Copper-magnesium-aluminum spot welding apparatus and method

Abstract

Disclosed is a copper-magnesium-aluminum spot welding apparatus, relating to the technical field of heterogeneous material spot welding. The present invention comprises a hydraulic rotary seat; a driving assembly is mounted at the top portion of the hydraulic rotary seat; a driving shaft is mounted at the output end of the driving assembly; a top pressing sleeve assembly is fixedly mounted at the bottom portion of the hydraulic rotary seat; the driving shaft is rotatably connected inside the hydraulic rotary seat and the top pressing sleeve assembly; the bottom portion of the hydraulic rotary seat is fixedly connected to a jacking oil cylinder; there is a gap between the jacking oil cylinder and the top pressing sleeve assembly; and the sheets to be connected are placed between the jacking oil cylinder and the top pressing sleeve assembly. In the present invention, the unique design of internal and external threads of a plug sleeve and the synergistic effect of a drive motor and a hydraulic system allow for high-quality spot welding of copper-magnesium-aluminum heterogeneous alloys, thereby effectively obviating the problems of joint brittleness and gaps existing in traditional riveting caused by excessive intermetallic compounds in traditional fusion spot welding.

Description

A copper-magnesium-aluminum spot welding device and method Technical Field

[0001] This invention relates to the field of dissimilar material spot welding technology, specifically a copper-magnesium-aluminum spot welding device and method. Background Technology

[0002] Fusion welding, ultrasonic welding, laser welding, and resistance welding all suffer from low welding quality and the presence of a large number of brittle intermetallic compounds in the weld zone due to the melting and resolidation of the metal, which can easily lead to brittle fracture of the spot weld joint.

[0003] While molecular diffusion welding and brazing can effectively reduce the formation of brittle intermetallic compounds, their spot weld strength is low, making them unsuitable as spot welding processes for load-bearing structural components.

[0004] Friction stir welding, as a solid-state welding method, has good welding strength and fewer brittle intermetallic compounds. However, it also has problems such as long spot welding time, high equipment requirements, and large equipment footprint. At the same time, it is basically impossible to spot weld copper, magnesium and aluminum at the same time. For thicker plates, such as plates with a thickness of 5 mm or more, spot welding is also impossible. Therefore, this invention proposes a copper-magnesium-aluminum spot welding device and method. Summary of the Invention

[0005] The purpose of this invention is to provide a copper-magnesium-aluminum spot welding device and method to achieve high-quality spot welding of dissimilar copper-magnesium-aluminum alloys. This solves the problem of brittle joint fracture caused by excessive intermetallic compounds in traditional fusion spot welding, and also solves the problem of gaps in joints caused by traditional riveting.

[0006] According to a first aspect of the present invention, in order to achieve the above-mentioned objective, the present invention provides the following technical solution: a copper-magnesium-aluminum spot welding device, comprising a hydraulic rotary seat, a drive assembly mounted on the top of the hydraulic rotary seat, a drive shaft mounted on the output end of the drive assembly, a top pressure sleeve assembly fixedly mounted on the bottom of the hydraulic rotary seat, and the drive shaft rotatably connected to the hydraulic rotary seat and the top pressure sleeve assembly.

[0007] A lifting cylinder is fixedly connected to the bottom of the hydraulic rotary seat. There is a gap between the lifting cylinder and the pressure sleeve assembly. The plate to be connected is placed between the lifting cylinder and the pressure sleeve assembly.

[0008] The bottom outer surface of the drive shaft is fitted with a compression sleeve, and the bottom end of the compression sleeve is coaxially fitted with a plug sleeve. The outer side of the plug sleeve has an external thread, and the inner side has an internal thread. The external thread and the internal thread have opposite directions of rotation and different pitches. The plug sleeve and the compression sleeve can rotate relative to each other.

[0009] When the drive shaft rotates, it will drive the plug sleeve and the extrusion sleeve to rotate simultaneously. During the rotation, the plug sleeve and the plate to be connected will generate high-speed friction and heat, softening the plate to be connected and forming solid phase welding. At the same time, the plug sleeve will be screwed into the plate to be connected under the downward force of the extrusion sleeve.

