Prismatic secondary battery pre-welding apparatus and pre-welding method

Abstract

The application relates to the technical field of battery production, and discloses a square-shell secondary battery pre-welding device and a pre-welding method. The square-shell secondary battery pre-welding device 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 pressing device comprises a base, a first jacking assembly, a first positioning assembly and a pressing 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 carries the battery and drives the battery to pass through the first through hole, the first positioning assembly is arranged on the base, the first positioning assembly abuts against the shell of the battery around the battery, so that the battery enters a pressing position, and the pressing assembly comprises a first lower pressing piece and a second lower pressing piece movably arranged on the base. The square-shell secondary battery pre-welding device and the pre-welding method can reduce product defects in the pre-welding production process of the battery.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of battery production, in particular to a square shell secondary battery pre-welding device and a pre-welding method. BACKGROUND

[0002] With the continuous development of energy storage technology, the demand for secondary batteries is also increasing. Secondary batteries can form a battery module through series connection or parallel connection, and realize the storage and effective utilization of electric energy by using the charge-discharge cycle characteristics of battery monomers. In the production of square shell secondary batteries, a pre-welding process is usually carried out to fix the top cover and the shell of the square shell secondary battery in advance when forming the battery monomer through full welding.

[0003] In order to improve the production efficiency of square shell secondary batteries, an automatic pre-welding device is usually used to complete the pre-welding process of the top cover and the shell. However, in the pre-welding process, the size of the top cover entering the shell may be poor or the welding may be poor. Therefore, how to reduce the product defects in the pre-welding production process of the battery is an important problem. SUMMARY

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

[0005] 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 comprises a press-fitting device located at a press-fitting station, a pre-welding device located at a pre-welding station, and a transfer device for transferring the battery from the press-fitting 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. The base is provided with a first through hole. The first lifting assembly is arranged on one side of the base and carries the battery and drives the battery to pass through the first through hole. The first positioning assembly is arranged on the base and abuts against the shell of the battery around the battery to make the battery enter a press-fitting position. The press-fitting assembly comprises a first lower pressing piece and a second lower pressing piece movably arranged on the base. The first lower pressing piece applies pressure to the top cover of the battery on the side of the positive electrode column of the battery in the press-fitting position away from the negative electrode column. The second lower pressing piece applies pressure to the top cover of the battery on the side of the negative electrode column of the battery in the press-fitting position away from the positive electrode column to press fit the battery.

[0007] The total area of the contact between the first lower pressing piece and the second lower pressing piece and the top cover is greater than or equal to 80mm 2 and less than or equal to 120mm 2 .

[0008] The pre-welding device comprises a base, a second lifting assembly, a second positioning assembly, a pressing member 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 battery after the pressing 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 shell of the battery around the battery to make the battery enter a pre-welding position. The pressing member is arranged on the base. The pressing member 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 at the pre-welding point.

[0009] The length of the pressing member in the length 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 also provides a pre-welding method using the above-mentioned square case secondary battery pre-welding device. The pre-welding method comprises the following steps:

[0011] The battery carried by the first lifting assembly of the pressing device is moved. The first positioning assembly abuts against the shell of the battery to make the battery enter a pressing position. The first pressing member of the pressing assembly applies pressure to the top cover of the battery on the side of the positive pole of the battery away from the negative pole in the pressing position. The second pressing member applies pressure to the top cover of the battery on the side of the negative pole of the battery away from the positive pole in the pressing position. The battery is pressed.

[0012] The battery after the pressing is transferred to a pre-welding station by the transfer device.

[0013] The battery carried by the first lifting assembly of the pre-welding device is moved. The second positioning assembly abuts against the shell of the battery to make the battery enter a pre-welding position. The pressing member 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 at the pre-welding point.

[0014] The square case secondary battery pre-welding device and the pre-welding method provided by the embodiment of the present application apply pressure to the top cover of the battery by the pressing device to complete the pressing operation and weld the joint between the top cover and the shell of the battery by the pre-welding device to complete the pre-welding operation. The pressing assembly of the pressing device adopts the first pressing member and the second pressing member to apply pressure to the top cover on the side of the positive pole and the negative pole of the battery away from each other, so that the middle part of the top cover forms a part for releasing interference, thereby ensuring the pressing effect when the top cover and the shell are interference-fitted. Meanwhile, the pre-welding device adopts the pressing member to apply pressure to the top cover on the side between the positive pole and the negative pole of the battery, so that the middle part of the top cover and the shell are kept in the interference-fitted state. Thus, the adverse phenomena in the production process of the battery caused by applying pressure to the whole large surface of the top cover are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0015] One or more embodiments are illustrated by way of example in the figures that are part of this disclosure and which are illustrative, but not restrictive, of the embodiments, wherein like references numerals refer to like elements, unless otherwise specified, and wherein the figures are not necessarily drawn to scale.

