WO2024046435A1 - Battery welding system and battery welding method - Google Patents

Abstract

A battery welding system, comprising: a welding head (10), a profilometer (20), and a servo motion module (30). The profilometer is used for acquiring a contour image of a step between a top cover and a casing, and obtaining a parameter measurement value of the step on the basis of the contour image. The profilometer and the welding head are arranged on the servo motion module and used for controlling, according to a preset welding track for the top cover and the casing and the parameter measurement value, the welding head to weld the top cover and the casing. By means of measuring the change of step width in real time and adjusting the position of a welding focus to achieve relative fixation relative to the boundary of the top cover and the boundary of the casing, the battery welding system can ensure that the welding of the top cover and the casing is always performed on the basis of an actual welding track, thereby achieving good welding quality. The present disclosure further relates to a battery welding method.

Description

Battery welding system and battery welding method

This disclosure claims priority to the Chinese patent application filed with the China Patent Office on September 2, 2022, with application number 202211072610.3 and the application name "Battery Welding System and Battery Welding Method", the entire content of which is incorporated into this disclosure by reference. .

Technical field

The present disclosure relates to the technical field of battery manufacturing, and in particular to a battery welding system and a battery welding method.

Background technique

In the related technology, when the top cover welding machine welds the top cover and casing of the battery, it uses key points to confirm and determine the welding trajectory.

Taking the square battery as an example, as shown in Figure 1a, it is based on the assumption that the gap between the top cover and the case cross section is a standard rectangle (the four vertices of the top cover and the case are key points). , the confirmed ideal welding trajectory; as shown in Figure 1b, the welding trajectory is wavy due to the influence of factors such as uneven gaps between the shell and the top cover, shell deformation, uneven tooling fixture pressure, etc. welding track.

During the welding process, due to the deformation of the welding track, it will lead to uneven defocus during welding, insufficient welding penetration consistency, welding penetration, bubbles, spatter and other welding defects. How to adjust the welding track of the top cover welding machine in real time is Ensure welding urgently needs to be solved.

Contents of the invention

The present disclosure is intended to alleviate or solve, at least to some extent, at least one of the above-mentioned problems.

In one aspect of the present disclosure, the present disclosure proposes a battery welding system for welding the top cover and casing of the battery, including: a welding head, a profiler and a servo motion module; wherein, the profiler is used for Obtain the outline image of the step between the top cover and the casing, and obtain the parameter measurement value of the step based on the outline image; wherein, after the battery core is inserted into the case, the The height and width between the top cover and the housing form the step; a servo movement module, the profiler and the welding head are provided on the servo movement module and are used to measure the top cover according to the The preset welding trajectory of the cover and the housing and the parameter measurement value control the welding head to weld the top cover and the housing.

In another aspect of the present disclosure, the present disclosure proposes a battery welding method for the above-mentioned battery welding system. The method includes: obtaining an outline image of the step between the top cover and the housing; based on the The outline image of the step is obtained to obtain the parameter measurement value of the step; the servo motion module moves according to the preset welding trajectory and adjusts the welding head to the preset welding position based on the parameter measurement value of the step to achieve alignment. Welding of the top cover and the casing.

Therefore, the battery welding system proposed in this disclosure can ensure that the welding of the top cover and the case is always based on actual conditions by detecting changes in step width in real time and adjusting the position of the welding focus relative to the top cover boundary and the case boundary. The welding path is carried out to achieve better welding quality.

Description of drawings

The above and/or additional aspects and advantages of the present disclosure will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

Figure 1a shows a schematic diagram of the ideal welding trajectory of the battery;

Figure 1b shows a schematic diagram of the actual welding trajectory of the battery;

Figure 2 shows a schematic diagram of a battery structure according to an embodiment of the present disclosure;

Figure 3 shows a schematic top view of the battery in Figure 2;

Figure 4 shows a schematic structural diagram of a battery welding system according to an embodiment of the present disclosure;

Figure 5 shows a schematic diagram of battery welding results according to one embodiment of the present disclosure;

Figure 6 shows a schematic flowchart of contour image detection according to an embodiment of the present disclosure;

Figure 7 shows a schematic diagram of battery welding results according to one embodiment of the present disclosure;

Figure 8 shows a schematic flow chart of step measurement parameter detection according to one embodiment of the present disclosure;

Figure 9 shows a schematic flow chart of welding quality inspection according to one embodiment of the present disclosure.

Explanation of reference symbols:
Welding head 10;
Profiler 20; emitted beam 21; reflected beam 22;
Servo motion module 30; welding feed motor 40; gantry bracket base 50; gantry bracket 60;
Industrial computer 70.

Detailed ways

In order to allow ordinary people in the art to better understand the technical solutions of the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings.

