Automatic welding device for square lithium battery module

Abstract

The invention provides an automatic welding device for a square lithium battery module. The automatic welding device comprises a feeding device, an automatic clamp, a rotary workbench and a welding robot. The battery module comprises a square battery cell, an insulating plate, an end plate and a side plate, and the welding position is the contact part of the side plate and the end plate. The automatic material taking device reciprocates among the part material taking position, the part fixing position, the welding station and the material taking station through the two linear motion modules perpendicular to each other, and the side plates are sucked and clamped through the vacuum suction cups and the fixing plates. The automatic clamp device fixes a battery module through a telescopic air cylinder with a guide rail and a clamp plate, and fixes a side plate through a vacuum chuck and a linear motion module so as to facilitate welding. The welding robot is composed of a mechanical arm and a welding gun and is used for welding parts. The rotary workbench is driven by a motor, the positions of two stations on the workbench can be switched when the rotary workbench rotates by 180 degrees each time, and continuous, efficient and circulating automatic welding operation can be conducted.

Description

Technical Field

[0001] The invention belongs to the field of lithium battery welding and assembly, and in particular relates to an automatic welding device for square lithium battery modules with high efficiency and continuous cycle operation. Background Art

[0002] As a new energy power device with high energy density, many cycles and long service life, lithium battery is gradually becoming the main energy storage device and power source for new energy vehicles. The lithium battery module is the component unit of the lithium battery pack, which is composed of several battery cells. The outside of the lithium battery module is a rectangular frame structure composed of side plates and end plates welded together, and the inside contains an insulating plate adjacent to the end plate and several battery cells.

[0003] Compared with manual assembly and welding, manual spot welding is required and the combined frame needs to be manually transferred. During this process, multiple positioning and transfer are required, which leads to low welding efficiency, high labor intensity, and low welding accuracy. For the existing automatic welding of assembly lines, although humans can realize robot-based automated welding assembly, the welding process does not achieve efficient continuous operation, and usually requires the mobilization of multiple robotic arms for cooperation, resulting in high overall costs. Summary of the invention

[0004] The purpose of the present invention is to provide an efficient and continuously operating square lithium battery module automatic welding device, which can complete the automatic welding of the side plates and end plates of the lithium battery module, and can perform cyclic automatic production operations of lithium battery module material taking, clamping and fixing, and automatic welding.

[0005] The present invention proposes an automatic welding device for side panels of a square lithium battery module, which is arranged on an automated lithium battery production line, after the cell end plate bonding process and before the circuit board welding process; it includes a battery module, a feeding device, an automatic fixture, a welding robot and a rotating workbench; wherein:

[0006] The battery module is composed of a square battery cell, a side plate and an end plate. The side plate and the end plate form a frame structure, and the square battery cell is placed in the frame structure.

[0007] The rotating workbench includes a base, a rotating mechanism and a work surface; the base is fixed on the ground, the rotating mechanism is installed on the base, and the work surface is installed on the rotating shaft of the rotating mechanism and can rotate with the rotating shaft;

[0008] The loading device includes a material-retrieving robot arm, a vacuum suction cup and a linear motion module; there are two sets of vacuum suction cups and linear motion modules respectively, each set of linear motion modules consists of two vertically arranged linear motion modules a and linear motion modules b, each set of linear motion modules is symmetrically arranged on the working surface of the rotary table, and the two sets of linear motion modules are fixed on the working surface respectively, and can move in two directions on the horizontal plane, and move periodically with the rotation of the rotary table, and each set of linear motion modules moves back and forth between the corresponding two stations and the parts supply area ; Linear motion module a is provided with screw a and servo motor b, both sides of screw a are fixed to linear motion module a through screw seats, and one end of screw a is connected to servo motor b; Linear motion module b is provided with screw b and servo motor a, both sides of screw b are fixed to linear motion module b through screw seats, and one end of screw b is connected to servo motor a; Linear motion module b is placed above linear motion module a, a fixing plate is placed on linear motion module b, and one side of the fixing plate is connected to a vacuum suction cup; The material-retrieving robot arm is used to place the battery module, and is arranged symmetrically with the welding robot;

[0009] The automatic fixture includes a telescopic cylinder and a fixture plate; the fixture plate is fixed on the symmetric axis of the rotating worktable, and the telescopic cylinder is fixed to the tail end of the fixture plate; the telescopic cylinder is provided with a guide rail, and the material taking mechanical arm places the battery module on the fixture plate, and the telescopic cylinder clamps the battery module;

[0010] The welding robot comprises an OTC FD-V20 mechanical arm and a welding gun; the OTC FD-V20 mechanical arm is fixed on the ground through a fixing base, and the welding gun is fixed on the end of the OTC FD-V20 mechanical arm.