[0016] Figure 1 is a perspective view of a pressing device in a square case secondary battery pre-welding device according to some embodiments of the present application;

[0017] Figure 2 is a front view of the pressing device in the square case secondary battery pre-welding device according to some embodiments of the present application;

[0018] Figure 3 is a side view of the pressing device in the square case secondary battery pre-welding device according to some embodiments of the present application;

[0019] Figure 4 is a positioning structure of the pressing device according to some embodiments of the present application;

[0020] Figure 5 is a front view of the positioning structure of the pressing device according to some embodiments of the present application; Figure 4

[0021] Figure 6 is a perspective view of a pre-welding device in a square case secondary battery pre-welding device according to some embodiments of the present application;

[0022] Figure 7 is a front view of the pre-welding device in the square case secondary battery pre-welding device according to some embodiments of the present application;

[0023] Figure 8 is a side view of the pre-welding device in the square case secondary battery pre-welding device according to some embodiments of the present application;

[0024] Figure 9 is a positioning structure of the pre-welding device according to some embodiments of the present application;

[0025] Figure 10 is a top view of a reference plate of the pre-welding device according to some embodiments of the present application;

[0026] Figure 11 is a perspective view of a square case secondary battery according to the prior art. DETAILED DESCRIPTION

[0027] ​In order to make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the various embodiments of the present application will be described in detail below with reference to the drawings. However, it should be understood by those of ordinary skill in the art that, in the various embodiments of the present application, many technical details are presented in order to make the present application better understood by the reader. However, the technical solutions claimed by the present application can be implemented even without these technical details and various changes and modifications based on the following various embodiments. The division of the following various embodiments is for the purpose of description and should not constitute any limitation on the specific implementation of the present application. The various embodiments can be combined 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 one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing the specific embodiments only and is not intended to be limiting of the present application; the terms "including," "comprising," and "having" and any variations thereof in the specification and in the claims and the above summary of the application are intended to cover the non-exclusive inclusion.

[0029] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0030] The battery pack, as an important part of the energy storage device, plays a crucial role in the storage and effective use of electrical energy. The battery pack includes a large number of battery monomers, each of which can store and release electrical energy. The battery monomer adopts a secondary battery, which has a charge-discharge cycle characteristic and can perform a charging process and a discharging process multiple times. Thus, the battery pack can be switched between the storage and use of electrical energy.

[0031] In order to fully utilize the space and improve the battery energy density of the battery pack, a square can secondary battery is usually used as the battery monomer. The square can secondary battery has a cuboid shape, i.e., a square shell is used as a containing shell of the battery cell. Meanwhile, the top opening of the shell is closed by a top cover. After the battery cell is put into the shell, the top cover is placed at the opening position of the top of the shell, and then pressing and pre-welding are sequentially performed. The pressing makes the top cover and the shell preliminarily fit, and the pre-welding welds part of the joint between the top cover and the shell to preliminarily fix the top cover and the shell. Figure 11 A perspective structure of the battery monomer formed after the battery cell is put into the shell and the top cover is welded is shown.

[0032] It should be noted that, in the pre-welding process of the square case battery, in order to make the welding effect good, avoid the occurrence of burst point, and avoid the situation that the laser hits the battery to cause damage to the battery, etc., the top cover needs to be pretreated by entering the shell compression assembly. That is, the top cover is compressed and compacted by the pressing plate, and the battery is pushed into the shell. In the compression assembly operation, the centering jig can be used to center the top cover and the shell, so that the top cover is accurately pressed into the shell, and the top cover surface and the shell opening surface are flat.

[0033] In actual operation, due to factors such as top cover mold defects, shell and top cover errors, etc., the compression assembly effect may not be good. The existing top cover and shell are made by mold, so there is a certain amount of tolerance. Therefore, when entering the shell compression assembly, the current pressing plate cannot make the top cover enter the shell step and gap to the ideal state, that is, near the pole, there is still a height difference.

[0034] At present, after the battery enters the shell, the top cover is compressed by the pressing plate on the whole large surface, that is, the large surface of the top cover. It is not convenient to release the interference part. Due to the size of the incoming material, deformation, and processing errors, etc., the interference fit between the shell and the top cover causes the shell compression assembly to be unable to be assembled in place. Therefore, the protrusion height after the top cover is welded cannot meet the process requirements, and there are many defects, rework or scrap phenomena.

[0035] In order to reduce the phenomenon of defects in the production process of the battery, some embodiments of the present application provide a square case secondary battery pre-welding equipment. By improving and optimizing the structure of the pressing plate and adjusting the pressing position, the current situation can be optimized to a certain extent, so that the height difference near the pole has little effect on the product, and the stability and consistency of the step height are higher. That is, only part of the position of the top cover is subjected to pressure in the square case secondary battery pre-welding equipment, so as to reserve a part for interference release at other positions of the top cover. In the process of top cover compression assembly, in order to ensure the compression assembly effect of the top cover, the compression assembly part is arranged at the two side edge positions near the top cover in the length direction to apply pressure, so that the interference fit position of the top cover and the shell reaches the specified fit size. At the same time, in the pre-welding process, the pressing part is used to apply pressure to the position between the positive and negative poles of the top cover, so as to ensure that the middle part of the top cover is kept in the fit state with the shell, and the joint between the top cover and the shell meets the welding requirements. Therefore, the welded battery meets the process requirements, and the phenomenon of defects in the production process of the battery is reduced.