It should be noted that the terms "first", "second", etc. in the description and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances so that the embodiments of the present disclosure described herein can be practiced in sequences other than those illustrated or described herein. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with aspects of the disclosure as detailed in the appended claims.

It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for display, data for analysis, etc.) involved in this disclosure are all authorized by the user. Or information and data fully authorized by all parties.

In the welding track between the battery top cover and the casing based on key point calibration, the actual preset welding track is compared with the ideal preset welding track due to the uneven gap between the casing and the top cover and the deformation of the casing. Under the influence of factors such as uneven pressure of tooling fixtures, the welding track is deformed.

As shown in Figures 2 and 3, after the battery cells (not shown) are inserted into the case, the height and width of the top cover and the case form steps. Taking the square case battery as an example, after the battery core is inserted into the case, the top cover closes the port where the power supply core enters the case and covers the battery core. The height of the top cover in the case is lower than the height of the case. This height is a step. height; the outer circumferential edge of the top cover and the inner circumferential edge of the shell have a certain width, which is the step width (also called a gap, which is a reserved welding gap used to form a molten pool after welding). During the welding process of the battery top cover and casing, it is necessary to detect changes in step width in real time to ensure that the welding focus is always at the same preset welding position for welding the top cover and casing. For example, make the focus of welding always be at the center of the width, etc. via real-time Detecting the change in step width and adjusting the position of the welding focus relative to the top cover boundary and the shell boundary can ensure that the welding of the top cover and the shell is always based on the actual welding trajectory and achieve better welding quality.

Based on this, embodiments of the present disclosure provide a battery welding system, as shown in Figure 4. The welding system includes: a welding head 10, a profiler 20, a servo motion module 30, a welding feed motor 40, and a gantry support base 50 , gantry bracket 60 and industrial computer 70.

The welding head 10 and the profiler 20 are provided in the servo motion module 30 . Among them, the welding head 10 can be a laser welding head, which can keep the defocus amount stable during the movement and weld the top cover and the shell; the profiler 20 can be a 3D profiler, which can collect the top cover in real time during the movement. The step profile image before welding the top cover and the shell, and the image of the molten pool after welding the top cover and the shell; if the servo motion module 30 can move axially and transversely, it can drive the welding head 10 and the profiler 20 along the top cover and The shells move along a preset welding trajectory, and during the movement, the welding focus of the welding head 10 is controlled to remain at the preset welding position based on parameter measurement values.

In the battery welding system, the servo motion module 30 and the welding feed motor 40 are in matching positions. For example, when the welding feed motor 40 carrying the battery top cover and case is located below, the servo motion module 30 may be located above the welding feed motor 40 . When the welding feed motor 40 carries the battery top cover and casing to be welded to the preset position, the servo motion module 30 can follow the edge of the top cover and the edge of the casing (ie: the horizontal direction of the top cover and the casing). Preset welding trajectory movement confirmed by a certain number of key points in the cross-sectional shape).

The servo motion module 30 is installed on the gantry bracket base 50 , and the gantry bracket base 50 is installed on the gantry bracket 60 . Thus, the servo motion module 30 , the profiler 20 and the welding head 10 are supported.

It should be further explained that the parameter measurement values of the steps can be obtained based on the profile image; the welding quality of the molten pool can be obtained based on the molten pool image.

Specifically, the profiler 20 includes a transmitting component (not labeled in the figure) and a receiving component (not labeled in the figure). The transmitting component emits a transmitting beam 21 to the top cover and the casing, and the receiving component receives the reflected beam 22 of the transmitting beam on the top cover and the casing respectively, thus obtaining a profile image of the step, and obtaining parameter measurements of the step based on the profile image. . In addition, the profiler 20 is also used to obtain an image of the molten pool after welding the top cover and the shell, so as to obtain a molten pool image of the molten pool, and obtain the welding quality based on the molten pool image.

The industrial computer 70 is communicated with the welding head 10, the profiler 20, the servo motion module 30, and the welding feed motor 40 respectively. For example, the communication connection is realized by using an Ethernet network. The industrial computer 70 calculates the parameter measurement value of the step based on the step profile image sent by the profiler 20, and controls the servo motion module 30 to adjust the welding focus of the welding head 10 at the preset welding position during the movement according to the preset welding trajectory to control The welding head 10 welds the top cover and the shell; simultaneously, the profiler 20 collects real-time images of the welded molten pool, and the industrial computer 70 judges the welding quality based on the image of the molten pool sent by the profiler 20 . After each battery is welded, the industrial computer 70 controls the welding feed motor 40 to carry the next battery top cover and casing to be welded to the preset position.