[0011] In the present invention, the vacuum suction cup absorbs the side plate on the battery module, and the linear motion module drives the vacuum suction cup to move horizontally.

[0012] In the present invention, the welding gun on the welding robot is used as an end effector to weld the side plate and the end plate; the OTC FD-V20 mechanical arm is used to drive the welding gun to accurately move to the welding position.

[0013] In the present invention, the fixture plate is an L-shaped plate, the bottom of the long side of which is fixed to the work surface by bolts, and the inner side of the short side is in contact with the end plate, providing a clamping force in one direction; the telescopic cylinder is fixed to the other end of the fixture plate, and clamps the lithium battery module to be welded together with the fixture plate by telescopically clamping and loosening the end plate.

[0014] In the present invention, the vacuum suction cup can be flipped 180° on the linear motion module, with one side adsorbing the side plate and flipping to the other side to fix the side plate; when the vacuum suction cup is flipped to the inside, it can be moved to the sides of the two battery module stations through the longitudinal linear motion module, and then the side plate can be pressed against the side of the module through the transverse motion module; when the vacuum suction cup is flipped to the outside, the transverse linear motion module moves outward to allow the vacuum suction cup to take the side plate.

[0015] In the present invention, two battery module welding stations are arranged on the working table of the rotary table. The rotary table rotates 180 degrees each time to exchange the positions of the two stations, so that when one station is welding, the other station is carrying and placing the battery module.

[0016] In the present invention, the working steps of the overall device are as follows: first, the battery module to be welded is placed on a workstation far away from the welding robot, and is clamped and fixed by a telescopic cylinder and a fixture plate; then the workbench rotates 180° to move the battery module to be welded to the welding position, and at the same time, the linear motion module drives the vacuum suction cup to move and absorb the side panel parts, and after absorption, the linear motion module and the vacuum suction cup clamp the side panels on both sides of the battery module; then the welding robot welds the side panels and end panels, and while welding, the new module to be welded is placed and fixed at another workstation; after welding is completed, the workbench rotates 180° to swap the positions of the two workstations, and the linear motion module with the vacuum suction cup absorbs the new side panel parts and clamps and welds them, and while one workstation is welding, the other workstation removes the welded battery module and places a new battery module, thus forming a workflow cycle. Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. The present invention can effectively improve the working efficiency of lithium battery welding: Compared with manual welding that requires multiple fixations and movements and pre-spot welding, in this solution, when welding the side panels and end panels, it is only necessary to assemble the battery cells, insulating plates, and side panels in the previous process, and then fix and weld them through automatic material picking and automatic fixtures, which effectively reduces the steps of the welding process and improves the welding efficiency. Compared with the current partial automatic welding assembly scheme that requires multiple robotic arms and single-stations, this scheme adopts a rotating work platform. After the side panel welding of a module is completed, the work platform rotates 180° to interchange the positions of the two stations. The new module to be welded is moved to the welding station, and the welded module is taken away and placed in the new module, realizing continuous automatic operation. Although the linear motion modules on both sides will also rotate accordingly, because of their symmetrical arrangement, they can work normally through longitudinal movement and flipping without being affected. It effectively improves the welding efficiency and the effective working time of the welding robot.

[0018] 2. The present invention can effectively improve welding accuracy: compared with the prior art where deformation is prone to occur during spot welding pre-fixation, spot welding pre-fixation is no longer performed in the present application, thereby completely avoiding this problem; at the same time, the objects to be welded in the present application are completely in a fixed state, and welding is completed only through the movement of the robotic arm. After welding is completed, they will not be taken away immediately but moved to the next workstation, during which time the weld has a certain amount of time to cool, thereby ensuring accuracy during the welding process.

