CN116413199A

CN116413199A - Method and system for detecting battery welding quality by using vibration signal

Info

Publication number: CN116413199A
Application number: CN202111662363.8A
Authority: CN
Inventors: 吕黠物; 孙元俊
Original assignee: Wanmo Acoustics Co ltd
Current assignee: Wanmo Acoustics Co ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2023-07-11

Abstract

The application provides a method and a system for detecting the welding quality of a battery by using a vibration signal, wherein the first vibration signal is applied to a first welding workpiece of a welding component to be detected in the battery, after the first vibration signal excites the welding component to be detected, vibration parameters at a first detection position (namely a detection position) on the first welding workpiece and a second detection position (namely a reference detection position) on the second welding workpiece are detected respectively, the difference value of the first vibration parameter and the second vibration parameter which correspond to the detection position and the reference detection position respectively is compared with a parameter range determined by the welding component with good welding, so that the welding quality of the welding component to be detected is determined, the vibration condition (vibration parameter) of the reference detection position is deducted, namely the vibration parameter caused by external vibration to the welding component to be detected is deducted, the interference caused by external vibration to the welding component to be detected is reduced, the detection precision is improved, and the nondestructive detection of the welding component to be detected is realized.

Description

Method and system for detecting battery welding quality by using vibration signal

Technical Field

The present application relates to the field of batteries, and more particularly, to a method and system for detecting battery welding quality using vibration signals.

Background

In the production of batteries for terminal equipment, it is often necessary to weld together the different components. If the welding operation is improper, the poor welding or the over welding is easy to cause, the quality and the service life of the battery are seriously reduced, the battery is broken in the use process of a user, the use experience of the user is affected, and the safety of the user is possibly affected.

In order to check the welding effect, it is currently common to detect the welding effect by a welding tension test, or a method of testing the voltage and internal resistance of the battery. However, the above manner cannot accurately, effectively and timely detect whether the welding component has a fault welding or overselding defect, and the welding component to be detected may be damaged in the detection process, so that the detection efficiency and accuracy are low, and therefore, a method for accurately, effectively and continuously detecting whether the welding component in the battery has the fault welding or overselding is needed, so that the welding quality of the welding component in the battery is ensured, and the safety of a user using the battery is improved.

Disclosure of Invention

The method and the system for detecting the welding quality of the battery by using the vibration signals are characterized in that the vibration signals are applied to a welding part to be detected in the battery, vibration parameters generated on a detection position and a reference detection position respectively after the vibration signals are excited by the welding part to be detected are detected, the difference value of the vibration parameters corresponding to the detection position and the reference detection position respectively is compared with a parameter range determined by a plurality of welding parts with good welding so as to determine the welding quality of the welding part to be detected.

In a first aspect, there is provided a method of detecting welding quality of a battery using a vibration signal, the battery including a to-be-welded component including a first welded workpiece and a second welded workpiece, a ratio of a volume of the second welded workpiece to a volume of the first welded workpiece being greater than or equal to 2, the method comprising: applying a first vibration signal to a first location on a first weld workpiece; detecting vibration information on at least one first detection position on the first welded workpiece with the first laser probe; utilizing the vibration information of at least one second detection position on the second welding workpiece by the second laser probe; converting the vibration information at the at least one first detection position into a first vibration parameter; converting the vibration information at the at least one second detection location into a second vibration parameter; determining a first value according to the first vibration parameter and the second vibration parameter; when the first numerical value is in a predetermined numerical value range, determining that the welding quality of the to-be-welded part is good; when the first numerical value is not in the predetermined numerical range, determining that the welding defect exists in the to-be-welded component; wherein a welding area on the part to be welded is positioned between a first position and at least one first detection position, and the welding area comprises at least one welding spot; the predetermined numerical range is determined according to vibration parameters corresponding to a plurality of welding components with good welding performance, and the structure, the size, the welding position and the welding process of each welding component with good welding performance are the same as those of the welding component to be detected.

