Welding method and welding device

Abstract

The invention relates to the technical field of new energy, particularly provides a welding method and a welding device, and aims to solve the problems of poor welding quality and low production yield caused by welding a battery shell by adopting a penetration welding method in the prior art. Therefore, the welding method comprises the steps that firstly, the multiple connecting parts of the battery shell are attached, secondly, the outer end faces of the multiple connecting parts are welded, the stability of the outer end faces needing to be welded is guaranteed by tightly attaching the multiple connecting parts together, the welding difficulty is reduced by welding the outer end faces of the connecting parts, and the welding efficiency is improved. The welding quality and the production yield are greatly improved, and meanwhile the welding efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy, and particularly provides a welding method and a welding device. Background Art

[0002] The batteries of existing new energy vehicles usually include upper and lower shells, and the upper and lower shells are connected and fixed and sealed through flange welding. In the prior art, the sealing welding of the upper and lower shells mostly adopts the method of penetrating welding the flange by laser vertically emitting light from one side in the thickness direction of the flange.

[0003] The method of penetrating welding has two deficiencies. One is that to ensure the pressing effect of the flange before welding and leave space for the weld seam, it is necessary to extend the width of the flange in the product design, and then cut off the redundant flange after welding. This method adds a laser cutting process, reduces the efficiency of product manufacturing, and it is difficult to ensure the cutting quality. The other is that to ensure the welding quality, the penetration depth range of the penetrating welding of the flange is required to be between 0.7 mm and 0.85 mm. If the penetration depth is less than 0.7 mm, it is easy to cause a small effective joint surface of the welding, and it is easy to leak after bearing pressure. If the penetration depth is greater than 0.85 mm, it is easy to cause the bottom thin plate to be welded through. After being welded through, there will be spatter adhering to the lower surface of the shell and burrs at the bottom, posing a risk of piercing the subsequent battery film. Therefore, the method of penetrating welding has extremely high requirements for the control accuracy of the penetration depth, and it is difficult to ensure the welding quality and production yield.

[0004] Therefore, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0005] The present invention aims to solve the above technical problems, that is, to solve the problems of poor welding quality and low production yield caused by the existing welding method of penetrating welding for welding the battery shell.

[0006] In a first aspect, the present invention provides a welding method, which includes the following steps: Step 1: Fit multiple connecting parts of the battery shell; Step 2: Weld the outer end faces of the multiple connecting parts.

[0007] In the case of adopting the above technical solution, the present invention adopts the welding method of end face welding. By closely fitting multiple connecting parts together, the stability of the outer end face to be welded is ensured. By welding the outer end faces of the connecting parts, the welding difficulty is reduced, the welding quality and production yield are greatly improved, and the welding efficiency is also improved.

[0008] In a preferred technical solution of the above welding method, the battery shell includes a first shell and a second shell, and the connecting parts include a first connecting part provided on the first shell and a second connecting part provided on the second shell. Among them, Step 1 is specifically: Fit the first connecting part and the second connecting part.

[0009] In the case of adopting the above technical solution, the present invention sets the battery housing into two parts and tightly fits the two connecting parts together, ensuring the flatness and stability of the outer end faces to be welded, and improving the welding quality and production yield.

[0010] In a preferred technical solution of the above welding method, the battery housing includes a first housing, a second housing, and a partition disposed between the first housing and the second housing. The connecting part includes a first connecting part disposed on the first housing and a second connecting part disposed on the second housing. Specifically, step one is to fit the first connecting part, the partition, and the second connecting part together.

[0011] In the case of adopting the above technical solution, the present invention increases the capacity of the battery housing by setting the battery housing in the structural form of "first housing + partition + second housing", and ensures the stability of the outer end faces to be welded by tightly fitting the first connecting part, the edge of the partition, and the second connecting part together, improving the welding quality and production yield.

[0012] In a preferred technical solution of the above welding method, the connecting part includes four outer end faces. Specifically, step two is to weld the four outer end faces in sequence; or, to weld two opposite outer end faces among the four end faces simultaneously.

[0013] In the case of adopting the above technical solution, the present invention can either weld the four outer end faces of the connecting part in sequence or weld two opposite outer end faces among the four outer end faces simultaneously, improving the welding efficiency and preventing the housing from deforming when welding two opposite outer end faces simultaneously, ensuring the quality of the battery.

[0014] In a second aspect, the present invention further provides a welding device, which includes: a clamping structure for fitting multiple connecting parts of the battery housing together; and a welding structure for welding the outer end faces of the multiple connecting parts.

[0015] In the case of adopting the above technical solution, the welding device of the present invention can tightly fit multiple connecting parts of the battery housing together by setting the clamping structure, ensuring the stability of the outer end faces to be welded, improving the welding quality and production yield. By setting the welding structure, it can sequentially weld or simultaneously weld the outer end faces of the multiple connecting parts that are fitted together, improving the welding efficiency, and at the same time improving the welding quality and production yield.

[0016] In a preferred technical solution of the above welding device, the clamping structure includes at least two clamps for clamping the battery housing, and the clamp includes a pressing surface for pressing against the connecting part.