[0036] The structure of the square case secondary battery pre-welding equipment provided by some embodiments of the present application will be described below. Figures 1 to 10 Figure 11 ​The square cell secondary battery 100 shown is pre-welded, and the square cell secondary battery 100 includes a housing 110 in which an electric core is accommodated, and a top cover 120 closing the housing 110, the top cover 120 being provided with a positive pole 130 and a negative pole 140 electrically connected with electrodes of the electric core.

[0037] As shown in the drawings, Figures 1 to 10 Some embodiments of the present application provide a square cell secondary battery pre-welding device, which includes a pressing device 10 located at a pressing station, a pre-welding device 20 located at a pre-welding station, and a transfer device transferring the battery 100 from the pressing station to the pre-welding station.

[0038] The pressing device 10 includes a base 11, a first lifting assembly 12, a first positioning assembly 13, and a pressing assembly 14. The base 11 is provided with a first through hole 111, and the base 11 can be installed through a support 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 a pressing position. The pressing assembly 14 includes a first pressing piece 141 and a second pressing piece 142 movably arranged on the base 11. The first pressing piece 141 applies pressure to the top cover 120 of the battery 100 on the side of the positive pole 130 of the battery 100 in the pressing position away from the negative pole 140, and the second pressing piece 142 applies pressure to the top cover 120 of the battery 100 on the side of the negative pole 140 of the battery 100 in the pressing position away from the positive pole 130, so as to press 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 piece 24, and a welding tool. The base 21 is provided with a second through hole 211, and the base 21 can be installed through a support structure. The second lifting assembly 22 is arranged on one side of the base 21, and the second lifting assembly 22 carries the battery 100 after pressing 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 against the housing 110 of the battery 100 around the battery 100, so that the battery 100 enters a pre-welding position. The pressing piece 24 is arranged on the base 21, and the pressing piece 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 of the top cover 120 and the housing 110 of the battery 100 at a pre-welding point of the battery 100 in the pre-welding position.

[0040] The press-fitting device 10 is used for the press-fitting process of the battery 100 arriving at the press-fitting station. During the whole production flow of the battery 100 monomer, the press-fitting device 10 is adjacent to the cell housing equipment. The cell housing equipment includes the shell 110 and the feeding part of the cell, and the cleaning part, and after the cell is pushed into the shell 110 by the housing device, the battery 100 after housing is flowed 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 for carrying the battery 100 to move, a part for positioning the battery 100, and a part for applying pressure to the top cover 120 to complete the press-fitting operation. Through the cooperation between different parts, the interference fit between the top cover 120 of the battery 100 and the shell 110 is realized. The base 11 of the press-fitting device 10 forms the installation basis of the positioning part and the press-fitting part. The battery 100 is transferred to the first lifting assembly 12 before press-fitting, and the battery 100 is driven by the first lifting assembly 12 to approach the positioning part and the press-fitting part. Before the press-fitting operation, the position of the battery 100 is positioned by the first positioning assembly 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 pressing piece 141 and the second pressing piece 142. The first pressing piece 141 and the second pressing piece 142 apply pressure to the top cover 120 corresponding to the side away from the positive pole 130 and the negative pole 140, so as to reserve a part for interference release at the middle position of the top cover 120, avoiding the problem of incomplete press-fitting of the top cover 120. In the press-fitting operation, the cell enters the predetermined position inside the shell 110 by pushing the top cover 120 by the pressing piece, and at the same time the top cover 120 moves into the shell 110, ensuring the effect of pre-welding and full-welding of the top cover 120.

[0042] In actual cases, the total area of the first pressing piece 141 and the second pressing piece 142 contacting the top cover 120 can be greater than or equal to 80mm 2 (square millimeter), and less than or equal to 120mm 2 , for example, the total area of the first pressing piece 141 and the second pressing piece 142 contacting the top cover 120 can be 80mm 2 , 90mm 2 , 100mm 2 , 110mm 2 or 120mm 2 . The pressing surface of the first pressing piece 141 and the second pressing piece 142 can be set as a regular shape such as a rectangle, a square or a circle, or an irregular special-shaped surface.

[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 press the top cover 120, and a part for welding the joint between the top cover 120 and the shell 110. Through the cooperation between the different parts, the joint 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 basis of the positioning part and the pressing part. The battery 100 is transferred to the second lifting assembly 22 after the pressing process is completed, and the second lifting assembly 22 drives the battery 100 to approach the positioning part and the pressing part. Before the pre-welding operation is performed, 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, which applies pressure to the top cover 120 between the positive pole 130 and the negative pole 140. Thus, the joint between the middle position of the top cover 120 and the shell 110 is not too large to facilitate welding. The length of the pressing member 24 in the length direction of the long side of the top cover 120 can be set to within 2 / 3 of the length of the long side of the top cover 120. When the pressing member 24 is kept in the pressing state, the joint between the top cover 120 and the shell 110 is welded by the welding tool, and the welding position corresponds to the pre-set pre-welding point position. In actual cases, 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 long side edges and one pre-welding point is selected at the short side edge. Multiple pre-welding points can be evenly arranged around the center of the top cover 120.

