 307 fixedly connected to one side of the sealing ring 306, a push ring 308 fixedly connected to one side of the return spring 307, and the push ring 308 is sleeved on the trigger rod 305. Push bars 309 are symmetrically hinged to both sides of one end of the push ring 308, and one end of the push bars 309 is respectively hinged to the middle of the moving plate 302. A movable groove 310 is symmetrically opened inside the push ring 308, and a drive block 311 is slidably connected in the sliding groove. The drive block 311 abuts against the side of the sliding groove away from the spring.

[0045] Specifically, when welding the alloy tubes, the two alloy tubes are first welded together and positioned, then placed on the support assembly 11. One end is clamped by the clamping assembly 2. When clamping the inner wall of the alloy tube, the driving component 5 drives the moving block 21 to move within the moving groove 14. The driving component 5 drives the clamping component to move synchronously. When the clamping assembly 2 touches the inner wall of the alloy tube, the trigger rod 305 on the auxiliary assembly 3 is pressed into the sliding hole 304 and moves to one side. The trigger rod 305 drives the sealing ring 306. As the device moves away from the inner tube wall, the return spring 307 on the other side is stretched. The drive block 311 abuts against the push ring 308 and moves away from the inner tube wall. The push ring 308 pushes the two push bars 309 at one end. Since the push bar 309 and the trigger rod 305 are in contact and one end is raised, the two push bars 309 push the moving plates 302 on both sides to move in opposite directions in the limiting groove 301, so that the moving plates 302 seal one side of the airbag cavity 23. During this process, initially, the sealing ring 306 abuts against the sealing component 4, preventing the inflation channel 24 from communicating with the airbag. As the sealing ring 306 gradually moves, the inflation channel 24 communicates with the airbag, allowing the airbag to inflate. During inflation, the moving plate 302 continuously moves. If the airbag inflates quickly, the protruding compression block 303 on one side of the moving plate 302 can compress one side of the airbag. If the airbag inflates slowly, the moving plate 302 first blocks one side of the airbag cavity 23. This facilitates rapid inflation of the airbag to the other side, allowing it to compress and clamp the inner wall of the alloy tube, increasing the clamping contact area and preventing deformation of the thin wall of the large-diameter alloy tube. Simultaneously, when the trigger rod 305 is compressed and moves to one side, it stretches the return spring 307 on the other side. Since the push ring 308 on the other side is limited and stationary, the drive block 311 moves within the sliding groove. The above structural design enables the movable plate 302 on one side to move and block when clamping the inner wall of the tube, while the other side remains stationary, and vice versa. This allows for clamping the inner or outer wall of large-diameter thin-walled alloy tubes, improving the adaptability to clamping the inner and outer walls of alloy tubes of different sizes, and making it highly practical.

[0046] By coordinating the airbag clamping and the moving plate 302, local stress concentration is avoided. The airbag cavity 23 of the clamping component 2, together with the moving plate 302 of the auxiliary component 3, forms a "two-way pressure control" structure. When the airbag inflates, the moving plate 302 can guide the airbag to expand directionally towards the alloy tube wall by blocking one side of the airbag cavity 23 or squeezing the airbag, thereby expanding the clamping contact area (avoiding thin-walled depressions caused by point or line contact) and adapting to the material characteristics of the low thermal expansion alloy tube, which is "thin-walled and easily deformable". Through the trigger-type inflation design, the clamping timing is ensured to be precise. In the initial state, the sealing ring 306 blocks the inflation channel 24. Only when the trigger rod 305 is squeezed and moved by the alloy tube and the sealing ring 306 is separated from the sealing component 4, does the inflation channel 24 connect with the airbag. This design can avoid the airbag from inflating prematurely and causing clamping position deviation. It ensures that the clamping component 2 is initially aligned with the tube body, the auxiliary component 3 completes the inner wall positioning, and then the airbag accurately fits the tube wall, further reducing the risk of deformation of the thin-walled tube due to clamping misalignment. Furthermore, the clamping mode is flexible and adaptable to the needs of tubes of different sizes. The auxiliary component 3 achieves "bidirectional adaptation for clamping the inner or outer wall" through the linkage structure of the trigger rod 305, the push bar 309 and the moving plate 302. When clamping the inner wall, the trigger rod 305 is squeezed and moved, and the push bar 309 drives the moving plate 302 to move in opposite directions, which, together with the airbag, clamps the inner wall. If it is necessary to clamp the outer wall, the reverse drive of the clamping component can achieve the outer wall fit by limiting the movement of the moving plate 302 and expanding the airbag. Without changing the fixture, it can adapt to the clamping needs of alloy tubes of different diameters (within the large diameter range), reduce tooling change time, and improve processing versatility and efficiency.