[0010] Furthermore, it also includes a hydraulic pump, which is connected to the hydraulic rotary seat and the lifting cylinder through oil supply and return pipelines, respectively, to drive the hydraulic rotary seat and the lifting cylinder to extend and retract simultaneously.

[0011] Furthermore, the hydraulic rotary seat moves in the opposite direction to the lifting cylinder, and is used to fix the position of the plates to be connected.

[0012] Furthermore, the plates to be connected include an upper plate and a lower plate, and the upper plate and the lower plate are made of different materials.

[0013] Furthermore, the top pressure sleeve assembly includes a top pressure sleeve outer shell that is fixedly installed at the bottom of the hydraulic rotary seat by bolts. An inner cavity is formed between the top pressure sleeve outer shell and the hydraulic rotary seat. A piston is slidably connected inside the inner cavity along the axial direction. The drive shaft is rotatably connected inside the hydraulic rotary seat through a rotary bearing. The extrusion sleeve is rotatably connected inside the top pressure sleeve outer shell through a rotary bearing. When the piston cylinder moves up and down, it will drive the extrusion sleeve to move accordingly.

[0014] A guide cylinder is fixedly installed at the bottom end of the top pressure sleeve shell. The extrusion sleeve and the plug sleeve are rotatably connected inside the guide cylinder and are coaxially arranged with it.

[0015] Furthermore, the drive assembly is configured as a motor, with the motor output end fixedly connected to the drive shaft. The two sides of the drive shaft away from the motor are fixedly connected with protruding keys, and the inside of the extrusion sleeve and the plug sleeve are respectively provided with a first keyway and a second keyway that are adapted to the protruding keys.

[0016] Furthermore, the extrusion sleeve includes a coarse connecting part and a fine connecting part, which are integrally formed, and a through circular hole is opened in the center of the coarse connecting part and the fine connecting part. The first keyway is opened on the inner wall of the circular hole located at the position of the fine connecting part.

[0017] Furthermore, the plug sleeve is configured as a hollow cylindrical shape, and the thermal stability of the plug sleeve is greater than that of the plate to be connected.

[0018] Furthermore, the diameter of the plug sleeve is equal to the diameter of the thin connecting portion of the extrusion sleeve, and the first keyway and the second keyway are aligned.

[0019] According to a second aspect of the present invention, a copper-magnesium-aluminum spot welding method is provided, using a copper-magnesium-aluminum spot welding apparatus described in the first aspect, comprising the following steps:

[0020] S1. When preparing to start welding, first stack the two dissimilar plates to be connected and place them on the lifting cylinder. Then, use a hydraulic pump to supply hydraulic oil to the inside of the lifting cylinder and the hydraulic rotary seat, drive the lifting cylinder to move upward, and drive the hydraulic rotary seat to move the top pressure sleeve assembly downward, so that the plates to be connected can be completely squeezed and fixed. At this time, the lower end face of the drive shaft and the plug sleeve is completely in contact with the upper surface of the upper plate of the plates to be connected.

[0021] S2. When entering the welding stage, the start motor drives the drive shaft to rotate. The drive shaft will drive the extrusion sleeve and the plug sleeve to rotate simultaneously. At the same time, the extrusion sleeve presses down on the plug sleeve, forcing the plug sleeve to generate high-speed friction and heat between the plate to be connected and softening the plate to be connected, thus forming solid-phase welding.

[0022] S3. As the welding process proceeds, the plug sleeve is gradually and completely squeezed out until its upper end face coincides with the upper surface of the upper plate. At this time, the plug sleeve has completely disengaged from the drive shaft and loses its high-speed rotational motion instantly. At the same time, the extrusion sleeve stops extruding, and the plug sleeve is instantly stopped inside the plate to be connected. Its internal and external threads achieve a dual connection with the plate to be connected through solid-state welding and mechanical interlocking.

[0023] This invention has at least the following beneficial effects:

[0024] 1. This invention achieves high-quality spot welding of dissimilar copper-magnesium-aluminum alloys through a unique plug sleeve internal and external thread design and the synergistic effect of a drive motor and hydraulic system. It effectively avoids the joint brittle fracture caused by excessive intermetallic compounds in traditional fusion welding, as well as the gap problem existing in traditional riveting.

