Welding gas protection mechanism, laser welding equipment and battery production line

Abstract

The present application discloses a welding gas protection mechanism, laser welding equipment and a battery production line. The welding gas protection mechanism includes a first shell and a gas supply component. The first shell is used to be arranged outside the laser welding mechanism, and the interior of the first shell forms a first cavity having a laser injection port and a laser injection port, and the laser injection port and the laser injection port are respectively located at both ends of the first shell in the first direction. The first direction is parallel to the extension direction of the laser; the gas supply component is used to provide protective gas into the first cavity, and the protective gas leaves the first cavity through the laser injection port; wherein the laser injection port has a first edge and a second edge arranged oppositely in the second direction, and along the second direction, the distance between the second edge and the center of the laser injection port is greater than the distance between the first edge and the center of the laser injection port, and the second direction is perpendicular to the first direction. The welding gas protection mechanism of this structure can improve the cooling rate of the weld pool of the battery cell.

Description

Technical Field

[0001] The present application relates to the field of battery manufacturing, and more specifically, to a welding gas protection mechanism, laser welding equipment and a battery production line. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] A battery cell generally includes a shell, an end cap and an electrode assembly. The electrode assembly is accommodated in the shell and the end cap seals the opening of the shell through an assembly device. The end cap and the shell are generally packaged by welding. In the production process, the next process can only be carried out after the weld pool cools down. Therefore, how to improve the welding equipment of the battery cell to speed up the cooling of the weld pool of the battery cell has become an urgent problem to be solved in the field of battery manufacturing technology. Utility Model Content

[0004] The embodiments of the present application provide a welding gas protection mechanism, a laser welding device and a battery production line to increase the cooling rate of the weld pool of a battery cell.

[0005] In the first aspect, the embodiment of the present application provides a welding gas protection mechanism including a first shell and a gas supply component. The first shell is used to be arranged outside the laser welding mechanism, and the interior of the first shell forms a first cavity having a laser injection port and a laser injection port, the laser injection port and the laser injection port are respectively located at the two ends of the first shell in the first direction, and the laser beam passes through the laser injection port from the center of the laser injection port, and the first direction is parallel to the extension direction of the laser; the gas supply component is used to provide protective gas into the first cavity, and the protective gas leaves the first cavity through the laser injection port; wherein the laser injection port has a first edge and a second edge arranged oppositely in the second direction, and along the second direction, the distance between the second edge and the center of the laser injection port is greater than the distance between the first edge and the center of the laser injection port, and the second direction is perpendicular to the first direction.

[0006] In the above scheme, along the second direction, the distance between the second edge and the center of the laser entrance is greater than the distance between the first edge and the center of the laser entrance, so that when the laser beam is emitted from the center of the laser entrance along the first direction, the range covered in the second direction by the protective gas leaving the first cavity from the area between the laser beam and the second edge is greater than the range covered in the second direction by the protective gas leaving the first cavity from the area between the laser beam and the first edge. Therefore, when the laser welding mechanism drives the first shell to move in the direction from the second edge to the first edge, so that the formed weld pool is in the range covered by the protective gas that leaves the first cavity from the area between the laser beam and the second edge, the laser welding mechanism needs to continue to move a certain distance in the second direction before the weld pool is separated from the protection of the protective gas. Therefore, relative to the situation where the first edge and the second edge are symmetrically arranged relative to the laser along the second direction, the time that the weld pool is in the coverage of the protective gas is increased. On the one hand, the oxidation and contamination of the weld pool by oxygen and water vapor in the air can be limited for a longer time, thereby reducing defects such as pores and inclusions, and reducing the possibility of oxidation of the heat-affected zone, thereby reducing the oxide layer on the weld surface and improving the welding quality; on the other hand, the time for the shielding gas weld pool to perform heat exchange can be increased, thereby reducing the temperature of the weld pool more quickly, thereby improving the production efficiency of the battery cell.

[0007] In some embodiments, the shape of the laser emission port is a rectangle or a bar, and the length direction of the laser emission port is parallel to the second direction.

[0008] In the above scheme, when the laser welding mechanism drives the first shell to move in the direction from the second edge to the first edge, the laser ejection port is rectangular, and the length direction of the laser ejection port is parallel to the second direction. Therefore, relative to the situation where the laser ejection port is square or the laser ejection port is rectangular, and the length direction of the laser ejection port is parallel to the third direction (the first direction, the second direction and the third direction are perpendicular to each other), the shielding gas can be concentrated in the weld pool and the heat-affected zone on the side of the weld pool. On the one hand, the waste of shielding gas is reduced; on the other hand, the speed of shielding gas leaving the laser ejection port is increased, thereby reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air, improving the weld quality, and thereby increasing the reliability of the battery cell.

[0009] In some embodiments, the first shell has a first wall and a second wall that are oppositely disposed in the second direction, and the laser emission port extends from an inner surface of the first wall to an inner surface of the second wall.

[0010] In the above scheme, the laser emission outlet extends from the inner surface of the first wall to the inner surface of the second wall, thereby further increasing the range covered by the shielding gas in the second direction, so that the time that the weld pool is within the coverage of the shielding gas is further increased, thereby further improving the welding quality and enhancing the cooling efficiency of the weld pool.

[0011] In some embodiments, the inner surface of the first wall has a first vertical portion and a first inclined portion, the first vertical portion is parallel to the first direction, and along the first direction, the first vertical portion is located between the first inclined portion and the laser injection port; along the direction from the laser injection port to the laser injection port, the first inclined portion is inclined toward the second wall, and the first inclined portion is used to guide the protective gas to move toward the first edge.

[0012] In the above scheme, along the direction from the laser injection port to the laser injection port, the first inclined portion is inclined toward the second wall, and the first inclined portion is used to guide the shielding gas to move toward the first edge, so that when the laser welding mechanism drives the first shell to move from the second edge to the first edge for welding, the shielding gas can approach the weld pool in a direction at a certain angle to the second direction, so that after the shielding gas moving along the first inclined portion contacts the battery cell, part of the shielding gas can move in the second direction. On the one hand, it is convenient for the shielding gas to drive the air between the weld pool and the first shell away from the weld, thereby limiting the oxidation and contamination of the weld pool by oxygen and water vapor in the air, thereby reducing defects such as pores and inclusions; on the other hand, it is convenient for the shielding gas to exchange heat with the weld pool, thereby further improving the cooling efficiency of the weld.

[0013] In some embodiments, the inner surface of the first wall has a transition portion, and the first vertical portion is connected to the first inclined portion through the transition portion.

