An automated leveling system and method for tabs of pouch cell battery modules

Abstract

This invention discloses an automated leveling system and method for tabs of soft-pack battery modules, belonging to the field of new energy vehicles. The leveling system includes a frame, a battery module walking device, a servo motor, an ultrasonic welding machine, and a PLC control panel. The battery module walking device includes multiple mounting platforms mounted on sliders, driven by lead screws. The mounting platforms are used to fix the battery modules with tabs to be leveled. The ultrasonic welding machine is located above the battery module walking device and its operation is controlled by the PLC control panel. This invention can flexibly set relevant control programs according to the different number of tabs to be leveled for different battery modules. By setting the pressure of the welding head falling, the efficiency of tab leveling is maximized. This invention can effectively level the small burrs left during tab punching, thereby ensuring the flatness of the tab-bus fit.

Description

Technical Field

[0001] This invention belongs to the field of new energy vehicles, and in particular relates to an automated leveling system and method for the tabs of a soft-pack battery module. Background Technology

[0002] New energy vehicles require various battery packs to provide power through series and parallel connections. Battery cells in these packs come in various forms, including hard-shell and pouch cells. This invention focuses on pouch cells. After pouch cells are assembled into modules, their tabs typically need to be connected to a busbar to ensure the individual cells form the required series-parallel connection, guaranteeing a reliable and stable DC voltage and capacity output from the module. Laser welding is a commonly used method. Before laser welding, the weld area is generally required to be flat. This invention specifically addresses the method of flattening the tabs (made of copper or aluminum in thin sheet form) after bending them onto the busbar.

[0003] Current leveling methods, such as manual leveling with a small hammer and automatic small roller leveling at laser welding stations, have the following shortcomings:

[0004] (1) Manual flattening is prone to problems such as missing parts, excessive force causing severe deformation of the busbar, low efficiency, and operator fatigue.

[0005] (2) The laser welding station uses an automatic small roller to roll back and forth. Since the busbar cannot withstand too much pressure and the electrode is subjected to rolling force, the burrs on the edge of the electrode may not be effectively rolled. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies. In order to solve the problems that are easy to make mistakes when using a hammer to flatten the electrode by hand, and that the burrs on the edge of the electrode cannot be effectively flattened when using an automatic small roller to flatten the electrode in a laser welding station, this invention proposes an automated vibration flattening system and method for the electrode tabs of a soft-pack battery module.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] An automated leveling system for the tabs of a soft-pack battery module includes a frame, a battery module walking device, a servo motor, an ultrasonic welding machine, and a PLC control panel. The frame is equipped with guide rails, the battery module walking device is mounted on the guide rails, the ultrasonic welding machine is located above the guide rails, and the PLC control panel is connected to the ultrasonic welding machine. The battery module walking device includes a lead screw and slider pair and a mounting platform fixed on the lead screw and slider pair. The lead screw and slider pair is mounted on the guide rails, and the servo motor is connected to the lead screw and slider pair.

[0009] Preferably, the mounting platform of the battery module walking device includes an upper plate and a lower plate. The lower plate is fixed on the lead screw and slider pair, the upper plate is mounted on the lower plate, and the upper plate is rotatable.

[0010] Preferably, a lifting plate is installed on the frame. When the mounting platform moves above the lifting plate, the lifting plate can pass through the lower plate of the mounting platform and drive the upper plate of the mounting platform to rise, fall, and rotate.

[0011] Preferably, the working surface of the ultrasonic welding machine head is a plane, and the area of ​​the working surface is larger than the area of ​​the bent side of the electrode tab. The welding head of the ultrasonic welding machine used in this invention is different from the welding head of general ultrasonic welding. The contact part between the welding head and the electrode tab in this invention should be made into a smooth and straight shape, preferably rectangular (which can be changed according to different electrode tab sizes and shapes).

[0012] Preferably, the welding head of the ultrasonic welding machine is made of mold steel.

[0013] During operation, the ultrasonic welding machine uses an ultrasonic generator to convert 50Hz mains power into a 20kHz sinusoidal signal, which is then converted into mechanical motion of the same frequency by a transducer. The mechanical motion is then transmitted to the welding head, which transmits the received vibration energy to the surface of the electrode to be flattened. In this area, the vibration energy flattens the part of the electrode that contacts the busbar, while the rest is converted into heat energy and dissipated.

