Tube sheet connecting friction stir welding device and tube sheet connecting method

Abstract

The application relates to the technical field of friction stir welding, in particular to a pipe plate connecting friction stir welding device and a pipe plate connecting method, which comprises a machine table, a clamping bearing assembly arranged on the machine table, a lifting table slidingly installed on the machine table, a lifting assembly arranged on the lifting table, a fixing plate connected to the lifting assembly, a rotating rod rotatably installed on the fixing plate, a connecting locking mechanism arranged on the rotating rod, a shaft shoulder connected to the connecting locking mechanism, a stirring needle slidingly installed on the shaft shoulder, and a limiting mechanism arranged on the connecting locking mechanism and connected to the stirring needle. Through cooperation of the connecting locking mechanism and the limiting mechanism, the shaft shoulder and the stirring needle can be positioned when the inner diameter of the required welding pipe changes, so that the required specification shaft shoulder and the stirring needle can be quickly replaced.

Description

Technical Field

[0001] This invention relates to the field of friction stir welding technology, specifically a friction stir welding apparatus and method for tube sheet connection. Background Technology

[0002] Tube sheet welding is a core process in the manufacturing of equipment such as boilers, heat exchangers, and pressure vessels, and its quality directly determines the pressure-bearing capacity and sealing performance of the equipment.

[0003] Currently, tube sheet connections mainly involve several methods, including expansion joints, welding, and a combination of expansion and welding. Due to the large thermal stress and deformation generated by the dense weld seams, problems such as incomplete fusion, incomplete penetration, porosity, and cracks are prone to occur when welding using these methods. This leads to poor sealing performance and short service life during subsequent use.

[0004] Therefore, tube sheet can be connected by friction stir welding. Through frictional heat and mechanical stirring, the material is plasticized without melting, thus forming a dense solid-phase bond.

[0005] Because the required tube sheet dimensions vary, if the inner diameter of the tube changes, the shoulder and the agitator need to be replaced to prevent the agitator from being too large and making hard contact with the tube, causing tube deformation, or the agitator from being too small and causing incomplete welding. However, to ensure welding stability, the agitator and the shoulder are usually bolted and hydraulically locked, which makes it difficult to disassemble and replace the agitator and the shoulder. Furthermore, during installation, the agitator and the shoulder cannot be quickly centered, requiring frequent centering and pre-tightening operations, which in turn affects the progress of subsequent tube sheet welding. Summary of the Invention

[0006] The purpose of this invention is to provide a tube sheet connection friction stir welding device and tube sheet connection method to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A tube sheet connection friction stir welding apparatus, comprising:

[0009] The machine base and the clamping and bearing components set on the machine base. A lifting platform is slidably installed on the machine base. A lifting component is set on the lifting platform. A fixed plate is connected to the lifting component.

[0010] Also includes:

[0011] A rotating rod is rotatably mounted on the fixed plate. A connecting locking mechanism is provided on the rotating rod. A shoulder is connected to the connecting locking mechanism. A stirring needle is slidably mounted on the shoulder.

[0012] A limiting mechanism is provided on the connecting locking mechanism and connected to the stirring needle. The connecting locking mechanism can limit the shoulder and connect the stirring needle to the rotating rod through the limiting mechanism.

[0013] As a further embodiment of the present invention: the connecting locking mechanism includes a limiting disk that slides along the axial direction of the rotating rod, a limiting block is fixed at the end of the rotating rod, and a limiting groove that cooperates with the limiting block is formed on the limiting disk;

[0014] It also includes a fitting assembly and a driven assembly disposed on the limiting plate and connected to the rotating rod.

[0015] As a further embodiment of the present invention: the fitting assembly includes a connecting plate fixed on the rotating rod, and symmetrically arranged guide posts are slidably mounted on the connecting plate. A first fixing ring and a second fixing ring are fixed on the guide posts. The first fixing ring abuts against the connecting plate, and the second fixing ring abuts against the limiting plate. The limiting plate has a limiting hole that slides and fits with the guide posts.