[0025] 2. This invention enables the simultaneous superposition welding of various dissimilar copper-magnesium-aluminum alloys, including simultaneous superposition welding of three metals and welding of plates of different thicknesses. This is difficult to achieve with traditional fusion welding, which broadens the application range of welding technology. Furthermore, when dissimilar alloy plates are superimposed, there is no need to consider the placement order of the plates, thus improving the flexibility and convenience of welding.

[0026] 3. The optimized design and reasonable coordination of each component in this invention ensures the stability and reliability of the welding process, reduces the number of welding interruptions and adjustments, improves welding efficiency, and facilitates the manufacturing and assembly of each component, simplifies maintenance and repair work, reduces equipment maintenance costs and downtime, and improves production efficiency and economic benefits.

[0027] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

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

[0029] Figure 2 is a frontal cross-sectional view of the overall structure of the present invention;

[0030] Figure 3 is a side sectional view of the overall structure of the present invention.

[0031] Figure 4 is a schematic diagram of the welding process of the plates to be connected according to the present invention, wherein (a) represents the welding start state, (b) represents the welding intermediate state, and (c) represents the welding end state.

[0032] Figure 5 is a side view of the drive shaft in this invention;

[0033] Figure 6 is a top view of the drive shaft in this invention.

[0034] Figure 7 is a side sectional view of the extrusion sleeve in this invention;

[0035] Figure 8 is a top view of the extrusion sleeve in this invention;

[0036] Figure 9 is a side sectional view of the plug sleeve in this invention;

[0037] Figure 10 is a top view of the plug sleeve in this invention.

[0038] Reference numerals: 1. Drive assembly; 2. Hydraulic pump; 3. Hydraulic rotary seat; 4. Top pressure sleeve assembly; 41. Top pressure sleeve outer shell; 42. Inner cavity; 43. Piston; 44. Slewing bearing; 45. Guide cylinder; 5. Plates to be connected; 51. Upper plate; 52. Lower plate; 6. Lifting cylinder; 7. Drive shaft; 71. Protruding key; 8. Extrusion sleeve; 81. First keyway; 82. Coarse connection part; 83. Fine connection part; 9. Plug sleeve; 91. Second keyway; 92. External thread; 93. Internal thread. Detailed Implementation

[0039] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0040] Example 1:

[0041] Please refer to Figures 1-3. The present invention provides a technical solution: a copper-magnesium-aluminum spot welding device, applied in the field of welding dissimilar materials of copper, magnesium and aluminum, including a hydraulic rotary seat 3, a drive assembly 1 installed on the top of the hydraulic rotary seat 3, a drive shaft 7 installed at the output end of the drive assembly 1, and a top pressure sleeve assembly 4 fixedly installed at the bottom of the hydraulic rotary seat 3. The drive shaft 7 is rotatably connected to the hydraulic rotary seat 3 and the top pressure sleeve assembly 4.

[0042] A lifting cylinder 6 is fixedly connected to the bottom of the hydraulic rotary seat 3. There is a gap between the lifting cylinder 6 and the top pressure sleeve assembly 4. The plate 5 to be connected is placed between the lifting cylinder 6 and the top pressure sleeve assembly 4.

[0043] A compression sleeve 8 is fitted on the outer surface of the bottom end of the drive shaft 7. A plug sleeve 9 is coaxially provided at the bottom end of the compression sleeve 8. The plug sleeve 9 has an external thread 92 on the outer side and an internal thread 93 on the inner side. The external thread 92 and the internal thread 93 have opposite directions of rotation and different pitches. The plug sleeve 9 and the compression sleeve 8 can rotate relative to each other.

[0044] As shown in Figure 4, when the drive shaft 7 rotates, it will drive the plug sleeve 9 and the extrusion sleeve 8 to rotate simultaneously. During the rotation, the plug sleeve 9 and the plate to be connected 5 generate high-speed friction and heat, softening the plate to be connected 5 and forming solid-phase welding. At the same time, the plug sleeve 9 will be screwed into the plate to be connected 5 under the downward force of the extrusion sleeve 8, and will stop instantly when it is fully screwed into the plate to be connected 5, realizing the mechanical interlock between the plug sleeve 9 and the plate to be connected 5.