[0014] The beneficial effects of this invention are as follows:

[0015] This invention effectively solves the problems of errors and omissions that easily occur when manually flattening with a hammer, and the inability to effectively flatten burrs on the edge of the electrode tabs when using automatic small rollers for flattening in laser welding stations. Specifically, as follows:

[0016] (1) According to the different number of tabs to be leveled for different battery modules, the relevant control program can be flexibly set. As long as the reference direction is determined, the ultrasonic welding machine will automatically vibrate and level the tabs at each determined position according to the predetermined program, thereby eliminating the possibility of missing the tabs. Since the welding head is controlled by air pressure, as long as the air pressure is set to a suitable value, there will be no situation where the busbar is bent due to excessive force. The movement of the battery module walking device is achieved by a speed-adjustable screw. The ultrasonic welding time is very short, which greatly improves efficiency and eliminates the problem of operator fatigue.

[0017] (2) The ultrasonic welding machine emits high-frequency mechanical vibration through the transducer, and then acts on the electrode ear through the welding head. Since the working surface area of ​​the welding head is larger than the area of ​​the bent side of the electrode ear, it can effectively smooth out the small burrs left when the electrode ear is punched, thus ensuring the flatness of the electrode ear and the busbar. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the automated leveling system for the tabs of the soft-pack battery module of the present invention;

[0019] Figure 2 This is a top view of the entire vibratory leveling system when the upper plate rotates.

[0020] In the diagram: 1 Battery module, 2 Welding head, 3 PLC control panel, 4 Upper plate, 5 Lower plate, 6 Lifting plate, 7 Frame, 8 Lead screw and slider pair, 9 Guide rail. Detailed Implementation

[0021] The preferred embodiments of the present invention will now be described in detail.

[0022] An automated leveling system for the tabs of a soft-pack battery module, such as Figure 1 As shown, it includes a frame 7, a battery module walking device, a servo motor, an ultrasonic welding machine, and a PLC control screen 3; the frame 7 is provided with a guide rail 9, the battery module walking device is installed on the guide rail 9, the ultrasonic welding machine is located above the guide rail 9, and the PLC control screen 3 is connected to the ultrasonic welding machine.

[0023] The ultrasonic welding machine used in this embodiment was manufactured by Wuxi Xinnuo Ultrasonic Technology Co., Ltd. The overall dimensions of the machine are L*W*H: 1800mm*800mm*1200mm, and it is a semi-automatic type. The rated power of the ultrasonic welding machine is 3000W, 20kHz, and the welding head is made of mold steel.

[0024] The battery module walking device includes a lead screw and slider assembly 8 and a mounting platform fixed on the lead screw and slider assembly 8. The lead screw and slider assembly is mounted on a guide rail. The servo motor is connected to the lead screw and slider assembly 8 and is driven by the servo motor, which has a power of 1.5 kW.

[0025] In a preferred embodiment of the present invention, the mounting platform of the battery module walking device includes an upper plate and a lower plate. The lower plate 5 is fixed on the slider, and the upper plate 4 is mounted on the lower plate 5. A lifting plate is mounted on the frame. When the mounting platform moves above the lifting plate, the lifting plate can pass through the lower plate of the mounting platform and drive the upper plate of the mounting platform to rise, fall, and rotate. For example, a hole can be provided on the lower plate of the mounting platform for the lifting plate to pass through, so as to achieve contact between the lifting plate and the upper plate. A schematic diagram of the entire system when the upper plate 4 rotates is shown below. Figure 2 As shown. In a preferred embodiment of the present invention, the working surface area of ​​the ultrasonic welding machine head 2 is larger than the area of ​​the bent side of the electrode lug, and the working surface is smooth and flat, preferably rectangular.

[0026] The above-mentioned automated leveling system for soft-pack battery module tabs is used to level the tabs. The specific steps are as follows:

[0027] Step 1: Fix the busbar to the battery module, bend the tabs on the battery module 1 to the direction where they need to fit with the busbar, and fix the battery module 1 with the busbar after the initial bending to the mounting platform of the battery module walking device.

[0028] Step 2: Set the vibration leveling position (i.e., the position of the battery module to be vibrated) of the ultrasonic welding machine during operation via the PLC control panel, the vibration leveling time to 0.6s, the delay protection time to 1s, the trigger time to 2.5s, and the welding head falling pressure to 0.22Mpa. Control the traveling speed of the battery module walking device to 10mm / s via the servo motor, and set the no-load sound wave amplitude of the ultrasonic generator to 1.6A.

[0029] Step 3: Start the system. When the battery module on the battery module walking device mounting platform moves to the preset leveling position, the first tab on the side closest to the ultrasonic welding machine is located directly below the welding head of the ultrasonic welding machine. The welding head automatically falls and levels the tab. After the preset leveling time is reached, the welding head rises, and the battery module continues to move, repeating the leveling process until all the tabs on one side of the battery module are leveled.