[0017] In the case of adopting the above technical solution, the present invention clamps the battery housing through a fixture, enabling the battery housing to accurately adjust its position, so that multiple connecting parts can be accurately fitted together, ensuring the stability of the outer end face to be welded. By providing a pressing surface on the fixture for pressing against the connecting parts, multiple connecting parts can be closely fitted together, ensuring the flatness and stability of the outer end face to be welded, and improving the welding quality and production yield.

[0018] In a preferred technical solution of the above welding device, the fixture further includes an inclined outer side surface, and the included angle between the outer side surface and the pressing surface ranges from any value between 20° and 40°; and / or, the fixture is provided with a receiving groove for receiving the battery housing.

[0019] In the case of adopting the above technical solution, by obliquely arranging the outer side surface of the fixture, the present invention can prevent welding fumes from spreading everywhere, effectively reducing the pollution caused by welding. By setting the included angle range between the outer side surface and the pressing surface to any value between 20° and 40°, more choices are given to the user. By providing a receiving groove on the fixture, the battery housing can be effectively protected during the welding process.

[0020] In a preferred technical solution of the above welding device, the welding structure includes a first welding head, a first optical fiber and a laser. The first end of the first optical fiber is connected to the first welding head, and the second end of the first optical fiber is connected to the laser; or, the welding structure includes a first welding head, a second welding head, a first optical fiber, a second optical fiber, a beam splitter and a laser. The first end of the first optical fiber is connected to the first welding head, the second end of the first optical fiber is connected to the beam splitter, the first end of the second optical fiber is connected to the second welding head, the second end of the second optical fiber is connected to the beam splitter, and the beam splitter is connected to the laser.

[0021] In the case of adopting the above technical solution, the present invention can either set the welding device in a structural form where one laser is connected to one welding head, or set the welding device in a structural form where one laser is connected to two welding heads simultaneously through a beam splitter, thus giving more choices to the user.

[0022] In a preferred technical solution of the above welding device, there are two welding structures, and the first welding heads of the two welding structures are respectively located on opposite sides of the battery housing, and the second welding heads of the two welding structures are respectively located on the other opposite sides of the battery housing.

[0023] In the case of adopting the above technical solution, the present invention sets the welding device to two, so as to be able to simultaneously perform symmetric seal welding on two opposite outer end faces of the connecting part. The symmetric seal welding can effectively reduce the welding deformation and welding stress, and improve the quality of the seal welding.

[0024] In a preferred technical solution of the above welding device, the welding device further includes a moving component for driving the welding structure to move along the outer end face of the connecting part, and the moving component is connected to the welding structure; and / or, the welding device further includes a rotating component for driving the clamping structure to rotate, and the rotating component is connected to the clamping structure.

[0025] In the case of adopting the above technical solution, the present invention drives the welding structure to move along the outer end face of the connecting part by setting the moving component, which can realize the full-automatic welding of the outer end face of the connecting part by the welding structure, improve the welding efficiency, and improve the welding quality. By installing the clamping structure on the rotating component, the rotation of the clamping structure can be realized, so that different outer end faces of the connecting part can be aligned with the welding structure in sequence, improving the welding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The following describes the preferred embodiments of the present invention with reference to the drawings, in which:

[0027] Figure 1 is a schematic structural diagram of Embodiment 1 of the welding device of the present invention Figure 1 ;

[0028] Figure 2 is a schematic structural diagram of Embodiment 1 of the welding device of the present invention Figure 2 ;

[0029] Figure 3 is a schematic structural diagram of Embodiment 2 of the welding device of the present invention Figure 1 ;

[0030] Figure 4 is a schematic structural diagram of Embodiment 2 of the welding device of the present invention Figure 2 ;

[0031] Figure 5 is Figure 2 and Figure 4 a partial enlarged schematic view of A in

[0032] Figure 6 is a flowchart of the welding method of the present invention;

[0033] Figure 7 is a flowchart of Embodiment 1 of the welding method of the present invention;

[0034] Figure 8It is the flowchart of the second embodiment of the welding method of the present invention;

[0035] Figure 9 It is the flowchart of the third embodiment of the welding method of the present invention;

[0036] Figure 10 It is the flowchart of the fourth embodiment of the welding method of the present invention.

[0037] List of reference numerals:

[0038] 1. Clamping structure; 11. First clamp; 12. Second clamp; 13. Pressing mechanism; 111. Substrate; 112. Side plate; 113. Pressing surface; 114. Outer side surface; 115. Receiving groove;

[0039] 2. Battery housing; 21. First housing; 22. Second housing; 23. Partition; 211. First connecting portion; 221. Second connecting portion;

[0040] 3. Welding structure; 31. Laser; 32. First welding head; 33. Second welding head; 34. First optical fiber; 35. Second optical fiber;

[0041] 4. Rotating assembly; 41. Driving motor; 42. Workbench;

[0042] 5. Moving assembly. Detailed implementation manners

[0043] The preferred implementation manners of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention.

[0044] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "left", "right", "up", "down", "top", "bottom", "horizontal", "vertical", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0045] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly defined and limited, the terms "set", "connected", "installed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0046] Based on the problems pointed out in the background art, namely, the existing welding method using penetration welding for welding the battery case leads to poor welding quality and low production yield, the present invention provides a welding method and a welding device, aiming to ensure the stability of the outer end face to be welded by closely fitting a plurality of connecting parts together, reduce the welding difficulty by welding the outer end face of the connecting parts, greatly improve the welding quality and production yield, and at the same time improve the welding efficiency.

