CN115533407A

CN115533407A - Battery welding system and battery welding method

Info

Publication number: CN115533407A
Application number: CN202211072610.3A
Authority: CN
Inventors: 不公告发明人
Original assignee: Wuxi Lead Intelligent Equipment Co Ltd
Current assignee: Wuxi Lead Intelligent Equipment Co Ltd
Priority date: 2022-09-02
Filing date: 2022-09-02
Publication date: 2022-12-30
Also published as: WO2024046435A1

Abstract

The present application relates to a battery welding system and a battery welding method, the battery welding system including: a welding head, a contourgraph and a servo motion module; the contourgraph is used for acquiring a contour image of a step between the top cover and the shell and obtaining a parameter measurement value of the step based on the contour image; the servo motion module is arranged on the top cover, and the contourgraph and the welding head are arranged on the servo motion module and used for controlling the welding head to weld the top cover and the shell according to a preset welding track of the top cover and the shell and the parameter measured value. Through the change of the step width detected in real time and the relative fixation of the position of the welding focus adjusted relative to the top cover boundary and the shell boundary, the welding of the top cover and the shell can be ensured to be carried out all the time based on the actual welding track, and the better welding quality is realized.

Description

Battery welding system and battery welding method

Technical Field

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

Background

At present, when a top cover welding machine is used for welding a top cover and a shell of a battery, a key point position mode is adopted to confirm and determine a welding track.

Taking a square battery as an example, as shown in fig. 1a, it is an ideal welding track confirmed on the premise of assuming that a gap between the top cover and the cross section of the case is a standard rectangle (four vertexes of the top cover and the case are key points); as shown in fig. 1b, the welding track is a wave-shaped welding track due to the influence of uneven gap between the housing and the top cover, deformation of the housing, uneven pressure of the tool fixture, and the like.

In the welding process, due to the deformation of a welding track, the welding defects of non-uniform defocusing amount, insufficient welding penetration consistency, welding penetration, bubbles, splashing and the like can be caused during welding; how to adjust the welding track of top cap welding machine in real time is the problem that guarantees that the welding needs to be solved urgently.

Disclosure of Invention

The application provides a battery welding system and a battery welding method, which aim to solve the problem that the welding quality is guaranteed by adjusting the position of a welding head in real time in the process of welding a battery top cover and a shell. The technical scheme of the application is as follows:

according to a first aspect of embodiments of the present application, there is provided a battery welding system for welding a top cover and a case of a battery, comprising: a welding head, a contourgraph and a servo motion module; the contourgraph is used for acquiring a contour image of a step between the top cover and the shell and obtaining a parameter measurement value of the step based on the contour image; after the battery core of the battery is placed into the shell, the height and the width between the top cover and the shell form the step; the servo motion module is arranged on the top cover, and the contourgraph and the welding head are arranged on the servo motion module and used for controlling the welding head to weld the top cover and the shell according to a preset welding track of the top cover and the shell and the parameter measured value.

According to a second aspect of the embodiments of the present application, there is provided a battery welding method for the above battery welding system, the method including: acquiring a contour image of a step between the top cover and the shell; obtaining a parameter measurement value of the step based on the contour image of the step; and the servo motion module moves according to a preset welding track and adjusts the welding head to be at a preset welding position based on the parameter measurement value of the step so as to realize the welding of the top cover and the shell.

The technical scheme provided by the embodiment of the application at least has the following beneficial effects:

in the embodiment of the application, the change of the step width is detected in real time, and the position of the welding focus is adjusted to be relatively fixed relative to the boundary of the top cover and the boundary of the shell, so that the top cover and the shell can be always welded based on an actual welding track, and better welding quality is realized.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application and are not to be construed as limiting the application.

FIG. 1a is a schematic illustration of an ideal welding trajectory for a battery;

FIG. 1b is a schematic illustration of the actual welding trajectory of the battery;

fig. 2 is a schematic diagram of a battery structure provided in an embodiment of the present application;

fig. 3 is a schematic top view of the battery of fig. 2;

FIG. 4 is a schematic structural diagram of a battery welding system provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of the welding results of a battery provided by an embodiment of the present application;

FIG. 6 is a schematic flow chart of contour image detection provided by an embodiment of the present application;

FIG. 7 is a graph illustrating the welding results of a battery provided by an embodiment of the present application;

FIG. 8 is a schematic view of a step measurement parameter detection process provided in an embodiment of the present application;

fig. 9 is a schematic view of a welding quality detection process provided in an embodiment of the present application.

