Connecting structure and laser welding method

Abstract

The invention provides a connecting structure and a laser welding method.The connecting structure comprises at least one boss arranged on the welding face of a to-be-welded part in a protruding mode, welding positions are arranged in the bosses, and the connecting structure further comprises adhesive track strips which are bonded to the welding face and distributed with all the bosses at intervals; and the to-be-welded part is connected to the external welding part through laser welding of the welding position and bonding of the adhesive track strip. Through the arrangement of the boss, the to-be-welded part is stably welded with the external welding part through the welding position arranged in the boss, and meanwhile, the extruded adhesive track strip is blocked by the outer side of the boss and does not diffuse to the welding position, so that the adverse effect of the adhesive track strip on welding is eliminated, and the welding strength and the welding stability are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of welding, and in particular relates to a connection structure and a laser welding method. Background Art

[0002] Laser welding has become a popular welding method for body-in-white (BIW) welding in the automotive industry. Existing laser welding techniques may require bonding multiple stacked metal workpieces. This process, due to the presence of adhesive, can easily enter the weld joint during welding. This adhesive is then burned away by the high temperature, forming inclusions in the weld joint. This weakens the joint strength and affects weld stability. Summary of the Invention

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

[0004] In view of the above technical problems, an embodiment of the present invention provides a connection structure, including at least one boss protruding from the welding surface of the part to be welded, a welding position being provided in the boss, and the connection structure also includes an adhesive track bar adhered to the welding surface and spaced apart from all the bosses; the part to be welded is connected to the external welding part by laser welding of the welding position and bonding of the adhesive track bar.

[0005] An embodiment of the present invention further provides a laser welding method for welding parts to be welded having the above-mentioned connection structure, the laser welding method comprising:

[0006] The workpiece to be welded is stacked with an external welding part, with the welding surface of the workpiece to be welded facing the external welding part;

[0007] 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 spot between the part to be welded and the external welding part; the preset arc trajectory includes multiple arc trajectories, and the multiple arc trajectories are arranged around the center point.

[0008] In the present invention, the connection structure includes at least one boss protruding from the welding surface of the workpiece to be welded, with welding locations defined within the boss. The connection structure also includes adhesive track strips adhered to the welding surface and spaced apart from all of the bosses. The workpiece to be welded is connected to the external welding part through laser welding of the welding locations and adhesive bonding of the adhesive track strips. By providing bosses on the welding surfaces of the workpiece to be welded that oppose the external welding part, the present invention allows the workpiece to be laser welded to the external welding part through the welding locations defined within the bosses, while the squeezed adhesive track strips are blocked by the outside of the bosses and prevented from spreading to the welding locations. This eliminates the adverse effects of the adhesive track strips on welding and improves welding strength and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention will be further described below with reference to the accompanying drawings and examples.

[0010] Figure 1 It is a structural diagram of the connection structure provided by the first embodiment of the present invention.

[0011] Figure 2 It is a structural schematic diagram of the part to be welded and the external welding part connected by the connection structure in the first embodiment of the present invention.

[0012] Figure 3 It is a structural diagram of the connection structure provided by the second embodiment of the present invention.

[0013] Figure 4 It is a structural schematic diagram of the part to be welded and the external welding part connected by the connection structure in the second embodiment of the present invention.

[0014] Figure 5 It is a structural diagram of the connection structure provided by the third embodiment of the present invention.

[0015] Figure 6 It is a structural schematic diagram of the part to be welded and the external welding part connected by the connection structure in the third embodiment of the present invention.

[0016] Figure 7 It is a schematic diagram of the connection structure provided by the fourth embodiment of the present invention.

[0017] Figure 8 It is a schematic structural diagram of the part to be welded and the external welding part connected by the connection structure in the fourth embodiment of the present invention.

[0018] Figure 9 It is a schematic flow chart of a laser welding method provided by one embodiment of the present invention.

[0019] Figure 10 Schematic diagram of a preset arc trajectory provided by an embodiment of the present invention.