[0047] Reference Figures 8-9 The push bar 309 is arc-shaped, and the trigger rod 305 has an arc-shaped groove 312 that fits and abuts against one side of the push bar 309.

[0048] Specifically, the trigger rod 305 facilitates the movement of the push bar 309 to squeeze and push the moving plate 302 when it moves. The arc shape of the adapting moving groove 14, compared with the straight push bar 309, allows for precise control of the force transmission path, making it easier to quickly push the moving plate 302.

[0049] Example 2, refer to Figures 10-12 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that a sealing component is also provided in the middle of the sliding hole 304. In the initial state, the sealing ring 306 abuts against the sealing component 4. The sealing component 4 includes a closed hole 41 opened in the middle of the sliding hole 304 and connected to the inflation channel 24, a sealing rod 42 slidably connected in the closed hole 41, a baffle 43 fixedly connected to one end of the sealing rod 42, a connecting spring 44 fixedly connected to one side of the baffle 43, and a mounting groove opened in one side of the closed hole 41. One end of the connecting spring 44 is fixedly connected to one side of the mounting groove, and the connecting spring 44 is sleeved on the sealing rod 42.

[0050] Specifically, when the trigger rod 305 moves the sealing ring 306, the sealing ring 306 releases the pressure on the sealing rod 42, causing the connecting spring 44 to reset. This allows the sealing rod 42 to move out of the inflation channel 24, enabling gas to smoothly enter the airbag. In the initial state, the sealing ring 306 tightly abuts against the sealing rod 42, and the sealing rod 42 blocks the sealing hole 41, completely isolating the inflation channel 24 from the airbag. At this time, even if the air pump is in standby mode, gas cannot enter the airbag, preventing the clamping block 22 from shifting due to premature inflation of the airbag, which could cause misalignment of the alloy tube joint end (especially for large-diameter thin-walled tubes, where even slight misalignment can affect welding accuracy).

[0051] Reference Figure 8 The middle of both sides of the air bladder cavity 23 is convex, and one side of the air bladder cavity 23 is W-shaped.

[0052] Specifically, the raised structures in the middle of both sides of the airbag cavity 23 can form a physical barrier. When the airbag inflates, it will be blocked by the raised parts, forcing the airbag to expand only towards the side closer to the alloy tube (i.e., the clamping direction). This avoids the airbag expanding to both sides, which would result in insufficient clamping force. It ensures that the inflation pressure is concentrated on the tube wall, which is suitable for the "precise clamping" requirements of large-diameter tubes. The concave part of the W-shaped structure can form a "gas accumulation area". When inflated, the gas first fills the concave part of the W-shaped structure, and then gradually diffuses towards the tube wall along the W-shaped curved surface. This avoids excessive local expansion of the airbag (such as corner protrusions) and ensures that the airbag and the tube wall have a "uniform arc-shaped surface contact" rather than point or line contact. This optimizes the expansion path and further reduces the risk of local pressure deformation of thin-walled tubes.