[0014] In the above scheme, the inner surface of the first wall has a transition portion, and the first vertical portion is connected to the first inclined portion through the transition portion, so that the shielding gas moving along the first vertical portion can be more smoothly converted along the transition portion to move along the first inclined portion, thereby reducing the shielding gas moving along the first vertical portion and directly colliding with the first inclined portion to cause turbulence, thereby affecting the risk of reducing the flow rate of the shielding gas.

[0015] In some embodiments, the inner surface of the second wall has a second vertical portion and a second inclined portion, the second vertical portion is parallel to the first direction; along the direction from the laser injection port to the laser injection port, the second inclined portion is inclined away from the first wall, and the second inclined portion is used to guide the protective gas to move closer to the second edge.

[0016] In the above scheme, along the direction from the laser inlet to the laser outlet, the second inclined portion is inclined away from the first wall, and the second inclined portion is used to guide the shielding gas to move toward the second edge, so that after the shielding gas moving along the second inclined portion contacts the battery cell, part of the shielding gas can move along the second direction, so that after the weld pool leaves the coverage of the shielding gas along the second direction, part of the shielding gas can still move in the direction from the first edge to the second edge to protect the weld pool, thereby further improving the welding quality and improving the cooling efficiency of the weld pool.

[0017] In some embodiments, along the third direction, the first shell has a third wall and a fourth wall arranged opposite to each other, the laser emission port extends from the inner surface of the third wall to the inner surface of the fourth wall, and the first direction, the second direction and the third direction are perpendicular to each other; along the direction from the laser emission port to the laser emission port, the distance between the inner surface of the third wall and the inner surface of the fourth wall in the third direction gradually decreases.

[0018] In the above scheme, along the direction from the laser injection port to the laser injection port, the distance between the inner surface of the third wall and the inner surface of the fourth wall in the third direction gradually decreases, so that when the shielding gas passes through the first cavity, the movement speed gradually increases, thereby increasing the speed of the shielding gas when leaving the laser injection port, thereby improving the shielding gas's ability to restrict the air between the weld molten pool and the first shell, reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air, improving the weld quality, and thereby increasing the reliability of the battery cell.

[0019] In some embodiments, along the second direction, the distance between the first edge and the center of the laser injection port is H1, satisfying 3.5 mm≤H1≤5 mm.

[0020] In the above scheme, when H1≥3.5mm, a certain distance can be created between the first edge and the laser, thereby reducing the risk of the laser burning the first edge; when H1≤5mm, the shielding gas leaving the first cavity from the range between the first edge and the laser can be reduced, thereby allowing more shielding gas to leave the first cavity from the range between the second edge and the laser, thereby enhancing the shielding gas's ability to restrict the air between the weld pool and the first shell, thereby reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air; therefore, when 3.5mm≤H1≤5mm, it can both reduce the risk of the laser burning the first edge and enhance the shielding gas's ability to restrict the air between the weld pool and the first shell, thereby reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air.

[0021] In some embodiments, along the second direction, a distance between the second edge and the center of the laser entrance is H2, satisfying 10 mm ≤ H2 ≤ 100 mm.

[0022] In the above scheme, when H2≥10mm, the weld pool can be within the coverage of the protective gas for a certain period of time. On the one hand, the oxidation and contamination of the weld pool by oxygen and water vapor in the air can be limited within a certain period of time, thereby reducing defects such as pores and inclusions, and reducing the possibility of oxidation in the heat-affected zone, thereby reducing the oxide layer on the weld surface and improving the welding quality; on the other hand, the heat exchange time of the weld pool of the protective gas can be increased, thereby reducing the temperature of the weld pool more quickly, thereby improving the production efficiency of the battery cell; when H2≤100mm, the laser outlet can be The size of H2 is within a certain range, so that the shielding gas can be more concentrated, thereby improving the shielding gas's ability to restrict the air between the weld pool and the first shell, and reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air; therefore, when 10mm≤H2≤100mm, the weld pool can be kept within the coverage of the shielding gas for a certain period of time, thereby improving the welding quality and the cooling efficiency of the weld, and the shielding gas's ability to restrict the air between the weld pool and the first shell can be improved, reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air.

[0023] In some embodiments, a dimension of the laser emission port in the third direction is B, satisfying 7mm≤B≤10mm, and the first direction, the second direction and the third direction are perpendicular to each other.

[0024] In the above scheme, when B≥7mm, a certain distance can be created between the two edges of the laser outlet that are relatively arranged in the third direction and the laser, thereby reducing the risk of the laser burning the laser outlet; when B≤10mm, the size of the laser outlet can be within a certain range, so that the shielding gas can be more concentrated, thereby improving the ability of the shielding gas to restrict the air between the weld pool and the first shell, and reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air; therefore, when 7mm≤B≤10mm, it can not only reduce the risk of the laser burning the laser outlet, but also improve the ability of the shielding gas to restrict the air between the weld pool and the first shell, and reduce the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air.

[0025] In some embodiments, the welding gas protection mechanism also includes a second shell; the second shell is used to be arranged outside the lens of the laser welding mechanism to form a second cavity with the lens, the second shell has a first side located in the second cavity and facing the lens, the first side is provided with a plurality of first air channels and a first channel that penetrates the first shell along the first direction and is connected to the laser injection port, the first channel is used for laser to pass through, and the plurality of first air channels are arranged at intervals along the periphery of the first channel; the gas supply component is used to provide protective gas to the second cavity through the plurality of first air channels.

[0026] In the above scheme, a plurality of first gas channels are arranged at intervals along the periphery of the first channel, and the gas supply component provides protective gas to the second cavity through the plurality of first gas channels, so that the gas supply component can evenly provide protective gas to the second cavity, thereby increasing the gas pressure in the second cavity, thereby forming a positive pressure in the first channel relative to the first cavity. Thus, the protective gas is discharged from the second cavity through the first channel, and the structure is simple and easy to implement.

[0027] In a second aspect, an embodiment of the present application provides a laser welding device including a laser welding mechanism and a welding gas protection mechanism in any of the above embodiments.

[0028] In a third aspect, an embodiment of the present application provides a battery production line including the laser welding equipment in the above embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the structure of a laser welding device provided in some embodiments of the present application;

[0031] Figure 2 A schematic diagram of the structure of a first housing and a battery cell provided in some embodiments of the present application;

[0032] Figure 3 for Figure 2 Sectional view of AA in the middle;

[0033] Figure 4 A cross-sectional view of another first housing provided for some embodiments of the present application;

[0034] Figure 5A cross-sectional view of the first housing in another direction provided in some embodiments of the present application;

[0035] Figure 6 A schematic diagram of the structure of a welding gas protection mechanism provided in some embodiments of the present application;

[0036] Figure 7 for Figure 6 Cross-sectional view of the middle BB;

[0037] Figure 8 for Figure 6 A partial enlarged view of point C in the middle.