[0044] The transfer device is used to transfer the battery 100 from the pressing station to the pre-welding station, and the transfer device can be realized by a mechanical hand or a clamping mechanism. When the battery 100 completes the pressing operation and returns to the receiving position of the first lifting assembly 12, the transfer device can clamp the battery 100 and transfer the clamped battery 100 to the pre-welding station. The battery 100 after pressing is received by the second lifting assembly 22 of the pre-welding station, and then the pre-welding process is performed.

[0045] The pre-welding equipment for prismatic secondary batteries provided in some embodiments of this application applies pressure to the top cover 120 of the battery 100 using a pressing device 10 to complete the pressing operation, and welds the joint between the top cover 120 and the housing 110 of the battery 100 using a pre-welding device 20 to complete the pre-welding operation. The pressing assembly 14 of the pressing device 10 uses a first pressing member 141 and a second pressing member 142, applying pressure to the top cover 120 on the side of the battery 100 where the positive terminal 130 and the negative terminal 140 are far apart, thereby forming an interference-release portion in the middle of the top cover 120, ensuring the pressing effect when the top cover 120 and the housing 110 are in an interference fit. Simultaneously, the pre-welding device 20 uses a clamping member 24, applying pressure to the top cover 120 in the area between the positive terminal 130 and the negative terminal 140 of the battery 100, maintaining an interference fit between the middle of the top cover 120 and the housing 110. This reduces the occurrence of defects in the battery 100 production process caused by applying pressure to the entire surface of the top cover 120.

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

[0047] The pressing action of the pressing component is accomplished by driving the drive component. Furthermore, the first pressing component 141 and the second pressing component 142 are driven by independent drive components. When pressure is applied to the top cover 120, pushing the top cover 120 into the housing 110, the first pressing component 141 and the second pressing component 142 can operate synchronously or asynchronously. The first pressing component 141 is connected to the output terminal of the first drive component 143, and the second pressing component 142 is connected to the output terminal of the second drive component 144. The first drive component 143 and the second drive component 144 can be servo-driven to control the accuracy and pressure of the pressing component's movement.

[0048] like Figure 1 As shown, to facilitate the installation of the press-fit assembly 14, different parts of the press-fit assembly 14 can be installed on the same mounting platform 112, and then the mounting platform 112 can be fixed to the base 11 using the support column 113 as a support structure. In this way, it is not only easy to fix the press-fit assembly 14, but also to 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 characteristics of the positive and negative electrodes of the battery 100, the first lower pressing member 141 and the second lower pressing member 142 can be controlled to act in an asynchronous manner. That is, in some embodiments, the first driving member 143 can be preferentially driven than the second driving member 144, so that the first lower pressing member 141 preferentially applies pressure to the top cover 120 of the battery 100 in the pressing position than the second lower pressing member 142.

[0050] It should be noted that in 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, the reaction forces received by the corresponding parts of the positive electrode post 130 and the negative electrode post 140 on the top cover 120 are also different during the pressing of the top cover 120. In order to ensure the pressing effect of the top cover 120, different lower pressing members can be controlled to act separately to avoid the imbalance of the forces on both sides when simultaneously pushing. The first lower pressing member 141 close to the positive electrode post 130 is controlled to complete the pressing action first, and then the second lower pressing member 142 close to the negative electrode post 140 is controlled to complete the pressing action, so as to perform the pressing operation on the top cover 120.

[0051] In some embodiments, the first lower pressing member 141 can include a first mounting portion 1411 and first and second extension portions 1412 and 1413 arranged at intervals on the first mounting portion 1411. The first mounting portion 1411 is movably arranged on the base 11, and the first and second extension portions 1412 and 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 lower pressing member 142 can include a second mounting portion 1421 and third and fourth extension portions 1422 and 1423 arranged at intervals on the second mounting portion 1421. The second mounting portion 1421 is movably arranged on the base 11, and the third and fourth extension portions 1422 and 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, the first pressing member 141 and the second pressing member 142 adopt a plurality of parts to press the edge of the top cover 120 close to the R angle, that is, the circular arc angle. The first mounting part 1411 of the first pressing member 141 is a part connected with other components, which can be directly connected with the output end of the first driving member 143 to move under the driving of the first driving member 143. The first extension part 1412 and the second extension part 1413 are parts for pressing the top cover 120. The first extension part 1412 and the second extension part 1413 have a spacing for pressing operation corresponding to different angles on one side of the top cover 120. The second mounting part 1421 of the second pressing member 142 is a part connected with other components, which can be directly connected with the output end of the second driving member 144 to move under the driving of the second driving member 144. The third extension part 1422 and the second extension part 1413 are parts for pressing the top cover 120. The third extension part 1422 and the fourth extension part 1423 have a spacing for pressing operation corresponding to different angles 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 rupture of the battery 100 when subjected to impact or extrusion, and can disperse stress, making the battery 100 more safe and reliable. Since the top cover 120 and the shell 110 adopt an interference fit, one-to-one pressing operation is performed at the position of the top cover 120 close to the corner, which can ensure the pressing fit effect between the top cover 120 and the shell 110.

