A retracting spot welding apparatus and a spot welding method

Abstract

The application relates to the technical field of welding, in particular to a back-pulling spot welding device and a spot welding method, which comprise a lifting support, a first assembly plate movably arranged on the lifting support and a second assembly plate movably arranged on the first assembly plate, further comprising: a first motor mounted on the second assembly plate, a horizontal table fixedly connected to an output shaft of the first motor through a connecting plate, a stirring needle arranged on the horizontal table, and the stirring needle being capable of being driven to rotate by a first power mechanism arranged on the horizontal table; the high-performance particle adding function is realized without moving the stirring needle, so that only one positioning is needed during welding, the secondary positioning process is saved, on one hand, the error caused by the secondary positioning can be effectively avoided, the welding precision is not high, on the other hand, the high-performance particle adding mode simplifies the technological process and the operation difficulty.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding, in particular to a retraction spot welding device and a spot welding method. BACKGROUND

[0002] With the increasing demand for reducing structural weight, protecting the environment, and saving energy, lightweight materials such as aluminum alloys and magnesium alloys are increasingly widely used in the automotive and aerospace industries. In actual production, the welding of these materials is one of the key links, and the retraction spot welding technology is an ideal choice due to its efficiency and convenience. This technology does not require complex welding tools or specially customized equipment and can be completed directly on a conventional friction stir welding device.

[0003] However, the existing retraction spot welding technology has some challenges in the implementation process. Specifically, the operation process first adjusts the stir pin to a specified length and penetrates into the parts to be welded. Then, after the stir shaft shoulder contacts the parts to be welded, the stir pin and shaft shoulder are lifted, at which time the stir pin and shaft shoulder need to be moved away and moved above the hole by a special adding device to add high-performance particles such as SiC. High-performance particles are usually used in the form of powder or fine particles. High-performance particles can refine the microstructure of the weld point, making the grains of the material finer and more evenly distributed, thereby enhancing the mechanical strength, toughness, and wear resistance of the weld point. In addition, they can also improve heat conduction during welding, helping to more evenly distribute heat and reduce welding defects such as porosity and inclusions. This not only improves the density of the weld point but also enhances its corrosion resistance and fatigue resistance, prolonging the service life of the weld point.

[0004] Among them, after the addition of high-performance particles is completed, the stir pin and shaft shoulder must be repositioned to the welding position. This process requires the stir pin to be positioned once before and twice after the addition of particles. During the second positioning process, positioning deviations may occur, causing the stir pin and shaft shoulder to fail to accurately align with the welding hole, thereby affecting the precision and quality of welding, and being not conducive to continuous welding, resulting in low welding efficiency. SUMMARY

[0005] The present application aims to provide a retraction spot welding device and a spot welding method to solve the problems raised in the background art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A retraction spot welding device, comprising a lifting support, a first assembly plate movably arranged on the lifting support, and a second assembly plate movably arranged on the first assembly plate, further comprising:

[0008] The first motor is installed on the second assembling plate, the output shaft of the first motor is fixedly connected with the horizontal table through the connecting plate, the horizontal table is provided with the stirring needle, the stirring needle can be driven to rotate by the first power mechanism arranged on the horizontal table, the output shaft of the first motor is concentric with the stirring needle, when the first motor works, the horizontal table can drive the stirring needle to move along the circumferential track, meanwhile, the threaded driving mechanism arranged on the horizontal table can drive the stirring needle to perform the retracting action;

[0009] The outer cylinder is rotatably installed at the bottom of the horizontal table, the loading mechanism for containing the high-performance particles is arranged in the inner portion of the outer cylinder, and the bottom end of the outer cylinder is provided with a plurality of arc-shaped members, and the horizontal table is further provided with the second power mechanism for driving the outer cylinder to rotate with the plurality of arc-shaped members;

[0010] The plurality of arc-shaped members can be driven by the pneumatic mechanism arranged on the horizontal table to perform the opening and closing action, when the plurality of arc-shaped members are in the closing state, the plurality of arc-shaped members are in sliding fit with the stirring needle to form the stirring shaft shoulder, when the plurality of arc-shaped members are in the opening state, the plurality of arc-shaped members form the discharging gap with the stirring needle, and the loading mechanism is triggered, and the high-performance particles enter the welding hole through the discharging gap.