[0038] Icon: 100-Laser welding equipment;

[0039] 10-Welding gas protection mechanism;

[0040] 11-first shell; 110-first cavity; 1101-laser injection port; 1102-laser injection port; 1102A-first edge; 1102B-second edge; 111-first wall; 111A-first vertical portion; 111B-first inclined portion; 111C-transition portion; 112-second wall; 112A-second vertical portion; 112B-second inclined portion; 113-third wall; 114-fourth wall; 115-blocking portion;

[0041] 12-second shell; 120-second cavity; 1201-first side; 1202-first channel; 1203-first air channel; 1204-third cavity; 1205-fourth cavity; 1206-second air channel; 1207-second channel;

[0042] 20-laser welding mechanism; 21-laser beam; 22-lens;

[0043] 30 - battery cell; 31 - housing; 32 - end cover; 33 - molten pool;

[0044] X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0047] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0048] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0049] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0050] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0051] The term “plurality” used in this application refers to two or more (including two).

[0052] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0053] The battery cell includes a shell, an end cover and an electrode assembly, and the electrode assembly is accommodated in the shell. The shell has an opening, and the shell has a first wall facing away from the end cover. The end cover is used to seal the opening so that the end cover and the shell together form a storage space for accommodating the electrode assembly. The end cover and the shell are generally packaged by welding. In the production process of battery cells, a steel shell is used to reduce the volume of the battery cell occupied by the shell, thereby increasing the volume of the electrode assembly to improve the energy density of the battery cell. However, the laser absorption rate of the steel shell is higher than that of the aluminum shell, so that the temperature of the molten pool generated by welding is higher, so that the cooling time of the weld molten pool of the steel shell is longer than that of the weld molten pool of the aluminum shell, and in the production process, it is necessary to wait for the weld molten pool to cool before the next process can be carried out. The increase in the cooling time of the weld molten pool will lead to a decrease in the production efficiency of the battery cell.

[0054] Based on the above considerations, in order to reduce the cooling time of the weld pool and improve the production efficiency of battery cells. The embodiment of the present application provides a welding gas protection mechanism including a first shell and a gas supply component. The first shell is used to be arranged outside the laser welding mechanism, and the interior of the first shell forms a first cavity having a laser injection port and a laser injection port. The laser injection port and the laser injection port are respectively located at the two ends of the first shell in the first direction, and the first direction is parallel to the extension direction of the laser; the gas supply component is used to provide protective gas into the first cavity, and the protective gas leaves the first cavity through the laser injection port; wherein the laser injection port has a first edge and a second edge arranged oppositely in the second direction, and along the second direction, the distance between the second edge and the center of the laser injection port is greater than the distance between the first edge and the center of the laser injection port, and the second direction is perpendicular to the first direction.

[0055] In a welding gas shielding mechanism of this structure, along the second direction, the distance between the second edge and the center of the laser entrance is greater than the distance between the first edge and the center of the laser entrance, so that when the laser is incident from the center of the laser entrance along the first direction, the range covered in the second direction by the shielding gas leaving the first cavity from the area between the laser and the second edge is greater than the range covered in the second direction by the shielding gas leaving the first cavity from the area between the laser and the first edge. Therefore, when the laser welding mechanism drives the first shell to move in the direction from the second edge to the first edge, so that the formed weld pool is in the range covered by the protective gas that leaves the first cavity from the area between the laser and the second edge, the laser welding mechanism needs to continue to move a certain distance in the second direction before the weld pool is separated from the protection of the protective gas. Therefore, relative to the situation where the first edge and the second edge are symmetrically arranged relative to the laser along the second direction, the time that the weld pool is in the coverage of the protective gas is increased. On the one hand, the oxidation and contamination of the weld pool by oxygen and water vapor in the air can be limited for a longer time, thereby reducing defects such as pores and inclusions, and reducing the possibility of oxidation of the heat-affected zone, thereby reducing the oxide layer on the weld surface and improving the welding quality; on the other hand, the time for the shielding gas weld pool to perform heat exchange can be increased, thereby reducing the temperature of the weld pool more quickly, thereby improving the production efficiency of the battery cell.

[0056] The specific structure of the welding gas protection mechanism is described in detail below in conjunction with the accompanying drawings.

[0057] Please refer to Figure 1 and Figure 2 , and please refer to Figure 3 and Figure 4 , Figure 1 This is a schematic diagram of the structure of a laser welding device 100 provided in some embodiments of the present application. Figure 2 This is a schematic diagram of the structure of the first housing 11 and the battery cell 30 provided in some embodiments of the present application. Figure 3 for Figure 2 The cross-sectional view of AA in the figure, Figure 4Another cross-sectional view of a first shell 11 provided for some embodiments of the present application. The embodiment of the present application provides a welding gas shielding mechanism 10 including a first shell 11 and a gas supply component. The first shell 11 is used to be arranged outside the laser welding mechanism 20, and the interior of the first shell 11 forms a first cavity 110 having a laser injection port 1101 and a laser injection port 1102. The laser injection port 1101 and the laser injection port 1102 are respectively located at two ends of the first shell 11 in the first direction X. The laser beam 21 passes through the laser injection port 1101 from the center of the laser injection port 1101, and the first direction X is parallel to the extension direction of the laser. The gas supply component is used to provide shielding gas into the first cavity 110, and the shielding gas leaves the first cavity 110 through the laser injection port 1102. In which, the laser emission port 1102 has a first edge 1102A and a second edge 1102B arranged opposite to each other in the second direction Y. Along the second direction Y, the distance between the second edge 1102B and the center of the laser emission port 1101 is greater than the distance between the first edge 1102A and the center of the laser emission port 1101. The second direction Y is perpendicular to the first direction X.

[0058] The first shell 11 is the main structure of the welding gas shielding mechanism 10 , and the interior thereof is a hollow structure having a first cavity 110 . The first cavity 110 has a laser injection port 1101 and a laser injection port 1102 communicated with the outside.

[0059] In some embodiments, reference Figure 3 The first shell 11 is open at two opposite ends in the first direction X, wherein the opening at one end is a laser injection port 1101, and the opening at the other end is a laser injection port 1102. The laser injection port 1101 is used for the laser beam 21 to enter the first cavity 110, and the laser injection port 1102 is used for the laser beam 21 to leave the first cavity 110.

[0060] The first direction X is a direction parallel to the laser beam 21 . For example, the first direction X may be parallel to a width direction or a length direction of the battery cell 30 .

[0061] The gas supply component (not shown in the figure) is a component for providing protective gas into the first cavity 110. Exemplarily, the gas supply component (not shown in the figure) can be a gas supply pipe, or can be a mechanism or device capable of providing gas. Exemplarily, the gas supply component (not shown in the figure) can be a gas tank, a fan, etc.