Detailed Description

In order to make the technical solutions of the present application better understood by those of ordinary skill in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

It should be noted that, the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for presentation, analyzed data, etc.) referred to in the present application are both information and data authorized by the user or sufficiently authorized by each party.

According to the welding track between the battery top cover and the shell based on key point calibration, the actual preset welding track is compared with the ideal preset welding track, and the welding track is deformed due to the influences of factors such as uneven gaps between the shell and the top cover, deformation of the shell, uneven pressure of a tool clamp and the like.

As shown in fig. 2 and 3, after a battery cell (not shown) of the battery is inserted into the case, the top cover and the case have a height and a width that form a step therebetween. Taking a square-shell battery as an example, after the battery core is placed into the shell, the top cover seals the port of the shell for the power supply core of the shell and covers the battery core, and the height of the top cover in the shell is lower than that of the shell and is the height of the step; the outer circumferential edge of the top cover and the inner circumferential edge of the shell have a certain width, which is a step width (also called a gap, which is reserved for a welding gap to form a welded molten pool). In the welding process of the battery top cover and the shell, the change of the step width needs to be detected in real time, and the welding focus is guaranteed to be always located at the same preset welding position to weld the top cover and the shell. For example, the focal point of welding is always located at the center of the width. Through the change of the step width detected in real time and the relative fixation of the position of the welding focus adjusted relative to the top cover boundary and the shell boundary, the welding of the top cover and the shell can be ensured to be carried out all the time based on the actual welding track, and the better welding quality is realized.

Based on this, this application embodiment provides a battery welding system, as shown in fig. 4, this welding system includes: the welding device comprises a welding head 10, a profile instrument 20, a servo motion module 30, a welding feed motor 40, a gantry support base 50, a gantry support 60 and an industrial personal computer 70.

The bond head 10 and profiler 20 are disposed in a servo motion module 30. Wherein, the welding head 10 can be a laser welding head which can keep defocusing amount stable and weld the top cover and the shell in the moving process; the profiler 20 can be a 3D profiler which can acquire step profile images before welding the top cover and the shell and molten pool images after welding the top cover and the shell in real time in the motion process; the servo movement module 30 can move along the axial direction and the transverse direction, and can drive the welding head 10 and the profiler 20 to move along a preset welding track between the top cover and the shell, and control the welding focus of the welding head 10 to be kept at a preset welding position based on the parameter measured value during the movement.

In the battery welding system, the servo motion module 30 and the welding feed motor 40 are in matched positions. For example, the servo motion module 30 may be located above the weld feed motor 40 when the weld feed motor 40 carrying the battery top cover and housing is located below. When the welding feed motor 40 carries the battery top cover and the housing to be welded to the preset positions, the servo motion module 30 can move according to the preset welding track confirmed by a certain number of key points in the edge of the top cover and the edge of the housing (i.e., the cross-sectional shapes of the top cover and the housing).

The servo motion module 30 is mounted on the gantry support base 50, and the gantry support base 50 is mounted on the gantry support 60. This realizes support of the servo motion module 30, the profiler 20, and the bonding head 10.

It is further noted that the parameter measurement value of the step can be obtained based on the contour image; the welding quality of the weld pool can be obtained based on the weld pool image.

Specifically, the profiler 20 includes a transmitting assembly (not shown) and a receiving assembly (not shown). The emitting assembly emits a radiation beam 21 towards the cover and the housing, and the receiving assembly receives a radiation beam 22 at the cover and the housing, respectively, such that a profile image of the step is obtained, and a parameter measurement of said step is obtained on the basis of the profile image. In addition, the profiler is also used for acquiring a molten pool image after the top cover and the shell are welded, so that a molten pool image of the molten pool is acquired, and the welding quality is acquired based on the molten pool image.

The industrial personal computer 70 is in communication connection with the welding head 10, the profiler 20, the servo motion module 30 and the welding feed motor 40 respectively, for example, in an ethernet manner. The industrial personal computer 70 calculates a 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 to be positioned at a preset welding position in the process of moving according to a preset welding track so as to control the welding head 10 to weld the top cover and the shell; and synchronously, the contourgraph 20 carries out real-time image acquisition on the welded molten pool, and the industrial personal computer 70 judges the welding quality based on the molten pool image sent by the contourgraph 20. After each battery welding is completed, the industrial personal computer 70 controls the welding feed motor 40 to carry the next battery top cover and case to be welded to a preset position.