[0011] As a further scheme of the present application, the pneumatic mechanism comprises a ring body slidingly arranged on the outer cylinder, the ring body can be driven by the two groups of lifting assemblies arranged on the horizontal table to slide upward or downward relative to the outer cylinder, the ring body is connected with the arc-shaped members through the push-pull structure, and the ring body is further connected with the loading mechanism.

[0012] As a further scheme of the present application, the push-pull structure comprises a supporting arm fixedly arranged on the outer wall of the outer cylinder, a sliding plate slidingly combined with the supporting arm, and a connecting rod hinged with the ring body, one end of the connecting rod away from the ring body is hinged with the sliding plate, and the sliding plate is fixed with the arc-shaped members.

[0013] As a further scheme of the present application, the lifting assembly comprises a pneumatic cylinder fixedly installed on the horizontal table and a sliding block fixedly connected with the movable end of the pneumatic cylinder, and the ring body is provided with an annular groove, and the sliding block is slidingly embedded in the annular groove.

[0014] As a further scheme of the present application, the loading mechanism comprises an inner cylinder rotatably installed in the inner portion of the outer cylinder, and the bottom walls of the inner cylinder and the outer cylinder are in sliding fit, and a plurality of first through holes and second through holes are equidistantly arranged along the circumference on the bottom walls of the inner cylinder and the outer cylinder respectively.

[0015] When the plurality of arc-shaped members are in the closing state, the first through holes and the second through holes are staggered, when the plurality of arc-shaped members are switched to the opening state, the ring body can drive the inner cylinder to rotate relative to the outer cylinder through the two groups of sliding fit structures, so that the first through holes and the second through holes have the overlapping position.

[0016] As a further embodiment of the present invention: the sliding fit structure includes a protrusion fixed on the inner wall of the ring and a sliding groove provided on the outer wall of the inner cylinder and adapted to the protrusion. The protrusion passes through the outer cylinder and extends into the sliding groove, and is slidably connected to the inner cylinder.

[0017] The groove is spirally arranged, and the outer cylinder is also provided with a strip-shaped through groove for the movement of the protrusion, the strip-shaped through groove being parallel to the central axis of the outer cylinder.

[0018] As a further embodiment of the present invention: the thread drive mechanism includes two movable blocks movably disposed on the horizontal platform, a connecting seat is fixed between the two movable blocks, the connecting seat is rotatably connected to the stirring needle, and each of the two movable blocks is connected to a set of servo drive components, the servo drive components being able to drive the movable blocks to rise and fall on the horizontal platform.

[0019] As a further embodiment of the present invention: the first power mechanism includes a drive tube rotatably mounted on the cross platform and slidably fitted with the stirring needle, the outer wall of the stirring needle is provided with a strip-shaped protrusion, and the inner wall of the drive tube is provided with a strip-shaped groove adapted to the strip-shaped protrusion.

[0020] The strip-shaped protrusion and the strip-shaped groove are parallel to the central axis of the stirring needle. A second motor is also installed on the cross platform. A first gear is fixed on the output shaft of the second motor. The first gear meshes with a second gear fixed on the drive tube.

[0021] As a further embodiment of the present invention: the second power mechanism includes a third motor mounted on the cross platform and a third gear fixed on the output shaft of the third motor, and a gear ring that meshes with the third gear is fixed on the outer cylinder.

[0022] As a further aspect of the present invention: a spot welding method, employing the aforementioned retraction spot welding equipment, includes the following steps:

[0023] Step 1: Control the movement of the first assembly plate and the second assembly plate so that the stirring pin corresponds to the welding position;

[0024] Step 2: The threaded drive mechanism adjusts the length of the stirring needle, and the lifting bracket moves down so that the stirring needle penetrates the part to be welded.

[0025] Step 3: The stirring shoulder contacts the part to be welded, and the stirring pin is lifted from the stirring shoulder;

[0026] Step four: The pneumatic mechanism drives multiple arc-shaped parts to expand, forming a feeding gap. The loading mechanism releases high-performance particles, which enter the welding hole through the feeding gap.

