A self-clamping backfilling friction stir spot welding device

Abstract

This invention discloses a self-clamping backfill friction stir spot welding device, relating to the field of friction stir spot welding technology. It includes a clamping adjustment module, a welding working module slidably mounted on the clamping adjustment module, and a stirring pin shaft drive system and a stirring sleeve shaft drive system within the welding working module to control the axial displacement of the stirring pin shaft and stirring sleeve shaft respectively. The welding working module also includes a welding rotation system for driving the rotation of the stirring pin shaft and stirring sleeve shaft. By setting four power sources and structural designs, the workpiece is clamped, rotated for friction welding, and the stirring pin and stirring sleeve are driven, improving welding quality. By controlling the simultaneous rotation of the stirring pin shaft and stirring sleeve shaft, and simultaneously using a lead screw assembly and spline coordination to control the reverse displacement of the stirring pin and stirring sleeve, parameters such as rotation speed, penetration depth, and welding dwell time can be set according to different welding materials, allowing for more precise control of the welding process.

Description

Technical Field

[0001] This invention relates to the field of friction stir spot welding technology, specifically to a backfill friction stir spot welding device. Background Technology

[0002] Backfill friction stir spot welding is a new type of spot welding technology based on friction stir spot welding. It has attracted widespread attention because there is no keyhole after welding. In recent years, it has gradually developed into a new technology that can replace traditional spot welding methods such as riveting and resistance spot welding. It is widely used in the welding of common lightweight metals such as aluminum alloys and magnesium alloys in aerospace, automotive, shipbuilding and other fields.

[0003] Currently used technologies include dual-gear rack and pinion synchronous reverse feed mechanisms, such as the Chinese patent document with publication number CN108213690A, which uses a large and a small gear and a stepper motor. However, the installation precision of the gear structure is relatively high, and the cost is also high. If the gear installation precision is insufficient, it will generate significant noise and friction, which will greatly affect the welding formation and welding accuracy. Another example is the Chinese patent document with publication number CN108857044A, which adopts a lightweight friction stir spot welding structure design and uses two power sources. The first power source controls the rotation of the stirring pin and the stirring sleeve, and the second power source controls the up and down movement of the stirring pin and the stirring sleeve. The disadvantage of this structure is that although it reduces the number of power sources, the stirring pin and the stirring sleeve can only move synchronously in opposite directions and cannot move independently. This makes it difficult to adjust specific parameters according to the actual situation and different welding materials, thus limiting its application range. Therefore, we provide a backfill friction stir spot welding device. Summary of the Invention

[0004] The purpose of this invention is to provide a self-clamping backfill friction stir spot welding device, which uses four power sources to control different parts, thereby improving the service life of the machine and reducing wear, noise, vibration, deformation, etc. It can better independently control the stirring pin and stirring sleeve, realize two working modes, and at the same time, the spline design is used to better position the stirring pin and stirring sleeve, and can transmit torque well, so that they can cooperate better during the working process, while simplifying the clamping process.

[0005] The present invention can be achieved through the following technical solution: a self-clamping backfill friction stir spot welding device, comprising a clamping adjustment module and a welding working module, wherein the welding working module is slidably mounted on the clamping adjustment module, and the welding working module is provided with a stirring pin shaft drive system and a stirring sleeve shaft drive system for controlling the axial displacement of the stirring pin shaft and the stirring sleeve shaft respectively, and the welding working module is also provided with a welding rotation system for driving the stirring pin shaft and the stirring sleeve shaft to rotate.

[0006] A further technical improvement of the present invention is that: the clamping adjustment module includes a mounting frame, an electric cylinder is mounted on the top of the mounting frame, sliding components are mounted on both sides of the mounting frame, a mounting plate is fixedly connected to each sliding component, the welding working module is fixed between the two mounting plates, and the output end of the electric cylinder controls the sliding components to drive the welding working module to move up and down.

[0007] A further technical improvement of the present invention is that a C-type clamp is provided directly below the electric cylinder, and a universal ball joint is installed on the top of the end of the C-type clamp located directly below the welding working module.

[0008] A further technical improvement of the present invention is that a stirring sleeve shaft is slidably sleeved on the outside of the stirring needle shaft, and the stirring sleeve shaft and the stirring needle shaft are connected by a spline.

[0009] A further technical improvement of the present invention is that the welding rotary system includes a spindle motor, the output end of which is provided with a belt drive assembly, and the belt drive assembly drives the stirring needle shaft to rotate, and the stirring needle shaft can move axially relative to the belt drive assembly.