The method for detecting welding quality of a battery by using a vibration signal according to the first aspect applies the vibration signal (i.e. the first vibration signal) to a first position of a first welding workpiece of a welding component to be detected in the battery, detects vibration parameters (i.e. a first vibration parameter and a second vibration parameter) generated at a detection position (i.e. a first detection position) on the first welding workpiece and a reference detection position (i.e. a second detection position) on the second welding workpiece after excitation of the vibration signal by the welding component to be detected, and compares a difference value of the vibration parameters (i.e. a difference value of the first vibration parameter and the second vibration parameter) corresponding to the detection position and the reference detection position with a parameter range determined by the welding component to be detected. According to the method, the vibration condition of the reference detection position is eliminated, namely, the vibration parameters of the welding part to be detected caused by external vibration are deducted, the interference of the external vibration to the detection result is reduced, the detection precision is improved, the welding quality of the welding part to be detected can be accurately and timely detected, the welding defective products can be effectively screened out, and nondestructive (or nondestructive) detection of the welding part to be detected can be realized. And moreover, the welding condition of the part to be detected can be continuously detected on line, so that the welding effect of all the welding parts can be monitored in real time, the welding quality of the battery is ensured, the occurrence of false welding or overselding defects is avoided, the quality and the service life of the battery are improved, and the user experience of a user when using terminal equipment provided with the battery is improved.

In the application, the ratio of the volume of the second welding workpiece to the volume of the first welding workpiece is greater than or equal to 2, and the application position (i.e., the first position) and the detection position (i.e., the first detection position) of the first vibration signal are both located on the first welding workpiece with smaller volume, and the vibration brought by the first vibration signal is larger at the detection position (i.e., the first detection position). The reference detection position (namely the second detection position) is positioned on the second welding workpiece with larger volume, the vibration caused by the first vibration signal is smaller in the reference detection position (namely the second detection position), and meanwhile, the vibration caused by external interference exists in both the detection position and the reference detection position, so that the vibration information in the detection position mainly reflects the vibration condition of the welding part to be detected caused by the excitation of the vibration signal and the external interference, and the vibration information in the reference detection position mainly reflects the vibration condition of the welding part to be detected caused by the external interference.

In the embodiment of the present application, the number of the laser probes may be one, or may be multiple.

In a possible implementation manner of the first aspect, determining the first value according to the first vibration parameter and the second vibration parameter includes: determining an average value of the first vibration parameters corresponding to at least one first detection position according to the first vibration parameters corresponding to each first detection position; determining an average value of the second vibration parameters corresponding to at least one second detection position according to the second vibration parameters corresponding to each second detection position; and taking the difference value between the average value of the first vibration parameters corresponding to the at least one first detection position and the average value of the second vibration parameters corresponding to the at least one second detection position as a first numerical value. In the implementation mode, the vibration condition of the reference detection position is deducted, namely, the vibration parameter of the welding part to be detected caused by external vibration is deducted, the interference of the external vibration on the detection result is reduced, and the detection precision is improved.

In a possible implementation manner of the first aspect, a distance between the first position and the welding point is 0.5 mm-50 mm, a distance between the first detection position and the welding point is 0.5 mm-10 mm, and a distance between the second detection position and the welding point is 0.5 mm-10 mm. In this implementation, the accuracy and repeatability of the test results can be guaranteed.

In a possible implementation manner of the first aspect, if there are a plurality of welding spots in the welding area of the welding component to be measured, and the detection position (i.e. the first detection position) and the reference detection position (i.e. the second detection position) are each a plurality, in this case, a distance between the first position (i.e. the application position of the first vibration signal) and each welding spot is between 0.5mm and 50mm, a distance between any one of the first detection positions (i.e. the detection positions) and any one of the welding spots is between 0.5mm and 10mm, and a distance between any one of the second detection positions (i.e. the reference detection positions) and any one of the welding spots is between 0.5mm and 10mm. In other words, there are a plurality of different distances between the different first detection positions and the different welding spots, each of the plurality of different distances being between 0.5mm and 10 mm; there are also a plurality of different distances between the different second detection positions and the different welding spots, each of the plurality of different distances being between 0.5mm and 10mm.

