Connection structure and laser welding method

Abstract

The application provides a connecting structure and a laser welding method. The connecting structure comprises at least one boss protruding on a welding surface of a to-be-welded part, the boss is provided with a welding site, and the connecting structure further comprises a glue track strip adhered on the welding surface and spaced from all the bosses. The to-be-welded part is connected to an external welding part through laser welding of the welding site and adhesion of the glue track strip. The boss is arranged, the to-be-welded part is stably welded to the external welding part through the welding site arranged in the boss, the squeezed glue track strip is blocked by the outside of the boss and cannot spread to the welding site, the adverse effect of the glue track strip on welding is eliminated, and the welding strength and welding stability are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of welding, in particular relates to a connecting structure and a laser welding method. BACKGROUND

[0002] At present, laser welding has become a welding method applied to the body-in-white in the automobile industry. In the prior art, the metal workpieces stacked in multiple layers may need to be bonded in laser welding. At this time, because of the existence of the adhesive, the adhesive is easy to mix into the welded joint during welding, and then is ablated by high temperature in the welded joint to form inclusions, thereby weakening the connection strength and affecting the stability of welding. SUMMARY

[0003] The present application provides a connecting structure and a laser welding method to solve the technical problems of low welding strength and stability in the prior art.

[0004] In view of the above technical problems, the present application provides a connecting structure, which comprises at least one boss protruding on the welding surface of a to-be-welded part, wherein a welding site is arranged in the boss, and the connecting structure further comprises an adhesive track strip bonded on the welding surface and spaced apart from all the bosses; the to-be-welded part is connected to an external welding part through laser welding of the welding site and bonding of the adhesive track strip.

[0005] An embodiment of the present application further provides a laser welding method for welding the to-be-welded part with the above connecting structure, which comprises the following steps.

[0006] Stacking the to-be-welded part and the external welding part, and arranging the welding surface of the to-be-welded part opposite to the external welding part;

[0007] Controlling the laser beam to move and irradiate the welding site along a preset arc-shaped track from the center point of the welding site of the boss, so as to form a welded spot between the to-be-welded part and the external welding part; the preset arc-shaped track comprises a plurality of circular arc tracks, and the plurality of circular arc tracks are arranged around the center point.

[0008] The connecting structure comprises at least one boss protruding on the welding surface of the to-be-welded member, and the boss is provided with a welding site; the connecting structure further comprises a glue track strip adhered on the welding surface and spaced from all the bosses; and the to-be-welded member is connected to the external welding member through laser welding of the welding site and adhesion of the glue track strip. BRIEF DESCRIPTION OF DRAWINGS

[0009] The application will be further described below in combination with the drawings and examples.

[0010] Figure 1 Fig. 1 is a structural schematic diagram of the connecting structure provided by the first embodiment of the application.

[0011] Figure 2 Fig. 2 is a structural schematic diagram of the to-be-welded member and the external welding member connected by the connecting structure in the first embodiment of the application.

[0012] Figure 3 Fig. 3 is a structural schematic diagram of the connecting structure provided by the second embodiment of the application.

[0013] Figure 4 Fig. 4 is a structural schematic diagram of the to-be-welded member and the external welding member connected by the connecting structure in the second embodiment of the application.

[0014] Figure 5 Fig. 5 is a structural schematic diagram of the connecting structure provided by the third embodiment of the application.

[0015] Figure 6 Fig. 6 is a structural schematic diagram of the to-be-welded member and the external welding member connected by the connecting structure in the third embodiment of the application.

[0016] Figure 7 Fig. 7 is a structural schematic diagram of the connecting structure provided by the fourth embodiment of the application.

[0017] Figure 8 Fig. 8 is a structural schematic diagram of the to-be-welded member and the external welding member connected by the connecting structure in the fourth embodiment of the application.

[0018] Figure 9 Fig. 9 is a flow schematic diagram of the laser welding method provided by an embodiment of the application.

[0019] Figure 10 Fig. 10 is a schematic diagram of the preset arc-shaped track provided by an embodiment of the application.

[0020] Figure 11 is a schematic diagram of a preset arc-shaped trajectory provided by another embodiment of the present application.