[0016] As a further embodiment of the present invention: the driven component includes a support rod fixed on the limiting plate, a connecting plate fixed to the end of the support rod, and the connecting plate being fixedly connected to the shoulder.

[0017] As a further embodiment of the present invention: the limiting mechanism includes a limiting ring fixed on the support rod, and a follower plate that is slidably connected to the support rod is fixed on the stirring needle, and the follower plate abuts against the limiting ring.

[0018] As a further embodiment of the present invention: the limiting mechanism further includes a through groove and a slot formed at the end of the rotating rod, and the end of the stirring needle is fixed with a protrusion that engages with the through groove and the slot.

[0019] As a further embodiment of the present invention: the clamping and bearing assembly includes a bidirectional translation module disposed on the machine base, and the bidirectional translation module is connected to movable plates arranged symmetrically.

[0020] As a further embodiment of the present invention: the clamping and bearing assembly further includes a clamping plate fixed on the movable plate, and a receiving plate is fixed on the clamping plate.

[0021] As a further embodiment of the present invention: the lifting assembly includes a linear drive module disposed on the lifting platform, a sliding plate connected to the linear drive module, and the sliding plate being fixedly connected to the fixed plate.

[0022] A tube sheet connection method includes the following steps:

[0023] Step 1: Clamp the tube sheet using the clamping support assembly;

[0024] Step 2: Connect the shaft shoulder to the rotating rod through the connecting locking mechanism, and connect the stirring needle to the rotating rod through the limiting mechanism;

[0025] Step 3: The rotating rod drives the shaft shoulder and stirring needle to rotate through the connecting locking mechanism;

[0026] Step 4: The lifting assembly drives the fixed plate to move, and drives the shoulder and stirring needle to move towards the tube sheet via the rotating rod. When the shoulder is in contact with the plate and the stirring needle enters the tube, friction stir welding is performed on the tube sheet.

[0027] Step 5: After welding is completed, the lifting assembly control shoulder and stirring pin are reset.

[0028] Compared with the prior art, the beneficial effects of the present invention are: when the limiting groove passes through the limiting block, the present invention can control the guide post to perform the yielding action first, and when the limiting plate rotates 90°, control the limiting hole to move to the position to cooperate with the guide post. Under the cooperation of the guide post and the limiting hole, and the axial limiting effect of the limiting block on the limiting plate, it can ensure that the limiting plate will not detach from the rotating rod and will always rotate synchronously with the rotating rod, thereby completing the installation of the shaft shoulder;

[0029] When the limiting plate controls the limiting groove to pass through the limiting block, it can also drive the protrusion to pass through the through groove and enter the slot through the limiting mechanism. When the limiting plate rotates, it synchronously controls the protrusion to fit into the slot, thereby realizing the locking of the position of the stirring needle while limiting the shoulder. This allows the stirring needle to rotate synchronously with the rotating rod and keep its position relative to the rotating rod. In this way, by controlling the limiting plate to fit into the rotating rod and rotate it, the installation of the shoulder and the stirring needle can be completed.

[0030] By combining the first and second springs, when the shoulder is in contact with the plate surface, the compression of the first spring provides a certain downward pressure to the plate to ensure welding stability. The compression of the second spring controls the vertical misalignment between the shoulder and the stirring needle, allowing the stirring needle to be smoothly inserted into the pipe to the specified depth, thus ensuring the best welding effect. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of one embodiment of a friction stir welding apparatus for tube sheet connection.

[0032] Figure 2 This is a structural schematic diagram from another angle in one embodiment of the friction stir welding device for tube sheet connection.

[0033] Figure 3This is a schematic diagram showing the connection relationship between the lifting assembly, part of the connection locking mechanism, and part of the limiting mechanism in one embodiment of the tube sheet connection friction stir welding device.

[0034] Figure 4 for Figure 3 A magnified schematic diagram of the structure at point A in the middle.