It should be further explained that the parameter measurement value of the step includes the coordinates of the center point of the step. While the servo motion module 30 moves according to the preset welding trajectory, the industrial computer 70 adjusts the welding focus of the welding head 10 to the position of the coordinates of the center point of the step. Since the coordinates of the center point are detected in real time, when the welding gap between the top cover and the shell changes (that is, the width and/or width of the step changes), it can always be ensured that the welding focus of the welding head 10 is at the time when the change occurs. The coordinate position of the step center point ensures the stability of the defocus amount and the fit between the actual welding trajectory and the actual step path.

In addition, the profiler 20 is also used to collect the grayscale image of the completed welding pool in real time. The profiler 20 can be arranged at an angle with the welding head 10, and the welding focus axis of the welding head 10 forms an acute angle with the emitted beam of the profiler 20. state, so that the acquisition area of the profilometer 20 includes the step longitudinal section, so that the grayscale image of the molten pool collected by the profilometer 20 includes the image content of the molten pool in the step height direction. The profiler 20 sends the grayscale image of the molten pool to the industrial computer 70, and the industrial computer 70 detects the welding quality of the molten pool based on the grayscale image of the molten pool.

Based on the above battery welding system, embodiments of the present disclosure also provide a battery welding method. As shown in Figure 5, the method includes the following steps:

Step 510: Obtain an outline image of the step between the top cover and the housing.

Step 520: Obtain the parameter measurement value of the step based on the outline image of the step. Combined with Figure 3, it can be seen that the parameter measurement values of the steps include the width of the steps (ie, the welding gap), height and center point coordinates.

Step 530: During the movement of the servo motion module 30 according to the preset welding trajectory, adjust the welding head 10 to the preset welding position based on the parameter measurement value of the step to achieve Welding of the top cover and the casing.

As shown in Figure 6 and Figure 7, the above step 510 includes:

Step 610: Obtain the point cloud image of the top cover and the point cloud image of the housing.

Step 620: Reconstruct the point cloud image of the top cover and the point cloud image of the housing to obtain an outline image of the step.

Specifically, the light beam emitted by the transmitting component is irradiated to the top cover and the casing respectively, and the reflection component receives the top cover point cloud image reflected by the top cover and the casing point cloud image reflected by the casing, and compares the top cover point cloud image and the casing. The point cloud image is reconstructed to obtain the top cover contour image, the shell contour image and the contour image of the steps between them.

As shown in Figure 8, the above step 520 includes:

Step 810: Obtain the width and height of the step based on the first reflected beam, the second emitted beam and the profile image of the step;

Step 820: Based on the width and the height, obtain the center point coordinates of the step.

Specifically, as shown in FIG. 7 , for example, when the top cover is embedded in the casing, the top cover is low and the casing is high. The first emitting beam and the second emitting beam are on two planes corresponding to the top cover and the casing respectively. A misaligned parallel line is formed on the step, and the width and height of the step can be obtained based on the misaligned parallel line. In the same way, the center point based on the width is the transverse center coordinate of the center point, and the center point based on the height is the longitudinal center coordinate of the center point. From this, the center point coordinates of the step are obtained.

As shown in Figure 9, the above step 530 includes:

Step 910: Based on the preset welding trajectory and the center point coordinates, during the movement of the servo motion module 30 according to the preset welding trajectory, determine the preset welding position of the welding head 10, wherein, The preset welding track is obtained based on the edge of the top cover and the edge of the housing;

Step 920: Control the welding head 10 to weld the top cover and the shell and form a molten pool in the step.

As shown in Figure 5, the battery welding system detects the welding quality in real time while welding. The method also includes the following steps:

Step 540: During the movement of the servo motion module 30 according to the preset welding trajectory, obtain the grayscale image of the molten pool of the top cover and the shell by the profiler 20;

Step 550: Confirm the welding quality of the step and the shell based on the grayscale image of the molten pool.

From the beginning to the end of welding, the profiler 20 collects the molten pool image in real time during the welding process, and the pre-trained defect detection neural network in the industrial computer 70 identifies the grayscale image of the molten pool to determine the welding quality. And record the welding quality evaluation results of each frame into the database.

The current method of testing the welding quality of the battery top cover and casing uses visual inspection after the welding is completed and cutting samples to sample and measure the welding penetration. This method has the following shortcomings: (1) After the welding is completed Visual inspection only collects images of the surface topography of the weld, and performs defect detection through image processing. It cannot observe the penetration depth and internal defects of the weld, and is easily affected by welding slag, welding ash, etc., leading to a high degree of misjudgment. rate; (2) Sampling the products after welding is completed, cutting the welds, observing the penetration data of the end face to detect the welding quality, and estimating the welding quality of large batches of product welds through a smaller number of sample data, there is randomness sex and subjectivity. Based on the above method, the quality of the molten pool can be detected in real time, and the quality results are guaranteed to include penetration depth and internal defects, achieving better detection results.