Illustratively, the second weld workpiece is a pole piece and the first weld workpiece is a tab. Or the second welding workpiece is a battery shell, and the first welding workpiece is a nickel sheet.

In a possible implementation manner of the first aspect, the method further includes: detecting a non-coating area and a coating area on a welding component to be detected by using an optical fiber sensor, and detecting vibration information of the non-coating area after a first vibration signal is applied by using a first power by using a first laser probe and a second laser probe when the optical fiber sensor detects the non-coating area on the welding component to be detected; when the optical fiber sensor detects that the optical fiber sensor detects the coating area on the welding part to be detected, the first laser probe and the second laser probe detect vibration information of the coating area after the first vibration signal is applied by using the second power; the second power is less than the first power, and the weld region is located in the non-coated region. In the detection process, the power of the laser probe in operation can be reduced, and the service life of the laser probe is prolonged.

When the welding quality of the pole piece and the pole lug is detected on line, the welding area is positioned in the non-coating area of the pole piece, and when the optical fiber sensor detects the non-coating area, the power of the laser probe is increased to a normal working value; when the fiber sensor detects the coated area, the power of the laser probe is reduced to a smaller power value. The method can reduce the power of the laser during operation and prolong the service life of the laser probe.

In a possible implementation manner of the first aspect, the vibration information includes: at least one of vibration displacement information, vibration velocity information, vibration acceleration information, vibration frequency information, vibration amplitude information, vibration energy information, and vibration waveform information; the vibration parameters include: at least one of vibration displacement parameter, vibration speed parameter, vibration acceleration parameter, vibration frequency parameter, vibration amplitude parameter, vibration energy parameter, and vibration waveform parameter.

In a possible implementation manner of the first aspect, the predetermined numerical range is obtained by the following method: applying a second vibration signal to the plurality of welded parts, wherein the amplitudes and frequencies of the first vibration signal and the second vibration signal are the same, and the application positions of the second vibration signal on the plurality of welded parts are the same as the first positions; detecting vibration information of each welding-good welding component after the second vibration signal is applied on a third detection position and a fourth detection position on each welding-good welding component respectively, wherein the number and the positions of the third detection position and the fourth detection position on different welding-good welding components are the same, the number and the positions of the third detection position on each welding-good welding component and the number and the positions of the first detection position on a welding component to be detected are the same, and the number and the positions of the fourth detection position on each welding-good welding component and the number and the positions of the second detection position on the welding component to be detected are the same; converting vibration information at a third detection position on the plurality of welded parts with good welding performance into a third vibration parameter; converting vibration information at a fourth detection position on the plurality of welded parts with good welding performance into a fourth vibration parameter; and obtaining the predetermined numerical range according to the third vibration parameter and the fourth vibration parameter.

In a possible implementation manner of the first aspect, the obtaining the predetermined range of values according to the third vibration parameter and the fourth vibration parameter includes: determining an average value of a third vibration parameter corresponding to each well-welded part; determining an average value of a fourth vibration parameter corresponding to each well-welded part; determining a difference value between an average value of a third vibration parameter and an average value of a fourth vibration parameter corresponding to each welded good welding component as a vibration quality parameter of each welded good welding component; determining an average value X of vibration quality parameters corresponding to the plurality of welded parts ₁ And standard deviation sigma;

the predetermined range of values is:

[X ₁ -3×σ,X ₁ +3×σ]。

in a possible implementation manner of the first aspect, the method further includes: the vibration parameter is displayed using a display. In the implementation mode, the converted data can be displayed in a chart or digital form on a display, so that the vibration condition of different components can be conveniently compared and analyzed.