[0062] The protective gas can be an inert gas such as nitrogen, argon, etc.

[0063] The air supply component may be directly connected to the first cavity 110 , or may be indirectly connected to the first cavity 110 via other structural components.

[0064] In some embodiments, the gas outlet pipe of the gas supply component is connected to the peripheral side of the first shell 11 to provide protective gas to the first cavity 110. In some embodiments, the gas outlet pipe of the gas supply component is connected to the laser injection port 1101 to provide protective gas to the first cavity 110.

[0065] It can be understood that the laser welding mechanism 20 moves relative to the battery cell 30 and provides a laser beam 21 to the gap between the shell 31 and the end cover 32 to melt the shell 31 and the end cover 32 to form a weld pool 33 .

[0066] The second direction Y may be the movement direction of the laser welding mechanism 20 relative to the battery cell 30 , that is, the second direction Y is parallel to the weld. For example, the second direction Y may be parallel to the length direction or the width direction of the battery cell 30 .

[0067] In some embodiments, the first direction X is parallel to the length direction of the battery cell 30 , the second direction Y is parallel to the width direction of the battery cell 30 , and the laser welding mechanism 20 moves along the second direction Y to weld the end cover 32 and the shell 31 parallel to the width direction of the battery cell 30 .

[0068] In some embodiments, the second direction Y is parallel to the length direction of the battery cell 30 , the first direction X is parallel to the width direction of the battery cell 30 , and the laser welding mechanism 20 moves along the second direction Y to weld the end cap 32 and the shell 31 with a gap parallel to the length direction of the battery cell 30 .

[0069] The first edge 1102A and the second edge 1102B are two edges of the laser emission port 1102 that are opposite to each other in the second direction Y.

[0070] In some embodiments, the first edge 1102A and the second edge 1102B are both straight lines, and the first edge 1102A and the second edge 1102B may be parallel to each other or form an angle with each other.

[0071] In some embodiments, the first edge 1102A and the second edge 1102B are both arc-shaped, the center of curvature of the first edge 1102A is located on the side of the first edge 1102A close to the second edge 1102B, and the center of curvature of the second edge 1102B is located on the side of the second edge 1102B close to the first edge 1102A.

[0072] The center of the laser entrance 1101 refers to the geometric center of the laser entrance 1101 .

[0073] “The distance between the first edge 1102A and the center of the laser entrance 1101 along the second direction Y” can be understood as the distance between the geometric center of the orthographic projection of the laser entrance 1101 and the orthographic projection of the first edge 1102A in the second direction Y on a plane perpendicular to the first direction X.

[0074] “The distance between the second edge 1102B and the center of the laser entrance 1101 along the second direction Y” can be understood as the distance between the geometric center of the orthographic projection of the laser entrance 1101 and the orthographic projection of the second edge 1102B in the second direction Y on a plane perpendicular to the first direction X.

[0075] Along the second direction Y, the distance between the second edge 1102B and the center of the laser entrance 1101 is greater than the distance between the first edge 1102A and the center of the laser entrance 1101, so that when the laser is emitted from the center of the laser entrance 1101 along the first direction X, the range covered by the protective gas leaving the first cavity 110 from the area between the laser and the second edge 1102B in the second direction Y is greater than the range covered by the protective gas leaving the first cavity 110 from the area between the laser and the first edge 1102A in the second direction Y.

[0076] In some embodiments, please refer to Figure 4 The first shell 11 is provided with openings at both opposite ends in the first direction X, one of the openings is a laser incident port, and the first shell 11 also includes a blocking portion 115, which is used to block the other opening and extend along the second direction Y to form a laser incident port 1102, and the laser incident port 1102 has a first edge 1102A and a second edge 1102B that are relatively arranged in the second direction Y, and along the second direction Y, the distance between the second edge 1102B and the center of the laser incident port 1101 is greater than the distance between the first edge 1102A and the center of the laser incident port 1101, and the second direction Y is perpendicular to the first direction X.

[0077] In this embodiment, along the second direction Y, the distance between the second edge 1102B and the center of the laser entrance 1101 is greater than the distance between the first edge 1102A and the center of the laser entrance 1101, so that when the laser beam 21 is emitted from the center of the laser entrance 1101 along the first direction X, the range covered by the protective gas leaving the first cavity 110 from the area between the laser beam 21 and the second edge 1102B in the second direction Y is greater than the range covered by the protective gas leaving the first cavity 110 from the area between the laser beam 21 and the first edge 1102A in the second direction Y. Therefore, when the laser welding mechanism 20 drives the first shell 11 to move in the direction from the second edge 1102B to the first edge 1102A, so that the formed weld pool 33 is in the range covered by the protective gas of the first cavity 110 from the area between the laser beam 21 and the second edge 1102B, the laser welding mechanism 20 needs to continue to move a certain distance along the second direction Y to make the weld pool 33 break away from the protection of the protective gas, so that the time that the weld pool 33 is in the coverage of the protective gas is increased relative to the situation that the first edge 1102A and the second edge 1102B are symmetrically arranged relative to the laser along the second direction Y. On the one hand, the oxidation and contamination of the weld pool by oxygen and water vapor in the air can be limited for a longer time, thereby reducing defects such as pores and inclusions, and reducing the possibility of oxidation of the heat-affected zone, thereby reducing the oxide layer on the weld surface and improving the welding quality. On the other hand, the time for the shielding gas weld pool 33 to perform heat exchange can be increased, thereby reducing the temperature of the weld pool 33 more quickly, thereby improving the production efficiency of the battery cell 30.

[0078] Please refer to Figure 3 According to some embodiments of the present application, the shape of the laser emission port 1102 is a rectangle or a bar, and the length direction of the laser emission port 1102 is parallel to the second direction Y.

[0079] Optionally, the shape of the laser emission port 1102 may be a rectangle, a bar, or other irregular shapes.

[0080] In some embodiments, the laser emission port 1102 is a waist-shaped hole.

[0081] In some embodiments, the laser emission port 1102 is rectangular, and the four corners of the rectangle are all provided with arc-shaped chamfers.

[0082] “The shape of the laser emission outlet 1102 is a rectangle or a bar, and the length direction of the laser emission outlet 1102 is parallel to the second direction Y” means that the size of the laser emission outlet 1102 in the second direction Y is smaller than the size of the laser emission outlet 1102 in the third direction Z.

