Pre-welding equipment and pre-welding method for square-shell secondary battery

Abstract

The invention relates to the technical field of battery production, and discloses pre-welding equipment and a pre-welding method for a square-shell secondary battery. The pre-welding equipment for the square-shell secondary battery comprises a press-fitting device located at a press-fitting station, a pre-welding device located at a pre-welding station, and a transferring device for transferring the battery from the press-fitting station to the pre-welding station; the press-fitting device comprises a base, a first jacking assembly, a first positioning assembly and a press-fitting assembly, the base is provided with a first through hole, the first jacking assembly is arranged on one side of the base, the first jacking assembly bears the battery and drives the battery to penetrate through the first through hole, and the first positioning assembly is arranged on the base; the first positioning assembly abuts against a shell of the battery on the periphery of the battery so that the battery can enter the press-fitting position, and the press-fitting assembly comprises a first press-down piece and a second press-down piece which are movably arranged on the base. According to the pre-welding equipment and the pre-welding method for the square-shell secondary battery provided by the invention, the bad product phenomenon in the pre-welding production process of the battery can be reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of battery production technology, and in particular to a pre-welding device and a pre-welding method for a square shell secondary battery. Background Art

[0002] With the continuous development of energy storage technology, the demand for secondary batteries is also increasing. Secondary batteries can form battery modules by connecting in series or in parallel, and use the charge and discharge cycle characteristics of battery cells to achieve the storage and effective use of electrical energy. When producing square shell secondary batteries, they will go through a pre-welding process so that the top cover and shell of the square shell secondary battery can be fixed in advance when the battery cells are formed by full welding.

[0003] In order to improve the production efficiency of square shell secondary batteries, automated pre-welding equipment is usually used to complete the pre-welding process of the top cover and the shell. During the pre-welding process, it is easy to have problems such as poor size of the top cover into the shell or poor welding. Therefore, how to reduce product defects in the battery pre-welding production process is an important issue. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a square shell secondary battery pre-welding device and a pre-welding method, which can help reduce product defects in the battery pre-welding production process.

[0005] In order to solve the above technical problems, the embodiment of the present application provides a square shell secondary battery pre-welding device. The square shell secondary battery pre-welding device includes a pressing device located at a pressing station, a pre-welding device located at a pre-welding station, and a transfer device for transferring the battery from the pressing station to the pre-welding station;

[0006] The press-fitting device comprises a base, a first lifting assembly, a first positioning assembly and a press-fitting assembly, wherein the base is provided with a first through hole, the first lifting assembly is provided on one side of the base, the first lifting assembly carries the battery and drives the battery to pass through the first through hole, the first positioning assembly is provided on the base, the first positioning assembly abuts against the battery housing around the battery to make the battery enter the press-fitting position, the press-fitting assembly comprises a first pressing member and a second pressing member movably provided on the base, the first pressing member applies pressure to the top cover of the battery at a side of the positive pole of the battery at the press-fitting position away from the negative pole, and the second pressing member applies pressure to the top cover of the battery at a side of the negative pole of the battery at the press-fitting position away from the positive pole, so as to press-fit the battery;

[0007] The total area of ​​the first pressing member and the second pressing member contacting the top cover is greater than or equal to 80 mm 2 , and less than or equal to 120mm 2 ;

[0008] The pre-welding device includes a base, a second lifting assembly, a second positioning assembly, a pressing piece and a welding tool. The base is provided with a second through hole. The second lifting assembly is arranged on one side of the base. The second lifting assembly carries the pressed battery and drives the battery to pass through the second through hole. The second positioning assembly is arranged on the base. The second positioning assembly abuts against the battery shell around the battery to make the battery enter the pre-welding position. The pressing piece is arranged on the base. The pressing piece applies pressure to the top cover of the battery between the positive pole and the negative pole of the battery in the pre-welding position. The welding tool pre-welds the joint between the top cover and the shell of the battery in the pre-welding position at the pre-welding point.

[0009] The length of the pressing piece in the extending direction of the long side of the top cover is less than 2 / 3 of the length of the long side of the top cover.

[0010] The embodiment of the present application further provides a method for pre-welding using the above-mentioned square shell secondary battery pre-welding device, the pre-welding method comprising:

[0011] The battery is moved by driving the carried battery through the first lifting assembly of the press-fitting device, and the battery is brought into the press-fitting position by abutting against the battery housing through the first positioning assembly, and the battery is press-fitted by applying pressure to the top cover of the battery at the side of the positive electrode column of the battery at the press-fitting position away from the negative electrode column, and applying pressure to the top cover of the battery at the side of the negative electrode column of the battery at the press-fitting position away from the positive electrode column through the first pressing member of the press-fitting assembly;

[0012] The pressed batteries are transferred to the pre-welding station by a transfer device;

[0013] The first lifting component of the pre-welding device drives the loaded pressed battery to move, and the second positioning component abuts against the battery shell to make the battery enter the pre-welding position, and the clamping member applies pressure to the top cover of the battery between the positive electrode column and the negative electrode column of the battery in the pre-welding position, and the welding tool is used to pre-weld the joint between the top cover and the shell of the battery in the pre-welding position at the pre-welding point.

[0014] The square shell secondary battery pre-welding equipment and pre-welding method provided in the embodiment of the present application apply pressure to the top cover of the battery through a press-fitting device to complete the press-fitting operation, and weld the seam between the top cover and the shell of the battery through the pre-welding device to complete the pre-welding operation. The press-fitting assembly of the press-fitting device adopts a first pressing member and a second pressing member, which apply pressure to the top cover in the area on the side where the positive pole and the negative pole of the battery are far away from each other, thereby forming an interference release part in the middle of the top cover to ensure the press-fitting effect when the top cover and the shell are in interference fit. At the same time, the pre-welding device adopts a clamping member to apply pressure to the top cover in the area between the positive pole and the negative pole of the battery, so that the middle part of the top cover maintains an interference fit with the shell. Thereby reducing the adverse phenomena caused by applying pressure to the entire large surface of the top cover during the battery production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0016] Figure 1 It is a schematic diagram of the three-dimensional structure of a press-fitting device in a square shell secondary battery pre-welding device provided in some embodiments of the present application;

[0017] Figure 2 It is a schematic diagram of the main structure of a press-fitting device in a square-shell secondary battery pre-welding device provided in some embodiments of the present application;