[0030] Step 4: The battery module rotates 180 degrees with the upper plate, and the upper plate falls and is fixed to the lower plate. The battery module traveling device moves in the opposite direction, and the ultrasonic welding machine automatically repeats the leveling process of step 3) until all the tabs on the other side of the battery module on the mounting platform are leveled. In a specific embodiment of the present invention, the 180-degree rotation of the upper plate of the battery module is specifically implemented as follows: A lifting plate is installed on the frame. After all the tabs on one side of the battery module are leveled, when the battery module traveling device continues to move above the lifting plate, the lifting plate rises, lifting the upper plate of the mounting platform and causing the upper plate of the mounting platform to rotate. After completing the 180-degree rotation, the lifting plate descends, and the upper plate of the mounting platform falls and is fixed to the lower plate.

[0031] Step 5: Inspect the leveled tabs. The specific method is as follows: Use an epoxy plate with a flat bottom to press the tabs tightly so that the tabs are in close contact with the busbar. When no gaps or bulges are visible between the tabs and the busbar, the leveled tabs are qualified.

[0032] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for planarizing the tabs of a battery module using a soft-pack cell battery module tab automatic planarization system, characterized in that, The soft package battery cell module tab automatic vibration flattening system comprises a rack, a battery module walking device, a servo motor, an ultrasonic welding machine and a PLC control screen; the rack is provided with guide rails, the battery module walking device is installed on the guide rails, the ultrasonic welding machine is located above the guide rails, the PLC control screen is connected with the ultrasonic welding machine, and the rack is provided with a jacking plate; when the installation table runs above the jacking plate, the jacking plate can pass through the lower plate of the installation table and drive the upper plate of the installation table to lift and rotate; The battery module walking device comprises a screw block pair and an installation table fixed on the screw block pair, and the screw block pair is installed on the guide rails; the servo motor is connected with the screw block pair; The installation table of the battery module walking device comprises an upper plate and a lower plate; the lower plate is fixed on the screw block pair, and the upper plate is installed on the lower plate and can rotate; The working surface of the welding head of the ultrasonic welding machine is a plane, and the area of the working surface is larger than that of the tab bending side; The method for vibrating and flattening the tab by using the soft package battery cell module tab automatic vibration flattening system comprises the following steps: 1) fixing the busbar on the battery module, preliminarily bending the tab on the battery module to the direction required to be attached to the busbar, and fixing the battery module with the preliminarily bent busbar on the installation table of the battery module walking device; 2) setting the vibration flattening position, vibration flattening time and welding head falling pressure of the ultrasonic welding machine during work through the PLC control screen, and controlling the walking speed of the battery module walking device through the servo motor; the vibration flattening time is 0.6 s, and the welding head falling pressure is 0.22 Mpa; 3) starting the system, when the battery module on the installation table of the battery module walking device walks to the preset vibration flattening position, the first tab near the ultrasonic welding machine is located directly below the welding head of the ultrasonic welding machine, the welding head automatically falls and vibrates and flattens the tab; when the preset vibration flattening time is reached, the welding head rises, the battery module continues to walk, and the vibration flattening process is repeated until all the single-sided tabs on the battery module are vibrated and flattened; 4) rotating the battery module by 180 degrees, reversing the walking of the battery module walking device, and automatically repeating the vibration flattening process of step 3) of the ultrasonic welding machine until all the tabs on the other side of the battery module on the installation table are vibrated and flattened.

2. The method for planarizing the tab by using the soft-pack cell battery module tab automatic planarization system according to claim 1, wherein, The material of the welding head of the ultrasonic welding machine is die steel.

3. The method for using the soft-pack battery cell module tab automatic vibration flattening system to flatten the tabs according to claim 1, characterized in that, The walking speed of the battery module walking device is 10 mm / s.

4. The method of claim 1, wherein the method of automatically planarizing the tabs of the battery module using the soft-pack battery cell module tab automatic planarization system comprises: The battery module is rotated by 180 degrees as follows: the rack is provided with a jacking plate, when the battery module walking device continues to walk above the jacking plate after all the single-sided tabs on the battery module are vibrated and flattened, the jacking plate rises, the upper plate of the installation table is lifted and drives the upper plate of the installation table to rotate; after the rotation by 180 degrees is completed, the jacking plate descends, and the upper plate of the installation table falls and is fixed on the lower plate.

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