In an exemplary embodiment, a computer-readable storage medium is also provided, which when instructions in the storage medium are executed by the processor of the industrial computer 70 enables the electronic device to perform the method in the embodiment of the present disclosure.

Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. , when executed, the computer program may include the processes of the above method embodiments. Any reference to memory, storage, database or other media used in the various embodiments provided by this disclosure may include non-volatile and/or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous chain Synchlink DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

Other embodiments of the disclosure will be readily apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the disclosure that follow the general principles of the disclosure and include common common sense or customary technical means in the technical field that are not disclosed in the disclosure. . It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise structures described above and illustrated in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the disclosure is limited only by the appended claims.

Claims (11)

A battery welding system used for welding the top cover and casing of the battery, which is characterized by including: Welding head(10); A profiler (20), used to obtain a profile image of the step between the top cover and the casing, and obtain parameter measurement values of the step based on the profile image; wherein the battery core is inserted into the casing. Finally, the height and width of the top cover and the housing form the step; The servo motion module (30), the profiler (20) and the welding head (10) are provided in the servo motion module (30), and are used to adjust the top cover and the housing according to the preset conditions. It is assumed that the welding trajectory and the parameter measurement value control the welding head (10) to weld the top cover and the shell. The battery welding system according to claim 1, characterized in that the profiler (20) includes a transmitting component and a receiving component, and the transmitting component emits light beams to the top cover and the housing respectively, and the The receiving component receives the reflected light beam from the top cover and the housing, obtains the profile image according to the reflected light beam, and obtains the preset welding position for welding the step according to the parameter measurement value of the step; The servo motion module (30) controls the welding focus of the welding head (10) to be at the preset welding position during movement along the preset welding trajectory. The battery welding system according to claim 1 or 2, characterized in that the acquisition area of the profiler (20) includes the step longitudinal section; the profiler (20) is also used to acquire the top cover and the The image of the molten pool after the shell is welded, and the welding quality is obtained based on the image of the molten pool. The battery welding system according to claim 2 or 3, further comprising: an industrial computer (70), which calculates the step profile based on the step profile image sent by the profiler (20). parameter measurement values of the steps, and control the servo motion module (30) to The welding focus of the welding head (10) is adjusted to be at the preset welding position during movement according to the preset welding trajectory, so as to control the welding head (10) to weld the top cover and the casing. The battery welding system according to claim 4, characterized in that the parameter measurement value includes the center point coordinate of the step, and the servo movement module (30) adjusts during the movement according to the preset welding trajectory. The welding focus of the welding head (10) is located at the coordinates of the center point of the step. The battery welding system according to claim 4 or 5, characterized in that, during the movement of the servo motion module (30) according to the preset welding trajectory, the profiler (20) is also used to complete real-time collection Welding the grayscale image of the molten pool, and sending the grayscale image of the molten pool to the industrial computer (70), the industrial computer (70) Check the welding quality of the pool. A battery welding method, used in the battery welding system as claimed in any one of claims 1 to 6, the method comprising: Obtain an outline image of the step between the top cover and the housing; Based on the contour image of the step, obtain the parameter measurement value of the step; The servo motion module (30) moves according to the preset welding trajectory and adjusts the welding head (10) to the preset welding position based on the parameter measurement value of the step, so as to realize the welding of the top cover and the casing. of welding. The battery welding method according to claim 7, wherein said obtaining the outline image of the step between the top cover and the casing includes: Obtain a point cloud image of the top cover and a point cloud image of the housing; The point cloud image of the top cover and the point cloud image of the housing are reconstructed to obtain an outline image of the step. The battery welding method according to claim 7 or 8, characterized in that, based on the contour image of the step, obtaining the parameter measurement value of the step includes: Based on the outline image of the step, the width and height of the step are obtained; Based on the width and the height, the center point coordinates of the step are obtained. The battery welding method according to any one of claims 7 to 9, characterized in that during the movement of the servo motion module (30) according to the preset welding trajectory, the parameters based on the steps are The measured value adjusts the welding head (10) to the preset welding position to achieve welding of the top cover and the shell, including: Based on the preset welding trajectory and the center point coordinates, the preset welding position of the welding head (10) is determined during the movement of the servo motion module (30) according to the preset welding trajectory, where , the preset welding track is obtained based on the edge of the top cover and the edge of the housing; The welding head (10) is controlled to weld the top cover and the shell and form a molten pool in the step. The battery welding method according to any one of claims 7-10, characterized in that the method further includes: During the movement of the servo motion module (30) according to the preset welding trajectory, obtain the grayscale image of the molten pool of the top cover and the housing by the profiler (20); Based on the grayscale image of the molten pool, the welding quality of the step and the shell is confirmed.