[0010] A further technical improvement of the present invention is that: the stirring needle shaft drive system includes a lead screw transmission assembly, a bearing bracket is provided between the lead screw transmission assembly and the stirring needle shaft, the bearing bracket is axially fixed to the stirring needle shaft and the stirring sleeve shaft is rotatable relative to the bearing bracket, and the bearing bracket is fixedly connected to the moving part of the lead screw transmission assembly.

[0011] A further technical improvement of the present invention is that: the stirring sleeve shaft drive system includes a lead screw transmission assembly, a bearing bracket is provided between the lead screw transmission assembly and the stirring sleeve shaft, the bearing bracket is axially fixed to the stirring sleeve shaft and the stirring needle shaft can rotate relative to the bearing bracket, and the bearing bracket is fixedly connected to the moving part of the lead screw transmission assembly.

[0012] A further technical improvement of the present invention is that: a mounting groove is provided at the bottom of the stirring needle shaft, the stirring needle is installed in the mounting groove by spline engagement and locked and fixed by a nut, and a stirring sleeve is fixedly installed at the bottom of the stirring sleeve shaft, the stirring sleeve slides relative to the stirring needle and forms a hug around the stirring needle.

[0013] A further technical improvement of the present invention is that the welding working module also includes a jacket fixedly installed at its bottom, the bottom of the jacket being slidably disposed with the stirring sleeve and forming a hug with the stirring sleeve, and the contact surfaces between the stirring sleeve and the jacket, and between the stirring sleeve and the stirring needle, are all set as mirror surfaces.

[0014] A further technical improvement of the present invention is that: a welding fixture stabilizing structure is also provided in the jacket, the welding fixture stabilizing structure includes a welding fixture stabilizing bearing, a sliding sleeve is provided inside the welding fixture stabilizing bearing, the sliding sleeve forms a clamping effect on the stirring sleeve, a welding fixture stabilizing bearing end cap is provided on the top of the welding fixture stabilizing bearing, and the welding fixture stabilizing bearing end cap is fixedly connected to the jacket to limit the position of the welding fixture stabilizing bearing.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention employs four power sources and structural designs to clamp the workpiece, perform rotational friction welding, and drive the stirring pin and stirring sleeve. When clamping the workpiece, the C-clamp and universal ball joint design ensure that the surface of the workpiece is always perpendicular to the welding tool axis, and the lower plane of the C-clamp is always parallel to the lower end face of the welding tool, improving welding quality. By controlling the rotation of the stirring pin shaft and the stirring sleeve shaft simultaneously, and using a lead screw assembly and spline coordination to control the reverse displacement of the stirring pin and stirring sleeve, parameters such as rotation speed, penetration depth, and welding dwell time can be set according to different welding materials, allowing for more precise control of the welding process.

[0017] In the structural connection, a spline fit is used to transmit power, which better fixes the stirring shaft and stirring pin, and can transmit torque well. At the same time, it simplifies the clamping process. The whole equipment has a compact structure, is stable and durable, can autonomously complete high-quality stirring friction spot welding work, and has a long service life and is easy to operate. Attached Figure Description

[0018] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the overall external structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the overall external structure of the present invention from a bottom view.

[0021] Figure 3 This is a cross-sectional view of the welding module of the present invention;

[0022] Figure 4 For the present invention Figure 3 Schematic diagram of cross-section along line A;

[0023] Figure 5 For the present invention Figure 4 Detailed diagram of the central section;

[0024] Figure 6 For the present invention Figure 4 Enlarged view of details in area B.

[0025] In the diagram: 1. Clamping and adjusting module; 2. Welding working module; 3. Electric cylinder; 4. Spindle motor; 5. Mounting plate; 6. C-clamp; 7. Universal ball joint; 8. Drive motor one; 9. Drive motor two; 10. Pulley one; 11. Pulley two; 12. Drive screw one; 13. Drive screw two; 14. Screw end bearing one; 15. Screw end bearing two; 16. Screw nut one; 17. Screw nut two; 18. Stirring needle shaft bearing bracket; 19. Stirring sleeve shaft bearing bracket; 20. Stirring needle shaft; 21. Stirring sleeve shaft; 22. Stirring sleeve; 23. Stirring needle; 24. Jacket; 25. Welding fixture retaining bearing end cover; 26. Welding fixture retaining bearing; 27. Outer shell. Detailed Implementation