[0045] It should be noted that the pitch of the external thread 92 of the plug sleeve 9 is greater than that of the internal thread 93. This is because the external thread 92 has a larger contact area with the plate 5 to be connected, requiring more material flow to be accommodated during screwing. When the plug sleeve 9 rotates at high speed, the high-speed friction generates heat, softening the plate 5 to be connected. Therefore, the softened material of the plate 5 will flow between the threads during high-speed rotation of the plug sleeve 9. The larger pitch of the external thread 92 allows for more material flow. The internal thread 93, however, rotates in the opposite direction to the external thread 92. Its main function is to allow for more material flow during high-speed rotation. The thread 93 will generate greater friction with the plate 5, which will facilitate the generation of more heat to soften the plate 5 to be connected. After the plate 5 is softened, the plug sleeve 9 can better bond with the metal of the plate 5 to form a solid phase weld. Furthermore, due to the softening of the plate 5 and the downward force of the compression sleeve 8 when the plug sleeve 9 rotates, the plug sleeve 9 will not interfere with the internal and external threads 92. The plug sleeve 9 will be squeezed into the softened plate 5 to be connected. In this way, after the plate 5 is cooled, a solid phase weld and mechanical interlock will be formed simultaneously.

[0046] Furthermore, the plug sleeve 9 is configured as a hollow cylindrical shape. The thermal stability of the plug sleeve 9 is greater than that of the plate 5 to be connected. Therefore, the thermal stability of the plug sleeve 9 is stronger than that of the plate 5 to be connected. During high-speed friction, the screws of the internal thread 93 and external thread 92 of the plug sleeve 9 will not be damaged and will not affect the screwing process of the plug sleeve 9. For the technical solution of this embodiment, the plug sleeve 9 is made of H13 mold steel, SKD61 mold steel or DC53 mold steel.

[0047] As shown in Figure 1, for the technical solution of this embodiment, the copper-magnesium-aluminum spot welding device also includes a hydraulic pump 2. The hydraulic pump 2 is connected to the hydraulic rotary seat 3 and the lifting cylinder 6 through the oil supply pipe and the oil return pipe respectively, and is used to drive the hydraulic rotary seat 3 and the lifting cylinder 6 to extend and retract simultaneously. When extending, the hydraulic pump 2 will deliver high-pressure oil to the hydraulic rotary seat 3 and the lifting cylinder 6 through the oil supply pipe, push the piston 43 to move, and realize the extension. When the piston 43 moves, the oil on the other side needs to return to the oil tank through the oil return pipe to maintain the circulation and balance of the hydraulic system.

[0048] Regarding the technical solution of this embodiment, as shown in Figures 2 and 3, the hydraulic rotary seat 3 and the lifting cylinder 6 always move in opposite directions to fix the position of the plate 5 to be connected. When welding is required on the plate 5 to be connected, the lifting cylinder 6 extends upward, and at the same time, the hydraulic rotary seat 3 drives the top pressure sleeve assembly 4 to move downward, completely pressing and fixing the plate 5 to be connected. At this time, the lower end face of the drive shaft 7 and the plug sleeve 9 are completely in contact with the upper surface of the plate 5 to be connected. It should be noted that copper, magnesium and aluminum dissimilar alloys can be welded in any combination form without considering the placement order of the plates 5, which increases the flexibility and applicability of welding.

[0049] Regarding the technical solution of this embodiment, as shown in Figure 4, the plate 5 to be connected includes an upper plate 51 and a lower plate 52. The upper plate 51 and the lower plate 52 are made of different materials. The material of the upper plate 51 or the lower plate 52 can be any one of copper, magnesium or aluminum. However, since the materials of the upper plate 51 and the lower plate 52 are different, when the upper plate 51 is copper, the material of the lower plate 52 is set to magnesium or aluminum, and so on. It should be noted that this embodiment uses copper, magnesium or aluminum as an example for explanation, but does not limit the specific type of material of the plate 5. If the technical solution used in other technologies is only different from that of this embodiment in terms of the type of material of the plate 5, it will also fall within the protection scope of this embodiment.