[0053] Reference Figures 4-6 The drive component 5 includes a small motor (not shown) installed inside the clamping seat 13, a rotating shaft 51 fixedly connected to one side of the output shaft of the small motor, a drive bevel gear fixedly connected to one end of the rotating shaft 51, several driven bevel gears meshing with one side of the drive bevel gear, a lead screw 52 fixedly connected to one end of the driven bevel gear, a moving block 21 threadedly connected to the lead screw 52, ​​and the lead screw 52 is limited in the moving groove 14. The outer end of the lead screw 52 is fixedly connected to an anti-detachment plate 53 to prevent the moving block 21 from falling off.

[0054] Specifically, a small motor drives the rotating shaft 51 to rotate, which causes the driving bevel gear to drive several driven bevel gears to rotate, thereby driving the lead screw 52 to rotate, so that the moving block 21 moves synchronously on the lead screw 52 to achieve the clamping function.

[0055] Reference Figures 5-7The inflation port of the inflation channel 24 is located on one side of the moving block 21. An inflation tube is fixedly connected to the inflation port. A strip groove 6 for the inflation tube to move is opened on one side of the top of the moving groove 14. An air pump connected to the inflation tube is provided inside the clamping seat 13 (neither the inflation tube nor the air pump is shown; it can be set at the corresponding position inside the clamping seat 13).

[0056] Specifically, when the movable block 21 moves, the inflation tube connected to the inflation port moves along with it within the strip groove 6, and the inflation tube is long enough to avoid affecting the movement of the movable block 21. The rest of the structure is the same as that in Embodiment 1.

[0057] Based on embodiments 1-2, the working principle of this invention is as follows: When the laser welding device is working, the two alloy tubes to be welded are first welded together and positioned, and then placed on the support component 11 (composed of a support plate with rollers) of the welding table 1, relying on the rollers to achieve rotational support of the tube body. After startup, the small motor of the drive component 5 in the clamping seat 13 drives the rotating shaft 51 and the drive bevel gear to rotate, and drives the lead screw 52 to rotate through the meshing driven bevel gear, so that the moving block 21 in the moving groove 14 synchronously drives the clamping block 22 to move closer to the alloy tube. When the clamping block 22 touches the inner or outer wall of the alloy tube, the trigger rod 305 of the auxiliary component 3 is squeezed and moves along the sliding hole 304, causing the sealing ring 306 to disengage from the sealing rod 42 of the sealing component; the connecting spring 44 resets and pushes the sealing rod 42 out of the sealing hole 41, so that the inflation channel 24 is connected to the airbag. At the same time, the trigger rod 305 drives the arc-shaped moving plate 302 to slide along the limiting groove 301 through the arc-shaped pushing strip 309 (adapted to the arc-shaped groove 312 of the trigger rod 305), so that the squeezing block 303 fits against the tube body. Then the air pump in the clamping seat 13 supplies air to the airbag cavity 23 through the inflation tube (moving along the strip groove 6). The protrusions on both sides of the airbag cavity 23 restrict the lateral expansion of the airbag, and the W-shaped side guides the airbag to expand directionally towards the tube body, forming a bidirectional pressure-controlled clamping with the moving plate 302 to avoid thin-wall deformation. Then the rotating motor 12 drives the clamping seat 13 and the alloy tube to rotate at a uniform speed, and the laser welding gun completes the full circle welding at the joint of the tube body. After welding, the air pump releases air to contract the airbag, the small motor reverses to reset the clamping components, the extrusion block 303 detaches from the tube, and finally the welded alloy tube is removed, completing one operation.

[0058] Example 3, referring to Figures 1-12 The third embodiment of the present invention provides a laser welding process for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes, comprising the following steps:

[0059] S1: First, spot weld the two alloy tubes together to position them, then place the two alloy tubes to be welded on top of the support assembly 11 and adjust the welding gun to the appropriate welding operation range.