[0021] The reference signs in the description are as follows:

[0022] 100, to-be-welded part; 110, welding surface; 120, boss; 121, welding site; 130, adhesive trajectory strip; 200, external welding part; 140, anti-excess adhesive groove; 150, first bonding gap; 160, second bonding gap; 170, third bonding gap; 310, first circle; 320, second circle; 330, third circle; 340, fourth circle; 350, fifth circle; 360, sixth circle; 370, seventh circle; 380, first arc segment; 390, second arc segment; 400, center point; 410, first connecting point; 420, second connecting point; 430, third connecting point; 440, fourth connecting point; 450, fifth connecting point; 460, sixth connecting point; 470, seventh connecting point; 480, eighth connecting point; 490, ninth connecting point. DETAILED DESCRIPTION

[0023] In order to make the technical problems solved by the present application, the technical solutions and the beneficial effects more clearly understood, the present application 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 only used to explain the present application and should not be used to limit the present application.

[0024] It should be understood that the terms "upper", "lower", "left", "right", "front", "back", "middle" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0025] As shown in FIGS. 1 and 2, an embodiment of the present application provides a connecting structure, which comprises at least one boss 120 protrudingly arranged on a welding surface 110 of a to-be-welded part 100, wherein the boss 120 is internally provided with a welding site 121, and the connecting structure further comprises an adhesive trajectory strip 130 adhered to the welding surface 110 and spacedly distributed with all the bosses 120; the to-be-welded part 100 is connected to an external welding part 200 through laser welding of the welding site 121 and adhesion of the adhesive trajectory strip 130. Figure 1 Figure 2 As shown in FIGS. 1 and 2, an embodiment of the present application provides a connecting structure, which comprises at least one boss 120 protrudingly arranged on a welding surface 110 of a to-be-welded part 100, wherein the boss 120 is internally provided with a welding site 121, and the connecting structure further comprises an adhesive trajectory strip 130 adhered to the welding surface 110 and spacedly distributed with all the bosses 120; the to-be-welded part 100 is connected to an external welding part 200 through laser welding of the welding site 121 and adhesion of the adhesive trajectory strip 130.

[0026] ​The number of the workpiece to be welded 100 and the external weldment 200 can both be one or more. In one embodiment, at least one of the workpiece to be welded 100 and the external weldment 200 has a surface coating layer, which includes one or more of zinc, zinc alloy, aluminum, aluminum-silicon alloy, aluminum-zinc alloy, or aluminum-magnesium alloy coating layers. In another embodiment, at least one of the workpiece to be welded 100 and the external weldment 200 is an aluminum alloy workpiece, which includes an oxide coating layer. The boss 120 can be formed on the welding surface 110 by methods such as casting, stamping, or machining.

[0027] Understandably, the welding position 121 is used to perform laser welding between the workpiece 100 to be welded and the external welding component 200, thereby connecting the workpiece 100 to the external welding component 200. There may be multiple bosses 120, and these bosses 120 are spaced apart on the welding surface 110. Adhesive track strips 130 are spaced apart from all the bosses 120. The adhesive track strips 130 are used to bond the workpiece 100 to the external welding component 200. After the workpiece 100 and the external welding component 200 are stacked, the adhesive track strips 130 will diffuse towards the welding position 121 when compressed. Since the bosses 120 have a certain height, the outer side of the bosses 120 can prevent the adhesive track strips 130 from diffusing into the welding position 121 located within the bosses 120, thereby avoiding the adverse effects of adhesive diffusing from the adhesive track strips 130 on the welding, and improving the welding strength and welding stability.

[0028] In this embodiment of the invention, by providing a boss 120 on the welding surface 110 of the workpiece to be welded 100 and the external welding part 200 respectively, while the workpiece to be welded 100 is laser welded to the external welding part 200 through the welding position 121 provided in the boss 120, the extruded adhesive track strip 130 is blocked by the outside of the boss 120 and will not spread to the welding position 121, thereby eliminating the adverse effect of the adhesive track strip 130 on the welding and improving the welding strength and welding stability.

[0029] like Figures 3 to 8As shown, in one embodiment, the connection structure further includes an anti-overflow adhesive groove 140 recessed on the welding surface 110 and located outside the boss 120. Understandably, the anti-overflow adhesive groove 140 is used to accommodate adhesive that diffuses from the adhesive track strip 130 towards the welding position 121 during the extrusion process, so as to prevent the adhesive track strip 130 from being extruded and diffused into the welding position 121 while the workpiece to be welded 100 is welded to the external weldment 200. Further, the anti-overflow adhesive groove 140 is located outside and adjacent to the boss 120, thereby accommodating the diffusion of the adhesive track strip 130 towards the welding position 121 during the extrusion process without affecting the diffusion of the adhesive track strip 130 to other locations during the extrusion process, thus improving the bonding effect. Understandably, the anti-overflow adhesive groove 140 can be provided on the welding surface 110 by methods such as casting, stamping, or machining.