[0050] Regarding the technical solution of this embodiment, as shown in Figures 2 and 3, the function of the top pressure sleeve assembly 4 is to provide top pressure for the extrusion sleeve 8. The top pressure sleeve assembly 4 includes a top pressure sleeve outer shell 41 that is fixedly installed at the bottom of the hydraulic rotary seat 3 by bolts. An inner cavity 42 is formed between the top pressure sleeve outer shell 41 and the hydraulic rotary seat 3. A piston 43 is slidably connected inside the inner cavity 42 along the axial direction. The drive shaft 7 is rotatably connected inside the hydraulic rotary seat 3 through a rotary bearing 44. The extrusion sleeve 8 is rotatably connected inside the top pressure sleeve outer shell 41 through the rotary bearing 44. When the piston 43 moves up and down, it will drive the extrusion sleeve 8 to move accordingly.

[0051] A guide cylinder 45 is fixedly installed at the bottom end of the top pressure sleeve housing 41. The extrusion sleeve 8 and the plug sleeve 9 are rotatably connected inside the guide cylinder 45 and are coaxially arranged with it. The guide cylinder 45 can provide guidance for the extrusion sleeve 8 and the plug sleeve 9 when they move downward.

[0052] It should be noted that the number of slewing bearings 44 is at least two. Both slewing bearings 44 are fixed to the side wall of the inner cavity 42 by bolts. The two slewing bearings 44 can support the rotation of the drive shaft 7 and the extrusion sleeve 8 respectively, and will not interfere with the rotation of the extrusion sleeve 8 when the piston 43 drives the extrusion sleeve 8 to move downward.

[0053] Specifically, when the hydraulic rotary seat 3 needs to drive the top pressure sleeve assembly 4 to move downward, the hydraulic pump 2 is started. By supplying hydraulic oil to the upper part of the inner cavity 42, the piston 43 moves downward. When the piston 43 moves downward, it will drive the extrusion sleeve 8 to move accordingly, which can extrude the plug sleeve 9 and provide downward driving force for the plug sleeve 9 to be screwed into the plate 5 to be connected.

[0054] It should be further explained that, as shown in Figure 3, the top pressure sleeve outer shell 41 and the lifting cylinder 6 are connected and fixed by a connecting plate, which facilitates the maintenance of the overall integrity of the device and also facilitates the support of the lifting cylinder 6.

[0055] Regarding the technical solution of this embodiment, as shown in Figures 5 and 6, the drive assembly 1 is configured as a servo motor. The motor output end is fixedly connected to the drive shaft 7. A convex key 71 is fixedly connected to both sides of the end of the drive shaft 7 furthest from the motor. The extrusion sleeve 8 and the plug sleeve 9 are respectively provided with a first keyway 81 and a second keyway 91 that are compatible with the convex key 71. The cooperation between the convex key 71 and the first keyway 81 and the second keyway 91 ensures a firm circumferential connection between the drive shaft 7 and the extrusion sleeve 8 and the plug sleeve 9, ensuring that the rotational power output by the motor can be stably and accurately transmitted to the extrusion sleeve 8 and the plug sleeve 9. This avoids torque transmission failure caused by loose connections during high-speed rotation, ensuring the continuity and stability of the welding process. Furthermore, during assembly, the cooperation between the convex key 71 and the keyway also plays a guiding and positioning role, enabling the extrusion sleeve 8 and the plug sleeve 9 to be accurately installed along the axial direction of the drive shaft 7. This improves the coaxiality and assembly accuracy of the entire device, helps reduce vibration and abnormal wear caused by eccentric rotation of components during welding, and thus improves welding quality.

[0056] Regarding the technical solution of this embodiment, as shown in Figures 7 and 8, the extrusion sleeve 8 includes a coarse connecting part 82 and a fine connecting part 83. The coarse connecting part 82 and the fine connecting part 83 are integrally formed, and a through circular hole is opened in the center of the coarse connecting part 82 and the fine connecting part 83. The first keyway 81 is opened on the inner wall of the circular hole located at the position of the fine connecting part 83. The coarse connecting part 82 and the fine connecting part 83 are integrally formed, and a through circular hole is opened in the center. This structure makes the overall stress of the extrusion sleeve 8 more uniform. The coarse connecting part 82 can bear a large radial force and axial force, while the fine connecting part 83 can achieve precise cooperation with the drive shaft 7 while ensuring strength. During the welding process, when the extrusion sleeve 8 presses the plug sleeve 9 downward, the coarse connecting part 82 can withstand a large reaction force, avoiding deformation or damage of the extrusion sleeve 8 due to local stress concentration, thereby improving the overall strength and stability of the extrusion sleeve 8.