[0019] 3. The welding cost is significantly reduced: Compared with the existing solution that uses multiple robotic arms to work together, this application only uses two robotic arms, and the material-grabbing robotic arm that clamps and places module parts also serves other processes besides welding. Therefore, it can be understood that only the welding robotic arm is used, and the material-grabbing robotic arm is not shown in the schematic diagram. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a top view of the rotating workbench and its auxiliary devices of the automatic welding device for square battery modules of the present invention;

[0021] Figure 2 It is a schematic diagram of the overall structure of the automatic welding device for square battery modules of the present invention;

[0022] Figure 3 It is a front view of the overall structure of the automatic welding device for square battery modules of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of a square battery module in the automatic welding device for square battery modules of the present invention;

[0024] Figure 5 It is a schematic diagram of the structure of the battery module and the end plate fixture in the automatic welding device for square battery modules of the present invention;

[0025] Figure 6 This is a schematic diagram of the structure of a single linear motion module in the automatic welding device for square battery modules of the present invention;

[0026] Figure 7 It is a structural schematic diagram of the combined linear motion module and the vacuum suction cup in the automatic welding device for square battery modules of the present invention when they are in a certain position;

[0027] Figure 8 It is a structural schematic diagram of the combined linear motion module and the vacuum suction cup in another different position in the automatic welding device for square battery modules of the present invention;

[0028] Fig. 9 It is a structural schematic diagram of a rotating workbench in the automatic welding device for square battery modules of the present invention;

[0029] Fig.10It is a schematic diagram of the side plate fixing method in the automatic welding device of the square battery module of the present invention;

[0030] Numbers in the figure: 1-square battery cell; 2-side plate; 3-end plate; 4-fixture plate; 5-telescopic cylinder; 6-rotating workbench; 7-linear motion module A; 8-screw rod A; 9-linear motion module B; 10-screw rod B; 11-servo motor A; 12-fixed plate; 13-vacuum suction cup; 14-servo motor B; 15-OTC FD-V20 robot arm; 16-welding gun; 17-electric rotating mechanism; 18-workbench base; 19-insulating plate. DETAILED DESCRIPTION

[0031] In order to make the technical problems to be solved by the present invention clearer, the concept, specific structure and technical effects of the present invention will be clearly and completely described below in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the present invention. In addition, all the connection relationships involved in the patent do not refer to the construction of direct connection, but refer to the formation of a better connection structure by adding or reducing connection aids according to the specific implementation situation. The various technical features in the present invention can be combined interactively without conflicting with each other.

[0032] It should be noted that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate that a device or element must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating relative importance or indicating the number of technical features. In the description of the present invention, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0034] Example 1: In order to solve the problem of automatic welding and assembly of square lithium battery modules, Figures 1 to 9As shown, the present invention provides an automatic welding device, which mainly includes an automatic feeding device, an automatic fixture, an automatic welding robot and a rotating worktable, including a square battery cell 1, a side plate 2, an end plate 3, a fixture plate 4, a telescopic cylinder 5, a rotating worktable 6, a linear motion module a7, a screw a8, a linear motion module b9, a screw b10, a servo motor a11, a fixed plate 12, a vacuum suction cup 13, a servo motor b14, an OTC FD-V20 mechanical arm 15, a welding gun 16, an electric rotating mechanism 17, a worktable base 18, and an insulating plate 19. Reference Figure 4 and Figure 5 , wherein the battery module composed of several square battery cells 1, side plates 2, and end plates 3 is the part to be welded, wherein the welding position is the connection between the side plates and the end plates, that is, the edge of the end surface of the side plates. The part to be welded composed of the square battery cells 1, the end plates 3, and the insulating plates 19 is bonded through the pre-process of the battery module production line, and then placed on the fixture plate 4 by the material taking robot arm. At this time, the telescopic cylinder 5 with the guide rail is in a retracted state, leaving space margin for the placement of the battery module. After the placement is completed, the telescopic cylinder 5 extends to clamp it, and the telescopic block of the telescopic cylinder 5 is in direct contact with the end plate 3.

[0035] refer to Figure 5 When the square battery module to be welded is placed in the fixture position and fixed, it does not include the side panels on both sides. The side panels in the figure are the effect after welding. Several square battery cells 1, end plates 3 and insulating plates 19 are clamped together. Since the above parts are connected by glue coating, the glue coating layer will be compressed after clamping. Therefore, the telescopic cylinder with guide rails needs to exert a certain degree of force to ensure that the module to be welded is compressed to the appropriate size. Here, the clamping force of the telescopic cylinder can be controlled by controlling the air pressure of the pneumatic system.