[0027] Step 5: Start welding. The stirring pin moves along a circular trajectory. The threaded drive mechanism drives the stirring pin to retract until it is flush with the stirring shaft shoulder.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] This invention incorporates multiple arc-shaped components capable of opening and closing. When these components are closed, they slide and adhere to the stirring needle, forming a stirring shoulder. The pneumatic mechanism drives these components to expand, creating a feeding gap between them and the stirring needle. Simultaneously, the pneumatic mechanism triggers the loading mechanism, which releases high-performance particles, allowing them to directly enter the welding hole through the feeding gap.

[0030] Through the cooperation of various mechanisms and components, a high-performance particle addition function is achieved without the need to remove the stirring pin. Therefore, during welding, only one positioning is required, eliminating the need for a secondary positioning process. On the one hand, this effectively avoids the error caused by secondary positioning, which leads to low welding accuracy. On the other hand, this high-performance particle addition method simplifies the process flow and reduces operational difficulty, which is conducive to continuous welding and thus significantly improves welding efficiency. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of one embodiment of a retraction spot welding equipment.

[0032] Figure 2 This is a structural schematic diagram from another angle of one embodiment of the retraction spot welding equipment.

[0033] Figure 3 This is a structural schematic diagram from another angle of one embodiment of a retraction spot welding equipment.

[0034] Figure 4 This is a schematic diagram of a structure in one embodiment of a retraction spot welding device, showing multiple arc-shaped components in a closed state.

[0035] Figure 5 This is a schematic diagram showing the connection state between the first power mechanism and the stirring needle in one embodiment of a retraction spot welding device.

[0036] Figure 6 for Figure 5 A structural diagram from another angle.

[0037] Figure 7 This is a schematic diagram of the bottom structure of the crossbeam in one embodiment of a retraction spot welding device.

[0038] Figure 8 This is a schematic diagram of the loading mechanism in one embodiment of a retraction spot welding device.

[0039] Figure 9 This is an exploded view of the pneumatic mechanism in one embodiment of a retraction spot welding device.

[0040] Figure 10 for Figure 9 A structural diagram from another angle.

[0041] Figure 11 This is a diagram showing two solder joints.

[0042] Figure 12 This is a cross-sectional view of one of the weld points.

[0043] Figure 13 This is a cross-sectional view of another weld point.

[0044] In the diagram: 1. Lifting bracket; 2. First assembly plate; 3. Second assembly plate; 4. First linear drive module; 5. Second linear drive module; 6. First motor; 7. Connecting plate; 8. Horizontal platform; 801. Assembly base; 802. Feed inlet; 9. Inner cylinder; 901. Slide groove; 902. First through-hole; 10. Outer cylinder; 1001. Support arm; 1002. Second through-hole; 1003. Strip groove; 11. Drive tube; 1101, Strip groove; 12, Second motor; 13, Third motor; 14, First gear; 15, Second gear; 16, Stirring needle; 1601, Strip protrusion; 17, Movable block; 1701, Connecting seat; 18, Arc-shaped part; 19, Slide plate; 20, Ring body; 2001, Connecting rod; 2002, Annular groove; 2003, Protruding column; 21, Cylinder; 22, Slider; 23, Third gear; 24, Gear ring. Detailed Implementation

[0045] 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.

[0046] 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.

[0047] Please see Figures 1-10In this embodiment of the invention, a retraction spot welding device includes a lifting support 1, a first assembly plate 2 movably mounted on the lifting support 1, and a second assembly plate 3 movably mounted on the first assembly plate 2, and further includes:

[0048] The first motor 6 is mounted on the second assembly plate 3. The output shaft of the first motor 6 is fixedly connected to the cross platform 8 through the connecting plate 7. The cross platform 8 is provided with a stirring needle 16. The stirring needle 16 can be driven to rotate by the first power mechanism provided on the cross platform 8. The output shaft of the first motor 6 is not concentric with the stirring needle 16. When the first motor 6 works, it can drive the cross platform 8 to drive the stirring needle 16 to move along a circular trajectory. At the same time, the threaded drive mechanism provided on the cross platform 8 can drive the stirring needle 16 to perform a retraction action.