[0047] Specifically, first refer to Figures 1 to 4 , Figure 1 which is a schematic structural diagram of the first embodiment of the welding device of the present invention Figure 1 , Figure 2 which is a schematic structural diagram of the first embodiment of the welding device of the present invention Figure 2 , Figure 3 which is a schematic structural diagram of the second embodiment of the welding device of the present invention Figure 1 , Figure 4 which is a schematic structural diagram of the second embodiment of the welding device of the present invention Figure 2 .

[0048] As Figures 1 to 4 shown, the welding device of the present invention is used for hermetically welding the battery case 2. The welding device includes a welding structure 3 and a clamping structure 1. The clamping structure 1 can fix the battery case 2 and press the connecting parts of the battery case 2 together to fit, and the welding structure 3 can hermetically weld the outer end faces of the connecting parts.

[0049] Exemplarily, as Figure 1 and Figure 2 shown, the battery case 2 is set in a cuboid shape. The inside of the battery case 2 is used for installing the battery cells. The battery case 2 is composed of a first case 21, a partition 23 and a second case 22 arranged along the thickness direction. The contact surfaces of the first case 21 and the second case 22 with the partition 23 are respectively provided with a first connecting part 211 and a second connecting part 221 that fit with the partition 23. The first connecting part 211 and the second connecting part 221 are respectively arranged in a circle along the circumferences of the first case 21 and the second case 22. The clamping structure 1 tightly fixes the first case 21, the partition 23 and the second case 22 together in a sandwich manner, and also fits and presses the first connecting part 211, the edge of the partition 23 and the second connecting part 221 together in a sandwich manner, so as to form four welded outer end faces. The welding structure 3 can hermetically weld the four welded outer end faces of the connecting parts.

[0050] It should be noted that the welding device of the present invention is not limited to hermetically welding the battery case of the above-mentioned "first case 21 + partition 23 + second case 22". For example, it can also hermetically weld the battery case 2 of "first case 21 + second case 22". Such adjustments and changes to the specific structural form of the battery case 2 do not deviate from the principle and scope of the present invention and should all be defined within the protection scope of the present invention.

[0051] Taking the hermetic welding of the battery case 2 of "first case 21 + partition 23 + second case 22" as an example, the welding device of the present invention will be further introduced below.

[0052] In addition, it should be noted that the present invention does not limit the number of welding structures 3 provided. For example, those skilled in the art can set four groups of welding structures 3, and the four groups of welding structures 3 can simultaneously hermetically weld the four outer end faces of the connecting portion. Or two groups of welding structures 3 can be set, and the two groups of welding structures 3 can simultaneously hermetically weld the two outer end faces of the connecting portion. Or, only one group of welding structures 3 can be set, etc. Such adjustments and changes to the specific number of welding structures 3 provided do not deviate from the principle and scope of the present invention and should all be defined within the protection scope of the present invention.

[0053] Preferably, as Figures 1 to 4 shown, the welding device of the present invention further includes a moving component 5, and the moving component 5 is used to drive the welding structure 3 to move along the outer end face of the connecting portion.

[0054] Exemplarily, as Figures 1 to 4 shown, the clamping structure 1 of the present invention fixedly places the battery case 2 on the workbench 42, the welding structure is arranged opposite to the outer end face of the connecting portion, the welding structure is fixedly installed on the moving component 5, and the moving component 5 can drive the welding structure to move along a straight line, that is, along the outer end face of the connecting portion, so as to be able to hermetically weld the outer end face of the connecting portion evenly and stably.

[0055] It should be noted that the present invention does not limit the connection method between the welding structure and the moving component 5. For example, those skilled in the art can set the connection method between the welding structure and the moving component 5 as snap connection or bolt connection, etc. Such adjustments and changes to the specific connection method between the welding structure and the moving component 5 do not deviate from the principle and scope of the present invention and should all be defined within the protection scope of the present invention.

[0056] It should also be noted that the present invention does not limit the structural form of the moving component 5. For example, those skilled in the art can set the moving component 5 as a linear motor, etc. Such adjustments and changes to the specific structural form of the moving component 5 do not deviate from the principle and scope of the present invention and should all be defined within the protection scope of the present invention.

[0057] In the first preferred case, as Figure 1 and Figure 2 shown, the welding structure 3 of the present invention is provided with one, and the welding structure 3 includes a laser 31, a first welding head 32, and a first optical fiber 34 for connecting the laser 31 and the first welding head 32. The first end of the first optical fiber 34 is connected to the first welding head 32, and the second end of the first optical fiber 34 is connected to the laser 31. The laser emitted by the laser 31 enters the first welding head 32 through the first optical fiber 34, and the first welding head 32 can focus and irradiate the laser on the outer end face of the connecting portion.

[0058] Exemplarily, the laser 31 transmits the emitted laser to the first welding head 32 through the first optical fiber 34. The first welding head 32 can focus and irradiate the laser on the outer end face of the connecting portion to be welded. The first welding head 32 is fixedly installed on the moving assembly 5, and the moving assembly 5 can drive the first welding head 32 to linearly move along the outer end face of the connecting portion for sealed welding.