It should be further noted that the parameter measurement of the step includes the coordinates of the center point of the step. In the process that the servo motion module 30 moves according to the preset welding track, the industrial personal computer 70 adjusts the position of the welding focus of the welding head 10 at the center point coordinate of the step. Because the coordinate of the central point is detected in real time, when a welding gap (namely, the width and/or the width of the step is changed) between the top cover and the shell is changed, the coordinate position of the welding focus of the welding head 10 at the central point of the step when the change occurs can be always ensured, so that the stability of the defocusing amount and the attachment of the actual welding track and the actual step path are ensured.

In addition, the profiler 20 is also used for acquiring the gray level image of the completed welding molten pool in real time, the profiler 20 can be obliquely arranged with the welding head 10, and the welding focus axis of the welding head 10 and the emitted light beam of the profiler 20 are in an acute angle state, so that the acquisition area of the profiler 20 comprises the longitudinal section of the step, and the gray level image of the molten pool acquired by the profiler 20 comprises the image content of the molten pool in the height direction of the step. The profiler 20 sends the grayscale image of the molten pool to the industrial personal computer 70, and the industrial personal 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, an embodiment of the present application further provides a battery welding method, as shown in fig. 5, the method includes the following steps:

step 510: and acquiring a contour image of a step between the top cover and the shell.

Step 520: and obtaining a parameter measurement value of the step based on the contour image of the step. As can be seen in fig. 3, the parameter measurements for the step include the width (i.e., the weld gap), height, and center point coordinates of the step.

Step 530: and in the process that the servo movement module moves according to a preset welding track, adjusting the welding head to be at a preset welding position based on the parameter measurement value of the step so as to weld the top cover and the shell.

As shown in fig. 6 and 7, the step 510 includes:

step 610: and acquiring the point cloud image of the top cover and the point cloud image of the shell.

Step 620: and reconstructing the point cloud image of the top cover and the point cloud image of the shell to obtain the outline image of the step.

Specifically, light beams emitted by the emission assembly are respectively irradiated on the top cover and the shell, the reflection assembly receives a top cover point cloud image reflected by the top cover and a shell point cloud image reflected by the shell, the top cover palace point cloud image and the shell point cloud image are reconstructed, and a top cover profile image, a shell profile image and profile images of steps between the top cover profile image and the shell profile image are respectively obtained.

As shown in fig. 8, the step 520 includes:

step 810: obtaining the width and the height of the step based on the first reflected light beam, the second reflected light beam and the contour image of the step;

step 820: and obtaining the coordinates of the central point of the step based on the width and the height.

Specifically, as shown in fig. 7, for example, when the top cover is embedded in the housing, the top cover is low and the housing is high, the first emission beam and the second emission beam form offset parallel lines on two corresponding planes of the top cover and the housing, and the width and the height of the step can be obtained based on the offset parallel lines. Similarly, the horizontal center coordinate of the center point is obtained based on the center line point of the width, and the longitudinal center coordinate of the center point is obtained based on the center point of the height, so that the center point coordinate of the step is obtained.

As shown in fig. 9, the step 530 includes:

step 910: based on the preset welding track and the central point coordinate, determining a preset welding position of the welding head in the process that the servo motion module moves according to the preset welding track, wherein the preset welding track is obtained based on the edge of the top cover and the edge of the shell;

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

As described with reference to fig. 5, the battery welding system detects the welding quality in real time while welding. The method further comprises the following steps:

step 540: acquiring gray images of the contourgraph on a top cover and a molten pool of the shell in the process that the servo motion module moves according to a preset welding track;

step 550: confirming the welding quality of the step and the shell based on the gray scale image of the molten pool.

In the process from the beginning of welding to the end of welding, the contourgraph 20 collects the molten pool image in the welding process in real time, the molten pool gray level image is identified by a pre-trained defect detection neural network in the industrial personal computer, the welding quality is determined, and the welding quality evaluation result of each frame is recorded into a database.