[0049] The outer cylinder 10 is rotatably installed at the bottom of the horizontal platform 8. The outer cylinder 10 is equipped with a loading mechanism for holding high-performance particles, and the bottom end of the outer cylinder 10 is equipped with multiple arc-shaped parts 18. The horizontal platform 8 is also equipped with a second power mechanism for driving the outer cylinder 10 to rotate the multiple arc-shaped parts 18.

[0050] Among them, multiple arc-shaped parts 18 can be driven by a pneumatic mechanism set on the horizontal platform 8 to perform opening and closing actions. When the multiple arc-shaped parts 18 are in the closed state, they slide and fit with the stirring needle 16 to form a stirring shoulder. When they are in the opening action, a feeding gap is formed between them and the stirring needle 16, and the loading mechanism is triggered, and high-performance particles enter the welding hole through the feeding gap.

[0051] In detail (see) Figure 4 and Figure 7 A ring-shaped mounting base 801 is fixedly installed at the bottom of the horizontal platform 8. The upper end of the outer cylinder 10 is rotatably connected to the mounting base 801. The horizontal platform 8 is also provided with a feed port 802, which corresponds to the position of the outer cylinder 10 and is used to periodically replenish high-performance particles to the loading mechanism.

[0052] It should be further explained that two sets of opposing first linear drive modules 4 are provided on the lifting bracket 1, the first assembly plate 2 is located between the two sets of first linear drive modules 4, and both ends are respectively connected to the two sets of first linear drive modules 4. A second linear drive module 5 is installed on the first assembly plate 2, and the second assembly plate 3 is connected to the second linear drive module 5.

[0053] It should be noted that the first linear drive module 4 and the second linear drive module 5 have the same structure (both are driven by threaded rods), but their installation orientations are different. Specifically, in actual operation, the two sets of the first linear drive modules 4 can drive the first assembly plate 2 to move along a direction perpendicular to its own length, and the second linear drive module 5 can drive the second assembly plate 3 to move along the first assembly plate 2. Thus, the function of adjusting the lateral and longitudinal displacement of the stirring needle 16 is realized.

[0054] It should also be noted that the lifting bracket 1 is a lifting design, specifically, it can be hydraulically driven. This will not be elaborated further in this application. During operation, the position of the stirring needle 16 is adjusted by the first linear drive module 4 and the second linear drive module 5 so that the stirring needle 16 corresponds to the welding position. Subsequently, the threaded drive mechanism can drive the stirring needle 16 to move relative to the arc-shaped part 18, so that the stirring needle 16 extends to a suitable length. Then the lifting bracket 1 lowers its height so that the stirring needle 16 penetrates the part to be welded. After the bottom end of the arc-shaped part 18 contacts the part, the lifting bracket 1 is raised again.

[0055] Subsequently, the pneumatic mechanism operates, driving multiple arc-shaped components 18 to perform an expansion action, switching from a closed state to an open state. Thus, the feeding gap is formed between the arc-shaped component 18 and the stirring needle 16. At the same time, the loading mechanism is triggered to release high-performance particles, which then enter the welding hole through the feeding gap, realizing the function of adding high-performance particles.

[0056] To address this, the present invention provides multiple arc-shaped components 18 capable of opening and closing. When the multiple arc-shaped components 18 are in a closed state, they can slide and fit against the stirring needle 16 to form a stirring shoulder. The pneumatic mechanism can drive the multiple arc-shaped components 18 to perform an expansion action, creating a feeding gap between the arc-shaped components 18 and the stirring needle 16. Simultaneously, the pneumatic mechanism can trigger the loading mechanism, which then releases the high-performance particles, allowing them to directly enter the welding hole through the feeding gap.

[0057] Through the cooperation of various mechanisms and components, a high-performance particle addition function is achieved without the need to remove the stirring pin 16. Therefore, during welding, only one positioning is required, eliminating the need for a secondary positioning process. On the one hand, this effectively avoids the error caused by secondary positioning, which leads to low welding accuracy. On the other hand, this high-performance particle addition method simplifies the process flow and reduces operational difficulty, which is conducive to continuous welding and thus significantly improves welding efficiency.