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

[0021] The reference numerals in the specification are as follows:

[0022] 100. Part to be welded; 110. Welding surface; 120. Boss; 121. Welding position; 130. Glue track bar; 200. External welding part; 140. Anti-overflow glue 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 connection point; 420. Second connection point; 430. Third connection point; 440. Fourth connection point; 450. Fifth connection point; 460. Sixth connection point; 470. Seventh connection point; 480. Eighth connection point; 490. Ninth connection point. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is 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 invention and are not intended to limit the present invention.

[0024] It should be understood that the terms "upper", "lower", "left", "right", "front", "back", "middle", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0025] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a connection structure, including at least one boss 120 protruding from the welding surface 110 of the part to be welded 100, a welding position 121 being provided in the boss 120, and the connection structure also includes an adhesive track bar 130 bonded to the welding surface 110 and spaced apart from all the bosses 120; the part to be welded 100 is connected to the external welding part 200 by laser welding the welding position 121 and bonding the adhesive track bar 130.

[0026] The number of the workpiece to be welded 100 and the external weld part 200 can be one or more. In one embodiment, at least one of the workpiece to be welded 100 and the external weld part 200 has a surface coating layer, and the surface coating layer 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 weld part 200 is an aluminum alloy workpiece, and the aluminum alloy workpiece includes an oxide coating layer. The boss 120 can be provided on the welding surface 110 by casting, stamping, or machining.

[0027] It can be understood that the welding position 121 is used to perform a laser welding operation between the workpiece to be welded 100 and the external welding part 200, thereby connecting the workpiece to be welded 100 to the external welding part 200. The bosses 120 may be multiple, and the bosses 120 are arranged at intervals on the welding surface 110. The adhesive track strips 130 are spaced apart from all the bosses 120. The adhesive track strips 130 are used to bond the workpiece to be welded 100 and the external welding part 200. After the workpiece to be welded 100 and the external welding part 200 are stacked, the adhesive track strips 130 will diffuse toward the welding position 121 when squeezed. 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 set in the bosses 120, thereby avoiding the adverse effects of the adhesive diffused from the adhesive track strips 130 on welding, thereby improving the welding strength and welding stability.

[0028] In an embodiment of the present invention, a boss 120 is provided on a welding surface 110 opposite to the workpiece 100 to be welded and the external welding part 200, so that while the workpiece 100 to be welded is laser welded to the external welding part 200 through a welding position 121 provided in the boss 120, the squeezed adhesive track bar 130 is blocked by the outside of the boss 120 and will not diffuse to the welding position 121, thereby eliminating the adverse effects of the adhesive track bar 130 on 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 glue groove 140 formed on the welding surface 110 and located on the outside of the boss 120. It is understandable that the anti-overflow glue groove 140 is used to accommodate the glue that the adhesive track bar 130 diffuses toward the welding position 121 during the extrusion process, so as to prevent the adhesive track bar 130 from being squeezed and diffused into the welding position 121 while the welded part 100 is welded to the external welding part 200. Furthermore, the anti-overflow glue groove 140 is located on the outside of the boss 120 and is adjacent to the boss 120, so that while accommodating the adhesive track bar 130 from diffusing toward the welding position 121 during the extrusion process, it will not affect the diffusion of the adhesive track bar 130 to other positions during the extrusion process, thereby improving the bonding effect. It is understandable that the anti-overflow glue groove 140 can be set on the welding surface 110 by casting, stamping or machining.

[0030] Such as 3 and Figure 4 As shown, in one embodiment, the boss 120 is an annular boss. It is understandable that the welding position 121 is located in the internal space enclosed by the annular boss. The annular boss can be a circular annular boss or an annular boss of other shapes (for example, a triangle or square). As long as the raised portion of the annular boss is connected end to end in a closed shape, and the workpiece 100 to be welded and the external welding part 200 are firmly welded, a barrier can be formed to separate the internal space of the annular boss from the outside, so that the adhesive track bar 130 that is squeezed and spreads toward the annular boss is blocked by the outside of the annular boss and does not enter 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 bosses 120; a first bonding gap 150 is formed between adjacent two bosses 120; and the adhesive track strip 130 is a wavy track strip that sequentially passes through the plurality of first bonding gaps 150. It is understood that when the bosses 120 are a plurality of spaced-apart annular bosses, the intervals between adjacent two bosses 120 form the first bonding gaps 150, and the adhesive track strip 130 is a wavy track strip that sequentially passes through the plurality of first bonding gaps 150 and is approximately equidistant from the adjacent two bosses 120 (specifically, the wavy track strip is formed by sequentially connecting a plurality of arcs end to end, with the curvature directions of the adjacent two arcs being different, but the wavy track strip may also have other shapes). This ensures that the adhesive track strip 130 is evenly distributed on the welding surface 110 while reducing the spread of the adhesive track strip 130 toward 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 understandable that the welding position 121 is located inside the circular boss. The circular boss can be a true circular boss or a circular boss of other shapes (e.g., an elliptical shape), as long as the outer side of the circular boss can prevent the squeezed adhesive track bar 130 from spreading to the welding position 121 inside the circular boss.