[0035] Figure 5 This is a schematic diagram of the structure of a tube sheet connection friction stir welding device, including a locking mechanism, a partial limiting mechanism, a shoulder, and a stirring needle.

[0036] Figure 6 This is a schematic diagram of the clamping and bearing component in one embodiment of a friction stir welding device for tube sheet connection.

[0037] Figure 7 This is a schematic diagram of a portion of the clamping and bearing components in one embodiment of a friction stir welding apparatus for tube sheet connection.

[0038] Figure 8 This is a schematic diagram of a partial connection locking mechanism in one embodiment of a friction stir welding device for tube sheet connection.

[0039] Figure 9 This is a schematic diagram of a portion of the connection locking mechanism and a portion of the limiting mechanism in one embodiment of a tube sheet connection friction stir welding device.

[0040] Figure 10 This is an exploded structural diagram of part of the connection locking mechanism and part of the limiting mechanism in one embodiment of the tube sheet connection friction stir welding device.

[0041] Figure 11 This is a schematic diagram of the rotating rod, a partial connecting locking mechanism, and a slot in one embodiment of a tube sheet connection friction stir welding device.

[0042] Figure 12 This is an exploded structural diagram of a portion of the connection locking mechanism in one embodiment of a friction stir welding apparatus for tube sheet connection.

[0043] Figure 13 This is a schematic diagram of the structure of the stirring pin and the shoulder in an embodiment of a friction stir welding device for connecting tube sheets.

[0044] Figure 14 This is a schematic diagram of the structure of the stirring pin and the shoulder in the friction stir welding device for tube sheet connection, as shown in Embodiment 2.

[0045] Figure 15 This is a schematic diagram of the structure of the stirring pin and the shoulder in Embodiment 3 of a friction stir welding device for connecting tube sheets.

[0046] Figure 16This is a schematic diagram of the structure of the stirring pin and the shoulder in the friction stir welding device for tube sheet connection, as shown in Embodiment 4.

[0047] In the diagram: 1. Machine base; 2. Lifting platform; 3. Linear drive module; 4. Sliding plate; 5. Fixed plate; 6. Bidirectional translation module; 7. Movable plate; 8. Card plate; 9. Receiving plate; 10. Drive source; 11. Rotating rod; 1101. Through groove; 1102. Card slot; 12. Limiting block; 13. Connecting plate; 14. Guide column; 1401. First fixing ring; 1402. Second fixing ring; 15. First spring; 16. Limiting plate; 1601. Limiting groove; 1602. Limiting hole; 17. Support rod; 1701. Limiting ring; 18. Connecting plate; 19. Shoulder; 20. Stirring needle; 21. Follower plate; 22. Second spring; 23. Protrusion block. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] Furthermore, elements in this invention are referred to as being "fixed to" or "set on" another element, which may be directly on the other element or may also include an intervening element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or may also include an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementations.

[0050] Please see Figures 1-13 In this embodiment of the invention, a tube sheet connection friction stir welding apparatus includes:

[0051] Machine base 1, and clamping and bearing components set on machine base 1, lifting platform 2 is slidably installed on machine base 1, lifting components are set on lifting platform 2, and fixed plate 5 is connected to lifting components;

[0052] Also includes:

[0053] A rotating rod 11 is rotatably mounted on the fixed plate 5. A connecting locking mechanism is provided on the rotating rod 11. A shoulder 19 is connected to the connecting locking mechanism. A stirring needle 20 is slidably mounted on the shoulder 19.

[0054] A limiting mechanism is provided on the connecting locking mechanism and connected to the stirring needle 20. The connecting locking mechanism can limit the shoulder 19 and connect the stirring needle 20 to the rotating rod 11 through the limiting mechanism.