[0057] Regarding the technical solution of this embodiment, as shown in Figures 9 and 10, the plug sleeve 9 is configured as a hollow cylindrical shape. The outer side of the plug sleeve 9 has an external thread 92, and the inner side has an internal thread 93. The external thread 92 and the internal thread 93 have opposite directions of rotation and different pitches. The outer diameter of the plug sleeve 9 is D, and the inner diameter is d. During the welding process, when the extrusion sleeve 8 presses the plug sleeve 9 downward, the plug sleeve 9 is gradually and completely extruded until its upper end face coincides with the upper surface of the upper plate 51. At this time, the plug sleeve 9 has completely disengaged from the drive shaft 7 and instantly loses its high-speed rotational motion. At the same time, the extrusion sleeve 8 stops extruding, and the plug sleeve 9 is instantly stopped inside the upper plate 51 and the lower plate 52. Because the plug sleeve 9 stops instantly, the surface temperature of the plate 5 to be connected drops instantly, and the plate 5 to be connected will not soften excessively, ensuring the realization of solid-state welding. At this time, the internal thread 93 and the external thread 92 of the plug sleeve 9 achieve a dual connection effect of solid-state and mechanical threads with the plate 5 to be connected, achieving the purpose of high-quality welding.

[0058] In this embodiment, the diameter of the plug sleeve 9 is equal to the diameter of the thin connecting portion 83 of the extrusion sleeve 8, and the first keyway 81 and the second keyway 91 are aligned. The alignment of the keyways allows the convex key 71 to simultaneously and tightly engage with the first keyway 81 and the second keyway 91. During rotation, when power is transmitted from the motor output end to the extrusion sleeve 8 and the plug sleeve 9 through the drive shaft 7, precise and uniform power transmission can be achieved, ensuring that the rotation speed and torque of both are consistent. This avoids uneven or delayed power transmission caused by inconsistent diameters or misaligned keyways, improving the stability and reliability of the welding process. Furthermore, the aligned keyways prevent relative sliding between the extrusion sleeve 8 and the plug sleeve 9 during rotation, ensuring their synchronization.

[0059] The principle and process of using this invention:

[0060] When preparing to start welding, first stack the two dissimilar plates 5 to be connected and place them on the lifting cylinder 6. Then, the hydraulic pump 2 supplies hydraulic oil to the lifting cylinder 6 and the hydraulic rotary seat 3, driving the lifting cylinder 6 to move upward and driving the hydraulic rotary seat 3 to move the top pressure sleeve assembly 4 downward, so that the plates 5 to be connected can be completely squeezed and fixed. At this time, the lower end face of the drive shaft 7 and the plug sleeve 9 is completely in contact with the surface of the plates 5 to be connected. The plates 5 to be connected include an upper plate 51 and a lower plate 52. Specifically, the lower end face of the drive shaft 7 and the plug sleeve 9 is in contact with the upper surface of the upper plate 51.

[0061] When the welding stage begins, the starter motor drives the drive shaft 7 to rotate. The drive shaft 7 will drive the extrusion sleeve 8 and the plug sleeve 9 to rotate simultaneously. At the same time, the extrusion sleeve 8 presses the plug sleeve 9 downward, forcing the plug sleeve 9 to generate high-speed friction heat between it and the plate 5 to be connected, softening the plate 5 to be connected, forming a solid-phase weld. The internal thread 93 and the external thread 92 can produce a mechanical interlocking effect with the plate 5 to be connected.

[0062] As the welding process proceeds, the plug sleeve 9 is gradually and completely squeezed out until its upper end face coincides with the upper surface of the upper plate 51. At this time, the plug sleeve 9 has completely separated from the drive shaft 7 and instantly loses its high-speed rotational motion. At the same time, the extrusion sleeve 8 stops extruding, and the plug sleeve 9 is instantly stopped inside the plate 5 to be connected. Its internal thread 93 and external thread 92 achieve a dual connection effect of solid phase and mechanical thread with the plate 5 to be connected, thus achieving the purpose of high-quality welding.