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

[0054] As 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 a sliding rail mechanism, and the output end of the first driving member 143 is connected with the first mounting portion 1411, and the output end of the second driving member 144 is connected with the second mounting portion 1421. In actual cases, a guide seat 145 can be fixed on the mounting platform 112 to set the sliding rail mechanism and mount the pressing members. Different driving members can be mounted by fixing a seat body 146 on the mounting platform 112.

[0055] In some embodiments, the pressing device 10 can further include a detector 15 arranged on the base 11, and the detector 15 is used to detect the joint between the top cover 120 and the shell 110 of the battery 100 after pressing.

[0056] In actual cases, in order to improve the yield of the battery 100 in the production process, the battery 100 after completing the corresponding process is usually detected. The detection process is carried out by the detector 15, which can be a profile gauge or a detection camera of different types, and can detect the step and gap at the joint between the top cover 120 and the shell 110. If the detection result is OK, the pre-welding operation can be continued. By arranging the detector 15 in the pressing device 10, the battery 100 after the pressing operation can be detected in time to avoid the situation that the battery 100 flows into the pre-welding station and then the defect is found. Thus, the step defect of the battery 100 after pressing cannot be detected immediately in the pressing process without online detection, so that the pressing defect cannot be found until the subsequent detection, which requires secondary rework and wastes equipment rhythm. Detecting the step at the same time as the pressing operation is completed can perform secondary remediation and secondary pressing in the pressing process. Thus, the step defect of the top cover 120 into the shell and the raised edge defect of the top cover 120 welding can be reduced, and the first yield and equipment OEE (Overall Equipment Effectiveness) of the shell and the top cover 120 welding process can be greatly improved. The OEE is an index reflecting the percentage of the actual effective planned production time of the equipment.

[0057] In some embodiments, the pressing member 24 extends beyond the edge of the top cover 120 in the direction of the short side of the top cover 120. Figure 9 As shown, the pressing member 24 beyond the edge of the top cover 120 can be provided with a recess slot 241 for exposing 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 position.

[0058] In order to avoid the influence of the pressing member 24 on the normal welding of the welding tool during the pressing process, a clearance groove 241 can be formed at the edge of the pressing 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. During the process of keeping the pressing state of the pressing member 24, the joint between the top cover 120 and the shell 110 at the pre-welding point position is not blocked by the edge part of the pressing 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 joint position between the top cover 120 and the shell 110, thereby completing the welding process.

[0059] In some embodiments, the first positioning assembly 13 can 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 oppositely arranged on the base 11, and the first positioning member 1311 and the second positioning member 1312 are movable in the direction of approaching / away from each other. The second side positioning assembly 132 includes a third positioning member 1321 and a fourth positioning member 1322 oppositely arranged on the base 11, and the third positioning member 1321 and the fourth positioning member 1322 are movable in the direction of approaching / 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 pressing device 10 includes independently arranged side positioning assemblies, and different positioning members of the side positioning assemblies are used to position different sides of the shell 110 when the battery 100 is vertically placed. The first side positioning assembly 131 is arranged corresponding to the two larger front and back surfaces of the shell 110 of the battery 100, and the second side positioning assembly 132 is arranged corresponding to the two smaller sides connecting the front and back surfaces of the shell 110 of the battery 100.

[0061] As shown in Figure 4 and Figure 5 Different positioning members can be driven by independent driving mechanisms. The positioning members can be installed on the base 11 through a sliding rail mechanism and equipped with corresponding driving components for driving. The driving effect of the driving components realizes the telescopic movement of different positioning members, and then the battery 100 is pressed on each side when positioning is needed. Thus, the battery 100 is ensured to be in a predetermined pressing position.

[0062] As shown in Figure 4 and Figure 5As shown, the press-fitting device 10 can further include a suction assembly 16, which includes a first suction cup 161 and a second suction cup 162 arranged oppositely, the first suction cup 161 being connected with the first positioning member 1311, and the second suction cup 162 being connected with the second positioning member 1312, the first suction cup 161 and the second suction cup 162 being used to be adsorbed 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 used to adsorb the two larger-area front surface and back surface of the battery 100. The suction cups can be connected with a vacuum pump through a pipeline, and before the press-fitting operation of the battery 100 is performed, the vacuum pump is started to pull the shell 110 backward, so as to open the opening of the shell 110 by a distance, thereby facilitating the press-down member to complete the press-fitting operation of the top cover 120.