[0055] Specifically, when performing friction stir welding on the tube sheet, the size of the stirring pin 20 needs to be adjusted according to the inner diameter of the tube to be welded. To this end, after selecting the corresponding stirring pin 20 and shoulder 19, the shoulder 19 can be connected to the rotating rod 11 via a locking mechanism, allowing the shoulder 19 to rotate synchronously with the rotating rod 11. Simultaneously, under the action of a limiting mechanism, the stirring pin 20 is connected to the rotating rod 11, enabling the stirring pin 20 to rotate and move synchronously with the rotating rod 11. After the shoulder 19 and stirring pin 20 are assembled, the tube and plate are fixed under the action of the clamping and bearing assembly. Meanwhile, the rotating rod 11 can drive the shoulder 19 and stirring pin 20 to rotate synchronously through the locking and limiting mechanisms. Under the action of the lifting assembly, the fixed plate 5 is controlled to move vertically, thereby moving the shoulder 19 and stirring pin 20. When the shoulder 19 is in contact with the plate and the stirring pin 20 enters the tube, the tube sheet undergoes friction stir welding under the action of the stirring pin 20 and shoulder 19.

[0056] Please see Figures 1-3 The lifting assembly includes a linear drive module 3 mounted on the lifting platform 2, a sliding plate 4 connected to the linear drive module 3, and the sliding plate 4 being fixedly connected to the fixed plate 5.

[0057] It should be noted that a drive source 10 is fixed on the fixed plate 5. The drive source 10 can be a drive motor, which is used to drive the rotating rod 11 to rotate. The linear drive module 3 is composed of a one-way lead screw, a motor, a first threaded sleeve, and a linear guide rail. The one-way lead screw is connected to the output shaft of the motor, the first threaded sleeve is threadedly connected to the one-way lead screw, and the sliding plate 4 is fixedly connected to the first threaded sleeve and slidably connected to the linear guide rail.

[0058] When friction welding is required on the tube sheet, the motor operates and drives the one-way screw to rotate, thereby driving the sliding plate 4 to move through the first threaded sleeve. The sliding plate 4 will slide along the linear guide rail. Under the action of the linear guide rail and the sliding plate 4, the first threaded sleeve slides along the axial direction of the one-way screw and will not rotate with the one-way screw. The sliding plate 4 will also drive the fixed plate 5 to move towards the machine base 1, so as to adjust the height of the shoulder 19 and the stirring needle 20 by rotating the rod 11.

[0059] Please see Figures 1-5 , Figures 8-12The connecting locking mechanism includes a limiting disk 16 that slides axially along the rotating rod 11, a limiting block 12 fixed at the end of the rotating rod 11, and a limiting groove 1601 formed on the limiting disk 16 to cooperate with the limiting block 12; it also includes a fitting assembly and a driven assembly disposed on the limiting disk 16 and connected to the rotating rod 11, the fitting assembly including a connecting plate 13 fixed on the rotating rod 11, and guide posts 14 symmetrically arranged and slidably mounted on the connecting plate 13. A first fixing ring 1401 and a second fixing ring 1402 are fixed on the column 14. The first fixing ring 1401 abuts against the connecting plate 13, and the second fixing ring 1402 abuts against the limiting plate 16. The limiting plate 16 has a limiting hole 1602 that slides and fits into the guide column 14. The driven component includes a support rod 17 fixed on the limiting plate 16. A connecting plate 18 is fixed to the end of the support rod 17. The connecting plate 18 is fixedly connected to the shoulder 19.

[0060] Please see Figures 1-5 , Figures 8-12 The limiting mechanism includes a limiting ring 1701 fixed on the support rod 17, a follower plate 21 slidably connected to the support rod 17 fixed on the stirring needle 20, the follower plate 21 abutting against the limiting ring 1701, the limiting mechanism also includes a through groove 1101 and a slot 1102 formed at the end of the rotating rod 11, and a protrusion 23 fixed at the end of the stirring needle 20 that fits into the through groove 1101 and the slot 1102.