[0018] Figure 3 is a schematic side structural view of a press-fitting device in a square-shell secondary battery pre-welding device provided in some embodiments of the present application;

[0019] Figure 4 It is a schematic diagram of the positioning structure of the press-fitting device in the square shell secondary battery pre-welding equipment provided in some embodiments of the present application;

[0020] Figure 5 yes Figure 4 A schematic diagram of the positioning structure of the press-fitting device shown in FIG. 1 from a top view;

[0021] Figure 6 It is a schematic diagram of the three-dimensional structure of a pre-welding device in a square shell secondary battery pre-welding device provided in some embodiments of the present application;

[0022] Figure 7 It is a schematic diagram of the main structure of a pre-welding device in a square shell secondary battery pre-welding device provided in some embodiments of the present application;

[0023] Figure 8 is a side structural schematic diagram of a pre-welding device in a square shell secondary battery pre-welding device provided in some embodiments of the present application;

[0024] Fig. 9 It is a schematic diagram of the positioning structure of the pre-welding device in the square shell secondary battery pre-welding equipment provided in some embodiments of the present application;

[0025] Fig.10 It is a schematic diagram of the top view of the structure of a reference plate of a pre-welding device in a square shell secondary battery pre-welding device provided in some embodiments of the present application;

[0026] Fig.11 It is a schematic diagram of the three-dimensional structure of a square shell secondary battery in the prior art. DETAILED DESCRIPTION

[0027] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, each embodiment of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in each embodiment of the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not constitute any limitation, and the various embodiments can be combined with each other and referenced to each other without contradiction.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein 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 figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0029] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected" and the like 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 mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0030] As an important part of energy storage equipment, battery packs play an extremely critical role in the storage and effective use of electric energy. Battery packs include a large number of battery cells, each of which can store and release electric energy. Battery cells use secondary batteries, have charge and discharge cycle characteristics, and can be charged and discharged multiple times. This allows the battery pack to switch between the storage and use of electric energy.

[0031] In order to make full use of space and improve the battery energy density of the battery pack, square shell secondary batteries are usually used as battery cells. The appearance of square shell secondary batteries is a rectangular parallelepiped, that is, a square shell is used as the outer shell to contain the battery cell. At the same time, the top opening of the shell is closed by a top cover. After the battery cell is put into the shell, the top cover will be placed at the opening position at the top of the shell, and then press-fit and pre-weld will be carried out in sequence. The top cover and the shell are preliminarily matched by press-fitting, and the partial seams between the top cover and the shell are welded by pre-welding to achieve the preliminary fixation of the top cover and the shell. Fig.11 The three-dimensional structure of the battery cell is shown after the battery cell is placed in the shell and the top cover is welded.

[0032] It should be noted that in the pre-welding process of square shell batteries, in order to achieve good welding results, avoid explosion points, and avoid laser hitting the battery cell and causing damage to the battery cell, the top cover needs to be pre-processed for pressing into the shell. That is, the top cover is pressed and compacted by the pressing plate, and the battery cell is pushed into the shell. During the pressing operation, the top cover and the shell can be aligned by the positioning fixture, so that the top cover is accurately pressed into the shell to ensure that the top cover surface is flat with the shell mouth surface.

[0033] In actual operation, due to factors such as poor top cover molds and errors between the shell and top cover, the press-fitting effect may not be good enough. The existing top cover and shell are made by molds, so there is a certain amount of tolerance. Therefore, when pressing into the shell, the current pressing plate cannot press the steps and gaps of the top cover into the shell to the ideal state, that is, there is still a height difference near the pole.

[0034] At present, after the battery cell is put into the shell, the entire large surface of the top cover, that is, the top surface with a larger area of ​​the top cover, is pressed by a pressing plate, which is not convenient for releasing the interference part. However, due to the size of the incoming material, deformation, and processing errors, the interference fit between the shell and the top cover causes the shell to be pressed into place. As a result, the height of the bulge after the top cover is welded cannot meet the process requirements, resulting in many defects and rework or scrap.

[0035] In order to reduce the undesirable phenomena in the battery production process, some embodiments of the present application provide a square shell secondary battery pre-welding device. By improving and optimizing the pressure plate structure and adjusting the pressure position, the current situation can be optimized to a certain extent, so that the influence of the height difference near the pole on the product is compressed to a negligible degree, and the stability and consistency of the step height are higher. That is, in the pre-welding device of the square shell secondary battery, pressure is only applied to part of the top cover, so that the interference release position is reserved at other positions of the top cover. In the process of pressing the top cover, in order to ensure the pressing effect of the top cover, a pressing component is used to apply pressure at the edge positions of both sides relatively set along the length direction near the top cover, so that the interference fit position of the top cover and the shell reaches a predetermined fit size. At the same time, in the pre-welding process, a pressing component is used to apply pressure to the position between the positive pole and the negative pole of the top cover to ensure that the middle of the top cover remains in a state of matching with the shell, so that the seam between the top cover and the shell meets the welding requirements. Thereby ensuring that the battery after welding meets the process requirements and reducing the undesirable phenomena in the battery production process.

[0036] Combine the following Figures 1 to 10 The structure of the square shell secondary battery pre-welding device provided in some embodiments of the present application is described. The square shell secondary battery pre-welding device is used for Fig.11The square-shell secondary battery 100 shown is pre-welded and includes a shell 110 containing a battery cell and a top cover 120 sealing the shell 110 . The top cover 120 is provided with a positive electrode column 130 and a negative electrode column 140 electrically connected to the electrodes of the battery cell.

[0037] like Figures 1 to 10 As shown, some embodiments of the present application provide a square shell secondary battery pre-welding device including a pressing device 10 located at a pressing station, a pre-welding device 20 located at a pre-welding station, and a transfer device for transferring a battery 100 from the pressing station to the pre-welding station.

[0038] The press-fitting device 10 includes a base 11, a first lifting assembly 12, a first positioning assembly 13 and a press-fitting assembly 14. The base 11 is provided with a first through hole 111, and the base 11 can be installed through a supporting structure. The first lifting assembly 12 is arranged on one side of the base 11, and the first lifting assembly 12 carries the battery 100 and drives the battery 100 to pass through the first through hole 111. The first positioning assembly 13 is arranged on the base 11, and the first positioning assembly 13 abuts against the housing 110 of the battery 100 around the battery 100, so that the battery 100 enters the press-fitting position. The press-fitting assembly 14 includes a first pressing member 141 and a second pressing member 142 movably arranged on the base 11. The first pressing member 141 applies pressure to the top cover 120 of the battery 100 at the side of the positive electrode column 130 of the battery 100 in the press-fitting position away from the negative electrode column 140, and the second pressing member 142 applies pressure to the top cover 120 of the battery 100 at the side of the negative electrode column 140 of the battery 100 in the press-fitting position away from the positive electrode column 130, so as to press-fit the battery 100.