[0033] Such as 5 and Figure 6 As shown, in one embodiment, the connection structure includes a plurality of bosses 120 spaced apart and arranged in at least two rows; second bonding gaps 160 are formed between two adjacent rows of bosses 120; and the adhesive track strip 130 is a straight track strip passing through all of the second bonding gaps 160. It is understood that when there are multiple bosses 120 spaced apart and arranged in at least two rows, the gaps between two adjacent rows of bosses 120 form the second bonding gaps 160, and the adhesive track strip 130 can be a straight track strip passing through all of the second bonding gaps 160 (or can be a track strip of other shapes). This ensures that the adhesive track strip 130 is evenly distributed on the welding surface 110 while reducing the spread of the adhesive track strip 130 toward the welding position, thereby 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 can be understood that the welding position 121 is located inside the square boss. The square boss can be a square boss, or a square boss of other shapes (for example, a rectangle). Furthermore, the boss 120 can also be a triangle or other polygonal boss 120, and different bosses 120 in the same connection structure can also be set to different shapes. As long as the outer side of the square boss can block the squeezed adhesive track bar 130 from diffusing to the welding position 121 inside the square boss, it will be sufficient.

[0035] Such as 7 and Figure 8As shown, in one embodiment, the connection structure includes a plurality of the bosses 120 arranged at intervals; a third bonding gap 170 is formed between two adjacent bosses 120; and the adhesive track bar 130 is a square wave track bar that sequentially passes through the plurality of the third bonding gaps 170. It can be understood that when the bosses 120 are a plurality of square bosses arranged at intervals, the interval between two adjacent bosses 120 forms the third bonding gap 170, and the adhesive track bar 130 is a square wave track bar that sequentially passes through the plurality of the third bonding gaps 170 and is approximately equidistant from the two adjacent bosses 120 (specifically, the square wave track bar is formed by a plurality of square wave lines connected end to end in sequence, and each square wave line includes a first side, a second side, a third side, a fourth side, and a fifth side connected end to end in sequence; 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 The square wave lines can be set to be consistent or inconsistent, and the length of each side in each square wave line can be set according to needs, and the first side, the third side and the fifth side are not limited to being parallel to each other, but can be set to have a certain angle according to needs; similarly, the second side and the fourth side are not limited to being parallel to each other, but can be set to have a certain angle according to needs; and the angles between the other sides are not limited to being perpendicular as mentioned above, and can also be set to other angles), thereby reducing the diffusion of the adhesive track bar 130 to the welding position, ensuring that the adhesive track bar 130 is 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 further provides a laser welding method for welding the parts to be welded 100 having the connection structure in the above embodiments, the laser welding method comprising:

[0037] S10, the workpiece to be welded 100 is stacked with the external welding part 200, and the welding surface 110 of the workpiece to be welded 100 is arranged opposite to the external welding part 200. It can be understood that the laser welding method in this embodiment uses a laser beam to irradiate the surface corresponding to the welding position 121 on the metal workpiece (that is, the workpiece to be welded 100 or the external welding part 200), and the concentrated energy released by the laser beam causes the welding position 121 between the stacked workpieces 100 to be welded and the external welding part 200 to produce a weld joint. Therefore, in this embodiment, it is first necessary to stack the workpiece to be welded 100 and the external welding part 200. And the welding surface 110 of the workpiece to be welded 100 is arranged opposite to the external welding part 200, so that the adhesive track bar 130 that is squeezed and spreads is blocked by the boss 120 and will not eventually spread to the welding position 121 in the boss 120, thereby eliminating the adverse effects of the adhesive track bar 130 on welding, ensuring welding strength and welding stability.