[0030] Such as 3 and Figure 4 As shown, in one embodiment, the boss 120 is an annular boss. Understandably, the welding position 121 is located within the internal space enclosed by the annular boss. The annular boss can be a circular annular boss, or it can be an annular boss of other shapes (e.g., triangular or square, etc.), as long as the protrusions of the annular boss are closed and connected end-to-end, and while the workpiece to be welded 100 is securely welded to the external workpiece 200, it can form a barrier separating the internal space of the annular boss from the outside, thereby preventing the adhesive track strip 130, which is compressed and diffuses towards the annular boss, from entering the internal space of the annular boss.

[0031] Such as 3 and Figure 4 As shown, in one embodiment, the connection structure includes a plurality of spaced-apart protrusions 120; a first adhesive gap 150 is formed between two adjacent protrusions 120; and the adhesive track 130 is a wavy line track that sequentially passes through the plurality of first adhesive gaps 150. It can be understood that when the protrusions 120 are a plurality of spaced-apart annular protrusions, the gap between two adjacent protrusions 120 forms the first adhesive gap 150, and the adhesive track 130 is a wavy line (specifically, the wavy line track is formed by connecting multiple arcs sequentially end to end, and the bending directions of adjacent two arcs are not the same, but the wavy line track can also be other shapes) that sequentially passes through the plurality of first adhesive gaps 150 and is approximately equidistant from two adjacent protrusions 120. This ensures that the adhesive track 130 is evenly distributed on the welding surface 110 while reducing the diffusion of the adhesive track 130 to the welding position, thereby improving the connection quality of the connection structure.

[0032] Such as 5 and Figure 6 As shown, in one embodiment, the boss 120 is a circular boss. It is understood that the welding position 121 is located within the circular boss. The circular boss can be a perfect circle, or it can be a circular boss of other shapes (e.g., elliptical), as long as the outer side of the circular boss can prevent the compressed adhesive track strip 130 from spreading to the welding position 121 within the circular boss.

[0033] Such as 5 and Figure 6 As shown, in one embodiment, the connection structure includes a plurality of protrusions 120 arranged in at least two rows at intervals; a second adhesive gap 160 is formed between adjacent rows of protrusions 120; and the adhesive track 130 is a straight track passing through all the second adhesive gaps 160. It can be understood that when there are multiple protrusions 120 arranged in at least two rows at intervals, the interval between adjacent rows of protrusions 120 forms the second adhesive gap 160, and the adhesive track 130 can be a straight track passing through all the second adhesive gaps 160 (or a track of other shapes), thereby ensuring that the adhesive track 130 is evenly distributed on the welding surface 110 while reducing the diffusion of the adhesive track 130 to the welding position, thus improving the connection quality of the connection structure.

[0034] Such as 7 and Figure 8 As shown, in one embodiment, the boss 120 is a square boss. It is understood that the welding position 121 is located within the square boss, which can be a square boss or a square boss of other shapes (e.g., rectangles). Furthermore, the boss 120 can also be a triangular or other polygonal boss 120, and different bosses 120 in the same connection structure can also be set to different shapes. The requirement is that the outer side of the square boss can prevent the compressed adhesive track strip 130 from spreading to the welding position 121 within the square boss.

[0035] Such as 7 and Figure 8As shown, in one embodiment, the connecting structure includes a plurality of spaced-apart protrusions 120; a third adhesive gap 170 is formed between two adjacent protrusions 120; the adhesive track 130 is a square wave track that sequentially passes through the plurality of third adhesive gaps 170. It can be understood that when the protrusions 120 are a plurality of spaced-apart square protrusions, the gap between two adjacent protrusions 120 forms the third adhesive gap 170, and the adhesive track 130 is a square wave track that sequentially passes through the plurality of third adhesive gaps 170 and is approximately equidistant from two adjacent protrusions 120 (specifically, the square wave track is formed by sequentially connecting multiple square wave lines end to end, each square wave line including a first side, a second side, a third side, a fourth side, and a fifth side connected end to end; wherein the first side, the third side, and the fifth side are parallel to each other; the second side and the fourth side are parallel; the first side and the second side are perpendicular). It can be understood that in one embodiment, the above... Each square wave line can be set to be consistent or inconsistent, and the length of each side in each square wave line can be set according to requirements. The first, third, and fifth sides are not limited to being parallel to each other, but can be set to have a certain angle as required. Similarly, the second and fourth sides are not limited to being parallel to each other, but can be set to have a certain angle as required. The angles between the other sides are not limited to being perpendicular as mentioned above, and can be set to other angles as well. In this way, while reducing the diffusion of the adhesive track strip 130 to the welding position, the adhesive track strip 130 is ensured to be evenly distributed on the welding surface 110, thereby improving the connection quality of the connection structure.

