Rotary table for friction stir welding and friction stir welding assembly

Abstract

The invention provides a rotary table for friction stir welding. The rotary table comprises a rotary table base, a plurality of first sliding blocks, a plurality of second sliding blocks, a rotary table top and a driving assembly. A first circular sliding rail and a second circular sliding rail are arranged on the rotary table base in the circumferential direction, and the diameter of the first circular sliding rail is smaller than that of the second circular sliding rail. The first sliding block is slidably connected to the first circular sliding rail. The second sliding block is slidably connected to the second circular sliding rail. The rotary table top is used for mounting a rotary body welding workpiece, and the bottom of the rotary table top is connected to the first sliding block and the second sliding block; the driving assembly is connected to the rotary table top and used for driving the rotary table top to rotate along the axis of the rotary table top. According to the rotary table, the bearing capacity of the rotary table to the welding single-point large load effect is improved, and then the rotating precision under the radial large load effect is improved.

Description

Technical Field

[0001] This invention relates to the field of friction stir welding tooling technology, and more specifically, to a turntable and friction stir welding assembly for friction stir welding. Background Technology

[0002] Friction stir welding, as a novel solid-state joining method, utilizes the extrusion, friction, and shearing action of the stirring head on the weld metal to bring it to a thermoplastic state. This increases the energy of microscopic metal atoms at the weld joint, causing them to diffuse again and reconnect the metal bonds, thus achieving a macroscopic weld joint. This method avoids defects such as porosity and hot cracking found in conventional aluminum alloy fusion welding.

[0003] Currently, with the improvement of my country's industrial level, the rapid development of the aerospace industry, and the mature application of friction stir welding, the processing and production of large-size friction stir welded circumferential seam parts is increasing, leading to a growing demand for tooling and fixtures for large-size friction stir welded circumferential seams. As an important component of circumferential seam tooling, the turntable's dynamic accuracy under load has a significant impact on welding quality. Existing turntable technologies suffer from the following problems: poor resistance to overturning under large loads, rapid decrease in accuracy under load, and high manufacturing costs. Summary of the Invention

[0004] (a) Technical problems to be solved The technical problem to be solved by the present invention is that the turntable in the prior art has poor resistance to overturning under large loads, its accuracy decreases rapidly under load, and its manufacturing cost is high.

[0005] (II) Technical Solution To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a turntable for friction stir welding, comprising a turntable base, a plurality of first sliders, a plurality of second sliders, a turntable surface, and a drive assembly; the turntable base is provided with a first circular slide rail and a second circular slide rail along its circumference, the diameter of the first circular slide rail being smaller than the diameter of the second circular slide rail; the first sliders are slidably connected to the first circular slide rail; the second sliders are slidably connected to the second circular slide rail; the turntable surface is used to mount rotating welding workpieces, and the bottom of the turntable surface is connected to the first sliders and the second sliders; the drive assembly is connected to the turntable surface and is used to drive the turntable surface to rotate along its axis.

[0006] Preferably, it further includes a plurality of first positioning pins and a plurality of first stops. The plurality of first positioning pins are arranged at intervals along the outer diameter side of the first circular slide rail, and the periphery of the first positioning pins abuts against the outer diameter side of the first circular slide rail. The plurality of first stops are arranged at intervals along the inner diameter side of the first circular slide rail, and the end face of the first stop abuts against the inner diameter side of the first circular slide rail.

[0007] Preferably, it further includes a slider limiting plate, one end of which is connected to the first slider, and the other end of which abuts against the outer periphery of the turntable base.

[0008] Preferably, the drive assembly includes a drive gear and a drive motor, the output end of the drive motor is connected to the drive gear, the turntable base is rotatably connected to a driven gear, the turntable surface is fixedly connected to the top surface of the driven gear, and the drive gear meshes with the driven gear.

[0009] Preferably, the drive motor includes a first motor and a second motor, and the drive gear includes a first gear and a second gear. The output end of the first motor is connected to the first gear, and the output end of the second motor is connected to the second gear. The first gear and the second gear are respectively meshed with the teeth of the driven gear. The teeth of the driven gear have a first tooth surface and a second tooth surface that are disposed opposite to each other. The tooth surface of the first gear abuts against the first tooth surface, and the tooth surface of the second gear abuts against the second tooth surface.