[0060] S2: Start the clamping drive, turn on the small motor in the clamping seat 13, and drive the bevel gear and driven bevel gear to make the lead screw 52 rotate, which drives the moving block 21 to move along the moving groove 14 until the clamping block 22 is close to the inner wall or outer wall of the alloy tube.

[0061] S3: The inner or outer wall of the alloy tube pushes the trigger rod 305 to slide, and the sealing ring 306 disengages from the compression sealing rod 42. At this time, the inflation channel 24 is opened, and the air pump inflates the airbag through the inflation channel 24. At the same time, the push ring 308 compresses the reset spring 307, causing the arc-shaped push bar 309 on the corresponding side to drive the moving plate 302 to move, and compress and seal one side of the airbag.

[0062] S4: The airbag on the other side can be quickly inflated and expanded, expanding towards the alloy tube in the airbag cavity 23, clamping the inner or outer wall of the alloy tube.

[0063] S5: Start the rotating motor 12 to drive the clamping seat 13 and the alloy tube to rotate at a uniform speed, and simultaneously turn on the laser welding gun to continuously weld the joint until the whole circle is completed.

[0064] S6: Reset and remove parts, turn off the laser welding gun and rotate the motor 12, release air from the air pump to cause the airbag to contract, reverse the small motor to drive the clamping parts to reset, and the extrusion block 303 will detach from the inner or outer wall to remove the welded alloy tube.

[0065] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A laser welding apparatus for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes, comprising a body, a welding table (1) disposed on one side of the body, a support assembly (11) disposed on the welding table (1) for support, two alloy tubes for welding disposed on the top of the support assembly (11), a laser welding gun disposed on the welding table (1) and located on one side of the alloy tubes, a rotary motor (12) disposed on one side of the body, and a clamping seat (13) disposed on one side of the output shaft of the rotary motor (12), characterized in that, It also includes a clamping unit disposed on the clamping base (13); The clamping unit includes a plurality of movable slots (14) evenly opened on one side of the clamping seat (13), clamping components respectively disposed in the movable slots (14), and a driving component (5) disposed inside the clamping seat (13) for driving the clamping components to move and clamp. The clamping component includes a clamping assembly (2) disposed on the driving component (5) and an auxiliary assembly (3) disposed inside the clamping assembly (2); the clamping assembly (2) includes a moving block (21) disposed in the moving groove (14), a clamping block (22) disposed on the top of the moving block (21), airbag cavities (23) symmetrically opened on both sides of the clamping block (22), an airbag disposed on one side of the inner wall of the airbag cavity (23), and an inflation channel (24) opened inside the moving block (21) for connecting the airbag; The auxiliary component (3) includes a limiting groove (301) symmetrically opened inside the movable block (21) near the side, two symmetrically distributed movable plates (302) set in the limiting groove (301), the movable plates (302) are arc-shaped, a pressing block (303) is set on one side of the movable plate (302), a sliding hole (304) is opened through the middle of the entire movable plate (302), and a trigger rod (305) is set in the sliding hole (304).

2. The laser welding apparatus for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes according to claim 1, characterized in that, The auxiliary component (3) also includes a sealing ring (306) disposed in the middle of the trigger rod (305), a return spring (307) disposed on one side of the sealing ring (306), a push ring (308) disposed on one side of the return spring (307), and the push ring (308) is sleeved on the trigger rod (305). Push bars (309) are symmetrically disposed on both sides of one end of the push ring (308), and one end of the push bars (309) is respectively hinged to the middle of the moving plate (302). A movable groove (310) is symmetrically opened inside the push ring (308), and a drive block (311) is disposed in the sliding groove. The drive block (311) abuts against the side of the sliding groove away from the spring.

3. The laser welding apparatus for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes according to claim 2, characterized in that, The push bar (309) is arc-shaped, and the trigger rod (305) has an arc-shaped groove (312) that fits and abuts against one side of the push bar (309).