[0036] like Figure 9 As shown, an embodiment of the present invention also provides a laser welding method for welding the workpiece 100 having the connection structure described in the above embodiments. The laser welding method includes:

[0037] S10, the workpiece to be welded 100 is stacked with the external workpiece 200, and the welding surface 110 of the workpiece to be welded 100 is positioned opposite to the external workpiece 200. Understandably, in this embodiment of the laser welding method, a laser beam is used to irradiate the surface of the metal workpiece (i.e., the workpiece to be welded 100 or the external workpiece 200) corresponding to the welding position 121. The concentrated energy released by the laser beam causes a weld joint to be formed at the welding position 121 between the stacked workpiece to be welded 100 and the external workpiece 200. Therefore, in this embodiment, the workpiece to be welded 100 and the external workpiece 200 are first stacked. The welding surface 110 of the workpiece to be welded 100 is positioned opposite to the external workpiece 200, thereby preventing the adhesive track strip 130, which is diffused due to compression, from ultimately spreading to the welding position 121 within the boss 120. This eliminates the adverse effects of the adhesive track strip 130 on the welding, ensuring welding strength and welding stability.

[0038] S20, the laser beam is controlled to start from the center point of the welding position 121 of the boss 120, move along a preset arc trajectory and irradiate the welding position 121 to form a welding joint between the workpiece to be welded 100 and the external workpiece 200; the preset arc trajectory includes multiple circular arc trajectories, which are arranged around the center point 400. Preferably, the laser beam is an adjustable ring mode (ARM) laser, which is a composite laser. The adjustable ring mode laser includes a central beam with a first power density and a ring beam with a second power density. The central beam and the ring beam are integrated into an optical fiber and emitted through a deflecting galvanometer to achieve welding and positioning. When the adjustable ring laser irradiates the welding position 121 of the boss 120, the central beam melts the welding position 121 and forms a molten pool with a keyhole, while the ring beam irradiates the welding position 121 with a relatively low power density to stabilize the keyhole, preventing metal cooling and solidification, thereby forming a stable venting channel (i.e., the keyhole). In this embodiment, the adjustable ring laser moves along the aforementioned preset arc trajectory, thereby enhancing the stirring effect on the molten pool. This makes it easier for the gas in the molten pool to escape through the keyhole, thus eliminating the adverse effects of the gas in the molten pool on welding and ensuring welding strength and stability. Finally, after the molten pool cools, the welding joint is formed, connecting the workpiece 100 to the external welding component 200.

[0039] In existing technologies, galvanized steel workpieces widely used in automobile bodies (where the zinc layer evaporates rapidly, generating high-pressure zinc vapor on the surface of the steel workpiece, carrying away a large amount of molten metal, or being blocked by the surface of the molten pool, ultimately causing gas to accumulate inside the molten pool, all of which reduce the strength of the weld joint after cooling and solidification) or aluminum alloy workpieces (where cast aluminum and aluminum alloy profiles easily absorb gas during laser welding, and when the molten pool cools rapidly, pores form inside the weld, which also reduces the strength of the weld joint) will generate pores in the molten pool during laser welding, thereby reducing the strength of the weld joint and affecting the stability of the welding. In this embodiment of the invention, an adjustable ring laser starts from the center point of the welding position 121 of the boss 120 and moves along a preset arc trajectory to irradiate the welding position 121 of the stacked workpieces to be welded 100 and the external workpieces 200, so as to form a welding joint between the workpieces to be welded 100 and the external workpieces 200. In the above embodiment of the invention, the irradiation of the central beam melts the welding position 121 and forms a molten pool with a keyhole, and the irradiation of the ring beam stabilizes the keyhole, thereby venting the gas in the molten pool through the keyhole. At the same time, the adjustable ring laser moves along the preset arc trajectory, which enhances the stirring effect on the molten pool, thereby eliminating the adverse effects of the gas in the molten pool on the welding and ensuring the stability of the welding.