[0039] The pre-welding device 20 includes a base 21, a second lifting assembly 22, a second positioning assembly 23, a pressing member 24 and a welding tool. The base 21 is provided with a second through hole 211, and the base 21 can be installed by a supporting structure. The second lifting assembly 22 is arranged on one side of the base 21, and the second lifting assembly 22 carries the pressed battery 100 and drives the battery 100 to pass through the second through hole 211. The second positioning assembly 23 is arranged on the base 21, and the second positioning assembly 23 abuts on the shell 110 of the battery 100 around the battery 100, so that the battery 100 enters the pre-welding position. The pressing member 24 is arranged on the base 21, and the pressing member 24 applies pressure to the top cover 120 of the battery 100 between the positive pole 130 and the negative pole 140 of the battery 100 in the pre-welding position. The welding tool pre-welds the joint between the top cover 120 and the shell 110 of the battery 100 at the pre-welding point in the pre-welding position.

[0040] The press-fitting device 10 is used to perform the press-fitting process on the battery 100 that arrives at the press-fitting station. During the entire production flow of the battery 100, the press-fitting device 10 is adjacent to the battery cell shelling device. The battery cell shelling device includes a shell 110 and a battery cell loading part and a cleaning part, and after the battery cell is pushed into the shell 110 by the shelling device, the shelled battery 100 flows out to the next process. Before the battery 100 is press-fitted, the top cover 120 is placed at the opening position of the shell 110.

[0041] The press-fitting device 10 includes a part that carries the battery 100 for movement, a part that positions the battery 100, and a part that applies pressure to the top cover 120 to complete the press-fitting operation. Through the mutual cooperation between different parts, an interference fit is achieved between the top cover 120 of the battery 100 and the shell 110. The base 11 of the press-fitting device 10 forms the installation foundation of the positioning part and the press-fitting part. Before press-fitting, the battery 100 is transferred to the first lifting component 12 for receiving, and the battery 100 is driven close to the positioning part and the press-fitting part by the first lifting component 12. Before the press-fitting operation, the position of the battery 100 is positioned by the first positioning component 13 to ensure that the battery 100 is in a predetermined position during the press-fitting operation. The press-fitting operation is completed by the first lower pressing member 141 and the second lower pressing member 142. The first pressing member 141 and the second pressing member 142 apply pressure to the top cover 120 corresponding to the side where the positive pole 130 and the negative pole 140 are away from each other, thereby reserving a portion of interference release at the middle position of the top cover 120 to avoid the problem of the top cover 120 not being pressed into place. During the press-fitting operation, the top cover 120 is pushed by the pressing member so that the battery cell enters the predetermined position inside the shell 110, and the top cover 120 moves toward the inside of the shell 110, ensuring the effect of pre-welding and full welding of the top cover 120.

[0042] In actual situations, the total area of ​​the first pressing member 141 and the second pressing member 142 contacting the top cover 120 may be greater than or equal to 80 mm. 2 (square millimeters) and less than or equal to 120 mm 2 For example, the total area of ​​the first pressing member 141 and the second pressing member 142 contacting the top cover 120 may be 80 mm 2 , 90mm 2 , 100mm 2 , 110mm 2 or 120mm 2 The pressing surfaces of the first pressing member 141 and the second pressing member 142 can be set to regular shapes such as rectangle, square or circle, or irregular shapes.

[0043] The pre-welding device 20 includes a part for carrying the battery 100 to move, a part for positioning the battery 100, a part for applying pressure to the top cover 120 to compress the top cover 120, and a part for welding the seam between the top cover 120 and the shell 110. Through the mutual cooperation between the different parts, the seam between the top cover 120 and the shell 110 of the battery 100 is welded at the pre-welding point. The base 21 of the pre-welding device 20 forms the installation foundation of the positioning part and the pressing part. After the pressing process is completed, the battery 100 is transferred to the second lifting assembly 22 for acceptance, and the battery 100 is driven by the second lifting assembly 22 to approach the positioning part and the pressing part. Before the pre-welding operation, the position of the battery 100 is positioned by the second positioning assembly 23 to ensure that the battery 100 is in a predetermined position during the pressing operation. The pressing operation is completed by the pressing member 24, and the pressing member 24 applies pressure to the top cover 120 corresponding to the positive pole 130 and the negative pole 140. This avoids the problem that the size of the seam between the middle part of the top cover 120 and the shell 110 is too large, which is not conducive to welding. The length of the clamping piece 24 in the direction of the long side extension of the top cover 120 can be set to be within 2 / 3 of the length of the long side of the top cover 120. When the clamping piece 24 remains in a clamped state, the seam between the top cover 120 and the shell 110 is welded by a welding tool, and the welding position corresponds to the pre-set pre-welding point position. In actual situations, multiple pre-welding point positions can be designed at different edges of the top cover 120, for example, two pre-welding points are selected at the edge of the long side and one pre-welding point is selected at the edge of the short side. Multiple pre-welding points can be arranged relatively evenly around the center of the top cover 120.

[0044] The transfer device is used to transfer the battery 100 from the press-fitting station to the pre-welding station. The transfer device can be implemented by a manipulator or a clamping mechanism. When the battery 100 completes the press-fitting operation and returns to the receiving position of the first lifting component 12, the transfer device can clamp the battery 100 and transfer the clamped battery 100 to the pre-welding station. The second lifting component 22 of the pre-welding station receives the pressed battery 100, and then the pre-welding process is carried out.