4. The laser welding apparatus for processing large-diameter thin-walled low-thermal-expansion alloy tubes according to claim 1, characterized in that, The clamping block (22) is slidably connected to both ends of the trigger rod (305).

5. The laser welding apparatus for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes according to claim 1, characterized in that, A sealing component is also provided in the middle of the sliding hole (304). In the initial state, the sealing ring (306) abuts against the sealing component (4). The sealing component (4) includes a closed hole (41) opened in the middle of the sliding hole (304) and connected to the air passage (24), a sealing rod (42) set in the closed hole (41), a baffle (43) set at one end of the sealing rod (42), a connecting spring (44) set on one side of the baffle (43), and a mounting groove opened on one side of the closed hole (41). One end of the connecting spring (44) is fixedly connected to one side of the mounting groove, and the connecting spring (44) is sleeved on the sealing rod (42).

6. The laser welding apparatus for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes according to claim 1, characterized in that, The air bladder cavity (23) has convex sides in the middle, and one side of the air bladder cavity (23) is W-shaped.

7. The laser welding apparatus for processing large-diameter thin-walled low-thermal-expansion alloy tubes according to claim 1, characterized in that, The drive component (5) includes a small motor disposed inside the clamping seat (13), a rotating shaft (51) disposed on one side of the output shaft of the small motor, a drive bevel gear disposed at one end of the rotating shaft (51), a plurality of driven bevel gears disposed on one side of the drive bevel gear, a lead screw (52) disposed at one end of the driven bevel gear, a moving block (21) being threadedly connected to the lead screw (52), and the lead screw (52) being limited in the moving groove (14), and an anti-detachment plate (53) being provided at the outer end of the lead screw (52) to prevent the moving block (21) from falling off.

8. The laser welding apparatus for processing large-diameter, thin-walled, low-thermal-expansion alloy tubes according to claim 1, characterized in that, The inflation port of the inflation channel (24) is located on one side of the moving block (21), and an inflation pipe is provided at the inflation port. A strip groove (6) for the inflation pipe to move is opened on one side of the top of the moving groove (14), and an air pump connected to the inflation pipe is provided inside the clamping seat (13).

9. A laser welding process for processing large-diameter thin-walled low-thermal-expansion alloy tubes, comprising using the laser welding apparatus for processing large-diameter thin-walled low-thermal-expansion alloy tubes as described in any one of claims 2-8, characterized in that, Includes the following steps: S1: First, spot weld the two alloy pipes together to position them, then place the two alloy pipes to be welded on top of the support assembly (11) and adjust the welding gun to the appropriate welding operation range. S2: Start the clamping drive, turn on the small motor in the clamping seat (13), drive the bevel gear and driven bevel gear to make the lead screw (52) rotate, drive the moving block (21) to move along the moving groove (14) until the clamping block (22) is close to the inner wall or outer wall of the alloy tube; S3: The inner or outer wall of the alloy tube pushes the trigger rod (305) to slide, and the sealing ring (306) disengages from the compression sealing rod (42). At this time, the inflation channel (24) is opened, and the air pump inflates the airbag through the inflation channel (24). At the same time, the push ring (308) compresses the reset spring (307), causing the arc-shaped push bar (309) on the corresponding side to drive the moving plate (302) to move, and to compress and seal one side of the airbag. S4: The airbag on the other side can be rapidly inflated and expanded, expanding towards the alloy tube in the airbag cavity (23), clamping the inner or outer wall of the alloy tube. S5: Start the rotating motor (12) to drive the clamping seat (13) and alloy tube to rotate at a constant speed, and simultaneously turn on the laser welding gun to continuously weld the joint until the whole circle is completed; S6: Reset and remove parts, turn off the laser welding gun and the rotating motor (12), release air from the air pump to make the airbag contract, reverse the small motor to drive the clamping parts to reset, the extrusion block (303) detaches from the inner or outer wall, and remove the welded alloy tube.

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