[0083] In this embodiment, when the laser welding mechanism 20 drives the first shell 11 to move in the direction from the second edge 1102B to the first edge 1102A, the laser outlet 1102 is rectangular, and the length direction of the laser outlet 1102 is parallel to the second direction Y. Therefore, relative to the situation where the laser outlet 1102 is square or the laser outlet 1102 is rectangular, and the length direction of the laser outlet 1102 is parallel to the third direction Z (the first direction X, the second direction Y and the third direction Z are perpendicular to each other), the shielding gas can be concentrated in the weld pool 33 and the heat-affected zone around the weld pool 33, on the one hand, reducing the waste of shielding gas. On the other hand, the speed of the shielding gas leaving the laser outlet 1102 is increased, reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air, improving the quality of the weld, and thus increasing the reliability of the battery cell 30.

[0084] Please refer to Figure 3 and Figure 4 According to some embodiments of the present application, the first shell 11 has a first wall 111 and a second wall 112 that are oppositely arranged in the second direction Y, and the laser emission port 1102 extends from the inner surface of the first wall 111 to the inner surface of the second wall 112 .

[0085] The first wall 111 and the second wall 112 are two wall portions of the first housing 11 that are opposite to each other in the second direction Y.

[0086] It can be understood that the laser emission outlet 1102 extends from the inner surface of the first wall 111 to the inner surface of the second wall 112, thereby reducing the risk of reducing the overall flow rate of the protective gas due to part of the protective gas hitting the sealing portion 115 and rebounding along the first direction X, compared to the situation where a portion of another opening is blocked by the sealing portion 115 to form the laser emission outlet 1102.

[0087] In this embodiment, the laser emission outlet 1102 extends from the inner surface of the first wall 111 to the inner surface of the second wall 112, thereby further increasing the coverage of the shielding gas in the second direction Y, so that the time that the weld pool 33 is within the coverage of the shielding gas is further increased, thereby further improving the welding quality and enhancing the cooling efficiency of the weld pool 33.

[0088] Please refer to Figure 3According to some embodiments of the present application, the inner surface of the first wall 111 has a first vertical portion 111A and a first inclined portion 111B, the first vertical portion 111A is parallel to the first direction X, and along the first direction X, the first vertical portion 111A is located between the first inclined portion 111B and the laser injection port 1101. Along the direction from the laser injection port 1101 to the laser injection port 1102, the first inclined portion 111B is inclined toward the second wall 112, and the first inclined portion 111B is used to guide the shielding gas to move toward the first edge 1102A.

[0089] The first vertical portion 111A and the first inclined portion 111B are two parts of the inner surface of the first wall 111 , and are sequentially disposed along a direction from the laser injection port 1101 to the laser injection port 1102 .

[0090] “The first vertical portion 111A is parallel to the first direction X” may be understood as the extending direction of the first vertical portion 111A is parallel to the first direction X.

[0091] In some embodiments, the first vertical portion 111A is a plane, and the first vertical portion 111A is parallel to the first direction X. In some embodiments, the first vertical portion 111A is a partial cylindrical surface, and the axis of the first vertical portion 111A is parallel to the first direction X.

[0092] “Along the direction from the laser entrance 1101 to the laser exit 1102 , the first inclined portion 111B is inclined toward the second wall 112 ” can be understood as the distance between the first inclined portion 111B and the laser beam 21 in the second direction Y gradually decreases along the direction from the laser entrance 1101 to the laser exit 1102 .

[0093] In some embodiments, the first vertical portion 111A is a plane. In some embodiments, the first vertical portion 111A is a partial cylindrical surface.

[0094] In this embodiment, along the direction from the laser injection port 1101 to the laser injection port 1102, the first inclined portion 111B is inclined toward the second wall 112, and the first inclined portion 111B is used to guide the shielding gas to move toward the first edge 1102A, so that when the laser welding mechanism 20 drives the first shell 11 to move from the second edge 1102B to the first edge 1102A for welding, the shielding gas can approach the weld pool 33 along a direction at a certain angle to the second direction Y, so that after the shielding gas moving along the first inclined portion 111B contacts the battery cell 30, part of the shielding gas can move along the second direction Y, on the one hand, it is convenient for the shielding gas to drive the air between the weld pool 33 and the first shell 11 away from the weld, thereby limiting the oxidation and contamination of the weld pool by oxygen and water vapor in the air, thereby reducing defects such as pores and inclusions. On the other hand, it is convenient for the shielding gas to exchange heat with the weld pool 33, thereby further improving the cooling efficiency of the weld.

[0095] Please refer to Figure 3 According to some embodiments of the present application, the inner surface of the first wall 111 has a transition portion 111C, and the first vertical portion 111A is connected to the first inclined portion 111B through the transition portion 111C.

[0096] The transition portion 111C is a portion of the inner surface of the first wall 111 for connecting the first vertical portion 111A and the first inclined portion 111B. Exemplarily, the transition portion 111C is a curved surface, and the center of curvature of the transition portion 111C is located inside the first wall 111 .

[0097] In this embodiment, the inner surface of the first wall 111 has a transition portion 111C, and the first vertical portion 111A is connected to the first inclined portion 111B through the transition portion 111C, so that the shielding gas moving along the first vertical portion 111A can be more smoothly converted along the transition portion 111C to move along the first inclined portion 111B, thereby reducing the risk of the shielding gas moving along the first vertical portion 111A directly colliding with the first inclined portion 111B to cause turbulence, thereby affecting the flow rate of the shielding gas and reducing the risk.

[0098] Please refer to Figure 3 According to some embodiments of the present application, the inner surface of the second wall 112 has a second vertical portion 112A and a second inclined portion 112B, and the second vertical portion 112A is parallel to the first direction X. Along the direction from the laser injection port 1101 to the laser injection port 1102, the second inclined portion 112B is inclined away from the first wall 111, and the second inclined portion 112B is used to guide the shielding gas to move toward the second edge 1102B.

[0099] The second vertical portion 112A and the second inclined portion 112B are two parts of the inner surface of the second wall 112 , and the second vertical portion 112A and the second inclined portion 112B are sequentially arranged along the direction from the laser injection port 1101 to the laser injection port 1102 .

[0100] “The second vertical portion 112A is parallel to the first direction X” may be understood as the extension direction of the second vertical portion 112A is parallel to the first direction X.

[0101] In some embodiments, the second vertical portion 112A is a plane, and the second vertical portion 112A is parallel to the first direction X. In some embodiments, the second vertical portion 112A is a partial cylindrical surface, and the axis of the second vertical portion 112A is parallel to the first direction X.

[0102] “Along the direction from the laser entrance 1101 to the laser exit 1102 , the second inclined portion 112B is inclined away from the first wall 111 ” can be understood as that along the direction from the laser entrance 1101 to the laser exit 1102 , the distance between the second inclined portion 112B and the laser beam 21 in the second direction Y gradually increases.