[0045] The square shell secondary battery pre-welding device provided in some embodiments of the present application applies pressure to the top cover 120 of the battery 100 through the press-fitting device 10 to complete the press-fitting operation, and welds the joint between the top cover 120 and the shell 110 of the battery 100 through the pre-welding device 20 to complete the pre-welding operation. The press-fitting assembly 14 of the press-fitting device 10 uses a first pressing member 141 and a second pressing member 142 to apply pressure to the top cover 120 corresponding to the side area where the positive pole 130 and the negative pole 140 of the battery 100 are away from each other, thereby forming an interference release portion in the middle of the top cover 120 to ensure the press-fitting effect when the top cover 120 and the shell 110 are in interference fit. At the same time, the pre-welding device 20 uses a pressing member 24 to apply pressure to the top cover 120 corresponding to the area between the positive pole 130 and the negative pole 140 of the battery 100, so that the middle of the top cover 120 and the shell 110 maintain an interference fit state. This reduces the risk of adverse events occurring during the production of the battery 100 due to pressure being applied to the entire surface of the top cover 120 .

[0046] In some embodiments, the press assembly 14 may include a first driving member 143 and a second driving member 144. The first driving member 143 is disposed on the base 11, and the output end of the first driving member 143 is connected to the first pressing member 141. The second driving member 144 is disposed on the base 11, and the output end of the second driving member 144 is connected to the second pressing member 142.

[0047] The pressing action of the pressing member is completed by the driving of the driving member. In addition, the first pressing member 141 and the second pressing member 142 are driven by independent driving members. When pressure is applied to the top cover 120 to push the top cover 120 to move inside the housing 110, the first pressing member 141 and the second pressing member 142 can be made to act synchronously or asynchronously. The first pressing member 141 is connected to the output end of the first driving member 143, and the second pressing member 142 is connected to the output end of the second driving member 144. The first driving member 143 and the second driving member 144 can be servo-driven to control the action accuracy and pressure of the pressing member.

[0048] like Figure 1 As shown, in order to facilitate the installation of the press-fit assembly 14, different parts of the press-fit assembly 14 can be installed on the same installation platform 112, and then the support column 113 is used as a support structure to fix the installation platform 112 on the base 11. In this way, it is convenient to complete the fixation of the press-fit assembly 14, and at the same time, it can avoid interference between the press-fit assembly 14 and the first positioning assembly 13.

[0049] In actual situations, in order to adapt to the different material properties of the positive and negative electrodes of the battery 100, the first pressing member 141 and the second pressing member 142 can be controlled to move in an asynchronous manner. That is, in some embodiments, the first driving member 143 can be driven prior to the second driving member 144, so that the first pressing member 141 applies pressure to the top cover 120 of the battery 100 in the press-fit position prior to the second pressing member 142.

[0050] It should be noted that among the positive and negative electrode materials of the battery cell, the positive electrode usually includes metal aluminum, and the negative electrode usually includes metal copper. Due to the different hardness characteristics of metal aluminum and metal copper, during the process of pressing the top cover 120, the reaction forces received by the corresponding parts of the positive electrode column 130 and the negative electrode column 140 on the top cover 120 are also different. In order to ensure the pressing effect of the top cover 120, different pressing parts can be operated separately to avoid unbalanced forces on both sides when pushing at the same time. The first pressing part 141 close to the side of the positive electrode column 130 is controlled to complete the pressing action first, and then the second pressing part 142 close to the side of the negative electrode column 140 is controlled to complete the pressing action to perform the pressing operation on the top cover 120.

[0051] In some embodiments, the first pressing member 141 may include a first mounting portion 1411 and a first extension portion 1412 and a second extension portion 1413 spaced apart on the first mounting portion 1411. The first mounting portion 1411 is movably disposed on the base 11, and the first extension portion 1412 and the second extension portion 1413 are used to apply pressure to the top cover 120 at different corners close to one side of the top cover 120. The second pressing member 142 may include a second mounting portion 1421 and a third extension portion 1422 and a fourth extension portion 1423 spaced apart on the second mounting portion 1421. The second mounting portion 1421 is movably disposed on the base 11, and the third extension portion 1422 and the fourth extension portion 1423 are used to apply pressure to the top cover 120 at different corners close to the other side of the top cover 120.

[0052] That is to say, the first pressing member 141 and the second pressing member 142 use multiple parts to apply pressure to the edge of the top cover 120 near the R angle, that is, the position of the arc angle. The first mounting portion 1411 of the first pressing member 141 is a portion connected with other components, which can be directly connected to the output end of the first driving member 143 to move under the drive of the first driving member 143. The first extension portion 1412 and the second extension portion 1413 are portions for applying pressure to the top cover 120. The first extension portion 1412 and the second extension portion 1413 are spaced apart, and are used to perform press-fitting operations at different corners of one side of the corresponding top cover 120. The second mounting portion 1421 of the second pressing member 142 is a portion connected with other components, which can be directly connected to the output end of the second driving member 144 to move under the drive of the second driving member 144. The third extension portion 1422 and the second extension portion 1413 are portions for applying pressure to the top cover 120 and pushing. The third extension portion 1422 and the fourth extension portion 1423 are spaced apart to perform press-fitting operations at different corners on the other side of the top cover 120. It should be noted that the square shell secondary battery 100 is designed with an R angle structure at the corner of the top cover 120, which can reduce the risk of the battery 100 being broken when impacted or squeezed, and can disperse stress, making the battery 100 safer and more reliable. Since the top cover 120 and the shell 110 are interference fit, a one-to-one press-fitting operation is performed at the position of the top cover 120 near the corner, which can ensure the press-fitting effect between the top cover 120 as a whole and the shell 110.

[0053] In actual situations, the area of ​​the push surface of the extension of different pressing members contacting the top cover 120 can be set to be greater than or equal to 20 mm. 2 , and less than or equal to 20mm 2 . The surface of the first extension portion 1412 and the second extension portion 1413 of the first pressing member 141 that contacts the top cover 120 can be set to a regular shape such as a rectangle, a square or a circle, or can be set to an irregular special-shaped shape. The side length of the surface of the first extension portion 1412 and the second extension portion 1413 that contacts the top cover 120 can be set to about 5 mm (millimeter), such as 4.5 mm, 4.7 mm, 5 mm or 5.2 mm. The surface of the third extension portion 1422 and the fourth extension portion 1423 of the second pressing member 142 that contacts the top cover 120 can be set to a regular shape such as a rectangle, a square or a circle, or can be set to an irregular special-shaped shape. The side length of the surface of the third extension portion 1422 and the fourth extension portion 1423 that contacts the top cover 120 can be set to about 5 mm, such as 4.5 mm, 4.7 mm, 5 mm or 5.2 mm.