[0026] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0027] Please see Figure 1-6 As shown, a self-clamping backfill friction stir spot welding device includes a clamping adjustment module 1 and a welding working module 2. The welding working module 2 is mounted on the clamping adjustment module 1. The clamping adjustment module 1 includes a mounting frame. An electric cylinder 3 is fixedly mounted on the top of the mounting frame. Sliding components are mounted on both sides of the mounting frame. The sliding components include a guide rail and a slider that is slidably connected to the guide rail. A mounting plate 5 is fixedly mounted on the side of each slider by bolts. The welding working module 2 is fixed between two mounting plates 5. A connecting plate is also provided between two mounting plates 5. The output end of the electric cylinder 3 is fixedly connected to the connecting plate, so that the electric cylinder 3 can drive the welding working module 2 to move up and down.

[0028] A C-clamp 6 is located directly below the electric cylinder 3. The C-clamp 6 is fixedly connected to the mounting bracket. A universal ball head 7 is installed on the top of the end of the C-clamp 6 located directly below the welding work module 2. The purpose of the universal ball head 7 is to automatically adjust the parallelism between the welding tool and the lower surface of the C-clamp 6. During use, the C-clamp 6 will deform under the action of force. If deformation occurs, the lower surface of the C-clamp 6 will not be parallel to the welding tool, which will affect the welding quality and effect. The universal ball head 7 itself can rotate. When subjected to vertical downward pressure, the universal ball head 7 will automatically adjust the lower surface of the C-clamp 6 to always keep the lower surface of the C-clamp parallel to the lower end face of the welding tool.

[0029] The welding module 2 includes a spindle motor 4 and a housing 27. The spindle motor 4 is located on one side above the housing 27, and a pulley 10 is fixedly connected to the output end of the spindle motor 4. A stirring needle shaft 20 is vertically arranged inside the housing 27. A pulley 21 is slidably sleeved on the top of the stirring needle shaft 20. The pulley 10 and the pulley 21 are on the same horizontal plane, and a belt for transmitting power is provided between the pulley 10 and the pulley 21. The pulley 21 can only rotate in the horizontal plane, and it transmits power to the stirring needle shaft 20 through a spline engagement.

[0030] A drive motor 8 and a drive motor 9 are symmetrically mounted on the top two sides of the outer casing 27. A drive screw 12 is located directly below the drive motor 8, and a drive screw 13 is located below the drive motor 9. The upper and lower ends of the drive screw 12 are respectively provided with screw end bearings 14, and the drive screw 12 is axially positioned by the two screw end bearings 14. Similarly, the upper and lower ends of the drive screw 13 are respectively provided with screw end bearings 15, and the drive screw 13 is axially positioned by the two screw end bearings 15. The outer sides of the drive screw 12 and the drive screw 13 are respectively threaded with screw nuts 16 and 17.

[0031] A stirring needle shaft bearing bracket 18 is fixedly connected to one side of the lead screw nut 16. The stirring needle shaft bearing bracket 18 is sleeved on the outside of the stirring needle shaft 20. The stirring needle shaft 20 can rotate freely relative to the stirring needle shaft bearing bracket 18 through the bearing assembly inside the stirring needle shaft bearing bracket 18. A locking nut and a shaft shoulder are provided on the stirring needle shaft 20. The axis of the stirring needle shaft 20 is fixed by the locking nut and the shaft shoulder. Thus, in the axial direction, the stirring needle shaft 20 and the stirring needle shaft bearing bracket 18 move up and down together.

[0032] A stirring sleeve shaft bearing bracket 19 is fixedly connected to one side of the lead screw nut 21. A stirring sleeve shaft 21 is provided on the outer side of the lower end of the stirring needle shaft 20. A spline is provided on the section where the stirring needle shaft 20 and the stirring sleeve shaft 21 cooperate. A spline groove corresponding to the spline is opened on the inner wall of the stirring sleeve shaft 21. Through the spline cooperation, the stirring sleeve shaft 21 and the stirring needle shaft 20 can rotate together and slide against each other in the axial direction.

[0033] The stirring sleeve shaft 21 is set in the inner ring of the bearing assembly of the stirring sleeve shaft bearing bracket 19, so the stirring sleeve shaft 21 can rotate relative to the stirring sleeve shaft bearing bracket 19, its axial degree of freedom is restricted, and it moves up and down together with the stirring sleeve shaft bearing bracket 19.