[0103] In some embodiments, the second vertical portion 112A is a plane. In some embodiments, the second vertical portion 112A is a partial cylindrical surface.

[0104] In this embodiment, along the direction from the laser injection port 1101 to the laser injection port 1102, the second inclined portion 112B is inclined away from the first wall 111, and the second inclined portion 112B is used to guide the shielding gas to move toward the second edge 1102B, so that after the shielding gas moving along the second inclined portion 112B contacts the battery cell 30, part of the shielding gas can move along the second direction Y, so that after the weld pool 33 leaves the coverage of the shielding gas along the second direction Y, part of the shielding gas can still move in the direction from the first edge 1102A to the second edge 1102B to protect the weld pool 33, thereby further improving the welding quality and improving the cooling efficiency of the weld pool 33.

[0105] Please refer to Figure 5 , Figure 5 A cross-sectional view of the first housing 11 in another direction provided for some embodiments of the present application. According to some embodiments of the present application, along the third direction Z, the first housing 11 has a third wall 113 and a fourth wall 114 arranged opposite to each other, the laser emission port 1102 extends from the inner surface of the third wall 113 to the inner surface of the fourth wall 114, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other. Along the direction from the laser emission port 1101 to the laser emission port 1102, the distance between the inner surface of the third wall 113 and the inner surface of the fourth wall 114 in the third direction Z gradually decreases.

[0106] The third wall 113 and the fourth wall 114 are two wall portions of the first housing 11 that are opposite to each other in the third direction Z.

[0107] In some embodiments, the first wall 111 , the second wall 112 , the third wall 113 and the fourth wall 114 together form the first shell 11 , wherein inner surfaces of two adjacent wall portions are connected by arc surfaces.

[0108] In some embodiments, along the second direction Y, the laser outlet 1102 extends from the inner surface of the first wall 111 to the inner surface of the second wall 112 , and along the third direction Z, the laser outlet 1102 extends from the inner surface of the third wall 113 to the inner surface of the fourth wall 114 .

[0109] The third direction Z may be a height direction of the battery cell 30 , and the housing 31 and the end cover 32 may be buckled together along the third direction Z.

[0110] In some embodiments, please refer to Figure 5 , along the direction from the laser injection port 1101 to the laser injection port 1102 , the third wall 113 and the fourth wall 114 are both inclined toward the direction approaching the other.

[0111] In some embodiments, along the direction from the laser injection port 1101 to the laser injection port 1102 , one of the third wall 113 and the fourth wall 114 is inclined toward the other.

[0112] In some embodiments, along the direction from the laser injection port 1101 to the laser injection port 1102, one of the third wall 113 and the fourth wall 114 is inclined toward the direction approaching the other, and the other of the third wall 113 and the fourth wall 114 is inclined toward the direction away from the one, and the inclination angle of one of the third wall 113 and the fourth wall 114 is greater than the inclination angle of the other.

[0113] In this embodiment, along the direction from the laser injection port 1101 to the laser injection port 1102, the distance between the inner surface of the third wall 113 and the inner surface of the fourth wall 114 in the third direction Z gradually decreases, so that when the shielding gas passes through the first cavity 110, the movement speed gradually increases, thereby increasing the speed of the shielding gas when leaving the laser injection port 1102, thereby improving the shielding gas's ability to restrict the air between the weld pool 33 and the first shell 11, reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air, improving the weld quality, and thereby increasing the reliability of the battery cell 30.

[0114] Please refer to Figure 3 According to some embodiments of the present application, along the second direction Y, the distance between the first edge 1102A and the center of the laser entrance 1101 is H1, satisfying 3.5 mm ≤ H1 ≤ 5 mm.

[0115] H1 can be any point value among 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5mm, etc., or a range value between any two of them.

[0116] In this embodiment, when H1≥3.5mm, a certain distance can be created between the first edge 1102A and the laser, thereby reducing the risk of the laser burning the first edge 1102A. When H1≤5mm, the shielding gas leaving the first cavity 110 from the range between the first edge 1102A and the laser can be reduced, thereby allowing more shielding gas to leave the first cavity 110 from the range between the second edge 1102B and the laser, thereby increasing the shielding gas's ability to restrict the air between the weld pool 33 and the first shell 11, thereby reducing the risk of the oxygen and water vapor in the air oxidizing and contaminating the weld pool. Therefore, when 3.5mm≤H1≤5mm, both the risk of the laser burning the first edge 1102A can be reduced, and the shielding gas's ability to restrict the air between the weld pool 33 and the first shell 11 can be increased, thereby reducing the risk of the oxygen and water vapor in the air oxidizing and contaminating the weld pool.

[0117] Please refer to Figure 3 According to some embodiments of the present application, along the second direction Y, the distance between the second edge 1102B and the center of the laser entrance 1101 is H2, satisfying 10 mm ≤ H2 ≤ 100 mm.

[0118] H2 can be any point value among 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, etc., or a range value between any two of them.

[0119] In this embodiment, when H2≥10mm, the weld pool 33 can be within the coverage of the shielding gas for a certain period of time. On the one hand, the oxidation and contamination of the weld pool by oxygen and water vapor in the air can be limited within a certain period of time, thereby reducing defects such as pores and inclusions, and reducing the possibility of oxidation of the heat-affected zone, thereby reducing the oxide layer on the weld surface and improving the welding quality. On the other hand, the heat exchange time of the shielding gas weld pool 33 can be increased, thereby reducing the temperature of the weld pool 33 more quickly, thereby improving the production efficiency of the battery cell 30. When H2≤100mm, the size of the laser ejection port 1102 can be within a certain range, so that the shielding gas can be more concentrated, thereby improving the shielding gas's ability to restrict the air between the weld pool 33 and the first shell 11, and reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air. Therefore, when 10mm≤H2≤100mm, the weld pool 33 can be kept within the coverage of the shielding gas for a certain period of time, thereby improving the welding quality and the cooling efficiency of the weld, and the shielding gas's ability to restrict the air between the weld pool 33 and the first shell 11 can be enhanced, thereby reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air.

[0120] Please refer to Figure 5 According to some embodiments of the present application, the dimension of the laser emission port 1102 in the third direction Z is B, satisfying 7mm≤B≤10mm, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0121] B can be any point value among 7mm, 7.1mm, 7.2mm, 7.3mm, 7.4mm, 7.5mm, 7.6mm, 7.7mm, 7.8mm, 7.9mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc., or a range value between any two of them.