[0063] Example 2:

[0064] This embodiment provides a copper-magnesium-aluminum spot welding method, using a copper-magnesium-aluminum spot welding apparatus described in Embodiment 1, including the following steps:

[0065] S1. When preparing to start welding, first stack the two dissimilar plates 5 to be connected and place them on the lifting cylinder 6. Then, the hydraulic pump 2 supplies hydraulic oil to the lifting cylinder 6 and the hydraulic rotary seat 3 to drive the lifting cylinder 6 to move upward and drive the hydraulic rotary seat 3 to drive the top pressure sleeve assembly 4 to move downward, so that the plates 5 to be connected can be completely squeezed and fixed. At this time, the lower end face of the drive shaft 7 and the plug sleeve 9 is completely in contact with the upper surface of the upper plate 51 of the plates 5 to be connected.

[0066] S2. When entering the welding stage, the start motor drives the drive shaft 7 to rotate. The drive shaft 7 will drive the extrusion sleeve 8 and the plug sleeve 9 to rotate simultaneously. At the same time, the extrusion sleeve 8 presses the plug sleeve 9 downward, forcing the plug sleeve 9 to generate high-speed friction heat with the plate 5 to be connected and softening the plate 5 to be connected, forming solid phase welding.

[0067] S3. As the welding process proceeds, the plug sleeve 9 is gradually and completely squeezed out until its upper end face coincides with the upper surface of the upper plate 51. At this time, the plug sleeve 9 has completely separated from the drive shaft 7 and loses its high-speed rotation motion instantly. At the same time, the extrusion sleeve 8 stops extruding, and the plug sleeve 9 is instantly stopped inside the plate 5 to be connected. Its internal thread 93 and external thread 92 achieve a dual connection with the plate 5 to be connected through solid-state welding and mechanical interlocking.

[0068] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0069] For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances. When an element is referred to as being "assembled on," "mounted on," "fixed to," or "set on" another element, it may be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0070] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0071] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A copper-magnesium-aluminum spot welding device, characterized in that, The hydraulic rotary seat (3) includes a drive assembly (1) installed on the top of the hydraulic rotary seat (3), a drive shaft (7) installed at the output end of the drive assembly (1), and a top pressure sleeve assembly (4) fixedly installed at the bottom of the hydraulic rotary seat (3). The drive shaft (7) is rotatably connected to the hydraulic rotary seat (3) and the top pressure sleeve assembly (4). The bottom of the hydraulic rotary seat (3) is fixedly connected to a lifting cylinder (6), and there is a gap between the lifting cylinder (6) and the top pressure sleeve assembly (4). The plate to be connected (5) is placed between the lifting cylinder (6) and the top pressure sleeve assembly (4). The bottom outer surface of the drive shaft (7) is fitted with a compression sleeve (8), and a plug sleeve (9) is coaxially provided at the bottom end of the compression sleeve (8). The plug sleeve (9) has an external thread (92) on the outside and an internal thread (93) on the inside. The external thread (92) and the internal thread (93) have opposite directions of rotation and different pitches. The plug sleeve (9) and the compression sleeve (8) can rotate relative to each other. When the drive shaft (7) rotates, it will drive the plug sleeve (9) and the extrusion sleeve (8) to rotate simultaneously. During the rotation, the plug sleeve (9) and the plate to be connected (5) generate high-speed friction and heat, softening the plate to be connected (5) and forming solid phase welding. At the same time, the plug sleeve (9) will be screwed into the plate to be connected (5) under the downward force of the extrusion sleeve (8).

2. The copper-magnesium-aluminum spot welding device according to claim 1, characterized in that, It also includes a hydraulic pump (2), which is connected to the hydraulic rotary seat (3) and the lifting cylinder (6) through the oil supply pipeline and the oil return pipeline respectively, and is used to drive the hydraulic rotary seat (3) and the lifting cylinder (6) to extend and retract simultaneously.

3. The copper-magnesium-aluminum spot welding device according to claim 2, characterized in that: The hydraulic rotary seat (3) moves in the opposite direction to the lifting cylinder (6) and is used to fix the position of the plate (5) to be connected.