[0054] like Figure 1As shown, the first mounting portion 1411 of the first pressing member 141 and the second mounting portion 1421 of the second pressing member 142 can be mounted on the mounting platform 112 by using a slide rail mechanism, and the output end of the first driving member 143 is connected to the first mounting portion 1411, and the output end of the second driving member 144 is connected to the second mounting portion 1421. In actual situations, a guide seat 145 can be fixed on the mounting platform 112 to set up the slide rail mechanism and realize the installation of the pressing member. Different driving members can be installed by fixing the seat body 146 on the mounting platform 112.

[0055] In some embodiments, the press-fitting device 10 may further include a detector 15 , which is disposed on the base 11 , and is used to detect a seam between the top cover 120 and the shell 110 of the press-fitted battery 100 .

[0056] In actual situations, in order to improve the yield of the battery 100 during the production process, the battery 100 is usually inspected after completing the corresponding process. The detection process is carried out by the detector 15. The detector 15 can use different types of profilometers or detection cameras to detect the steps and gaps at the matching positions of the top cover 120 and the shell 110. If the detection result is OK, the pre-welding operation can continue. By setting the detector 15 in the press-fitting device 10, the press-fitting effect of the battery 100 after the press-fitting operation is completed can be detected in time to avoid the battery 100 flowing into the pre-welding station. The defective phenomenon of the step existing in the press-fitted battery 100 cannot be immediately detected due to the lack of online detection in the press-fitting process, which results in the press-fitting defect phenomenon being discovered only in subsequent detection, and the need for secondary rework to waste equipment beats. The step is detected at the same time as the press-fitting operation is completed, and secondary remediation can be performed during the press-fitting process, and secondary press-fitting can be performed. Thus, the step defect phenomenon of the top cover 120 entering the shell and the flange bulge defect phenomenon of the top cover 120 welding can be reduced, greatly improving the first-time good rate and equipment OEE (Overall Equipment Effectiveness) of the shell entry and top cover 120 welding process. Among them, OEE is an indicator that reflects the percentage of the planned production time that is truly effective for the equipment.

[0057] In some embodiments, the pressing member 24 extends beyond the edge of the top cover 120 in the direction in which the short side of the top cover 120 extends. Fig. 9 As shown, a clearance groove 241 may be provided at the edge of the pressing member 24 beyond the top cover 120 , and the clearance groove 241 is used to expose the joint between the top cover 120 and the shell 110 at the pre-welding point position of the battery 100 in the pre-welding position.

[0058] In order to prevent the clamping member 24 from affecting the normal welding of the welding tool during the clamping process, a clearance groove 241 can be opened at the edge of the clamping member 24. The position of the clearance groove 241 corresponds to the pre-welding point position of the long edge of the top cover 120. In the process of the clamping member 24 maintaining the clamping state, the seam between the top cover 120 and the shell 110 at the pre-welding point position is not blocked by the edge of the clamping member 24, thereby reserving a channel for the welding process of the welding tool. The welding tool can adopt the form of laser welding, and the laser can pass through the reserved channel to reach the seam position between the top cover 120 and the shell 110, thereby completing the welding process.

[0059] In some embodiments, the first positioning assembly 13 may include a first side positioning assembly 131 and a second side positioning assembly 132. The first side positioning assembly 131 includes a first positioning member 1311 and a second positioning member 1312 relatively arranged on the base 11. The first positioning member 1311 and the second positioning member 1312 can move in directions approaching / moving away from each other. The second side positioning assembly 132 includes a third positioning member 1321 and a fourth positioning member 1322 relatively arranged on the base 11. The third positioning member 1321 and the fourth positioning member 1322 can move in directions approaching / moving away from each other. The first positioning member 1311, the second positioning member 1312, the third positioning member 1321 and the fourth positioning member 1322 are arranged around the central axis direction of the first through hole 111.

[0060] The first positioning assembly 13 of the press-fitting device 10 includes an independently arranged side positioning assembly, and different positioning members of the side positioning assembly are used to position different sides of the housing 110 when the battery 100 is placed vertically. The first side positioning assembly 131 is arranged corresponding to the two larger front and back sides of the housing 110 of the battery 100, and the second side positioning assembly 132 is arranged corresponding to the two smaller sides of the housing 110 of the battery 100 connecting the front and back sides.

[0061] like Figure 4 and Figure 5 As shown, different positioning members can be driven by independent driving mechanisms, and the positioning members can be installed on the base 11 through a slide rail mechanism and equipped with corresponding driving components for driving. The different positioning members can be telescopically moved by the driving action of the driving components, and then pressed on various sides of the battery 100 when the battery 100 needs to be positioned, thereby ensuring that the battery 100 is in a predetermined press-fit position.

[0062] like Figure 4 and Figure 5As shown, the press-fitting device 10 may further include a suction assembly 16, which includes a first suction cup 161 and a second suction cup 162 that are relatively arranged, the first suction cup 161 is connected to the first positioning member 1311, and the second suction cup 162 is connected to the second positioning member 1312, and the first suction cup 161 and the second suction cup 162 are used to adsorb on the surface of the shell 110 of the battery 100 in the press-fitting position before the battery 100 is press-fitted, and to open the opening of the shell 110.

[0063] The suction cups are adapted to absorb the two larger front and back surfaces of the battery 100. The suction cups can be connected to a vacuum pump through a pipeline, and before the battery 100 is pressed, the vacuum pump is turned on to pull the housing 110 backwards so that the opening of the housing 110 is opened for a certain distance, thereby facilitating the lower pressing member to complete the press-fitting operation on the top cover 120.

[0064] In some embodiments, the second positioning assembly 23 may include a third side positioning assembly 231 and a fourth side positioning assembly 232. The third side positioning assembly 231 includes a fifth positioning member 2311 and a sixth positioning member 2312 relatively arranged on the base 21, and the fifth positioning member 2311 and the sixth positioning member 2312 can move in a direction approaching / moving away from each other. The fourth side positioning assembly 232 includes a seventh positioning member 2321 and an eighth positioning member 2322 relatively arranged on the base 11, and the seventh positioning member 2321 and the eighth positioning member 2322 can move in a direction approaching / moving away from each other. The fifth positioning member 2311, the sixth positioning member 2312, the seventh positioning member 2321 and the eighth positioning member 2322 are arranged around the central axis direction of the second through hole 211.