[0010] Preferably, the drive motor includes a motor body, a reducer, a mounting base, and fasteners. The motor body and the reducer are mounted and fixed on the mounting base. The output end of the motor body is connected to the input end of the reducer, and the output end of the motor body is connected to the drive gear. The mounting base has an oblong hole, and the fasteners pass through the oblong hole to securely connect the mounting base to the turntable base.

[0011] Preferably, the turntable surface is provided with a plurality of mounting slots at radial intervals, the mounting slots being used to engage with welding fixtures.

[0012] Preferably, the turntable base includes a circular mounting boss and a rectangular base connected to each other. The circular mounting boss is provided with a first circular slide rail and a second circular slide rail along the circumference, and the rectangular base is provided with a wire hole.

[0013] Secondly, the present invention also provides a friction stir welding assembly, including a welding robot, a rotating welding workpiece, a welding fixture, and a turntable for friction stir welding as described in any of the above technical solutions. The welding fixture is mounted on the turntable surface and clamps and fixes the rotating welding workpiece. The angle between the normal of the stirring head of the welding robot and the normal of the tangent plane of the welding starting point is 2.5°.

[0014] Preferably, the diameter of the annular weld of the rotating workpiece is greater than the inner diameter of the second circular slide rail and smaller than the outer diameter of the second circular slide rail.

[0015] (III) Beneficial Effects The above-described technical solution of the present invention has at least the following advantages: 1. This invention features a first circular slide rail and a second circular slide rail on a turntable base, with a first slider slidably connected to the first circular slide rail and a second slider slidably connected to the second circular slide rail. This achieves a rotational connection between the turntable surface and the turntable base. The first and second sliders support the rotating welding workpiece on the turntable surface, significantly improving the turntable's resistance to overturning moments and its ability to withstand large single-point loads during welding, thereby enhancing rotational accuracy under large radial loads. Compared to traditional thrust roller bearings for heavy-duty roller gears, this invention significantly reduces manufacturing costs and avoids welding defects caused by dynamic load accuracy issues in the turntable.

[0016] 2. In this invention, the first circular slide rail is positioned using a first locating pin and multiple first stops, and the second circular slide rail is positioned using a second locating pin and multiple second stops, significantly improving the radial accuracy of the turntable under lateral loads. The turntable surface is driven by a first gear and a second gear, eliminating backlash in gear transmission. The first and second gears are adjustable in two horizontal directions, eliminating machining and assembly errors and ensuring the stability and transmission accuracy of the gear transmission. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the turntable for friction stir welding provided in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the turntable surface provided in an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of the turntable base provided in an embodiment of the present invention.

[0021] Figure 4 This is a structural assembly diagram of the first circular slide rail and the first slider provided in an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of the structure of the first motor provided in an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the structure of the friction stir welding assembly provided in an embodiment of the present invention.

[0024] Figure 7 This is a schematic diagram of the structural assembly of the rotating welding workpiece and the welding fixture provided in an embodiment of the present invention.

[0025] The labels for the attached figures are as follows: 10. Rotary welding workpiece; 20. Welding fixture; 30. Welding robot; 1. Turntable base; 2. First slider; 3. Second slider; 4. Turntable surface; 5. Drive assembly; 11. First circular slide rail; 12. Second circular slide rail; 13. Driven gear; 14. Circular mounting boss; 15. Rectangular base; 41. Mounting slot; 51. First motor; 52. Second motor; 53. First gear; 54. Second gear; 61. First positioning pin; 62. First stop; 63. Slider limiting plate; 151. Wire hole; 511. Motor body; 512. Reducer; 513. Mounting base; 5131. Waist-shaped hole. Detailed Implementation

[0026] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0027] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be located directly on or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component.