[0058] Please refer to it again. Figure 6 , Figure 9as well as Figure 10 The pneumatic mechanism includes a ring 20 slidably sleeved on the outer cylinder 10. The ring 20 can be driven by two sets of lifting components mounted on the horizontal platform 8 to slide upwards or downwards relative to the outer cylinder 10. The ring 20 is connected to the arc-shaped member 18 via a push-pull structure and is also connected to the loading mechanism. The push-pull structure includes a support arm 1001 fixedly mounted on the outer wall of the outer cylinder 10, a sliding plate 19 slidably sleeved with the support arm 1001, and a connecting rod 2001 hinged to the ring 20. One end of the connecting rod 2001 away from the ring 20 is hinged to the sliding plate 19, and the sliding plate 19 is fixed to the arc-shaped member 18. The lifting components include a cylinder 21 fixedly mounted on the horizontal platform 8 and a slider 22 fixedly connected to the movable end of the cylinder 21. The ring 20 is provided with an annular groove 2002, and the slider 22 is slidably fitted into the annular groove 2002.

[0059] Furthermore, when the second power mechanism drives the outer cylinder 10 to rotate the arc-shaped component 18, the slider 22 slides relative to the ring body 20 within the annular groove 2002;

[0060] With attachment Figure 6 Taking the illustrated state as an example, at this time, the multiple arc-shaped parts 18 are in a closed state. When the movable end of the cylinder 21 extends, it can drive the ring body 20 to slide downward on the outer cylinder 10 through the slider 22. Correspondingly, the ring body 20 pushes the slide plate 19 to slide away from the outer cylinder 10 on the support arm 1001 through the connecting rod 2001. The arc-shaped parts 18 move away from the stirring needle 16. The multiple arc-shaped parts 18 perform an expansion action, and the feeding gap is formed between the arc-shaped parts 18 and the stirring needle 16. During this process, when the ring body 20 slides downward on the outer cylinder 10, it will cause the loading mechanism to be triggered. The loading mechanism will then release the high-performance particles so that the high-performance particles can enter the welding hole through the feeding gap.

[0061] Please refer to it again. Figure 10 The loading mechanism includes an inner cylinder 9 rotatably installed inside the outer cylinder 10, and the bottom walls of the inner cylinder 9 and the outer cylinder 10 are slidably attached. The bottoms of the two are provided with a plurality of first openings 902 and second openings 1002 at equal intervals along the circumference. When the plurality of arc-shaped parts 18 are in the closed state, the first openings 902 and the second openings 1002 are staggered. When the plurality of arc-shaped parts 18 switch to the open state, the ring body 20 can cause the inner cylinder 9 to rotate relative to the outer cylinder 10 through two sets of sliding fit structures, so that the first openings 902 and the second openings 1002 overlap.

[0062] The sliding fit structure includes a protruding post 2003 fixed on the inner wall of the ring body 20 and a sliding groove 901 provided on the outer wall of the inner cylinder 9 and adapted to the protruding post 2003. The protruding post 2003 penetrates the outer cylinder 10 and extends into the sliding groove 901, and is slidably connected to the inner cylinder 9. The sliding groove 901 is spirally arranged. The outer cylinder 10 is also provided with a strip-shaped through groove 1003 for the movement of the protruding post 2003. The strip-shaped through groove 1003 is parallel to the central axis of the outer cylinder 10.

[0063] The cylinder 21 drives the ring 20 to slide downward on the outer cylinder 10 through the slider 22, so that when the multiple arc-shaped parts 18 perform the opening action, the corresponding protrusion 2003 will slide with the inner cylinder 9 through the sliding groove 901, so that the inner cylinder 9 and the outer cylinder 10 rotate relative to each other. As a result, the first opening 902 and the second opening 1002, which were originally in a staggered state, gradually have overlapping parts. When the overlapping part is formed, the high-performance particles in the inner cylinder 9 can fall through the overlapping part and enter the welding hole through the feeding gap formed at this time.