[0065] The second positioning assembly 23 of the pre-welding device 20 includes an independently arranged side positioning assembly, and different positioning members of the side positioning assembly are used to position different sides of the housing 110 when the battery 100 is placed vertically. The third side positioning assembly 231 is arranged corresponding to the two larger front and back sides of the housing 110 of the battery 100, and the fourth side positioning assembly 232 is arranged corresponding to the two smaller sides of the housing 110 of the battery 100 connecting the front and back sides.

[0066] like Fig. 9 As shown, different positioning members can be driven by independent driving mechanisms, and the positioning members can be installed on the base 11 through a slide rail mechanism and equipped with corresponding driving components for driving. The different positioning members can be telescopically moved by the driving action of the driving components, and then pressed on various sides of the battery 100 when the battery 100 needs to be positioned, thereby ensuring that the battery 100 is in a predetermined press-fit position.

[0067] In some embodiments, the fifth positioning member 2311, the sixth positioning member 2312, the seventh positioning member 2321 and the eighth positioning member 2322 can all be connected with a positioning rod 233, and each positioning rod 233 is used to abut against the position of the shell 110 of the battery 100 in the pre-welding position near the pre-welding point.

[0068] That is to say, different positioning members of the second positioning assembly 23 are arranged corresponding to the pre-welding point positions of the battery 100. Each positioning member of the second positioning assembly 23 uses a pressure rod to position the battery 100, and the pressure rods press the areas on different sides of the shell 110, corresponding to the pre-welding point positions of the battery 100, that is, corresponding to the welding positions of the joints between the top cover 120 and the shell 110. By using the positioning rods 233 to press and hold in the vicinity of the pre-welding point positions of the battery 100, it is possible to ensure that the size of the joint between the top cover 120 and the shell 110 is small, so as to complete the welding process and ensure the welding quality.

[0069] like Figure 2 As shown, the press-fitting device 10 may include a first clamping assembly 17, the first clamping assembly 17 includes a first clamping member 171 and a second clamping member 172 disposed on the base 11, the first clamping member 171 and the second clamping member 172 can move in a direction of approaching / moving away from each other, and the first clamping member 171 and the second clamping member 172 are used to clamp the opposite sides of the housing 110 of the battery 100 in the press-fitting position;

[0070] The first lifting assembly 12 includes a first supporting member 121, which includes a first main body 1211 and a first clamping portion 1212 and a second clamping portion 1213 relatively arranged on the first main body 1211, and the first clamping portion 1212 and the second clamping portion 1213 are used to clamp the other two sides of the shell 110 of the battery 100 in the press-fit position.

[0071] The different clamping members of the first clamping assembly 17 can clamp from the two side surfaces with smaller areas of the housing 110. At the same time, the two clamping parts of the first supporting member 121 carrying the battery 100 are clamped on the two outer sides of the housing 110, i.e., the front and back surfaces with larger areas. When the battery 100 is positioned in the press-fitting position, the position of the battery 100 can be limited by the first clamping assembly 17 to ensure that the battery 100 always remains in the press-fitting position during the press-fitting operation.

[0072] like Figure 7As shown, the pre-welding device 20 may include a second clamping assembly 25, the second clamping assembly 25 includes a third clamping member 251 and a fourth clamping portion 2213 arranged on the base 21, the third clamping member 251 and the fourth clamping member 252 can move in a direction of approaching / moving away from each other, and the third clamping member 251 and the fourth clamping member 252 are used to clamp the opposite sides of the housing 110 of the battery 100 in the pre-welding position;

[0073] The second lifting assembly 22 includes a second supporting member 221, which includes a second main body 2211 and a third clamping portion 2212 and a fourth clamping portion 2213 relatively arranged on the second main body 2211, and the third clamping portion 2212 and the fourth clamping portion 2213 are used to clamp the other two sides of the shell 110 of the battery 100 in the pre-welding position.

[0074] The different clamping members of the second clamping assembly 25 can clamp from the two side surfaces with smaller areas of the housing 110. At the same time, the two clamping parts of the second supporting member 221 carrying the battery 100 are clamped on the two outer sides of the housing 110, i.e., the front and back surfaces with larger areas. When the battery 100 is positioned in the pre-welding position, the position of the battery 100 can be limited by the second clamping assembly 25 to ensure that the battery 100 always remains in the pre-welding position during the pre-welding operation.

[0075] like Figures 6 to 9 As shown, the base 21 is connected to a reference plate 212, and the second positioning assembly 23 and the pressing member 24 are both connected to the reference plate 212. Fig.10 As shown, the reference plate 212 is provided with a plurality of via holes 2121 , and each via hole 2121 is used to provide a clearance channel for a welding tool to weld a pre-welding point of the battery 100 .

[0076] The reference plate 212 can provide a reference position. The reference plate 212 is connected to the base 21 through a support structure formed by a guide column 213. The reference position provided by the reference plate 212 can facilitate the welding tool to locate the welding position of the joint between the top cover 120 and the shell 110. At the same time, the reference plate 212 provides convenience for the installation of the second positioning component 23 and the pressing member 24. In order to facilitate the second positioning component 23 to perform a positioning operation near the joint position between the top cover 120 and the shell 110, the second positioning component 23 can be fixed on the reference plate 212. At the same time, the pressing member 24 is fixed on the reference plate 212. The second positioning component 23 and the pressing member 24 are both fixed on the side of the reference plate 212 facing the base 21.

[0077] Before the pre-welding operation, the second lifting assembly 22 drives the battery 100 to move until the pressing member 24 is pressed against the top cover 120, exerting pressure on the top cover 120. This ensures that the battery 100 is level. The second positioning assembly 23 is used to perform the positioning operation.

[0078] At the same time, in order to expose the joint between the top cover 120 and the shell 110 at the pre-welding point, a corresponding via hole 2121 is provided on the reference plate 212, and the via hole 2121 provides a clearance channel for the welding operation. The clearance channel formed by the via hole 2121 can facilitate the laser emitted by the welding tool to reach the joint between the top cover 120 and the shell 110, so as to perform the welding process.