[0061] Please see Figure 8 In detail, when performing friction stir welding on the tube sheet, the corresponding stirring pin 20 and shoulder 19 need to be selected according to the inner diameter of the tube. In the initial state, the shoulder 19 and stirring pin 20 are not yet assembled. At this time, the guide post 14 is located at the end of the stroke away from the fixed plate 5. Under the action of the guide post 14, the first fixed ring 1401 and the connecting plate 13 are in abutting state, the distance between the second fixed ring 1402 and the connecting plate 13 is the largest, and the elongation of the first spring 15 in its natural state is greater than the maximum distance between the second fixed ring 1402 and the connecting plate 13. Therefore, the first spring 15 is in a pre-compressed state and provides the second fixed ring 1402 with a thrust towards the guide post 14 in the direction away from the fixed plate 5.

[0062] Please see Figure 9Meanwhile, the follower plate 21 and the limiting ring 1701 are in contact, making the distance between the follower plate 21 and the connecting plate 18 the largest. The extension of the second spring 22 in its natural state is greater than the maximum distance between the follower plate 21 and the connecting plate 18. Therefore, the second spring 22 is also in a pre-compressed state and always provides the follower plate 21 with a thrust in the direction away from the connecting plate 18. At this time, the distance between the stirring needle 20 and the limiting plate 16 is the smallest.

[0063] The through groove 1101 is formed with specifications and dimensions comparable to the protrusion 23, allowing the protrusion 23 to pass smoothly through the through groove 1101. The slot 1102 is formed by rotating the protrusion 23 90° around the rotation center of the stirring needle 20. The end face of the limiting block 12 away from the rotating rod 11 is set in a tapered shape. The specifications and dimensions of the limiting groove 1601 are comparable to the dimensions formed by combining the maximum end faces of the rotating rod 11 and the limiting block 12. That is, when the limiting groove 1601 passes through the limiting block 12, the limiting block 12 has a foolproof effect, which can ensure that the limiting groove 1601 passes smoothly. Therefore, when the limiting plate 16 is fitted on the rotating rod 11, it can pass smoothly through the limiting groove 1601 and the limiting block 12.

[0064] Please see Figure 5 When it is necessary to assemble the shoulder 19 and the stirring needle 20, the limiting plate 16 can be manually controlled to be fitted onto the rotating rod 11, and the limiting groove 1601 can be controlled to pass through the limiting block 12. At the same time, under the action of the second spring 22, the stirring needle 20 moves synchronously with the limiting plate 16, so as to drive the protrusion 23 to be inserted into the through groove 1101 and the slot 1102. If the limiting groove 1601 needs to pass through the limiting block 12, the limiting hole 1602 and the guide post 14 need to be in a misaligned state. Therefore, when the limiting plate 16 moves, it will abut against the guide post 14 and push the guide post 14 to move towards the fixing plate 5, so that the first fixing ring 1401 separates from the connecting plate 13 and compresses the first spring 15.

[0065] When the limiting groove 1601 completely passes through the limiting block 12, the controllable limiting disk 16 rotates around the rotating rod 11, causing the limiting groove 1601 and the limiting block 12 to be misaligned. The limiting disk 16 also drives the limiting hole 1602 to move in the direction of engaging with the guide post 14. When the limiting disk 16 rotates 90°, the limiting hole 1602 moves to the position of engaging with the guide post 14. At this time, the first spring 15 is released elastically and pushes the guide post 14 into the limiting hole 1602 through the second fixing ring 1402. Within 602, until the second fixing ring 1402 abuts against the surface of the limiting plate 16, under the action of the guide post 14 and the limiting hole 1602, the limiting plate 16 can rotate synchronously with the rotating rod 11. At the same time, since the limiting groove 1601 and the limiting block 12 are in a misaligned state, under the action of the limiting block 12, it is ensured that the limiting plate 16 will not detach from the rotating rod 11. In this way, the limiting plate 16 is restricted on the rotating rod 11, thereby completing the assembly of the shoulder 19 through the support rod 17 and the connecting plate 18.