[0064] It should be noted that when the multiple arc-shaped parts 18 are in the closed state, the second power mechanism drives the outer cylinder 10 to rotate. The outer cylinder 10 can drive the arc-shaped parts 18 to rotate synchronously through the support arm 1001 and the slide plate 19. In addition, the ring body 20 also rotates together, and the ring body 20 drives the inner cylinder 9 to rotate together through the protrusion 2003. The inner cylinder 9 and the outer cylinder 10 remain relatively stationary. When the multiple arc-shaped parts 18 perform the opening action, the ring body 20 changes in height, which causes the rotation of the inner cylinder 9 and the outer cylinder 10 to be different. By utilizing the relative rotation of the two, the first opening 902 and the second opening 1002 overlap, realizing the automatic release function of high-performance particles.

[0065] Conversely, after the high-performance particles are added, the moving end of the cylinder 21 drives all components to reset, and the first port 902 and the second port 1002 return to their staggered state, terminating the release of the high-performance particles.

[0066] Please refer to it again. Figure 5 and Figure 7 The thread drive mechanism includes two movable blocks 17 movably mounted on the horizontal platform 8. A connecting seat 1701 is fixed between the two movable blocks 17. The connecting seat 1701 is rotatably connected to the stirring needle 16. Each of the two movable blocks 17 is connected to a set of servo drive components. The servo drive components can drive the movable blocks 17 to move up and down on the horizontal platform 8.

[0067] In detail, the servo drive assembly includes a lead screw rotatably mounted on the horizontal platform 8 and a servo motor mounted on the horizontal platform 8. The output end of the servo motor is connected to the lead screw, and the lead screw passes through the movable block 17. The movable block 17 is threadedly connected to the lead screw.

[0068] During operation, the first motor 6 operates, which can drive the stirring needle 16 to move along a circular trajectory. During this process, the servo motor drives the lead screw to rotate, so that the movable block 17 moves upward on the horizontal platform 8. Thus, the connecting seat 1701 can drive the stirring needle 16 to move upward and gradually retract.

[0069] The retraction of the stirring needle 16 is controlled by a servo motor and a lead screw, which has high driving precision and good stability, and can effectively guarantee the welding effect.

[0070] Please refer to it again. Figure 5 and Figure 7 The first power mechanism includes a drive tube 11 rotatably mounted on the horizontal platform 8 and slidably fitted with the stirring needle 16. The outer wall of the stirring needle 16 is provided with a strip-shaped protrusion 1601, and the inner wall of the drive tube 11 is provided with a strip-shaped groove 1101 adapted to the strip-shaped protrusion 1601. The strip-shaped protrusion 1601 and the strip-shaped groove 1101 are parallel to the central axis of the stirring needle 16. A second motor 12 is also mounted on the horizontal platform 8. A first gear 14 is fixed on the output shaft of the second motor 12. The first gear 14 meshes with a second gear 15 fixed on the drive tube 11.

[0071] Please refer to it again. Figure 4 and Figure 6 The second power mechanism includes a third motor 13 mounted on the cross platform 8 and a third gear 23 fixed on the output shaft of the third motor 13. A gear ring 24 that meshes with the third gear 23 is fixed on the outer cylinder 10.

[0072] During operation, the second motor 12 operates and can drive the drive tube 11 to rotate through the first gear 14 and the second gear 15. In turn, the drive tube 11 drives the stirring needle 16 to rotate through the strip groove 1101 and the strip protrusion 1601.

[0073] Secondly, when the third motor 13 is working, it can drive the outer cylinder 10 to rotate through the third gear 23 and the gear ring 24, and the outer cylinder 10 can drive the multiple arc-shaped parts 18 to rotate synchronously.

[0074] Both the second motor 12 and the third motor 13 are speed-regulating motors, capable of independently driving the stirring pin 16 and the stirring shoulder (formed by multiple arc-shaped parts 18 in a closed state) to rotate. This allows for independent control of the movement of the stirring pin 16 and the stirring shoulder. Specifically, the rotational speed of the stirring shoulder is typically lower than that of the stirring pin 16. This is to achieve more precise heat management and material mixing during the welding process. The high rotational speed of the stirring pin 16 can quickly generate sufficient frictional heat to soften the material to be welded and create a good stirring effect, thereby ensuring the uniformity and strength of the weld joint. The low rotational speed of the stirring shoulder provides stable additional heat to help maintain the softened state of the material while preventing uneven distribution or defects caused by excessive stirring. Through this difference in rotational speed, the welding process can better control heat input and material flow, thereby improving welding quality, reducing welding defects, and ensuring the density and strength of the weld joint.