[0064] In some embodiments, the second positioning assembly 23 can 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 arranged oppositely on the base 21, and the fifth positioning member 2311 and the sixth positioning member 2312 are movable in the direction of approaching / away from each other. The fourth side positioning assembly 232 includes a seventh positioning member 2321 and an eighth positioning member 2322 arranged oppositely on the base 11, and the seventh positioning member 2321 and the eighth positioning member 2322 are movable in the direction of approaching / 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 independently arranged side positioning assemblies, and different positioning members of the side positioning assemblies are used to position different sides of the shell 110 of the battery 100 when the battery 100 is vertically placed. The third side positioning assembly 231 is arranged corresponding to the two larger-area front surface and back surface of the shell 110 of the battery 100, and the fourth side positioning assembly 232 is arranged corresponding to the two smaller-area sides of the shell 110 of the battery 100 connecting the front surface and the back surface.

[0066] As shown, Figure 9 Different positioning members can be driven by independent driving mechanisms, and the positioning members can be installed on the base 11 through a sliding rail mechanism and equipped with corresponding driving components for driving. The driving components are used to achieve the telescopic movement of different positioning members, and then the positioning members are pressed on the sides of the battery 100 when the battery 100 needs to be positioned. Thus, the battery 100 is ensured to be in a predetermined press-fitting 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 be connected with a positioning rod 233, and each positioning rod 233 is used for abutting against the shell 110 of the battery 100 at a position close to the pre-welding point in the pre-welding position.

[0068] That is, different positioning members of the second positioning assembly 23 correspond to the pre-welding point position of the battery 100. Each positioning member of the second positioning assembly 23 adopts a pressure rod form to position the battery 100, and the pressure rod is pressed and held on the area on different sides of the shell 110, and corresponds to the pre-welding point position of the battery 100, that is, corresponds to the welding position of the joint between the top cover 120 and the shell 110. By correspondingly pressing and holding the positioning rod 233 near the pre-welding point position of the battery 100, it can be ensured that the joint size between the top cover 120 and the shell 110 is small, so as to complete the welding process and ensure the welding quality.

[0069] As shown in Figure 2 The pressing device 10 can include a first clamping assembly 17 including a first clamping member 171 and a second clamping member 172 arranged on the base 11, the first clamping member 171 and the second clamping member 172 being movable in a direction of approaching / away from each other, and the first clamping member 171 and the second clamping member 172 being used for clamping the opposite two sides of the shell 110 of the battery 100 in the pressing position.

[0070] The first jacking assembly 12 includes a first supporting member 121 including a first main body part 1211 and a first clamping part 1212 and a second clamping part 1213 oppositely arranged on the first main body part 1211, and the first clamping part 1212 and the second clamping part 1213 being used for clamping the other two sides of the shell 110 of the battery 100 in the pressing position.

[0071] Different clamping members of the first clamping assembly 17 can clamp from the two sides of the shell 110 with smaller area. At the same time, the two clamping parts of the first supporting member 121 carrying the battery 100 clamp the two outer sides of the shell 110, that is, the two larger front and back surfaces. When the battery 100 is positioned in the pressing position, the position of the battery 100 can be limited by the first clamping assembly 17, so as to ensure that the battery 100 always remains in the pressing position during the pressing operation.

[0072] As shown in Figure 7As shown, the pre-welding device 20 can include a second clamping assembly 25, which includes a third clamping part 251 and a fourth clamping part 2213 arranged on the base 21, the third clamping part 251 and the fourth clamping part 252 are movable in the direction of approaching / away from each other, and are used to clamp the opposite two sides of the shell 110 of the battery 100 in the pre-welding position.

[0073] The second lifting assembly 22 includes a second supporting part 221, which includes a second main body part 2211 and a third clamping part 2212 and a fourth clamping part 2213 arranged oppositely on the second main body part 2211, and the third clamping part 2212 and the fourth clamping part 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 parts of the second clamping assembly 25 can clamp from the two sides of the shell 110 with smaller areas. At the same time, the two clamping parts of the second supporting part 221 carrying the battery 100 clamp the two outer sides of the shell 110, i.e. the two larger areas of the front and back. 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, so as to ensure that the battery 100 always remains in the pre-welding position during the pre-welding operation.

[0075] As shown in the Figures 6 to 9 As shown in the Figure 10 The reference plate 212 is provided with a plurality of through holes 2121, and each through hole 2121 is used to provide a channel for the welding tool to weld the pre-welding point of the battery 100.