[0066] During this process, when the limiting groove 1601 passes the limiting block 12, it means that the protruding block 23 has completely passed through the through groove 1101 and abuts against the inner wall of the slot 1102. Since the depth of the slot 1102 in the axial direction of the rotating rod 11 is equivalent to the size of the protruding block 23 in the axial direction of the rotating rod 11, when the limiting plate 16 rotates around the rotating rod 11, the limiting plate 16 will drive the follower plate 21 to move synchronously through the support rod 17, thereby driving the stirring needle 20 to rotate synchronously with the limiting plate 16. The stirring needle 20 will also drive the protruding block 23 to move, causing the protruding block 23 to be misaligned with the through groove 1101.

[0067] When the limiting plate 16 rotates 90°, the installation of the shoulder 19 is completed. The protrusion 23 also rotates to the position of the maximum arc side wall of the slot 1102 and abuts against the side wall of the slot 1102. The upper and lower sides of the protrusion 23 will fit against the upper and lower inner walls of the through groove 1101 and the slot 1102. In this way, the protrusion 23 is completely restricted in the slot 1102 and there will be no axial displacement between it and the rotating rod 11. When the rotating rod 11 rotates, it can drive the protrusion 23 to rotate synchronously through the side wall of the slot 1102, thereby driving the stirring needle 20 to rotate synchronously.

[0068] At this time, friction stir welding can be performed on the tube sheet. Driven by the drive source 10, the rotating rod 11 is controlled to rotate, thereby driving the shoulder 19 and the stirring needle 20 to rotate synchronously. At the same time, under the action of the lifting component, the fixed plate 5 is controlled to move towards the machine platform 1, so as to drive the shoulder 19 and the stirring needle 20 to move in the vertical direction. When the shoulder 19 is in contact with the plate, the stirring needle 20 is inserted into the tube. At this time, the lifting component continues to move. Since the shoulder 19 is already in contact with the plate, the shoulder 19 and the guide column 14 no longer move. The rotating rod 11 will compress the first spring 15 through the connecting plate 13, so that the shoulder 19 provides a certain downward pressure to the plate. At the same time, the rotating rod 11 drives the stirring needle 20 to continue to insert into the tube through the slot 1102 and the protrusion 23. Under the action of the stirring needle 20, the follower plate 21 is driven to slide along the support rod 17 and move away from the limit plate 16 to compress the second spring 22.

[0069] Once the stirring pin 20 reaches the required depth, the lifting assembly stops moving. Under the action of the stirring pin 20 and the shoulder 19, the tube sheet undergoes friction stir welding. After the stirring pin 20 stays for a certain period of time, the tube sheet welding is completed. At this time, under the action of the lifting assembly, the stirring pin 20 is controlled to detach from the tube, and the shoulder 19 is controlled to separate from the plate. The above steps are repeated to complete the welding of tube sheets of the same size.

[0070] If the size of the tube sheet to be welded changes, i.e. the inner diameter of the tube changes, in order to prevent the stirring pin 20 from being too large, causing deformation of the tube during welding, or the stirring pin 20 from being too small, causing the tube to be unable to be friction welded, it is necessary to disassemble and replace the stirring pin 20 and the shoulder 19. For this purpose, the guide column 14 can be manually driven to move away from the limiting plate 16 until the guide column 14 is separated from the limiting hole 1602. Then, the limiting plate 16 is rotated so that the limiting hole 1602 is misaligned with the guide column 14. When the limiting plate 16 rotates 90°, the limiting groove 1601 just moves to the position that matches the limiting block 12. At this time, the first spring 15 is released elastically and pushes the limiting plate 16 away from the rotating rod 11 through the guide column 14.

[0071] During this process, when the limiting plate 16 rotates, it will also drive the stirring needle 20 to rotate through the support rod 17 and the follower plate 21, thereby driving the protrusion 23 to move. When the limiting plate 16 rotates 90°, the protrusion 23 also rotates 90° and just moves to the position that matches the through groove 1101. Therefore, when the limiting plate 16 disengages from the rotating rod 11, the protrusion 23 also disengages from the through groove 1101. In this way, the disassembly of the shoulder 19 and the stirring needle 20 can be completed simply and quickly.