[0036] refer to Figure 7 , Figure 8 and Fig.10 After the square battery module to be welded is fixed on the fixture, the servo motor a11 and the screw a10 rotate to drive the transverse linear motion module 9 to move to the right, and then the fixed plate 12 turns 180° clockwise to drive the vacuum suction cup 13 to turn to the right, and the side panel on the right side of the device is sucked by the vacuum suction cup 13. After sucking the side panel, the vacuum suction cup 13 turns 180° counterclockwise to the left, that is, facing the side of the battery module, and the servo motor a11 and the screw b10 rotate to drive the transverse linear motion module to approach the square battery core 1. After approaching, the side panel 2 can be pressed and fixed on the battery module to be welded by continuing to move. The vertical positioning is determined by the structural dimensions of the device itself, and the vacuum suction cup is ensured to be adsorbed on the correct position of the side panel by adjusting the part feeding position. The horizontal positioning can be driven by the rotation of the servo motor b14 and the screw a8 to drive the transverse linear motion module 9 to move as a whole to ensure accuracy.

[0037] refer to Figure 1 The above-mentioned specific implementation is for fixing the battery module and removing and fixing the single-sided side panel at one station. Based on this specific implementation, it can be expanded to removing and fixing the double-sided side panels at one station. The two side panels are removed and fixed simultaneously, so that the thrusts on both sides of the battery module can offset each other during clamping, preventing the fixed battery module from displacement.

[0038] refer to Figure 2 When the two side panels are fixed on both sides of the battery module, welding can begin. The OTC FD-V20 robot arm 15 and welding gun 16 located on the left side of the rotating workbench perform welding, mainly welding the four seams at the junction of the end plate 3 and the side plate 2. The welding seams are distributed in a straight line in the vertical direction. The OTC FD-V20 robot arm 15 itself has 6 degrees of freedom, so it can complete the welding work.

[0039] refer to Figure 1 , Figure 2 and Fig.10 When performing the above welding steps, there is another station on the rotating workbench, which is far away from the welding robot. At this time, the welded battery module on the station is removed, and a new end plate battery module to be welded is placed and fastened. After the welding station completes the welding, the new unwelded battery module has also been fixed. At this time, the rotating workbench rotates 180° as a whole, and the two stations are swapped. While the workbench rotates, the side panels of the welded battery modules are still pressed against the sides of the battery by the vacuum suction cups, and the linear motion module itself does not move. This is to ensure that the weld does not undergo large deformation before cooling to ensure structural accuracy.

[0040] refer to Figure 1 , Figure 2 and Fig.10 After the above rotation step is completed, the linear motion module releases the side plate and absorbs the new side plate. At this time, the entire workflow returns to the initial step described in the specific implementation method. The battery module is fixed, the side plate is fixed, and the entire workflow forms a cycle that is connected end to end. After each module is welded, it is directly transferred to another workstation, and the new module is moved to the welder for welding. In this way, each device will always be in work and will not be idle.

[0041] refer to Fig. 9, the rotating table 6 and other auxiliary devices are arranged on the electric rotating mechanism 17, which is arranged on the table base 18. The electric rotating mechanism includes a motor a, a coupling b, a pinion c, a large ring gear d, a hollow shaft e and auxiliary bearings. The rotation of the motor a drives the pinion c to rotate synchronously through the coupling b, and the pinion c drives the large ring gear to rotate at a reduced speed. The large ring gear d and the hollow shaft e are fixed in the circumferential direction by bolts, and the hollow shaft e is fixed in the circumferential direction with the table 6 by bolts, so that the table is driven to rotate by the motor. The rotating mechanism 17 is arranged on the table base 18 to make the welding at a suitable height. The base 18 is a hollow structure with ribs on the outside to increase the structural rigidity and strength.