[0034] Linear bearings are provided between the stirring needle shaft bearing bracket 18 and the stirring sleeve shaft bearing bracket 19, and between the stirring sleeve shaft bearing bracket 19 and the outer shell 27. The linear bearing between the stirring needle shaft bearing bracket 18 and the stirring sleeve shaft bearing bracket 19 is fixed to the stirring sleeve shaft bearing bracket 19, and the linear bearing between the stirring sleeve shaft bearing bracket 19 and the outer shell 27 is fixed to the outer shell 27. The purpose of providing linear bearings is to improve the rigidity of the entire structure and make the relative sliding of each component smoother.

[0035] The bottom of the outer casing 27 is fixed with a jacket 24 by bolts. The bottom of the stirring sleeve shaft 21 is fixed with a stirring sleeve 22. The stirring sleeve 22 is slidably provided with a stirring needle 23 and forms a hug with the stirring needle 23. The bottom of the stirring needle shaft 20 is provided with an installation groove. The installation groove is splined with the stirring needle 23 and the stirring needle 23 is fixed to the bottom of the stirring needle shaft 20 by a locking nut. The contact surfaces between the stirring sleeve 22 and the jacket 24, and between the stirring sleeve 22 and the stirring needle 23 are all mirrored.

[0036] The jacket 24 is also provided with a welding fixture stabilizing structure, which includes a welding fixture stabilizing bearing 26. A sliding sleeve is provided inside the welding fixture stabilizing bearing 26, which forms a clamping effect on the stirring sleeve 22. A welding fixture stabilizing bearing end cap 25 is provided on the top of the welding fixture stabilizing bearing 26, and the welding fixture stabilizing bearing end cap 25 is fixedly connected to the jacket 24 by bolts to limit the position of the welding fixture stabilizing bearing 26.

[0037] When using this invention, firstly, parameters such as rotation speed, the downward (or retraction) distance of the stirring sleeve 22, the retraction (or downward) distance of the stirring pin 23, and the welding dwell time are set according to different welding processes and materials. The stirring pin 23 and the stirring sleeve 22 must be on the same plane.

[0038] After the equipment is started, the main spindle motor 4 drives the stirring needle shaft 20 and the stirring sleeve shaft 21 to rotate synchronously via belt drive. When the speed reaches the set value, the electric cylinder 3 drives the welding working module 2 to approach and contact the workpiece surface. After contacting the workpiece surface, it begins to rotate and generate heat through friction. When the surface of the workpiece reaches the plastic shape state, there are two welding action modes:

[0039] Stirring sleeve mode: Drive motor 8 and drive motor 9 start simultaneously. Drive motor 8 drives drive screw 12 to rotate, thereby causing screw nut 16, which is threaded to drive screw 12, to rise. Stirring needle shaft bearing bracket 18 rises accordingly, that is, stirring needle shaft 20 rises and drives stirring needle 23 to retract. Drive motor 9 drives drive screw 13 to rotate, thereby causing screw nut 17, which is threaded to drive screw 13, to fall. Stirring sleeve shaft bearing bracket 19 falls accordingly, that is, stirring sleeve shaft 21 falls and drives stirring sleeve 22 to drop. Then drive motor 8 and drive motor 9 rotate in opposite directions, causing stirring needle 23 to drop while stirring sleeve 22 retracts. When stirring needle 23 and stirring sleeve 22 reach the plane they were on before welding, electric cylinder 3 rises, and welding is completed.