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

[0077] Before the pre-welding operation, the battery 100 is moved by the second lifting assembly 22 until the pressing member 24 is pressed against the top cover 120 to apply pressure to the top cover 120. Thus, the battery 100 is ensured to be stepped. Then, the positioning operation is performed by the second positioning assembly 23,

[0078] Meanwhile, in order to expose the joint between the top cover 120 and the shell 110 at the pre-welding point position, a corresponding via hole 2121 is arranged on the reference plate 212, which provides a channel for the welding operation. The channel formed by the via hole 2121 can facilitate the laser emitted by the welding tool to reach the joint position 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 pre-welding method using the above-mentioned square can secondary battery pre-welding device. The pre-welding method comprises the following steps:

[0080] In step S110, the battery 100 carried by the pressing device 10 is moved by the first lifting assembly 12 of the pressing device 10. The first positioning assembly 13 abuts against the shell 110 of the battery 100, so that the battery 100 enters the pressing position. The first pressing member 141 of the pressing assembly 14 applies pressure to the top cover 120 of the battery 100 on the side away from the negative pole 140 of the positive pole 130 in the pressing position, and the second pressing member 142 applies pressure to the top cover 120 of the battery 100 on the side away from the positive pole 130 of the negative pole 140 in the pressing position, so as to press the battery 100.

[0081] After the un-welded battery 100 formed after the cell enters the shell is transferred to the first lifting assembly 12 of the pressing device 10 at the pressing station, the first lifting assembly 12 is lifted by the driving component, so that the battery 100 approaches the pressing position. Then, the first positioning assembly 13 respectively performs the length direction positioning and the width direction positioning of the battery 100, so as to ensure that the battery 100 is stably and accurately positioned at the pressing position.

[0082] After the battery 100 is positioned, the servo mechanism can push the pressing member to press the area close to the two short sides of the top cover 120 of the battery 100. After the pressing operation of the battery 100 is completed, the constraint on the side surface of the shell 110 of the battery 100 is cancelled, and the pressed battery 100 returns to the receiving position of the first lifting assembly 12 by the back-off of the first lifting assembly 12.

[0083] In step S120, the pressed battery 100 is transferred to the pre-welding station by the transfer device.

[0084] The transfer device can realize the position transfer of the battery 100 between the pressing device 10 and the pre-welding device 20, so as to realize the automatic production of the battery 100.

[0085] Step S130, the battery 100 is moved by the first lifting assembly 12 of the pre-welding device 20. 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 pressure element 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.

[0086] After the battery 100 is transferred to the second lifting assembly 22 of the pre-welding device 20 in the pre-welding station, the second lifting assembly 22 is lifted by the driving component, so that the battery 100 approaches the pre-welding position. Then the second positioning assembly 23 respectively positions the battery 100 in the length direction and the width direction, so that the battery 100 is stably and accurately positioned in the pre-welding position.

[0087] After the battery 100 is positioned, the pressure element 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 welding tool welds the joint between the top cover 120 and the shell 110 at the pre-welding point. 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 the retreat of the second lifting assembly 22.

[0088] In actual cases, after the pressing device 10 completes the pressing of the top cover 120 of the battery 100, the contour instrument can detect the joint between the top cover 120 and the shell 110 at the same time, and the detection result is fed back to the upper computer. If the detection structure meets the requirements, after the detection is completed, the first lifting assembly 12 is lowered, so that the battery 100 is transferred to the pre-welding station by the transfer device. If the detection structure does not meet the requirements, the pressing operation of the battery 100 can be remedied twice. After the remediation is successful, the position transfer of the battery 100 is realized again.

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

[0090] The surfaces of the first and second extension portions 1412 and 1413 of the first pressing member 141 that contact the top cover 120 can be arranged in regular shapes such as rectangles, squares or circles, or in irregular shapes. The length of the sides of the surfaces of the first and second extension portions 1412 and 1413 that contact the top cover 120 can be arranged to be about 5 mm, for example, 4.5 mm, 4.7 mm, 5 mm or 5.2 mm. The surfaces of the third and fourth extension portions 1422 and 1423 of the second pressing member 142 that contact the top cover 120 can be arranged in regular shapes such as rectangles, squares or circles, or in irregular shapes. The length of the sides of the surfaces of the third and fourth extension portions 1422 and 1423 that contact the top cover 120 can be arranged to be about 5 mm, for example, 4.5 mm, 4.7 mm, 5 mm or 5.2 mm.

[0091] In some embodiments, the length of the pressing member 24 in the direction of the long side of the top cover 120 can be arranged to be 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 of the top cover 120. In addition, the edge of the pressing member 24 that extends beyond the top cover 120 can be provided with a clearance groove 241 for exposing the joint between the top cover 120 and the shell 110 at the position of the pre-welding point of the battery 100 in the pre-welding position.

[0092] According to actual use, the pre-welding device provided in some embodiments of the present application can reduce the occurrence of the turned-up edge defect of the battery 100 from the original 0.3% to 0.02% and the occurrence of the step defect from the original 0.3% to 0.1% when pre-welding the battery 100, compared with the pre-welding device of the prior art that applies pressure to the entire surface of the top cover 120 of the battery 100. The OEE of the device can be improved by 2%.