[0038] S20, control the laser beam 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 spot between the to-be-welded part 100 and the external welding part 200; the preset arc trajectory includes multiple arc trajectories, and the multiple arc trajectories are arranged around the center point 400. Wherein, the laser beam is preferably an adjustable ring laser (Adjustable Ring Mode, referred to as ARM), which is a composite laser. The adjustable ring laser includes a central beam with a first power density and an annular beam with a second power density. The central beam and the annular beam are integrated into an optical fiber and emitted through a deflection galvanometer to achieve welding and positioning. When the adjustable ring laser is irradiated on the welding position 121 of the boss 120, the central beam can melt the welding position 121 and form a molten pool with a keyhole, and the annular beam is irradiated on the welding position 121 with a relatively low power density to stabilize the keyhole, prevent the metal from cooling and solidifying, and thus form a stable exhaust channel (i.e., keyhole). In this embodiment, the adjustable ring laser moves along the preset arc trajectory, thereby enhancing the stirring effect on the molten pool, allowing gases in the molten pool to be more easily discharged through the keyhole, thereby eliminating the adverse effects of gases in the molten pool on welding and ensuring weld strength and stability. Finally, after the molten pool cools, the weld point is formed, connecting the workpiece 100 to the external welding part 200.

[0039] In the prior art, galvanized steel workpieces (the galvanized layer evaporates rapidly, generating high-pressure zinc vapor on the surface of the steel workpiece, carrying away a large amount of molten metal liquid, or being blocked by the surface of the molten pool, and eventually the gas gathers inside the molten pool, both of which reduce the strength of the welded joints that solidify after cooling) or aluminum alloy workpieces (cast aluminum and aluminum alloy profiles easily absorb gas during laser welding. When the molten pool cools rapidly, pores are formed inside the weld, which also reduces the strength of the welded joint) will generate pores in the molten pool during laser welding, thereby reducing the strength of the welded joint and affecting the stability of the welding. In an embodiment of the present 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 overlapping parts to be welded 100 and the external welding part 200, so as to form a welding spot between the parts to be welded 100 and the external welding part 200; in the above embodiment of the present invention, the welding position 121 is melted by the irradiation of the central light beam and a molten pool with a keyhole is formed, and the keyhole is stabilized by the irradiation of the ring light beam, and the gas in the molten pool is discharged through the keyhole. At the same time, the adjustable ring laser moves along the above preset arc trajectory, thereby enhancing the stirring effect on the molten pool, thereby eliminating the adverse effects of the gas in the molten pool on welding, and ensuring the stability of 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 trajectory includes but is not limited to the first circle 310, the second circle 320, the third circle 330, and the fourth circle 340 mentioned below), each of the first arc trajectories is circumscribed and connected to at least two other first arc trajectories, and the number of connection points between any two of the first arc trajectories is less than or equal to one. It can be understood that in this embodiment, the preset arc trajectory takes the center point 400 (that is, the center point of the welding position 121 of the above-mentioned boss 120) as the starting point. 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, discharging the gas in the molten pool through the keyhole, and ensuring the stability of the welding.

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

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

[0043] Starting from the center point 400, move clockwise along the first circle 310 and move to the center point 400; starting from the center point 400, move counterclockwise along the second circle 320 and move to the second connection point 420; starting from the second connection point 420, move clockwise along the third circle 330 and move to the second connection point 420; starting from the second connection point 420, move counterclockwise along the second circle 320 and move to the center point 400; starting from the center point 400, move clockwise along the first circle 310 and move to the fourth connection point 440; starting from the fourth connection point 440, move counterclockwise along the fourth circle 340 and move to the third connection point 430. In this embodiment, the adjustable ring laser moves from the center point 400 along the above-mentioned 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, and eliminating the adverse effect of the gas in the molten pool on welding, thereby 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 (the second arc trajectories include but are not limited to the fifth circle 350 and the sixth circle 360 ​​mentioned below) with the center point 400 as the tangent point, and a third arc trajectory (the third arc trajectory includes but is not limited to the seventh circle 370 mentioned below, and an arc segment composed of the first arc segment 380 and the second arc segment 390) interwoven with the two second arc trajectories through at least three intersections. 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 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, discharging the gas in the molten pool through the keyhole, and ensuring the stability of the welding.