[0028] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate that the device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or the number of technical features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. The specific implementation of this invention will be described in more detail below with reference to specific embodiments: like Figure 1 , Figure 2 and Figure 3As shown, this embodiment of the invention provides a turntable for friction stir welding, including a turntable base 1, multiple first sliders 2, multiple second sliders 3, a turntable surface 4, and a drive assembly. The turntable base 1 is provided with a first circular slide rail 11 and a second circular slide rail 12 along its circumference, the diameter of the first circular slide rail 11 being smaller than the diameter of the second circular slide rail 12. The first sliders 2 are slidably connected to the first circular slide rail 11; the second sliders 3 are slidably connected to the second circular slide rail 12; the turntable surface 4 is used to mount a rotating welding workpiece 10, and the bottom of the turntable surface 4 is connected to the first sliders 2 and the second sliders 3; the drive assembly is connected to the turntable surface 4 and is used to drive the turntable surface 4 to rotate along its axis. Specifically, the first sliders 2 and the second sliders 3 are provided with threaded holes for screw connection, and the turntable surface 4 is also provided with threaded holes for screw connection at corresponding positions. By passing screws through the corresponding threaded holes, a detachable connection can be achieved between the second sliders 2 and the turntable surface, and a detachable connection can be achieved between the third sliders 3 and the turntable surface 4. More specifically, the first circular slide rail 11 is a 45mm guide rail with a diameter of 1600mm, and the number of first sliders 2 is preferably 6. The 6 first sliders 2 are evenly distributed along the circumference of the first circular slide rail 11. Each first slider 2 can withstand a dynamic load of 60KN and an overturning load of 1.8KNm. The second circular slide rail 12 is a 65mm guide rail with a diameter of 3000mm, and the number of second sliders 3 is preferably 6. The 6 second sliders 3 are evenly distributed along the circumference of the second circular slide rail 12. Each second slider 3 can withstand an overturning load of 5.8KNm. The first circular slide rail 11 mainly supports the central area of ​​the turntable, preventing deformation of the central area of ​​the table surface under large loads. The second circular slide rail 12 has a larger size, close to the circumferential seam size of the workpiece being welded, and has a stronger ability to withstand single-point overturning welding forces. The center of the turntable surface 4 is equipped with a center hole with a diameter of 500mmH7, which is used to cooperate with the mandrel of the welding fixture to ensure the concentricity of the rotating welding workpiece 10 and the turntable during the rotation of the turntable.

[0030] In one embodiment, the system further includes a plurality of first positioning pins 61 and a plurality of first stops 62. The plurality of first positioning pins 61 are spaced apart along the outer diameter side of the first circular slide rail 11, and the circumferential side of the first positioning pins 61 abuts against the outer diameter side of the first circular slide rail 11. The plurality of first stops 62 are spaced apart along the inner diameter side of the first circular slide rail 11, and the end face of the first stops 62 abuts against the inner diameter side of the first circular slide rail 11. The plurality of first positioning pins 61 and the plurality of first stops 62 are used to restrict the movement of the first slider 2 in the radial direction to prevent the first slider 2 from wobbling in the radial direction.

[0031] It also includes a plurality of second locating pins and a plurality of second stops. The plurality of second locating pins are spaced apart along the outer diameter side of the second circular slide rail 12, and the circumferential side of the second locating pins abuts against the outer diameter side of the second circular slide rail 12. The plurality of second stops are spaced apart along the inner diameter side of the second circular slide rail 12, and the end face of the second stops abuts against the inner diameter side of the second circular slide rail 12. The plurality of second locating pins and the plurality of second stops are used to restrict the movement of the second slider 3 in the radial direction to prevent the second slider 3 from wobbling in the radial direction.

[0032] In one embodiment, a slider limiting plate 63 is also included. One end of the slider limiting plate 63 is connected to the first slider 2, and the other end of the slider limiting plate 63 abuts against the outer periphery of the turntable base 1. In normal welding conditions, the welding torch is positioned such that the angle between it and the plane on the side where the first positioning pin 61 is located is acute, and the torch tip faces the side where the first stop block 62 is located. Therefore, the force exerted by the welding torch on the workpiece is radially directed towards the center, and this force acts on the first slider 2, tending to cause the first slider 2 to move radially inward. The slider limiting plate 63 can support the force during welding to prevent the first slider 2 from wobbling radially, ensuring the smooth operation of the first slider 2.