[0042] The above description is only a preferred specific implementation manner of the present application, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An automatic welding device for side panels of a square lithium battery module, which is arranged on an automated lithium battery production line, after the cell end plate bonding process and before the circuit board welding process; characterized in that: It includes battery modules, feeding devices, automatic fixtures, welding robots and rotary tables; among which: The battery module is composed of a square battery cell, a side plate and an end plate. The side plate and the end plate form a frame structure. The contact part between the side plate and the end plate is a welding position. The square battery cell is placed in the frame structure. The rotating workbench includes a base, a rotating mechanism and a work surface; the base is fixed on the ground, the rotating mechanism is installed on the base, and the work surface is installed on the rotating shaft of the rotating mechanism and can rotate with the rotating shaft; The loading device includes a material-retrieving robot arm, a vacuum suction cup and a linear motion module; there are two sets of vacuum suction cups and linear motion modules respectively, each set of linear motion modules consists of two vertically arranged linear motion modules a and linear motion modules b, each set of linear motion modules is symmetrically arranged on the working surface of the rotary table, and the two sets of linear motion modules are fixed on the working surface respectively, and can move in two directions on the horizontal plane, and move periodically with the rotation of the rotary table, and each set of linear motion modules moves back and forth between the corresponding two stations and the parts supply area ; Linear motion module a is provided with screw a and servo motor b, both sides of screw a are fixed to linear motion module a through screw seats, and one end of screw a is connected to servo motor b; Linear motion module b is provided with screw b and servo motor a, both sides of screw b are fixed to linear motion module b through screw seats, and one end of screw b is connected to servo motor a; Linear motion module b is placed above linear motion module a, a fixing plate is placed on linear motion module b, and one side of the fixing plate is connected to a vacuum suction cup; The material-retrieving robot arm is used to place the battery module, and is arranged symmetrically with the welding robot; The automatic fixture includes a telescopic cylinder and a fixture plate; the fixture plate is fixed on the symmetric axis of the rotating worktable, and the telescopic cylinder is fixed to the tail end of the fixture plate; the telescopic cylinder is provided with a guide rail, and the material taking mechanical arm places the battery module on the fixture plate, and the telescopic cylinder clamps the battery module; The welding robot comprises an OTC FD-V20 mechanical arm and a welding gun; the OTC FD-V20 mechanical arm is fixed on the ground through a fixing base, and the welding gun is fixed on the end of the OTC FD-V20 mechanical arm.

2. The automatic welding device for side panels of a square lithium battery module according to claim 1, characterized in that: The vacuum suction cup absorbs the side plate on the battery module, and the linear motion module drives the vacuum suction cup to move horizontally.

3. The automatic welding device for side panels of a square lithium battery module according to claim 1, characterized in that: The welding gun on the welding robot is used as the end effector to weld the side plate and the end plate; the OTC FD-V20 mechanical arm is used to drive the welding gun to move accurately to the welding position.

4. The automatic welding device for side panels of a square lithium battery module according to claim 1, characterized in that: The fixture plate is an L-shaped plate, the bottom of its long side is fixed to the work surface by bolts, and the inner side of the short side is in contact with the end plate, providing a clamping force in one direction; the telescopic cylinder is fixed to the other end of the fixture plate, and clamps the lithium battery module to be welded together with the fixture plate by telescopically clamping and loosening the end plate.

5. The automatic welding device for side panels of a square lithium battery module according to claim 1, characterized in that: The vacuum suction cup can be flipped 180° on the linear motion module, with one side adsorbing the side panel and flipping to the other side to fix the side panel; when the vacuum suction cup is flipped to the inside, it can be moved to the sides of the two battery module stations through the longitudinal linear motion module, and then the side panel can be pressed against the side of the module through the transverse motion module; when the vacuum suction cup is flipped to the outside, the transverse linear motion module moves outward to allow the vacuum suction cup to take the side panel.

6. The automatic welding device for side panels of a square lithium battery module according to claim 1, characterized in that: There are two battery module welding stations on the work surface of the rotary table. The rotary table rotates 180 degrees each time to exchange the positions of the two stations, so that when one station is welding, the other station is carrying and placing the battery module.

7. The automatic welding device for side panels of a square lithium battery module according to claim 1, characterized in that: The working steps of the welding device are as follows: first, the battery module to be welded is placed on a workstation farther away from the welding robot and clamped and fixed by a telescopic cylinder and a fixture plate; then the workbench rotates 180° to move the battery module to be welded to the welding position, and at the same time, the linear motion module drives the vacuum suction cup to move and absorb the side panel parts. After absorption, the linear motion module and the vacuum suction cup clamp the side panels on both sides of the battery module; then the welding robot welds the side panels and end panels, and while welding, a new module to be welded is placed and fixed at another workstation; after welding is completed, the workbench rotates 180° to swap the positions of the two workstations, and the linear motion module with the vacuum suction cup absorbs the new side panel parts and clamps them for welding. While one workstation is welding, the other workstation removes the welded battery module and places a new battery module, thus forming a workflow cycle.

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