[0072] Please see Figure 1 , Figure 2 , Figure 6 , Figure 7 The clamping and bearing assembly includes a bidirectional translation module 6 disposed on the machine base 1, and a symmetrically arranged movable plate 7 connected to the bidirectional translation module 6. The clamping and bearing assembly also includes a clamping plate 8 fixed on the movable plate 7, and a receiving plate 9 fixed on the clamping plate 8.

[0073] Furthermore, the bidirectional translation module 6 is composed of a bidirectional lead screw, a motor, a guide rod, a second threaded sleeve, and a guide sleeve. The bidirectional lead screw is connected to the output shaft of the motor. The second threaded sleeves are symmetrically arranged and threadedly connected to the bidirectional lead screw. The guide sleeve and the second threaded sleeve are fixedly connected to the movable plate 7. A groove is formed on the receiving plate 9, and a bolt is slidably installed in the groove. The bolt can slide along the groove according to the size of the plate to clamp and fix the edge of the plate.

[0074] When friction stir welding is required on the pipe, the motor drives the bidirectional lead screw to rotate, which in turn drives the two second threaded sleeves to move. The second threaded sleeves will drive the movable plate 7 to move, so that the guide sleeve slides along the axial direction of the guide rod. The guide sleeve and the guide rod have a guiding function, which can ensure that the second threaded sleeve slides along the axial direction of the bidirectional lead screw and will not follow the rotation of the bidirectional lead screw. The two movable plates 7 will also drive the two clamping plates 8 and the receiving plate 9 to move towards each other until the clamping plate 8 performs a clamping action on the pipe. At this time, the plate can be placed on the receiving plate 9 and the connecting hole on the plate can be fitted onto the pipe. The plate is fixed by the bolts. When the pipe and plate are clamped and fixed, the friction stir welding can be performed on the pipe and plate through the shoulder 19 and the stirring needle 20. Example

[0075] Please see Figure 14 The stirring needle 20 has a threaded section. By adding the threaded section, deformation at the tube sheet connection hole can be prevented during the stirring welding process. Example

[0076] Please see Figure 15 The diameter of the contact point between the stirring pin 20 and the inner wall of the tube is larger than the diameter of other positions of the stirring pin 20. During the stirring welding process, the shoulder 19 moves downward and the stirring pin 20 moves upward to achieve the stirring welding process. Example

[0077] Please see Figure 16 An extension ring is formed on the stirring pin 20, and an annular groove is formed on the inner side of the shoulder 19. The extension ring is placed in the annular groove. During the stirring welding process, the shoulder 19 moves downward and the stirring pin 20 moves upward to achieve the stirring welding process.

[0078] A tube sheet connection method includes the following steps:

[0079] Step 1: Select the stirring head (including shoulder 19 and stirring pin 20) according to the tube sheet size. The size of shoulder 19 is φ10-φ38, and the size of stirring pin 20 is φ2-φ34.

[0080] Step 2: Connect the shoulder 19 to the rotating rod 11 through the connecting locking mechanism, and connect the stirring needle 20 to the rotating rod 11 through the limiting mechanism;

[0081] Step 3: The rotating rod 11 drives the shoulder 19 and the stirring needle 20 to rotate through the connecting locking mechanism, with a rotation speed of 300rpm~3000rpm;

[0082] Step 4: Then move the stirring head downwards at a speed of 10-100 mm / min;

[0083] Step 5: Once the stirring head contacts the part to be welded, stop moving downwards and hold for 2-30 seconds;

[0084] Step Six: After the pause, lift the stirring head upwards, then stop rotating to finish welding.

[0085] One exemplary implementation:

[0086] The parts are made by welding 2mm aluminum plates and aluminum tubes with an outer diameter of φ20mm and an inner diameter of φ16mm.