[0033] In one embodiment, the drive assembly includes a drive gear and a drive motor. The output end of the drive motor is connected to the drive gear. A driven gear 13 is rotatably connected to the turntable base 1. The turntable surface 4 is fixedly connected to the top surface of the driven gear 13. The drive gear meshes with the driven gear 13. The drive motor can drive the drive gear to rotate, which in turn drives the driven gear 13 to rotate, ultimately achieving rotational drive of the turntable surface 4.

[0034] In one embodiment, the drive motor includes a first motor 51 and a second motor 52, and the drive gear includes a first gear 53 and a second gear 54. The output end of the first motor 51 is connected to the first gear 53, and the output end of the second motor 52 is connected to the second gear 54. The first gear 53 and the second gear 54 are respectively meshed with the teeth of the driven gear 13. The teeth of the driven gear 13 have a first tooth surface and a second tooth surface that are oppositely arranged. The tooth surface of the first gear 53 abuts against the first tooth surface, and the tooth surface of the second gear 54 abuts against the second tooth surface. Specifically, the first motor 51 and the second motor 52 provide torques of equal magnitude and opposite direction, forming an offset torque, so that the first gear 53 and the second gear 54 are respectively pressed against the two opposite meshing surfaces of the driven gear 13, preventing the driven gear 13 from swinging within the gear gap, thereby achieving the effect of eliminating backlash.

[0035] In one embodiment, the drive motor includes a motor body 511, a reducer 512, a mounting base 513, and fasteners. The motor body 511 and the reducer 512 are fixedly mounted on the mounting base 513. The output end of the motor body 511 is connected to the input end of the reducer 512, and the output end of the motor body 511 is connected to the drive gear. The mounting base 513 has a slotted hole 5131, through which fasteners pass to securely connect the mounting base 513 to the turntable base 1. The mounting base 513 can be adjusted a certain distance along the length direction of the slotted hole 5131, and its position is fixed by the fasteners. This allows for fine-tuning of the mounting base 513 along the length direction of the slotted hole 5131. Specifically, the length direction of the slotted hole 5131 is the tooth width direction of the driven gear 13. Fine-tuning through the slotted hole 5131 allows for adjustment of the tangential position of the gear.

[0036] Furthermore, the drive motor also includes a normal adjustment plate 514. The two ends of the normal adjustment plate 514 are respectively provided with tension screws 515. By rotating the tension screws 515, the position of the normal adjustment plate 514 can be adjusted, thereby adjusting the normal position of the first gear 53 / second gear 54 and adjusting the distance between the center lines of the gear set.

[0037] In one embodiment, the turntable surface 4 is provided with a plurality of mounting slots 41 at radial intervals, the mounting slots 41 being used to engage with welding fixtures. Specifically, screws are inserted into the mounting slots 41, and the welding fixtures are fastened together using the screws. The length direction of the mounting slots 41 is radial to the turntable surface 4, to accommodate the installation and fixing of welding fixtures of different diameters.

[0038] In one embodiment, the turntable base 1 includes a circular mounting boss 14 and a rectangular base 15 connected to each other. The circular mounting boss 14 is provided with a first circular slide rail 11 and a second circular slide rail 12 along its circumference. The rectangular base 15 has a wire hole 151. Specifically, the diameter of the circular mounting boss 14 is preferably 3200 μm. The rectangular surface of the rectangular base 15 is equipped with multiple sets of wire holes 151 to facilitate the routing of hydraulic and pneumatic cables.

[0039] This invention also provides a friction stir welding assembly, including a welding robot 30, a rotating welding workpiece 10, a welding fixture 20, and a friction stir welding turntable as described in any of the above embodiments. The welding fixture 20 is mounted on the turntable surface 4 and clamps and fixes the rotating welding workpiece 10. The angle between the normal of the stirring head of the welding robot 30 and the normal of the tangential plane at the welding starting point is 2.5°. Figure 6 and Figure 7As shown, a 5-axis cantilever friction stir welding machine (welding robot 30) is used to weld a certain type of part with a diameter of 3350mm. The rotating workpiece 10 and welding fixture 20 are mounted on the turntable surface 4. The welding robot 30 adjusts the position of its head, setting the angle between the normal of the stirring head and the normal of the tangent plane at the welding starting point to 2.5°, and then starts the welding spindle. During the welding process, the position and angle of the head remain unchanged, and the turntable surface 4 drives the rotating workpiece 10 to rotate, achieving precision welding of a large circumferential seam. After welding, the welded rotating workpiece and welding fixture 20 are hoisted down.