[0079] Some embodiments of the present application also provide a method for pre-welding using the above-mentioned square shell secondary battery pre-welding device, and the pre-welding method includes the following steps:

[0080] Step S110, the first lifting assembly 12 of the press-fit device 10 drives the carried battery 100 to move. The first positioning assembly 13 abuts against the housing 110 of the battery 100, so that the battery 100 enters the press-fit position. The first pressing member 141 of the press-fit assembly 14 applies pressure to the top cover 120 of the battery 100 at the side of the positive pole 130 of the battery 100 away from the negative pole 140 at the press-fit position, and the second pressing member 142 applies pressure to the top cover 120 of the battery 100 at the side of the negative pole 140 of the battery 100 at the press-fit position away from the positive pole 130, so as to press-fit the battery 100.

[0081] After the battery 100 is unwelded after the battery cell is placed in the shell, it is transferred to the first lifting assembly 12 of the press-fitting device 10 located at the press-fitting station, and the first lifting assembly 12 is lifted by the driving component to bring the battery 100 close to the press-fitting position. Then, the first positioning assembly 13 is used to position the battery 100 in the length direction and the width direction, respectively, to ensure that the battery 100 is stably and accurately in the press-fitting position.

[0082] After the battery 100 is positioned, the servo mechanism can be used to push the lower pressing member to press-fit the area near the two short sides of the top cover 120 of the battery 100. After the press-fitting operation of the battery 100 is completed, the constraint on the side of the battery 100 housing 110 is canceled, and the first lifting assembly 12 is retracted to return the pressed battery 100 to the receiving position of the first lifting assembly 12.

[0083] Step S120: Transfer the pressed battery 100 to the pre-welding station by means of a transfer device.

[0084] The transfer device can realize the position transfer of the battery 100 between the press-fitting device 10 and the pre-welding device 20 to realize the automated production of the battery 100 .

[0085] Step S130, the first lifting assembly 12 of the pre-welding device 20 drives the loaded press-assembled battery 100 to move. The second positioning assembly 23 abuts against the shell 110 of the battery 100, so that the battery 100 enters the pre-welding position. The pressing member 24 applies pressure to the top cover 120 of the battery 100 between the positive pole 130 and the negative pole 140 of the battery 100 in the pre-welding position. And the joint between the top cover 120 and the shell 110 of the battery 100 in the pre-welding position at the pre-welding point is pre-welded by a welding tool.

[0086] After the press-assembled battery 100 is transferred to the second lifting assembly 22 of the pre-welding device 20 located at the pre-welding station, the second lifting assembly 22 is lifted by the driving component to bring the battery 100 close to the pre-welding position. Then, the second positioning assembly 23 is used to position the battery 100 in the length direction and the width direction, respectively, to ensure that the battery 100 is stably and accurately in the press-assembled position.

[0087] After the battery 100 is positioned, the pressing member 24 can press the area of ​​the top cover 120 of the battery 100 between the positive pole 130 and the negative pole 140. Then, the joint between the top cover 120 and the shell 110 at the pre-welding point can be welded by a welding tool. After the pre-welding operation of the battery 100 is completed, the constraint on the side of the shell 110 of the battery 100 is cancelled, and the pre-welded battery 100 is returned to the receiving position of the second lifting assembly 22 by retreating the second lifting assembly 22.

[0088] In actual situations, after the press-fitting device 10 completes the press-fitting of the top cover 120 of the battery 100, the joint between the top cover 120 and the shell 110 can be simultaneously detected by a profilometer, and the detection results are fed back to the host computer. If the detection structure meets the requirements, the first lifting assembly 12 is lowered after the detection is completed, so that the battery 100 can be transferred to the pre-welding station through the transfer device. If the detection structure does not meet the requirements, the press-fitting operation of the battery 100 can be remedied for the second time. After the remedy is successful, the position transfer of the battery 100 is realized.

[0089] In addition, different pressing members can push the top cover 120 from multiple regions, and the area of ​​the pushing surface of each region contacting the top cover 120 can be set to be greater than or equal to 20 mm. 2 , and less than or equal to 20mm 2For example, in some embodiments, the first pressing member 141 may include a first mounting portion 1411 and a first extension portion 1412 and a second extension portion 1413 spaced apart on the first mounting portion 1411. The first mounting portion 1411 is movably disposed on the base 11, and the first extension portion 1412 and the second extension portion 1413 are used to apply pressure to the top cover 120 at different corners close to one side of the top cover 120. The second pressing member 142 may include a second mounting portion 1421 and a third extension portion 1422 and a fourth extension portion 1423 spaced apart on the second mounting portion 1421. The second mounting portion 1421 is movably disposed on the base 11, and the third extension portion 1422 and the fourth extension portion 1423 are used to apply pressure to the top cover 120 at different corners close to the other side of the top cover 120.

[0090] The surface of the first extension 1412 and the second extension 1413 of the first pressing member 141 that contacts the top cover 120 can be set to a regular shape such as a rectangle, a square or a circle, or it can be set to an irregular special-shaped shape. The side length of the surface of the first extension 1412 and the second extension 1413 that contacts the top cover 120 can be set to about 5mm (millimeter), such as 4.5mm, 4.7mm, 5mm or 5.2mm. The surface of the third extension 1422 and the fourth extension 1423 of the second pressing member 142 that contacts the top cover 120 can be set to a regular shape such as a rectangle, a square or a circle, or it can be set to an irregular special-shaped shape. The side length of the surface of the third extension 1422 and the fourth extension 1423 that contacts the top cover 120 can be set to about 5mm, such as 4.5mm, 4.7mm, 5mm or 5.2mm.

[0091] In some embodiments, the length of the pressing member 24 in the direction of the long side extension of the top cover 120 can be set within 2 / 3 of the length of the long side of the top cover 120. The pressing member 24 extends beyond the edge of the top cover 120 in the direction of the short side extension of the top cover 120. In addition, a clearance groove 241 can be provided at the edge where the pressing member 24 exceeds the top cover 120, and the clearance groove 241 is used to expose the joint between the top cover 120 and the shell 110 at the pre-welding point position of the battery 100 in the pre-welding position.

[0092] According to actual usage, when pre-welding the square-shell secondary battery 100, the pre-welding equipment provided in some embodiments of the present application can reduce the flange defect phenomenon of the produced battery 100 from the original 0.3% to 0.02%, and reduce the step defect phenomenon from the original 0.3% to 0.1%, and the equipment OEE can be improved by 2%.