[0040] like Figure 10 As shown, in one embodiment, in step S30, the preset arc trajectory includes multiple first arc trajectories (the first arc trajectories include, but are not limited to, the first circle 310, the second circle 320, the third circle 330, and the fourth circle 340 mentioned below). Each first arc trajectory is externally connected to at least two other first arc trajectories, and the connection point between any two first arc trajectories is less than or equal to one. Understandably, in this embodiment, the preset arc trajectory starts from the center point 400 (i.e., the center point of the welding position 121 of the aforementioned boss 120). Therefore, the adjustable ring laser moves along the preset arc trajectory from the center point 400 and irradiates the welding position 121, thereby enhancing the stirring effect on the molten pool, venting the gas in the molten pool through the keyhole, and ensuring the stability of the welding.

[0041] Furthermore, Figure 10The preset arc trajectory shown includes a first circle 310 with a first preset radius, a second circle 320 with a second preset radius, a third circle 330 with a third preset radius, and a fourth circle 340 with a fourth preset radius. The second circle 320 is tangent to the first circle 310 at its center point 400; the third circle 330 is tangent to the first circle 310 at a first connection point 410, and also tangent to the second circle 320 at a second connection point 420; the fourth circle 340 is tangent to the first circle 310 at a fourth connection point 440, and also tangent to the second circle 320 at a third connection point 430. Further, the first preset radius is equal to the second preset radius, and the third preset radius is equal to the fourth preset radius; the first preset radius is greater than the third preset radius.

[0042] like Figure 10 As shown, the sequence in which the adjustable ring laser moves along a preset arc trajectory includes:

[0043] Starting from the center point 400, proceed clockwise along the first circle 310 and move to the center point 400; starting from the center point 400, proceed counterclockwise along the second circle 320 and move to the second connection point 420; starting from the second connection point 420, proceed clockwise along the third circle 330 and move to the second connection point 420; starting from the second connection point 420, proceed counterclockwise along the second circle 320 and move to the center point 400; starting from the center point 400, proceed clockwise along the first circle 310 and move to the fourth connection point 440; starting from the fourth connection point 440, proceed counterclockwise along the fourth circle 340 and move to the third connection point 430. In this embodiment, an adjustable ring laser moves from the center point 400 along the preset arc trajectory and irradiates the welding position 121, thereby enhancing the stirring effect on the molten pool, discharging the gas in the molten pool through the keyhole, thus eliminating the adverse effects of the gas in the molten pool on welding and ensuring the stability of welding.

[0044] like Figure 11As shown, in one embodiment, in step S30, the preset arc trajectory includes two second arc trajectories with the center point 400 as the tangent point (the second arc trajectories include, but are not limited to, the fifth circle 350 and the sixth circle 360 ​​mentioned later), and a third arc trajectory (the third arc trajectory includes, but is not limited to, the seventh circle 370 mentioned later, and an arc segment composed of the first arc segment 380 and the second arc segment 390) that is interwoven and connected to the two second arc trajectories through at least three intersection points. It can be understood that in this embodiment, the preset arc trajectory starts from the center point 400 (i.e., the center point of the welding position 121 of the aforementioned boss 120). Therefore, the adjustable ring laser moves along the preset arc trajectory from the center point 400 and irradiates the welding position 121, thereby enhancing the stirring effect on the molten pool, venting the gas in the molten pool through the keyhole, and ensuring the stability of the welding.

[0045] Furthermore, Figure 11 The preset arc trajectory shown includes a fifth circle 350 with a fifth preset radius, a sixth circle 360 ​​with a sixth preset radius, a seventh circle 370 with a seventh preset radius, a first arc segment 380 with an eighth preset radius, and a second arc segment 390 with a ninth preset radius; wherein, the third arc trajectory includes the aforementioned seventh circle 370, and an arc segment formed by the combination of the first arc segment 380 and the second arc segment 390.

[0046] Specifically, such as Figure 11 As shown, the sixth circle 360 ​​is tangent to the fifth circle 350 at the center point 400; the seventh circle 370 passes through the center point 400 and intersects the fifth circle 350 at the fifth connection point 450, and the seventh circle 370 also intersects the sixth circle 360 ​​at the sixth connection point 460; the first arc segment 380 starts from the center point 400, intersects the sixth circle 360 ​​at the seventh connection point 470, and ends at the eighth connection point 480; the second arc segment 390 starts from the eighth connection point 480 and ends at the ninth connection point 490; wherein, the eighth connection point 480 is the intersection of the line connecting the center of the seventh circle 370 and the center point 400 with the first arc segment 380, and the ninth connection point 490 is the intersection of the line connecting the center of the fifth circle 350 and the center point 400 with the second arc segment 390.