[0059] Furthermore, as Figure 1 and Figure 2 shown, the welding device of the present invention further includes a rotating assembly 4. The clamping structure 1 is installed on the rotating assembly 4, and the rotating assembly 4 can drive the clamping structure 1 to rotate so as to sequentially align the outer end faces of the connecting portion with the welding structure 3.

[0060] Exemplarily, as Figure 1 and Figure 2 shown, the rotating assembly 4 of the present invention includes a driving motor 41 and a workbench 42 installed on the driving motor 41. The workbench 42 is horizontally arranged, and the driving motor 41 can drive the workbench 42 to rotate around the vertical axis. After the battery case 2 is assembled in the clamping structure 1, it is fixedly installed on the workbench 42. The connecting portion of the battery case 2 has two long-side outer end faces and two short-side outer end faces. The welding structure 3 first aligns with one long-side outer end face, and after sealing and welding the long-side outer end face through the welding structure 3, the driving motor 41 drives the workbench 42 to drive the clamping structure 1 and the battery case 2 to rotate, so that one short-side outer end face of the connecting portion aligns with the welding structure 3, and then the short-side outer end face is sealed and welded through the welding structure 3. After the welding is completed, the driving motor 41 is further driven to drive the workbench 42 to drive the clamping structure 1 and the battery case 2 to rotate, so that the other long-side outer end face of the connecting portion aligns with the welding structure 3, and then the long-side outer end face is sealed and welded through the welding structure 3. After the welding is completed, the driving motor 41 is further driven to drive the workbench 42 to drive the clamping structure 1 and the battery case 2 to rotate, so that the other short-side outer end face of the connecting portion aligns with the welding structure 3, and then the short-side outer end face is sealed and welded through the welding structure 3, thereby completing the sealed welding of the battery case 2.

[0061] It should be noted that the present invention does not limit the connection manner between the clamping structure 1 and the workbench 42. For example, those skilled in the art can set the connection manner between the clamping structure 1 and the workbench 42 as snap connection or bolt connection, etc. Such adjustments and changes to the specific connection manner between the clamping structure 1 and the workbench 42 do not deviate from the principle and scope of the present invention and should all be defined within the protection scope of the present invention.

[0062] It should also be noted that the rotating assembly 4 of the present invention is not limited to the above-mentioned structural form of "driving motor 41 + workbench 42". For example, the rotating assembly 4 can also be set as the structural form of "driving motor 41 + rotating shaft", etc., as long as the clamping structure 1 can be driven to rotate by the rotating assembly 4.

[0063] In the second preferred case, as Figure 3 and Figure 4 shown, two welding structures 3 of the present invention are provided. Each welding structure 3 includes a laser 31, a beam splitter (not shown in the figure), a first welding head 32, a second welding head 33, and a first optical fiber 34 and a second optical fiber 35 for connecting the laser 31 to the first welding head 32 and the second welding head 33 respectively. The first end of the first optical fiber 34 is connected to the first welding head 32, the second end of the first optical fiber 34 is connected to the beam splitter, the first end of the second optical fiber 35 is connected to the second welding head 33, the second end of the second optical fiber 35 is connected to the beam splitter, and the beam splitter is connected to the laser 31. The laser emitted by the laser 31 enters the first welding head 32 and the second welding head 33 through the first optical fiber 34 and the second optical fiber 35 respectively. The beam splitter can switch the laser between the first optical fiber 34 and the second optical fiber 35. The first welding head 32 and the second welding head 33 can focus the laser and irradiate it on two adjacent outer end faces of the connecting part respectively. The first welding heads 32 of the two welding structures 3 are respectively located on opposite sides of the battery case 2, and the second welding heads 33 of the two welding structures 3 are respectively located on the other opposite sides of the battery case 2.

[0064] Exemplarily, as Figure 3 and Figure 4As shown, after the battery housing 2 is assembled within the clamping structure 1, it is fixedly installed on the horizontally arranged workbench 42. The connecting portion of the battery housing 2 has two long-side outer end faces and two short-side outer end faces. The two welding structures 3 each include a laser 31, a beam splitter, a first welding head 32, and a second welding head 33. The first welding head 32 and the second welding head 33 of one of the welding structures 3 are respectively aligned with an adjacent long-side outer end face and an adjacent short-side outer end face of the connecting portion, and the first welding head 32 and the second welding head 33 of the other welding structure 3 are respectively aligned with the other adjacent long-side outer end face and the other adjacent short-side outer end face of the connecting portion. That is to say, the four welding heads of the welding structures 3 are respectively aligned with the four outer end faces of the connecting portion. During the welding process, the laser beams emitted by the two lasers 31 respectively enter the two first welding heads 32 through the two first optical fibers 34, and the two first welding heads 32 simultaneously perform hermetic welding on the two long-side outer end faces of the connecting portion. After the welding is completed, the two lasers 31 simultaneously switch the laser beams from the two first optical fibers 34 to the two second optical fibers 35 through the beam splitter, so that the laser beams can respectively enter the two second welding heads 33 through the two second optical fibers 35, and the two second welding heads 33 simultaneously perform hermetic welding on the two short-side outer end faces of the connecting portion, thus completing the welding work on the outer end faces of the connecting portion. By simultaneously welding the two symmetrical outer end faces of the connecting portion with the two sets of welding structures 3, the welding efficiency is greatly improved.