[0075] As another embodiment of the present invention, a spot welding method is also proposed, which uses the aforementioned retraction spot welding equipment and includes the following steps:

[0076] Step 1: Control the movement of the first assembly plate 2 and the second assembly plate 3 so that the stirring needle 16 corresponds to the welding position;

[0077] Step 2: The threaded drive mechanism adjusts the length of the stirring needle 16, and the lifting bracket 1 moves down so that the stirring needle 16 penetrates the part to be welded.

[0078] Step 3: The stirring shoulder contacts the part to be welded, and the stirring pin 16 and the stirring shoulder are lifted.

[0079] Step 4: The pneumatic mechanism drives multiple arc-shaped parts 18 to expand, forming a feeding gap. The loading mechanism releases high-performance particles, which enter the welding hole through the feeding gap.

[0080] Step 5: Start welding. The stirring pin 16 moves along a circular trajectory. The threaded drive mechanism drives the stirring pin 16 to retract until it is flush with the stirring shaft shoulder.

[0081] In one embodiment, please refer to Figure 11 and Figure 12 A spot welding method, comprising:

[0082] First, set the stirring needle 16 to a specified length, and then insert it into the part to be welded at a speed of 20 mm / min to 60 mm / min. Preferably, the part is a 2 mm and 3 mm overlapping plate, the length of the stirring needle 16 is set to 3 mm, and then it is inserted into the part to be welded at a speed of 20 mm / min.

[0083] After the stirring shoulder contacts the part to be welded, lift the needle and the shoulder, and then add high-performance particles such as SiC into the hole;

[0084] After the particles are placed in, welding is performed according to the set parameters: rotation speed 300 rpm to 1800 rpm, welding speed 40 mm / min to 120 mm / min, preferably 1200 rpm and 80 mm / min.

[0085] Depending on the welding depth, the welding trajectory is a circle with a diameter of φ2-φ6mm, preferably a circle with a diameter of φ4mm;

[0086] Once the welding process begins, the stirring pin moves along a circular path while slowly retracting. When it completes a full circle, the long end of the pin is retracted to be flush with the shoulder of the shaft. The retraction speed of the stirring pin is 20 mm / min to 60 mm / min. In this way, keyless welding is achieved while completing the lap spot welding.

[0087] 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.

[0088] 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 retraction spot welding device, comprising a lifting support, a first assembly plate movably mounted on the lifting support, and a second assembly plate movably mounted on the first assembly plate; Its features are, Also includes: The first motor is mounted on the second assembly plate. The output shaft of the first motor is fixedly connected to a cross platform through a connecting plate. A stirring needle is provided on the cross platform. The stirring needle can be driven to rotate by the first power mechanism on the cross platform. The output shaft of the first motor is not concentric with the stirring needle. When the first motor works, it can drive the cross platform to move the stirring needle along a circumferential trajectory. At the same time, the threaded drive mechanism on the cross platform can drive the stirring needle to perform a retraction action. The outer cylinder is rotatably installed at the bottom of the horizontal platform. The outer cylinder is equipped with a loading mechanism for holding high-performance particles. The bottom end of the outer cylinder is equipped with multiple arc-shaped parts. The horizontal platform is also equipped with a second power mechanism for driving the outer cylinder to rotate multiple arc-shaped parts. Among them, multiple arc-shaped parts can be driven by a pneumatic mechanism set on the horizontal platform to perform opening and closing actions. When the multiple arc-shaped parts are in the closed state, they slide and fit with the stirring needle to form a stirring shoulder. When they are in the opening action, a feeding gap is formed between them and the stirring needle, and the loading mechanism is triggered, and high-performance particles enter the welding hole through the feeding gap.