4. The copper-magnesium-aluminum spot welding device according to claim 3, characterized in that: The plate to be connected (5) includes an upper plate (51) and a lower plate (52), and the upper plate (51) and the lower plate (52) are made of different materials.

5. The copper-magnesium-aluminum spot welding device according to claim 4, characterized in that: The top pressure sleeve assembly (4) includes a top pressure sleeve outer shell (41) fixedly installed at the bottom of the hydraulic rotary seat (3) by bolts. An inner cavity (42) is formed between the top pressure sleeve outer shell (41) and the hydraulic rotary seat (3). A piston (43) is slidably connected inside the inner cavity (42) along the axial direction. The drive shaft (7) is rotatably connected inside the hydraulic rotary seat (3) through a rotary bearing (44). The extrusion sleeve (8) is rotatably connected inside the top pressure sleeve outer shell (41) through a rotary bearing (44). When the piston (43) moves up and down, it will drive the extrusion sleeve (8) to move accordingly. The bottom end of the top pressure sleeve shell (41) is fixedly installed with a guide cylinder (45), and the extrusion sleeve (8) and the plug sleeve (9) are rotatably connected inside the guide cylinder (45) and are coaxially arranged with it.

6. The copper-magnesium-aluminum spot welding device according to claim 5, characterized in that: The drive assembly (1) is configured as a motor, the output end of the motor is fixedly connected to the drive shaft (7), and the two sides of the drive shaft (7) away from the motor are fixedly connected with protruding keys (71). The extrusion sleeve (8) and the plug sleeve (9) are respectively provided with a first keyway (81) and a second keyway (91) that are adapted to the protruding keys (71).

7. The copper-magnesium-aluminum spot welding device according to claim 6, characterized in that: The extrusion sleeve (8) includes a coarse connecting part (82) and a fine connecting part (83). The coarse connecting part (82) and the fine connecting part (83) are integrally formed, and a through circular hole is provided in the center of the coarse connecting part (82) and the fine connecting part (83). The first keyway (81) is opened on the inner wall of the circular hole located at the position of the fine connecting part (83).

8. The copper-magnesium-aluminum spot welding device according to claim 7, characterized in that: The plug sleeve (9) is configured as a hollow cylinder, and the thermal stability of the plug sleeve (9) is greater than that of the plate (5) to be connected.

9. A copper-magnesium-aluminum spot welding device according to claim 8, characterized in that: The diameter of the plug sleeve (9) is equal to the diameter of the thin connecting part (83) of the extrusion sleeve (8), and the first keyway (81) and the second keyway (91) are aligned.

10. A method for spot welding copper, magnesium, and aluminum, characterized in that, The copper-magnesium-aluminum spot welding device according to claim 9 is characterized by comprising the following steps: S1. When preparing to start welding, first stack the two dissimilar plates (5) to be connected and place them on the lifting cylinder (6). Then, the hydraulic pump (2) supplies hydraulic oil to the inside of the lifting cylinder (6) and the hydraulic rotary seat (3), driving the lifting cylinder (6) to move upward and driving the hydraulic rotary seat (3) to drive the top pressure sleeve assembly (4) to move downward, so that the plates (5) to be connected can be completely squeezed and fixed. At this time, the lower end face of the drive shaft (7) and the plug sleeve (9) is completely in contact with the upper surface of the upper plate (51) in the plates (5) to be connected. S2. When entering the welding stage, start the motor to drive the drive shaft (7) to rotate. The drive shaft (7) will drive the extrusion sleeve (8) and the plug sleeve (9) to rotate at the same time. While rotating, the extrusion sleeve (8) will press down on the plug sleeve (9), forcing the plug sleeve (9) to generate high-speed friction heat between the plate to be connected (5) and the plate to be connected (5) and softening the plate to be connected (5) to form solid phase welding. S3. As the welding process proceeds, the plug sleeve (9) is gradually squeezed out completely until its upper end face coincides with the upper surface of the upper plate (51). At this time, the plug sleeve (9) has completely separated from the drive shaft (7) and loses its high-speed rotation motion instantly. At the same time, the extrusion sleeve (8) stops extruding, and the plug sleeve (9) is instantly stopped inside the plate (5) to be connected. Its internal thread (93) and external thread (92) achieve a dual connection of solid-state welding and mechanical interlocking with the plate (5) to be connected.

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