[0065] It should be noted that in the above second preferred case, the number of the welding structures 3 can also be set to one. In this case, it is preferably combined with the rotation assembly 4 introduced above to facilitate the welding of the multiple outer end faces of the connecting portion.

[0066] It should also be noted that the present invention does not limit the welding directions of the two welding structures 3. For example, those skilled in the art can set the welding directions of the two welding structures 3 to the same direction or opposite directions, etc. Such adjustments and changes to the specific welding directions of the two welding structures 3 do not deviate from the principle and scope of the present invention and should all be limited within the protection scope of the present invention.

[0067] It should also be noted that the present invention does not limit the type of the laser 31. For example, those skilled in the art can use a ring spot laser, etc. Such adjustments and changes to the specific type of the laser 31 do not deviate from the principle and scope of the present invention and should all be limited within the protection scope of the present invention.

[0068] It should also be noted that the present invention does not limit the specifications and dimensions of the optical fiber. For example, those skilled in the art can use an optical fiber with an inner diameter of 50 microns and an outer diameter of 200 microns, etc. Such adjustments and changes to the specific specifications and dimensions of the optical fiber do not deviate from the principle and scope of the present invention and should all be defined within the protection scope of the present invention.

[0069] It should be further noted that the present invention does not limit the specifications and models of the welding head. For example, those skilled in the art can use a welding head with a collimation / focus of F125 / F200 mm, etc. Such adjustments and changes to the specific specifications and models of the welding head do not deviate from the principle and scope of the present invention and should all be defined within the protection scope of the present invention.

[0070] Preferably, as Figure 2 and Figure 4 shown, the clamping structure 1 of the present invention includes two relatively arranged jigs. The jig has a receiving groove 115 for accommodating the battery housing 2 and a pressing surface 113 for abutting against the connecting portion.

[0071] Exemplarily, as Figure 2 shown, the clamping structure 1 further includes a pressing mechanism 13. The pressing mechanism 13 is arranged above the workbench 42. The two jigs are designed to be shape-matching with the battery housing 2. The first jig 11 is shape-matching with the first housing 21, and the second jig 12 is shape-matching with the second housing 22. Both the first jig 11 and the second jig 12 have receiving grooves 115 that can respectively accommodate the first housing 21 and the second housing 22, and a first pressing surface and a second pressing surface that can respectively abut against the first connecting portion 211 and the second connecting portion 221. The first jig 11 is fixedly installed on the pressing mechanism 13, and the second jig 12 is fixedly installed on the workbench 42. The pressing mechanism 13 can drive the first jig 11 to move up and down to press or separate the jig from the connecting portion, so as to press and fix the battery housing 2 on the workbench 42.

[0072] It should be noted that the present invention does not limit the connection manner between the first jig 11 and the pressing mechanism 13. For example, those skilled in the art can adopt connection manners such as snap connection or bolt connection. Such adjustments and changes to the specific connection manner between the first jig 11 and the pressing mechanism 13 do not deviate from the principle and scope of the present invention and should all be defined within the protection scope of the present invention.

[0073] Then refer to Figure 5 , Figure 5 is Figure 2 and Figure 4 a partial enlarged schematic view of the A position in

[0074] Preferably, as Figure 5As shown, when the welding device of the present invention is assembled, there is a first gap between the inner bottom wall of the receiving groove 115 of the fixture and the battery housing 2.

[0075] That is to say, there is a gap between the inner bottom wall of the receiving groove 115 and the outer wall of the battery housing 2, and they do not directly contact. By setting the first gap between the inner bottom wall of the receiving groove 115 and the battery housing 2, the pressing force applied by the pressing mechanism 13 on the fixture can all act on the connecting portion, improving the pressing effect, so that the connecting portions can be closely attached, ensuring the stability of the welding outer end face.

[0076] Preferably, as Figure 3 shown, when the welding device of the present invention is assembled, there is a second gap between the inner side wall of the receiving groove 115 of the fixture and the battery housing 2.

[0077] That is to say, there is a gap between the inner side wall of the receiving groove 115 and the outer side wall of the battery housing 2, and they do not directly contact. By setting the second gap between the inner side wall of the receiving groove 115 and the battery housing 2, it is convenient to take and place the battery housing 2 in the fixture, and the side wall of the fixture will not be scratched during the taking and placing process.

[0078] Preferably, as Figure 5 shown, the first gap of the present invention is any value between 0.1 mm and 0.2 mm.

[0079] By limiting the range value of the first gap, while ensuring the pressing effect, it also gives users more choices.

[0080] Exemplarily, the first gap can be set to 0.1 mm, 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm or 0.2 mm.

[0081] Preferably, as Figure 5 shown, the second gap of the present invention is any value between 0.1 mm and 0.15 mm.

[0082] By limiting the range value of the second gap, while ensuring the convenience of taking and placing the battery housing 2, it also gives users more choices.

[0083] Exemplarily, the second gap can be set to 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm or 0.15 mm.

[0084] Preferably, as Figure 5 shown, the width L0 of the pressing surface 113 of the fixture of the present invention is any value between 0.3 mm and 1.0 mm.

[0085] By defining the range value of the width of the pressing surface 113, it is possible to ensure that the pressing surface 113 and the connecting portion are pressed in a tightly fitting state.