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

Claims

1. A pre-welding device for square-shell secondary batteries, used for pre-welding square-shell secondary batteries, the square-shell secondary battery comprising a shell containing battery cells, and a top cover sealing the shell, the top cover being provided with a positive terminal and a negative terminal electrically connected to the electrodes of the battery cells, characterized in that, The square case secondary battery pre-welding device comprises a pressing device at a pressing station, a pre-welding device at a pre-welding station, and a transfer device for transferring the battery from the pressing station to the pre-welding station; The pressing device comprises a base, a first lifting assembly, a first positioning assembly, and a pressing assembly, the base is provided with a first through hole, the first lifting assembly is arranged 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 arranged on the base, the first positioning assembly abuts against the case of the battery around the battery to make the battery enter a pressing position, the pressing assembly comprises a first pressing piece and a second pressing piece movably arranged on the base, the first pressing piece applies pressure to the top cover of the battery on the side of the positive pole away from the negative pole of the battery in the pressing position, and the second pressing piece applies pressure to the top cover of the battery on the side of the negative pole away from the positive pole of the battery in the pressing position, so as to press the battery; The total area of the first lower presser and the second lower presser contacting the top cover is greater than or equal to 80 mm 2 , and less than or equal to 120 mm 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 arranged on one side of the base, the second lifting assembly carries the battery after pressing 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 case of the battery around the battery to make the battery enter a 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, and the welding tool pre-welds the joint between the top cover and the case of the battery at the pre-welding point in the pre-welding position; The length of the pressing piece in the length 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 case secondary battery pre-welding device according to claim 1, wherein: The pressing assembly comprises a first driving piece and a second driving piece, the first driving piece is arranged on the base, the output end of the first driving piece is connected with the first pressing piece, the second driving piece is arranged on the base, and the output end of the second driving piece is connected with the second pressing piece.

3. The square case secondary battery pre-welding device according to claim 2, wherein: The first driving piece is driven preferentially to the second driving piece, so that the first pressing piece preferentially applies pressure to the top cover of the battery in the pressing position to the second pressing piece.

4. The square case secondary battery pre-welding device according to claim 1, wherein: The first pressing piece comprises a first mounting part and first and second extension parts arranged at intervals on the first mounting part, the first mounting part is movably arranged on the base, and the first and second extension parts are used for applying pressure to the top cover at different corners close to the top cover. The second pressing member includes a second mounting portion movably disposed on the base, and a third extending portion and a fourth extending portion disposed on the second mounting portion and spaced apart from each other, the third and fourth extending portions being configured to apply pressure to the top cover at different corners on the other side of the top cover.

5. The prismatic secondary battery pre-welding apparatus of claim 1, wherein: The press-fitting device further includes a detector disposed on the base, the detector being configured to detect a joint between the top cover and the case of the battery after the press-fitting.

6. The prismatic secondary battery pre-welding apparatus of claim 1, wherein: The edge of the pressing member extends beyond the edge of the top cover in the direction of the short side of the top cover, and the pressing member is provided with a clearance groove at the edge thereof beyond the top cover, the clearance groove being configured to expose the joint between the top cover and the case of the battery at the pre-welding point position in the pre-welding position.

7. The prismatic secondary battery pre-welding apparatus of claim 1, wherein: The first positioning assembly includes a first side positioning assembly and a second side positioning assembly, the first side positioning assembly including a first positioning member and a second positioning member disposed opposite each other on the base, the first and second positioning members being movable toward and away from each other, and the second side positioning assembly including a third positioning member and a fourth positioning member disposed opposite each other on the base, the third and fourth positioning members being movable toward and away from each other, the first, second, third, and fourth positioning members being disposed around the central axis of the first through hole.

8. The prismatic secondary battery pre-welding apparatus of claim 1, wherein: The second positioning assembly includes a third side positioning assembly and a fourth side positioning assembly, the third side positioning assembly including a fifth positioning member and a sixth positioning member disposed opposite each other on the base, the fifth and sixth positioning members being movable toward and away from each other, and the fourth side positioning assembly including a seventh positioning member and an eighth positioning member disposed opposite each other on the base, the seventh and eighth positioning members being movable toward and away from each other, the fifth, sixth, seventh, and eighth positioning members being disposed around the central axis of the second through hole.

9. The prismatic secondary battery pre-welding apparatus of claim 8, wherein: The fifth, sixth, seventh, and eighth positioning members are each connected to a positioning rod, each of the positioning rods being configured to abut the case of the battery at a position near the pre-welding point in the pre-welding position.

10. A method of pre-welding using the square can secondary battery pre-welding apparatus according to any one of claims 1 to 9, characterized by, including: The first lifting assembly of the pressing device drives the battery to move, the first positioning assembly abuts against the shell of the battery, the battery enters a pressing position, the first pressing part of the pressing assembly applies pressure to the top cover of the battery on the side of the positive pole away from the negative pole of the battery in the pressing position, the second pressing part of the pressing assembly applies pressure to the top cover of the battery on the side of the negative pole away from the positive pole of the battery in the pressing position, and the battery is pressed; The battery after pressing is transferred to a pre-welding station by the transfer device; The first lifting assembly of the pre-welding device drives the battery to move, the second positioning assembly abuts against the shell of the battery, the battery enters a pre-welding position, the pressing part 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 at the pre-welding point in the pre-welding position.

Images