[0093] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A square shell secondary battery pre-welding device, used for pre-welding square shell secondary batteries, the square shell secondary batteries comprising a shell containing a battery cell, and a top cover of the shell, the top cover is provided with a positive electrode column and a negative electrode column electrically connected to the electrodes of the battery cell, characterized in that: The square shell secondary battery pre-welding equipment comprises a pressing device located at a pressing station, a pre-welding device located at a pre-welding station, and a transfer device for transferring the battery from the pressing station to the pre-welding station; The press-fitting device comprises a base, a first lifting assembly, a first positioning assembly and a press-fitting assembly, the base is provided with a first through hole, the first lifting assembly is provided on one side of the base, the first lifting assembly carries the battery and drives the battery to pass through the first through hole, the first positioning assembly is provided on the base, the first positioning assembly abuts against the battery shell around the battery to make the battery enter the press-fitting position, the press-fitting assembly comprises a first pressing member and a second pressing member movably provided on the base, the first pressing member applies pressure to the top cover of the battery at a side of the positive pole of the battery at the press-fitting position away from the negative pole, and the second pressing member applies pressure to the top cover of the battery at a side of the negative pole of the battery at the press-fitting position away from the positive pole, so as to press-fit the battery; The total area of ​​the first pressing member and the second pressing member contacting the top cover is greater than or equal to 80 mm 2 , and less than or equal to 120mm 2 ; The pre-welding device comprises a base, a second lifting assembly, a second positioning assembly, a pressing piece and a welding tool, the base is provided with a second through hole, the second lifting assembly is provided on one side of the base, the second lifting assembly carries the pressed battery and drives the battery to pass through the second through hole, the second positioning assembly is provided on the base, the second positioning assembly abuts against the battery shell around the battery to make the battery enter the pre-welding position, the pressing piece is provided on the base, the pressing piece applies pressure to the top cover of the battery between the positive pole and the negative pole of the battery in the pre-welding position, and the welding tool pre-welds the joint between the top cover and the shell of the battery in the pre-welding position at the pre-welding point; The length of the pressing piece in the extending direction of the long side of the top cover is less than 2 / 3 of the length of the long side of the top cover.

2. The square shell secondary battery pre-welding equipment according to claim 1, characterized in that: The press-fitting assembly includes a first driving member and a second driving member, wherein the first driving member is arranged on the base, and an output end of the first driving member is connected to the first pressing member, and the second driving member is arranged on the base, and an output end of the second driving member is connected to the second pressing member.

3. The square shell secondary battery pre-welding equipment according to claim 2, characterized in that: The first driving member is driven prior to the second driving member, so that the first pressing member applies pressure to the top cover of the battery in the press-fitting position prior to the second pressing member.

4. The square shell secondary battery pre-welding equipment according to claim 1, characterized in that: The first pressing member comprises a first mounting portion and a first extending portion and a second extending portion spaced apart on the first mounting portion, the first mounting portion being movably disposed on the base, and the first extending portion and the second extending portion being used to apply pressure to the top cover at different corners close to one side of the top cover; The second pressing member includes a second mounting portion and a third extending portion and a fourth extending portion spaced apart on the second mounting portion, the second mounting portion is movably disposed on the base, and the third extending portion and the fourth extending portion are used to apply pressure to the top cover at different corners close to the other side of the top cover.

5. The square shell secondary battery pre-welding equipment according to claim 1, characterized in that: The press-fitting device further comprises a detector, which is arranged on the base and is used to detect the joint between the top cover and the shell of the press-fitted battery.

6. The square shell secondary battery pre-welding equipment according to claim 1, characterized in that: The edge of the clamping piece extends beyond the edge of the top cover in the direction of extension of the short side of the top cover, and a clearance groove is provided at the edge of the clamping piece extending beyond the top cover, and the clearance groove is used to expose the seam between the top cover and the shell at the pre-welding point position of the battery in the pre-welding position.

7. The square shell secondary battery pre-welding equipment according to claim 1, characterized in that: The first positioning assembly includes a first side positioning assembly and a second side positioning assembly, the first side positioning assembly includes a first positioning member and a second positioning member relatively arranged on the base, the first positioning member and the second positioning member can move in directions approaching / moving away from each other, the second side positioning assembly includes a third positioning member and a fourth positioning member relatively arranged on the base, the third positioning member and the fourth positioning member can move in directions approaching / moving away from each other, and the first positioning member, the second positioning member, the third positioning member and the fourth positioning member are arranged around the central axis direction of the first through hole.

8. The square shell secondary battery pre-welding equipment according to claim 1, characterized in that: The second positioning assembly includes a third side positioning assembly and a fourth side positioning assembly, the third side positioning assembly includes a fifth positioning member and a sixth positioning member relatively arranged on the base, the fifth positioning member and the sixth positioning member can move in directions approaching / moving away from each other, the fourth side positioning assembly includes a seventh positioning member and an eighth positioning member relatively arranged on the base, the seventh positioning member and the eighth positioning member can move in directions approaching / moving away from each other, and the fifth positioning member, the sixth positioning member, the seventh positioning member and the eighth positioning member are arranged around the central axis direction of the second through hole.

9. The square shell secondary battery pre-welding equipment according to claim 8, characterized in that: The fifth positioning member, the sixth positioning member, the seventh positioning member and the eighth positioning member are all connected with positioning rods, and each positioning rod is used to abut against a position of the battery shell in the pre-welding position close to the pre-welding point.

10. A method for pre-welding using the square shell secondary battery pre-welding equipment according to any one of claims 1 to 9, characterized in that: include: The battery is moved by driving the carried battery through the first lifting assembly of the press-fitting device, and the battery is brought into the press-fitting position by abutting against the battery housing through the first positioning assembly, and the battery is press-fitted by applying pressure to the top cover of the battery at the side of the positive electrode column of the battery at the press-fitting position away from the negative electrode column through the first pressing member of the press-fitting assembly, and applying pressure to the top cover of the battery at the side of the negative electrode column of the battery at the press-fitting position away from the positive electrode column through the second pressing member; The pressed batteries are transferred to the pre-welding station by a transfer device; The first lifting component of the pre-welding device drives the loaded pressed battery to move, and the second positioning component abuts against the battery shell to make the battery enter the pre-welding position, and the clamping member applies pressure to the top cover of the battery between the positive electrode column and the negative electrode column of the battery in the pre-welding position, and the welding tool is used to pre-weld the joint between the top cover and the shell of the battery in the pre-welding position at the pre-welding point.

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