[0086] Exemplarily, the width L0 of the pressing surface 113 of the fixture can be set to 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1.0 mm. Among them, it is further preferred to set the width L0 of the pressing surface 113 of the fixture to 0.5 mm.

[0087] Preferably, as Figure 5 shown, in the case of completed assembly, the distance L1 between the first side of the pressing surface 113 of the present invention and the outer end surface of the connecting portion is any value between 0.5 mm and 0.7 mm, and the first side is the side of the pressing surface 113 close to the outer end surface of the connecting portion.

[0088] By defining the range value of the distance between the first side of the pressing surface 113 and the outer end surface of the connecting portion, sufficient welding space can be reserved to prevent the welding slag from contaminating and damaging the fixture.

[0089] Exemplarily, the distance L1 between the first side of the pressing surface 113 and the outer end surface of the connecting portion can be set to 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm or 0.7 mm.

[0090] Preferably, as Figure 5 shown, in the case of completed assembly, the distance L2 between the second side of the pressing surface 113 of the present invention and the battery housing 2 is any value between 0.8 mm and 1.0 mm, and the second side is the side of the pressing surface 113 away from the outer end surface of the connecting portion.

[0091] By defining the range value of the distance between the second side of the pressing surface 113 and the battery housing 2, it is possible to ensure that the pressing surface 113 and the connecting portion are pressed in a tightly fitting state.

[0092] Exemplarily, as Figure 5 shown, taking the width L of the connecting portion as 2 mm as an example, the width L0 of the pressing surface 113 is 0.5 mm, the distance L2 between the left side of the pressing surface 113 and the battery housing 2 is 0.8 mm, and the distance L1 between the right side of the pressing surface 113 and the outer end surface of the connecting portion is 0.7 mm, where L0 + L1 + L2 = L.

[0093] It should be noted that the present invention does not limit the sizes of L0, L1, L2, and L. For example, those skilled in the art can determine the sizes of L0, L1, and L2 according to the size of L0 in combination with the actual conditions such as the size of the fixture and the welding environment, as long as the pressing surface 113 can be tightly pressed against the connecting portion while leaving sufficient operating clearance and welding space. Such adjustments and changes to the specific sizes of L0, L1, L2, and L do not deviate from the principles and scope of the present invention and should be within the protection scope of the present invention.

[0094] Preferably, as Figure 5 shown, the fixture of the present invention includes a base plate 111 and a side plate 112. The base plate 111 and the side plate 112 jointly enclose a receiving groove 115. The pressing surface 113 is located at the end of the side plate 112. The outer side surface 114 of the side plate 112 extends obliquely away from the receiving groove 115 from the pressing surface 113.

[0095] Preferably, as Figure 5 shown, the angle α between the outer side surface 114 of the side plate 112 of the present invention and the plane where the pressing surface 113 is located is any value between 20° and 40°.

[0096] Exemplarily, as Figure 5 shown, taking the first fixture 11 as an example, the first fixture 11 is composed of a horizontally arranged base plate 111 and a vertically arranged side plate 112. The base plate 111 and the side plate 112 jointly enclose a receiving groove 115 with an opening facing downward. The pressing surface 113 is located at the bottom of the side plate 112. The inner side surface of the side plate 112 is vertically arranged, the outer side surface 114 of the side plate 112 is obliquely arranged and extends obliquely to the right from the pressing surface 113. The angle α between the outer side surface 114 and the plane where the pressing surface 113 is located is 20°, 25°, 30°, 35°, or 40°.

[0097] By arranging the outer side surface 114 of the side plate 112 obliquely, not only the rigidity of the fixture at the force-applying part of the fixture is ensured, but also the welding fumes can be prevented from spreading everywhere, effectively reducing the pollution caused by welding. By setting the angle between the outer side surface 114 and the plane where the pressing surface 113 is located to any value between 20° and 40°, more choices are given to the user.

[0098] Preferably, as Figure 5 shown, a chamfer structure or a fillet structure is provided at the connection between the inner side surface of the side plate 112 of the present invention and the pressing surface 113.

[0099] Exemplarily, as Figure 5As shown, a fillet structure is provided at the connection between the outer side wall of the battery case 2 and the connection part. Correspondingly, a chamfer structure is provided at the connection between the inner side surface of the side plate 112 and the pressing surface 113. By providing the chamfer structure, the pressing surface 113 can be more smoothly abutted against the connection part, improving the fit between the fixture and the connection part.

[0100] On the other hand, the present invention also provides a welding method. As Figure 6 shown, the welding method of the present invention includes the following steps:

[0101] S100: Fit multiple connection parts of the battery case 2 together.

[0102] Exemplarily, the multiple connection parts of the battery case 2 can be fitted together by the clamping structure 1 of the welding device introduced above.

[0103] S200: Weld the outer end faces of the multiple connection parts.

[0104] Exemplarily, the outer end faces of the multiple connection parts fitted together can be welded by the welding structure 3 of the welding device introduced above. The battery case of the present invention has four outer end faces. Those skilled in the art can choose to weld the four outer end faces in sequence, or can weld the four outer end faces simultaneously, or can also weld two opposite outer end faces among the four outer end faces simultaneously, etc.