[0122] In this embodiment, when B≥7mm, a certain distance can be created between the two edges of the laser outlet 1102 that are relatively arranged in the third direction Z and the laser, thereby reducing the risk of the laser burning the laser outlet 1102. When B≤10mm, the size of the laser outlet 1102 can be within a certain range, so that the shielding gas can be more concentrated, thereby improving the ability of the shielding gas to restrict the air between the weld pool 33 and the first shell 11, and reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air. Therefore, when 7mm≤B≤10mm, it can reduce the risk of the laser burning the laser outlet 1102, and improve the ability of the shielding gas to restrict the air between the weld pool 33 and the first shell 11, thereby reducing the risk of oxidation and contamination of the weld pool by oxygen and water vapor in the air.

[0123] Please refer to Figure 6 and Figure 7 , and please refer to Figure 8 According to some embodiments of the present application, the welding gas shielding mechanism 10 further includes a second shell 12. The second shell 12 is used to be arranged outside the lens 22 of the laser welding mechanism 20 to form a second cavity 120 with the lens 22. The second shell 12 has a first side 1201 located in the second cavity 120 and facing the lens 22. The first side 1201 is provided with a plurality of first gas passages 1203 and a first channel 1202 that penetrates the first shell 11 along the first direction X and is connected to the laser injection port 1101. The first channel 1202 is used for laser to pass through. The plurality of first gas passages 1203 are arranged at intervals along the periphery of the first channel 1202. The gas supply component is used to provide shielding gas to the second cavity 120 through the plurality of first gas passages 1203.

[0124] The second shell 12 is a component of the welding gas shielding mechanism 10 and is used to surround the lens 22 of the laser welding mechanism 20 to form a second cavity 120 .

[0125] Exemplarily, the second housing 12 is a hollow structure with an opening at one end, and the lens 22 of the laser welding mechanism 20 can be inserted into the second housing 12 through the opening side, and the other peripheral sides of the laser welding mechanism 20 cover the opening side to form the second cavity 120. Alternatively, the lens 22 of the laser welding mechanism 20 can also directly cover the opening side to form the second cavity 120.

[0126] The first side 1201 is a surface of the second housing 12 located in the second cavity 120 and facing the lens 22. Optionally, the first side 1201 may be a plane perpendicular to the first direction X.

[0127] The cross-section of the first channel 1202 may be circular, elliptical, or square.

[0128] Reference Figure 7 The first gas channel 1203 may be a circle arranged at intervals along the outer periphery of the first channel 1202, or may be a plurality of circles arranged at intervals along the outer periphery of the first channel 1202. Thus, the gas provided by the gas supply component (not shown in the figure) to the second cavity 120 can enter the second cavity 120 uniformly, so that the pressure of different regions of the second cavity 120 is uniformly increased, and the risk of reducing the flow rate of the protective gas due to the flow disturbance of the protective gas caused by the pressure difference in some regions of the second cavity 120 is reduced.

[0129] Reference Figure 6 and Figure 7The first housing 11 is disposed on a side of the second housing 12 away from the laser welding mechanism 20 in the first direction X, and the first channel 1202 is connected to the laser injection port 1101. The gas supply component (not shown) provides gas to the second cavity 120 to increase the pressure in the second cavity 120, thereby driving the gas in the second cavity 120 to enter the first cavity 110 along the first channel 1202 through the laser injection port 1101.

[0130] In some embodiments, reference Figure 6 , along the direction from the second cavity 120 to the first cavity 110 , the cross-sectional area of ​​the first channel 1202 gradually decreases.

[0131] In some embodiments, reference Figure 6-Figure 8 A third cavity 1204, a fourth cavity 1205, a plurality of second gas channels 1206 and a second channel 1207 are provided inside the second shell 12. The second cavity 120, the third cavity 1204, the fourth cavity 1205 and the first cavity 110 are arranged in sequence along the direction pointing from the second cavity 120 to the first cavity 110, wherein the third cavity 1204 and the fourth cavity 1205 are both arranged around the periphery of the first channel 1202, the first gas channel 1203 connects the third cavity 1204 and the second cavity 120, the second gas channel 1206 is arranged on the inner wall of the third cavity 1204 away from the second cavity 120, and is arranged around the outer peripheral side of the first channel 1202, the second channel 1207 is connected to the fourth cavity 1205, and the gas supply component (not shown in the figure) provides protective gas to the fourth cavity 1205 through the second channel 1207. It can be understood that the protective gas provided by the gas supply component (not shown in the figure) enters the second cavity 120 through the buffer of the fourth cavity 1205, the second gas channel 1206, the third cavity 1204 and the first gas channel 1203 in sequence, thereby reducing the flow rate of the protective gas entering the second cavity 120, thereby reducing the risk of gas flow turbulence.

[0132] In this embodiment, a plurality of first gas passages 1203 are arranged at intervals along the outer periphery of the first channel 1202, and the gas supply component provides protective gas to the second cavity 120 through the plurality of first gas passages 1203, so that the gas supply component can evenly provide protective gas to the second cavity 120, thereby increasing the gas pressure in the second cavity 120, thereby forming a positive pressure in the first channel 1202 relative to the first cavity 110. Thus, the protective gas is discharged from the second cavity 120 through the first channel 1202, and the structure is simple and easy to implement.

[0133] The embodiment of the present application provides a laser welding device 100 including a laser welding mechanism 20 and a welding gas protection mechanism 10 in any of the above embodiments.

[0134] An embodiment of the present application provides a battery production line including the laser welding device 100 in the above embodiment.