2. The retraction spot welding equipment according to claim 1, characterized in that, The pneumatic mechanism includes a ring that is slidably sleeved on the outer cylinder. The ring can be driven by two sets of lifting components on the horizontal platform to slide upward or downward relative to the outer cylinder. The ring is connected to the arc-shaped component through a push-pull structure and is also connected to the loading mechanism.

3. The retraction spot welding equipment according to claim 2, characterized in that, The push-pull structure includes a support arm fixedly mounted on the outer wall of the outer cylinder, a sliding plate that slidably engages with the support arm, and a connecting rod hinged to the ring body. The end of the connecting rod away from the ring body is hinged to the sliding plate, and the sliding plate is fixed to the arc-shaped component.

4. The retraction spot welding equipment according to claim 2, characterized in that, The lifting assembly includes a cylinder fixedly installed on the horizontal platform and a slider fixedly connected to the movable end of the cylinder. The ring body is provided with an annular groove, and the slider is slidably fitted into the annular groove.

5. The retraction spot welding equipment according to claim 2, characterized in that, The loading mechanism includes an inner cylinder rotatably installed inside the outer cylinder, and the bottom walls of the inner cylinder and the outer cylinder are slidably attached to each other. The bottoms of the two cylinders are provided with a plurality of first openings and second openings at equal intervals along the circumference. When the multiple arc-shaped components are in the closed state, the first opening and the second opening are offset. When the multiple arc-shaped components switch to the open state, the ring body can cause the inner cylinder to rotate relative to the outer cylinder through two sets of sliding fit structures, so that the first opening and the second opening have overlapping parts.

6. The retraction spot welding equipment according to claim 5, characterized in that, The sliding fit structure includes a protrusion fixed on the inner wall of the ring and a sliding groove provided on the outer wall of the inner cylinder and adapted to the protrusion. The protrusion passes through the outer cylinder and extends into the sliding groove, and is slidably connected to the inner cylinder. The slide groove is spirally arranged, and the outer cylinder is also provided with a strip-shaped through groove for the movement of the protrusion, the strip-shaped through groove being parallel to the central axis of the outer cylinder.

7. The spot welding equipment according to claim 1, characterized in that, The threaded drive mechanism includes two movable blocks movably mounted on the horizontal platform. A connecting seat is fixed between the two movable blocks. The connecting seat is rotatably connected to the stirring needle. Each of the two movable blocks is connected to a set of servo drive components, which can drive the movable blocks to move up and down on the horizontal platform.

8. The retraction spot welding equipment according to claim 1, characterized in that, The first power mechanism includes a drive tube rotatably mounted on the cross platform and slidably fitted with the stirring needle. The outer wall of the stirring needle is provided with a strip-shaped protrusion, and the inner wall of the drive tube is provided with a strip-shaped groove adapted to the strip-shaped protrusion. The strip-shaped protrusion and the strip-shaped groove are parallel to the central axis of the stirring needle. A second motor is also installed on the cross platform. A first gear is fixed on the output shaft of the second motor. The first gear meshes with a second gear fixed on the drive tube.

9. The retraction spot welding equipment according to claim 1, characterized in that, The second power mechanism includes a third motor mounted on the cross platform and a third gear fixed on the output shaft of the third motor. A gear ring that meshes with the third gear is fixed on the outer cylinder.

10. A spot welding method, employing the retraction spot welding equipment as described in claim 1, characterized in that, Includes the following steps: Step 1: Control the movement of the first assembly plate and the second assembly plate so that the stirring pin corresponds to the welding position; Step 2: The threaded drive mechanism adjusts the length of the stirring needle, and the lifting bracket moves down so that the stirring needle penetrates the part to be welded. Step 3: The stirring shoulder contacts the part to be welded, and the stirring pin is lifted from the stirring shoulder; Step four: The pneumatic mechanism drives multiple arc-shaped parts to expand, forming a feeding gap. The loading mechanism releases high-performance particles, which enter the welding hole through the feeding gap. Step 5: Start welding. The stirring pin moves along a circular trajectory. The threaded drive mechanism drives the stirring pin to retract until it is flush with the stirring shaft shoulder.

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