[0105] In the first preferred case, the battery case 2 includes a first case 21, a second case 22, and a partition 23 disposed between the first case 21 and the second case 22. The connection part includes a first connection part 211 disposed on the first case 21 and a second connection part 221 disposed on the second case 22. The edge of the partition 23 is between the first connection part 211 and the second connection part 221. As Figure 7 shown, the welding method of the present invention includes the following steps:

[0106] S110: Fit the first connection part 211 of the battery case 2, the edge of the partition 23, and the second connection part 221 together.

[0107] S210: Weld the four outer end faces fitted together in sequence.

[0108] Taking welding with the welding device introduced above as an example, among which, the welding device has a welding structure 3, and the welding structure has a welding head (i.e., the first welding head 32). The specific welding method of this embodiment is as follows: Fix the second fixture 12 on the workbench 42, place the battery case 2 into the second fixture 12, start the pressing mechanism 13, and the pressing mechanism 13 drives the first fixture 11 to move downward towards the first case 21. After the first case 21 enters the receiving groove 115 of the first fixture 11, the first pressing surface just abuts against the first connecting portion 211. By adjusting the pressure parameters of the pressing mechanism 13, the first fixture 11 and the second fixture 12 can fit and press the first connecting portion 211 and the second connecting portion 221 tightly. Start the moving assembly 5, and the moving assembly 5 drives the first welding head 32 to perform high-speed seal welding along one of the outer end faces of the connecting portion, with the welding speed ≥ 200 mm / s. After welding is completed, the drive motor 41 drives the workbench 42 to drive the clamping structure 1 and the battery case 2 to rotate integrally by 90°, and then perform seal welding on the other outer end face of the connecting portion. Furthermore, sequentially complete the seal welding of the four outer end faces of the connecting portion.

[0109] In the second preferred case, the battery case 2 includes a first case 21, a second case 22, and a partition 23 disposed between the first case 21 and the second case 22. The connecting portion includes a first connecting portion 211 disposed on the first case 21 and a second connecting portion 221 disposed on the second case 22. The edge of the partition 23 is between the first connecting portion 211 and the second connecting portion 221, as Figure 8 shown. The welding method of the present invention includes the following steps:

[0110] S110: Fit the first connecting portion 211 of the battery case 2, the edge of the partition 23, and the second connecting portion 221 together;

[0111] S210: Weld two opposite outer end faces among the four outer end faces that are fitted together simultaneously.

[0112] Taking welding with the welding device introduced above as an example, the welding device has two welding structures 3, and each welding structure has a first welding head 32 and a second welding head 33. The specific welding method of this embodiment is as follows: Fix the second fixture 12 on the workbench 42, place the battery case 2 into the second fixture 12, start the pressing mechanism 13, and the pressing mechanism 13 drives the first fixture 11 to move downward towards the first case 21. After the first case 21 enters the receiving groove 115 of the first fixture 11, the first pressing surface just abuts against the first connecting portion 211. By adjusting the pressure parameters of the pressing mechanism 13, the first fixture 11 and the second fixture 12 can fit and press the first connecting portion 211 and the second connecting portion 221 tightly. Start two groups of moving components 5 located at the outer end faces of the two long sides of the connecting portion of the battery case 2. The two groups of moving components 5 drive the two first welding heads 32 to perform high-speed seal welding respectively along the outer end faces of the two long sides of the connecting portion of the battery case 2, and the welding speed is ≥200 mm / s. After welding is completed, the two lasers 31 respectively switch the laser to the two second welding heads 33 located at the outer end faces of the two short sides of the connecting portion of the battery case 2 through the optical splitter. Start two groups of moving components 5 located at the outer end faces of the two short sides of the connecting portion of the battery case 2. The two groups of moving components 5 drive the two second welding heads 33 to perform high-speed seal welding respectively along the outer end faces of the two short sides of the connecting portion of the battery case 2, and the welding speed is ≥200 mm / s. Thus, the seal welding of the four outer end faces of the connecting portion is completed.

[0113] In the third preferred case, the battery case 2 includes a first case 21 and a second case 22, and the connecting portion includes a first connecting portion 211 provided on the first case 21 and a second connecting portion 221 provided on the second case 22. As Figure 7 shown, the welding method of the present invention includes the following steps:

[0114] S110: Fit the first connecting portion 211 and the second connecting portion 221 of the battery case 2.

[0115] S210: Weld the four outer end faces that are fitted together in sequence.

[0116] Taking the welding using the welding device introduced above as an example, among which, the welding device has a welding structure 3, and the welding structure has a welding head (i.e., the first welding head 32). The specific welding method of this embodiment is as follows: Fix the second fixture 12 on the workbench 42, place the battery case 2 into the second fixture 12, start the pressing mechanism 13, and the pressing mechanism 13 drives the first fixture 11 to move downward towards the first case 21. After the first case 21 enters the receiving groove 115 of the first fixture 11, the first pressing surface just abuts against the first connecting portion 211. By adjusting the pressure parameters of the pressing mechanism 13, the first fixture 11 and the second fixture 12 can fit and press the first connecting portion 211 and the second connecting portion 221 tightly. Start the moving component 5, and the moving component 5 drives the first welding head 32 to perform high-speed seal welding along one of the outer end faces of the connecting portion, with the welding speed ≥ 200 mm / s. After the welding is completed, the driving motor 41 drives the workbench 42 to drive the clamping structure 1 and the battery case 2 to rotate integrally by 90°, and then perform seal welding on the other outer end face of the connecting portion. Furthermore, the seal welding of the four outer end faces of the connecting portion is completed in sequence.