[0047] Furthermore, the fifth preset radius, the sixth preset radius, the seventh preset radius, and the eighth preset radius are equal, and the ninth preset radius is twice the fifth preset radius.

[0048] like Figure 11As shown, the sequence in which the adjustable ring laser moves along a preset arc trajectory includes:

[0049] Starting from the center point 400, proceed counterclockwise along the seventh circle 370 and move to the center point 400; starting from the center point 400, proceed clockwise along the first arc segment 380 and move to the eighth connection point 480; starting from the eighth connection point 480, proceed clockwise along the second arc segment 390 and move to the ninth connection point 490; starting from the ninth connection point 490, proceed clockwise along the fifth circle 350 and move to the center point 400; starting from the center point 400, proceed counterclockwise along the sixth circle 360 ​​and move to the center point 400; starting from the center point 400, proceed clockwise along the fifth circle 350 and move to the ninth connection point 490. In this embodiment, an adjustable ring laser moves from the center point 400 along the preset arc trajectory and irradiates the welding position 121, thereby enhancing the stirring effect on the molten pool, discharging the gas in the molten pool through the keyhole, thus eliminating the adverse effects of the gas in the molten pool on welding and ensuring the stability of welding.

[0050] The above are merely embodiments of the connection structure and laser welding method of the present invention, and are 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 connection structure, characterized in that, The connection structure includes at least one boss of a certain height protruding from the welding surface of the workpiece to be welded, the boss having a welding position within it, and adhesive track strips bonded to the welding surface and spaced apart from all the bosses. The workpiece to be welded is connected to an external weldment by laser welding of the welding positions and bonding of the adhesive track strips. The boss is used to prevent the adhesive track strips, which are compressed, from spreading into the welding position within the boss when the workpiece to be welded is laser welded to the external weldment through the welding position within the boss after the workpiece to be welded and the external weldment are stacked.

2. The connection structure according to claim 1, characterized in that, The connection structure also includes an anti-overflow adhesive groove recessed on the welding surface and located outside the boss.

3. The connection structure according to claim 1, characterized in that, The boss is a ring-shaped boss.

4. The connection structure according to claim 3, characterized in that, The connection structure includes a plurality of protrusions arranged at intervals; a first adhesive gap is formed between two adjacent protrusions; the adhesive track is a wavy line track that passes through the plurality of the first adhesive gaps in sequence.

5. The connection structure according to claim 1, characterized in that, The boss is a circular boss.

6. The connection structure according to claim 5, characterized in that, The connection structure includes a plurality of protrusions arranged in at least two rows at intervals; a second adhesive gap is formed between two adjacent rows of protrusions; the adhesive track is a straight track that passes through all the second adhesive gaps.

7. The connection structure according to claim 1, characterized in that, The boss is a square boss.

8. The connection structure according to claim 7, characterized in that, The connection structure includes a plurality of protrusions arranged at intervals; a third adhesive gap is formed between two adjacent protrusions; the adhesive track is a square wave track that passes sequentially through the plurality of third adhesive gaps.

9. A laser welding method, characterized in that, The laser welding method is used for welding workpieces having the connection structure as described in any one of claims 1 to 8, the laser welding method comprising: The workpiece to be welded is stacked with the external workpiece to be welded, and the welding surface of the workpiece to be welded is opposite to that of the external workpiece to be welded; The laser beam is controlled to start from the center point of the welding position of the boss, move along a preset arc trajectory and irradiate the welding position to form a welding joint between the workpiece to be welded and the external workpiece; the preset arc trajectory includes multiple circular arc trajectories, which are arranged around the center point.

10. The laser welding method according to claim 9, characterized in that, The preset arc trajectory includes multiple first arc trajectories, each of which is externally connected to at least two other first arc trajectories, and the connection point between any two first arc trajectories is less than or equal to one.

11. The laser welding method according to claim 9, characterized in that, The preset arc trajectory includes two second arc trajectories with the center point as the tangent point, and a third arc trajectory that is interwoven and connected to the two second arc trajectories through at least three intersection points.

Images