[0087] The diameter of the stirring needle shoulder 19 is set to φ25mm, and the diameter of the stirring needle 20 is set to φ15mm.

[0088] Align the stirring head with the center of the aluminum tube, set the stirring head speed to 1200 rpm, and the downward thrust speed to 20 mm / min.

[0089] The stirring head is lowered until it is flush with the aluminum plate, held for 10 seconds, and then lifted at a speed of 20 mm / min.

[0090] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0091] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A tube sheet connection friction stir welding apparatus, comprising: The machine base and the clamping and bearing components set on the machine base. A lifting platform is slidably installed on the machine base. A lifting component is set on the lifting platform. A fixed plate is connected to the lifting component. Its characteristic is that it further includes: A rotating rod is rotatably mounted on the fixed plate. A connecting locking mechanism is provided on the rotating rod. A shoulder is connected to the connecting locking mechanism. A stirring needle is slidably mounted on the shoulder. A limiting mechanism is provided on the connecting locking mechanism and connected to the stirring needle. The connecting locking mechanism can limit the shoulder and connect the stirring needle to the rotating rod through the limiting mechanism. The connecting locking mechanism includes a limiting disk that slides along the axial direction of the rotating rod, a limiting block is fixed at the end of the rotating rod, and a limiting groove that cooperates with the limiting block is formed on the limiting disk; It also includes a fitting assembly and a driven assembly disposed on the limiting plate and connected to the rotating rod; The fitting assembly includes a connecting plate fixed to the rotating rod, and symmetrically arranged guide posts slidably mounted on the connecting plate. A first fixing ring and a second fixing ring are fixed on the guide posts. The first fixing ring abuts against the connecting plate, and the second fixing ring abuts against the limiting plate. The limiting plate has a limiting hole that slides and fits with the guide posts. A first spring is sleeved on the guide posts, and the two ends of the first spring abut against the connecting plate and the second fixing ring, respectively. The driven component includes a support rod fixed on the limiting plate, a connecting plate fixed to the end of the support rod, and the connecting plate being fixedly connected to the shoulder; The limiting mechanism includes a limiting ring fixed on the support rod, a follower plate slidably connected to the support rod fixed on the stirring needle, the follower plate abutting against the limiting ring, and a second spring sleeved on the stirring needle, the two ends of the second spring abutting against the connecting plate and the follower plate respectively. The limiting mechanism also includes a through groove and a slot formed at the end of the rotating rod, and the end of the stirring needle is fixed with a protrusion that engages with the through groove and the slot.

2. The tube sheet connection friction stir welding device according to claim 1, characterized in that, The clamping and bearing assembly includes a bidirectional translation module disposed on the machine base, and the bidirectional translation module is connected to symmetrically arranged movable plates.

3. The tube sheet connection friction stir welding device according to claim 2, characterized in that, The clamping and bearing assembly also includes a clamping plate fixed on the movable plate, and a receiving plate is fixed on the clamping plate.

4. The tube sheet connection friction stir welding device according to claim 1, characterized in that, The lifting assembly includes a linear drive module mounted on a lifting platform, a sliding plate connected to the linear drive module, and the sliding plate being fixedly connected to the fixed plate.

5. A tube sheet connection method, employing the tube sheet connection friction stir welding apparatus as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Clamp the tube sheet using the clamping support assembly; Step 2: Connect the shaft shoulder to the rotating rod through the connecting locking mechanism, and connect the stirring needle to the rotating rod through the limiting mechanism; Step 3: The rotating rod drives the shaft shoulder and stirring needle to rotate through the connecting locking mechanism; Step 4: The lifting assembly drives the fixed plate to move, and drives the shoulder and stirring needle to move towards the tube sheet via the rotating rod. When the shoulder is in contact with the plate and the stirring needle enters the tube, friction stir welding is performed on the tube sheet. Step 5: After welding is completed, the lifting assembly control shoulder and stirring pin are reset.

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