In the existing detection method for the welding quality of the battery top cover and the shell, a mode of carrying out visual detection after welding and sampling measurement of welding penetration by cutting a sample is adopted, and the mode has the following defects: (1) After welding is finished, the visual inspection only acquires images of the appearance of the surface of the welding seam, detects defects through image processing, cannot observe the fusion depth and the internal defects of the welding seam, and is easily influenced by welding slag, welding dust and the like, so that the misjudgment rate is high; (2) And sampling products after welding is finished, cutting welding seams, detecting the welding quality in a mode of observing penetration data of end faces, and estimating the welding quality of the welding seams of a large batch of products by using a small amount of sample data, wherein randomness and subjectivity exist. Based on the mode, the quality of the molten pool can be detected in real time, the quality result of the molten pool is guaranteed to include the content of the penetration and the internal defects, and a better detection effect is achieved.

In an exemplary embodiment, a computer readable storage medium is also provided, the instructions in which, when executed by a processor of the industrial personal computer 70, enable the electronic device to perform the method in the embodiments of the present application.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically Programmable ROM (EPROM), electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double Data Rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), rambus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. A battery welding system for welding a top cover and a housing of a battery, comprising:

welding a head;

the contourgraph is used for acquiring a contour image of a step between the top cover and the shell and obtaining a parameter measurement value of the step based on the contour image; after the battery core of the battery is placed into the shell, the height and the width between the top cover and the shell form the step;

the servo motion module is arranged on the top cover, and the contourgraph and the welding head are arranged on the servo motion module and used for controlling the welding head to weld the top cover and the shell according to a preset welding track of the top cover and the shell and the parameter measured value.

2. The battery welding system of claim 1, wherein the profiler comprises a transmitter and a receiver, the transmitter respectively transmits light beams to the top cover and the housing, the receiver receives reflected light beams from the top cover and the housing, obtains the profile image according to the reflected light beams, and obtains the preset welding position for welding the step according to the measured parameter values of the step;

and the servo motion module controls the welding focus of the welding head to be positioned at the preset welding position in the process of moving along the preset welding track.

3. The battery welding system of claim 1, wherein the profiler acquisition area comprises the step longitudinal cross section; the contourgraph is further used for acquiring an image of a molten pool after the top cover and the shell are welded, and the welding quality is acquired based on the molten pool image.

4. The battery welding system of claim 2 or 3, further comprising an industrial personal computer; the industrial personal computer calculates the parameter measurement value of the step based on the step profile image sent by the contourgraph, and controls the servo motion module to adjust the welding focus of the welding head to be located at the preset welding position in the process of moving according to the preset welding track so as to control the welding head to weld the top cover and the shell.

5. The battery welding system of claim 4, wherein the parameter measurement value comprises a center point coordinate of the step, and the servo motion module adjusts a position of a welding focus of the welding head at the center point coordinate of the step during the movement according to a preset welding track.

6. The battery welding system according to claim 4, wherein the servo motion module is configured to acquire a gray image of the molten pool after welding is completed in real time in a process of moving according to a preset welding track, and send the gray image of the molten pool to the industrial personal computer, and the industrial personal computer detects the welding quality of the molten pool based on the gray image of the molten pool.

7. A battery welding method for use in the battery welding system of any one of claims 1-6, the method comprising:

acquiring a contour image of a step between the top cover and the shell;

obtaining a parameter measurement value of the step based on the contour image of the step;

the servo motion module moves according to a preset welding track and adjusts the welding head to be in a preset welding position based on the parameter measured value of the step, so that the top cover and the shell are welded.

8. The battery welding method of claim 7, wherein said obtaining a profile image of a step between said top cover and said housing comprises:

acquiring a point cloud image of the top cover and a point cloud image of the shell;

and reconstructing the point cloud image of the top cover and the point cloud image of the shell to obtain the outline image of the step.

9. The battery welding method of claim 8, wherein obtaining the parameter measurement of the step based on the profile image of the step comprises:

obtaining the width and the height of the step based on the outline image of the step;

and obtaining the coordinates of the central point of the step based on the width and the height.

10. The battery welding method of claim 9, wherein the adjusting the welding head to a preset welding position based on the measured parameter value of the step during the movement of the servo motion module according to a preset welding track to weld the top cover and the housing comprises:

determining a preset welding position of the welding head in the movement process of the servo movement module according to a preset welding track based on the preset welding track and the central point coordinate, wherein the preset welding track is obtained based on the edge of the top cover and the edge of the shell;

and controlling the welding head to weld the top cover and the shell and form a molten pool in the step.

11. The battery welding method of claim 10, further comprising:

acquiring gray images of the contourgraph on a top cover and a molten pool of the shell in the process that the servo motion module moves according to a preset welding track;

confirming the welding quality of the step and the shell based on the gray scale image of the molten pool.