[0045] Further, Figure 11 The preset arc trajectory shown in the figure 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 above-mentioned seventh circle 370, and an arc line segment composed of the first arc segment 380 and the second arc segment 390.

[0046] Specifically, if 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 with the fifth circle 350 at the fifth connection point 450, and the seventh circle 370 also intersects with the sixth circle 360 ​​at the sixth connection point 460; the first arc segment 380 takes the center point 400 as the starting point, intersects with the sixth circle 360 ​​at the seventh connection point 470 and ends at the eighth connection point 480; the second arc segment 390 takes the eighth connection point 480 as the starting point and ends at the ninth connection point 490; wherein the eighth connection point 480 is the intersection of the first arc segment 380 and the line connecting the center of the seventh circle 370 and the center point 400, and the ninth connection point 490 is the intersection of the second arc segment 390 and the line connecting the center of the fifth circle 350 and the center point 400.

[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 in , the sequence of the adjustable ring laser moving along the preset arc trajectory includes:

[0049] Taking the center point 400 as the starting point, move counterclockwise along the seventh circle 370 and move to the center point 400; taking the center point 400 as the starting point, move clockwise along the first arc segment 380 and move to the eighth connection point 480; taking the eighth connection point 480 as the starting point, move clockwise along the second arc segment 390 and move to the ninth connection point 490; taking the ninth connection point 490 as the starting point, move clockwise along the fifth circle 350 and move to the center point 400; taking the center point 400 as the starting point, move counterclockwise along the sixth circle 360 ​​and move to the center point 400; taking the center point 400 as the starting point, move clockwise along the fifth circle 350 and move to the ninth connection point 490. In this embodiment, the adjustable ring laser moves from the center point 400 along the above-mentioned 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, and eliminating the adverse effect of the gas in the molten pool on welding, thereby 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 in the scope of protection of the present invention.

Claims

1. A connection structure, characterized in that: It includes at least one boss protruding on the welding surface of the part to be welded, and a welding position is arranged inside the boss. The connection structure also includes an adhesive track bar adhered to the welding surface and spaced apart from all the bosses. The part to be welded is connected to the external welding part by laser welding the welding position and bonding the adhesive track bar.

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

3. The connection structure according to claim 1, characterized in that: The boss is an annular boss.

4. The connection structure according to claim 3, characterized in that: The connection structure includes a plurality of bosses arranged at intervals; a first bonding gap is formed between two adjacent bosses; and the adhesive track strip is a wavy track strip that sequentially passes through the plurality of the first bonding gaps.

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 comprises a plurality of bosses arranged in at least two rows at intervals; a second bonding gap is formed between two adjacent rows of bosses; and the adhesive track strip is a straight track strip passing through all the second bonding 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 bosses arranged at intervals; a third bonding gap is formed between two adjacent bosses; and the adhesive track strip is a square wave track strip that sequentially passes through the plurality of third bonding gaps.

9. A laser welding method, characterized in that: For welding a part to be welded having a connection structure according to any one of claims 1 to 8, the laser welding method comprises: The workpiece to be welded is stacked with an external welding part, and the welding surface of the workpiece to be welded is arranged opposite to the external welding part; 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 spot between the workpiece to be welded and the external welding workpiece; the preset arc trajectory includes a plurality of circular arc trajectories, and the plurality of circular arc trajectories are arranged around the center point.

10. The laser welding method according to claim 9, characterized in that: The preset arc trajectory includes a plurality of first arc trajectories, each of which is externally connected to at least two other first arc trajectories, and the connection point between any two of the 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 a tangent point, and a third arc trajectory interlaced and connected with the two second arc trajectories through at least three intersection points.

Images