[0135] According to some embodiments of this application, please refer to Figure 1-Figure 8The present application provides a welding gas shielding mechanism 10 including a first shell 11 and a gas supply component. The first shell 11 is used to be arranged outside the laser welding mechanism 20. The first shell 11 has a first cavity 110 having a laser injection port 1101 and a laser injection port 1102 formed inside. The laser injection port 1101 and the laser injection port 1102 are respectively located at two ends of the first shell 11 in a first direction X. The laser beam 21 passes through the laser injection port 1101 from the center of the laser injection port 1101. The first direction X is parallel to the extension direction of the laser. The gas supply component is used to provide shielding gas into the first cavity 110, and the shielding gas leaves the first cavity 110 through the laser injection port 1102. The laser injection port 1102 has a first edge 1102A and a second edge 1102B arranged opposite to each other in the second direction Y. Along the second direction Y, the distance between the second edge 1102B and the center of the laser injection port 1101 is greater than the distance between the first edge 1102A and the center of the laser injection port 1101. The second direction Y is perpendicular to the first direction X. The shape of the laser emission port 1102 is one of a rectangle and a strip, and the length direction of the laser emission port 1102 is parallel to the second direction Y. The first shell 11 has a first wall 111 and a second wall 112 that are arranged opposite to each other in the second direction Y, and the laser emission port 1102 extends from the inner surface of the first wall 111 to the inner surface of the second wall 112. The inner surface of the first wall 111 has a first vertical portion 111A and a first inclined portion 111B, and the first vertical portion 111A is parallel to the first direction X. Along the first direction X, the first vertical portion 111A is located between the first inclined portion 111B and the laser emission port 1101. Along the direction from the laser emission port 1101 to the laser emission port 1102, the first inclined portion 111B is inclined toward the second wall 112, and the first inclined portion 111B is used to guide the shielding gas to move toward the first edge 1102A. The inner surface of the first wall 111 has a transition portion 111C, and the first vertical portion 111A is connected to the first inclined portion 111B through the transition portion 111C. The inner surface of the second wall 112 has a second vertical portion 112A and a second inclined portion 112B, and the second vertical portion 112A is parallel to the first direction X. Along the direction from the laser injection port 1101 to the laser injection port 1102, the second inclined portion 112B is inclined away from the first wall 111, and the second inclined portion 112B is used to guide the protective gas to move closer to the second edge 1102B. Along the third direction Z, the first shell 11 has a third wall 113 and a fourth wall 114 arranged opposite to each other, and the laser injection port 1102 extends from the inner surface of the third wall 113 to the inner surface of the fourth wall 114, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other. Along the direction from the laser emission port 1101 to the laser emission port 1102 , the distance between the inner surface of the third wall 113 and the inner surface of the fourth wall 114 in the third direction Z gradually decreases.Along the second direction Y, the distance between the first edge 1102A and the center of the laser injection port 1101 is H1, which satisfies 3.5 mm ≤ H1 ≤ 5 mm. Along the second direction Y, the distance between the second edge 1102B and the center of the laser injection port 1101 is H2, which satisfies 10 mm ≤ H2 ≤ 100 mm. The dimension of the laser injection port 1102 in the third direction Z is B, which satisfies 7 mm ≤ B ≤ 10 mm. The welding gas shielding mechanism 10 further includes a second housing 12. The second housing 12 is used to be arranged outside the lens 22 of the laser welding mechanism 20 to form a second cavity 120 with the lens 22. The second housing 12 has a first side 1201 located in the second cavity 120 and facing the lens 22. The first side 1201 is provided with a plurality of first gas passages 1203 and a first channel 1202 that penetrates the first housing 11 along the first direction X and communicates with the laser injection port 1101. The first channel 1202 is used for laser to pass through. The plurality of first gas passages 1203 are arranged at intervals along the outer periphery of the first channel 1202. The gas supply component is used to provide protective gas to the second cavity 120 through the plurality of first gas passages 1203.

[0136] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0137] The above embodiments are only used to illustrate the technical solution of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A welding gas protection mechanism, characterized in that: include: A first shell is used to be arranged outside the laser welding mechanism, wherein a first cavity having a laser injection port and a laser injection port is formed inside the first shell, wherein the laser injection port and the laser injection port are respectively located at two ends of the first shell in a first direction, and a laser beam passes through the laser injection port from the center of the laser injection port, and the first direction is parallel to an extension direction of the laser beam; A gas supply component, the gas supply component is used to provide a protective gas to the first cavity, and the protective gas leaves the first cavity through the laser emission port; The laser exit port has a first edge and a second edge arranged opposite to each other in a second direction, and along the second direction, a distance between the second edge and the center of the laser exit port is greater than a distance between the first edge and the center of the laser exit port, and the second direction is perpendicular to the first direction.

2. The welding gas shielding mechanism according to claim 1, characterized in that: The shape of the laser emission port is a rectangle or a strip, and the length direction of the laser emission port is parallel to the second direction.

3. The welding gas shielding mechanism according to claim 1, characterized in that: The first housing has a first wall and a second wall that are oppositely disposed in the second direction, and the laser emission port extends from an inner surface of the first wall to an inner surface of the second wall.

4. The welding gas shielding mechanism according to claim 3, characterized in that: The inner surface of the first wall has a first vertical portion and a first inclined portion, the first vertical portion is parallel to the first direction, and along the first direction, the first vertical portion is located between the first inclined portion and the laser injection port; Along the direction from the laser injection port to the laser injection port, the first vertical first inclined portion is inclined toward a direction close to the second wall, and the first inclined portion is used to guide the protective gas to move toward the first edge.

5. The welding gas shielding mechanism according to claim 4, characterized in that: The inner surface of the first wall has a transition portion, and the first vertical portion is connected to the first inclined portion through the transition portion.

6. The welding gas shielding mechanism according to claim 3, characterized in that: The inner surface of the second wall has a second vertical portion and a second inclined portion, and the second vertical portion is parallel to the first direction; Along the direction from the laser injection port to the laser injection port, the second inclined portion is inclined in a direction away from the first wall, and the second inclined portion is used for guiding the protective gas to move toward the second edge.

7. The welding gas shielding mechanism according to claim 1, characterized in that: Along the third direction, the first housing has a third wall and a fourth wall that are arranged opposite to each other, the laser emission port extends from the inner surface of the third wall to the inner surface of the fourth wall, and the first direction, the second direction and the third direction are perpendicular to each other; Along the direction from the laser injection port to the laser injection port, the distance between the inner surface of the third wall and the inner surface of the fourth wall in the third direction gradually decreases.

8. The welding gas shielding mechanism according to claim 1, characterized in that: Along the second direction, a distance between the first edge and the center of the laser entrance is H1, satisfying 3.5 mm≤H1≤5 mm.

9. The welding gas shielding mechanism according to claim 1, characterized in that: Along the second direction, a distance between the second edge and the center of the laser entrance is H2, satisfying 10 mm ≤ H2 ≤ 100 mm.

10. The welding gas shielding mechanism according to claim 1, characterized in that: The dimension of the laser emission port in the third direction is B, which satisfies 7 mm ≤ B ≤ 10 mm, and the first direction, the second direction and the third direction are perpendicular to each other.

11. The welding gas shielding mechanism according to claim 1, characterized in that: The welding gas protection mechanism also includes: A second shell is used to be arranged outside the lens of the laser welding mechanism to form a second cavity with the lens, the second shell has a first side located in the second cavity and facing the lens, the first side is provided with a plurality of first air channels and a first channel that penetrates the first shell along the first direction and is connected to the laser injection port, the first channel is used for laser to pass through, and the plurality of first air channels are arranged at intervals along the periphery of the first channel; The gas supply component is used to provide protective gas to the second cavity through the plurality of first gas channels.

12. A laser welding device, characterized in that: The invention comprises a laser welding mechanism and a welding gas protection mechanism as claimed in any one of claims 1 to 11.

13. A battery production line, characterized in that: Comprising the laser welding equipment as claimed in claim 12.

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