[0040] Stirring needle mode: Drive motor 8 and drive motor 9 start simultaneously. Drive motor 8 drives drive screw 12 to rotate, which in turn drives screw nut 16, which is threaded to drive screw 12, to descend. Stirring needle shaft bearing bracket 18 descends accordingly, that is, stirring needle shaft 20 descends and drives stirring needle 23 to plunge downwards. Drive motor 9 drives drive screw 13 to rotate, which in turn drives screw nut 17, which is threaded to drive screw 13, to rise. Stirring sleeve shaft bearing bracket 19 rises accordingly, that is, stirring sleeve shaft 21 rises and drives stirring sleeve 22 to rise. Then drive motor 8 and drive motor 9 rotate in opposite directions, causing stirring needle 23 to rise while stirring sleeve 22 plunges downwards. When stirring needle 23 and stirring sleeve 22 reach the plane they were on before welding, electric cylinder 3 rises, and welding is completed.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A self-clamping backfill friction stir spot welding device, characterized in that: It includes a clamping adjustment module (1) and a welding working module (2). The welding working module (2) is slidably mounted on the clamping adjustment module (1). The welding working module (2) is equipped with a stirring needle shaft drive system and a stirring sleeve shaft drive system that control the axial displacement of the stirring needle shaft (20) and the stirring sleeve shaft (21) respectively. The welding working module (2) is also equipped with a welding rotation system for driving the stirring needle shaft (20) and the stirring sleeve shaft (21) to rotate. The welding work module (2) includes an outer shell (27); The top two sides of the outer casing (27) are symmetrically equipped with drive motor 1 (8) and drive motor 2 (9). Drive screw 1 (12) is located directly below drive motor 1 (8), and drive screw 2 (13) is located below drive motor 2 (9). Drive screw 1 (12) is equipped with screw end bearing 1 (14) at both ends and is axially positioned using the two screw end bearing 1 (14). Similarly, drive screw 2 (13) is equipped with screw end bearing 2 (15) at both ends and is axially positioned using the two screw end bearing 2 (15). Drive screw 1 (12) and drive screw 2 (13) are threadedly connected to the outer sides of drive screw 1 (12) and drive screw 2 (13). A stirring needle shaft bearing bracket (18) is fixedly connected to one side of the lead screw nut (16). The stirring needle shaft bearing bracket (18) is sleeved on the outside of the stirring needle shaft (20). The stirring needle shaft (20) can rotate freely relative to the stirring needle shaft bearing bracket (18) through the bearing assembly inside the stirring needle shaft bearing bracket (18). A locking nut and a shaft shoulder are provided on the stirring needle shaft. The axis of the stirring needle shaft (20) is fixed by the locking nut and the shaft shoulder. Thus, in the axial direction, the stirring needle shaft (20) and the stirring needle shaft bearing bracket (18) move up and down together. The stirring needle shaft (20) is slidably sleeved with a stirring sleeve shaft (21) on the outside, and the stirring sleeve shaft (21) and the stirring needle shaft (20) are connected by a spline. The bottom of the stirring needle shaft (20) is provided with an installation groove. The stirring needle (23) is installed in the installation groove by spline engagement and locked in place by a nut. The bottom of the stirring sleeve shaft (21) is fixedly installed with a stirring sleeve (22). The stirring sleeve (22) slides relative to the stirring needle (23) and forms a hug around the stirring needle (23).

2. The self-clamping backfill friction stir spot welding equipment according to claim 1, characterized in that, The clamping adjustment module includes a mounting frame, an electric cylinder (3) is mounted on the top of the mounting frame, and sliding components are mounted on both sides of the mounting frame. Each sliding component is fixedly connected to a mounting plate (5). The welding working module (2) is fixed between the two mounting plates (5). The output end of the electric cylinder (3) controls the sliding components to drive the welding working module (2) to move up and down.

3. The self-clamping backfilling friction stir spot welding equipment according to claim 2, characterized in that, A C-type clamp (6) is provided directly below the electric cylinder (3), and a universal ball head (7) is installed on the top of one end of the C-type clamp (6) located directly below the welding work module (2).

4. The self-clamping backfill friction stir spot welding equipment according to claim 1, characterized in that, The welding rotary system includes a main spindle motor (4), and a belt drive assembly is provided at the output end of the main spindle motor (4). The belt drive assembly drives the stirring needle shaft (20) to rotate, and the stirring needle shaft (20) can move axially relative to the belt drive assembly.

5. The self-clamping backfill friction stir spot welding equipment according to claim 1, characterized in that, The welding work module (2) also includes a jacket (24) fixedly installed at its bottom. The bottom of the jacket (24) is slidably disposed with the stirring sleeve (22) and forms a hug with the stirring sleeve (22). The contact surfaces between the stirring sleeve (22) and the jacket (24) and between the stirring sleeve (22) and the stirring needle (23) are all set as mirror surfaces.

6. The self-clamping backfilling friction stir spot welding equipment according to claim 5, characterized in that, The jacket (24) is also provided with a welding tool stabilizing structure, which includes a welding tool stabilizing bearing (26). A sliding sleeve is provided inside the welding tool stabilizing bearing (26), which forms a clamping effect on the stirring sleeve (22). A welding tool stabilizing bearing end cap (25) is provided on the top of the welding tool stabilizing bearing (26), and the welding tool stabilizing bearing end cap (25) is fixedly connected to the jacket (24) to limit the position of the welding tool stabilizing bearing (26).

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