[0040] In one embodiment, the diameter of the annular weld of the rotating welded workpiece 10 is greater than the inner diameter of the second circular slide rail 12 and smaller than the outer diameter of the second circular slide rail 12.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A turntable for friction stir welding, characterized in that, include: A turntable base, wherein the turntable base is provided with a first circular slide rail and a second circular slide rail along the circumference, and the diameter of the first circular slide rail is smaller than the diameter of the second circular slide rail; Multiple first sliders, each first slider being slidably connected to the first circular slide rail; Multiple second sliders are slidably connected to the second circular slide rail; A turntable surface is used to mount rotating welding workpieces, and the bottom of the turntable surface is connected to the first slider and the second slider. A drive assembly, connected to the turntable surface, is used to drive the turntable surface to rotate along its axis.

2. The turntable for friction stir welding as described in claim 1, characterized in that, It also includes a plurality of first positioning pins and a plurality of first stops. The plurality of first positioning pins are arranged at intervals along the outer diameter side of the first circular slide rail, and the periphery of the first positioning pins abuts against the outer diameter side of the first circular slide rail. The plurality of first stops are arranged at intervals along the inner diameter side of the first circular slide rail, and the end face of the first stop abuts against the inner diameter side of the first circular slide rail.

3. The turntable for friction stir welding as described in claim 2, characterized in that, It also includes a slider limiting plate, one end of which is connected to the first slider, and the other end of which abuts against the outer periphery of the turntable base.

4. The turntable for friction stir welding as described in claim 1, characterized in that, The drive assembly includes a drive gear and a drive motor. The output end of the drive motor is connected to the drive gear. The turntable base is rotatably connected to a driven gear. The turntable surface is fixedly connected to the top surface of the driven gear. The drive gear and the driven gear are meshed together.

5. The turntable for friction stir welding as described in claim 4, characterized in that, The drive motor includes a first motor and a second motor, and the drive gear includes a first gear and a second gear. The output end of the first motor is connected to the first gear, and the output end of the second motor is connected to the second gear. The first gear and the second gear are respectively meshed with the teeth of the driven gear. The teeth of the driven gear have a first tooth surface and a second tooth surface that are arranged opposite to each other. The tooth surface of the first gear abuts against the first tooth surface, and the tooth surface of the second gear abuts against the second tooth surface.

6. The turntable for friction stir welding as described in claim 4, characterized in that, The drive motor includes a motor body, a reducer, a mounting base, and fasteners. The motor body and the reducer are mounted and fixed on the mounting base. The output end of the motor body is connected to the input end of the reducer, and the output end of the motor body is connected to the drive gear. The mounting base has an oblong hole, and the fasteners pass through the oblong hole to securely connect the mounting base to the turntable base.

7. The turntable for friction stir welding as described in claim 1, characterized in that, The turntable surface is provided with multiple mounting slots at radial intervals, which are used to engage with welding fixtures.

8. The turntable for friction stir welding as described in claim 1, characterized in that, The turntable base includes a circular mounting boss and a rectangular base connected to each other. The circular mounting boss is provided with a first circular slide rail and a second circular slide rail along the circumference. The rectangular base is provided with a wire hole.

9. A friction stir welding assembly, characterized in that, The invention includes a welding robot, a rotating workpiece for welding, a welding fixture, and a turntable for friction stir welding as described in any one of claims 1-8, wherein the fixture is mounted on the turntable surface, the welding fixture clamps and fixes the rotating workpiece for welding, and the angle between the normal of the stirring head of the welding robot and the normal of the tangent plane at the welding starting point is 2.5°.

10. The friction stir welding assembly as described in claim 9, characterized in that, The diameter of the annular weld seam of the rotating workpiece is greater than the inner diameter of the second circular slide rail and smaller than the outer diameter of the second circular slide rail.

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