[0117] In the fourth preferred case, the battery case 2 includes a first case 21 and a second case 22, and the connecting portion includes a first connecting portion 211 provided on the first case 21 and a second connecting portion 221 provided on the second case 22. As Figure 8 shown, the welding method of the present invention includes the following steps:

[0118] S110: Fit the first connecting portion 211 and the second connecting portion 221 of the battery case 2;

[0119] S210: Simultaneously perform welding on two opposite outer end faces among the four outer end faces that are fitted together

[0120] Taking the welding using the above-described welding device as an example, wherein the welding device has two welding structures 3, and each welding structure has a first welding head 32 and a second welding head 33. The specific welding method of this embodiment is as follows: Fix the second fixture 12 on the workbench 42, place the battery housing 2 into the second fixture 12, start the pressing mechanism 13, and the pressing mechanism 13 drives the first fixture 11 to move downward toward the first housing 21. After the first housing 21 enters the receiving groove 115 of the first fixture 11, the first pressing surface just abuts against the first connecting portion 211. By adjusting the pressure parameters of the pressing mechanism 13, the first fixture 11 and the second fixture 12 can fit and press the first connecting portion 211 and the second connecting portion 221 tightly. Start two groups of moving components 5 located at the outer end faces of the two long sides of the connecting portion of the battery housing 2. The two groups of moving components 5 drive the two first welding heads 32 to perform high-speed seal welding along the outer end faces of the two long sides of the connecting portion of the battery housing 2 respectively, with the welding speed ≥ 200 mm / s. After welding is completed, the two lasers 31 respectively switch the laser to the two second welding heads 33 located at the outer end faces of the two short sides of the connecting portion of the battery housing 2 through the optical splitter. Start two groups of moving components 5 located at the outer end faces of the two short sides of the connecting portion of the battery housing 2. The two groups of moving components 5 drive the two second welding heads 33 to perform high-speed seal welding along the outer end faces of the two short sides of the connecting portion of the battery housing 2 respectively, with the welding speed ≥ 200 mm / s. Thus, the seal welding of the four outer end faces of the connecting portion is completed.

[0121] Those skilled in the art can understand that although some embodiments described herein include certain features included in other embodiments rather than other features, the combination of features of different embodiments means that it is within the scope of the present application and forms different embodiments. For example, in the claims of the present application, any one of the claimed embodiments can be used in any combination.

[0122] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A welding method, characterized in that, The welding method includes the following steps: Step 1: Fit multiple connecting parts of the battery housing together; Step 2: Weld the outer end faces of the multiple connecting parts.

2. The welding method according to claim 1, characterized in that, The battery housing includes a first housing and a second housing, and the connecting parts include a first connecting part provided on the first housing and a second connecting part provided on the second housing. Among them, Step 1 is specifically: Fit the first connecting part and the second connecting part together.

3. The welding method according to claim 1, characterized in that, The battery housing includes a first housing, a second housing, and a partition provided between the first housing and the second housing, and the connecting parts include a first connecting part provided on the first housing and a second connecting part provided on the second housing. Among them, Step 1 is specifically: Fit the first connecting part, the partition, and the second connecting part together.

4. The welding method according to any one of claims 1 to 3, characterized in that, The connecting part includes four outer end faces. Among them, Step 2 is specifically: Weld the four outer end faces in sequence; or, Weld two opposite outer end faces among the four outer end faces simultaneously respectively.

5. A welding device, characterized in that, The welding device includes: A clamping structure for fitting multiple connecting parts of the battery housing together; A welding structure for welding the outer end faces of the multiple connecting parts.

6. The welding device according to claim 5, characterized in that, The clamping structure includes at least two clamps for clamping the battery housing, and the clamp includes a pressing surface for pressing against the connecting part.

7. The welding device according to claim 6, characterized in that, The clamp further includes an inclined outer side surface, and the included angle between the outer side surface and the pressing surface ranges from 20° to 40°; and / or, The clamp is provided with a receiving groove for receiving the battery housing.

8. The welding device according to claim 5, characterized in that, The welding structure includes a first welding head, a first optical fiber, and a laser. The first end of the first optical fiber is connected to the first welding head, and the second end of the first optical fiber is connected to the laser; or, The welding structure includes a first welding head, a second welding head, a first optical fiber, a second optical fiber, a beam splitter, and a laser. The first end of the first optical fiber is connected to the first welding head, the second end of the first optical fiber is connected to the beam splitter, the first end of the second optical fiber is connected to the second welding head, the second end of the second optical fiber is connected to the beam splitter, and the beam splitter is connected to the laser.

9. The welding device according to claim 8, characterized in that, There are two welding structures, and the first welding heads of the two welding structures are respectively located on opposite sides of the battery housing, and the second welding heads of the two welding structures are respectively located on the other opposite sides of the battery housing.

10. The welding device according to any one of claims 5 to 9, characterized in that, The welding device further includes a moving component for driving the welding structure to move along the outer end face of the connecting part, and the moving component is connected to the welding structure; and / or, The welding device further includes a rotating component for driving the clamping structure to rotate, and the rotating component is connected to the clamping structure.

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