In a second aspect, a system for detecting battery weld quality using a vibration signal is provided, the system comprising: the system comprises a signal generator, a laser probe, a signal converter and a processor, wherein the laser probe comprises a first laser probe and a second laser probe, the battery comprises a to-be-welded part, the to-be-welded part comprises a first welded workpiece and a second welded workpiece, the ratio of the volume of the second welded workpiece to the volume of the first welded workpiece is greater than or equal to 2, at least one second detection position exists on the second welded workpiece, at least one first detection position exists on the first welded workpiece, a welding area on the to-be-welded part is positioned between the first position and the at least one first detection position, the welding area comprises at least one welding spot, and the system is used for executing the first aspect or the method in any possible implementation mode of the first aspect.

Other embodiments of the second aspect correspond to other embodiments of the first aspect, and are not described here again.

The technical effects corresponding to any implementation manner of the second aspect and the second aspect may refer to the technical effects corresponding to any implementation manner of the first aspect and the first aspect, and are not described herein again.

In a possible implementation manner of the second aspect, the system further includes: the optical fiber sensor is connected in series before the first laser probe and the second laser probe; the optical fiber sensor is used for: detecting non-coating areas and coating areas on the welding part to be detected; when the optical fiber sensor detects a non-coating area on the welding part to be detected, the first laser probe and the second laser probe detect vibration information of the non-coating area after a first vibration signal is applied by using first power; when the optical fiber sensor detects that the optical fiber sensor detects the coating area on the welding part to be detected, the first laser probe and the second laser probe detect vibration information of the coating area after the first vibration signal is applied by using the second power; the second power is less than the first power, and the weld region is located in the non-coated region. In the detection process, the power of the laser probe in operation can be reduced, and the service life of the laser probe is prolonged.

In a possible implementation manner of the second aspect, a distance between the optical fiber sensor and the first laser probe is less than or equal to 2mm; the distance between the optical fiber sensor and the second laser probe is less than or equal to 2mm. To ensure that the optical fiber sensor and the laser probe detect the same non-dressing area or the same dressing area.

In a possible implementation manner of the second aspect, the system further includes a display, and the display is configured to display the vibration parameter obtained by the signal converter. In the implementation mode, the converted data can be displayed in a chart or digital form on a display, so that the vibration condition of different components can be conveniently compared and analyzed.

According to the method and system for detecting the welding quality of the battery by using the vibration signal, the vibration signal (namely, the first vibration signal) is applied to the first position of the first welding workpiece of the welding component to be detected in the battery, after the vibration signal is excited, vibration information is generated on the detection position (namely, the first detection position) on the first welding workpiece and the reference detection position (namely, the second detection position) on the second welding workpiece respectively, after the vibration information is detected by the laser probe (the first laser probe and the second laser probe), the vibration information detected by the laser probe is converted into vibration parameters (the detection position corresponds to the first vibration parameters, the reference detection position corresponds to the second vibration parameters), the difference (namely, the difference is a first numerical value) of the vibration parameters corresponding to the detection position (namely, the second vibration parameters) and the reference detection position (namely, the second vibration parameters) are determined, the vibration parameters corresponding to the detection position (namely, the first vibration parameters) are determined, the vibration parameters corresponding to the first vibration parameters and the reference detection position (namely, the second vibration parameters) are determined, the vibration parameters corresponding to the first vibration parameters are subtracted, the welding parameters are determined, the welding quality to be detected is reduced, the welding quality to be detected is subtracted, and the welding quality to be detected is subtracted by the welding quality is determined by the welding quality to be detected by the welding quality, the welding defective products are effectively screened out, nondestructive (or nondestructive) detection of the welding parts to be detected is realized, the welding quality of the welding parts with complex detection mechanisms can be used, and the welding quality detection method has good universality. And moreover, the welding condition of the part to be detected can be continuously detected on line, so that the welding effect of all the welded parts can be monitored in real time, the welding quality of the battery is ensured, and the occurrence of false welding or over-welding defects is avoided.

Drawings

Fig. 1 is a schematic diagram of an example of a system for detecting welding quality of a battery using a vibration signal according to an embodiment of the present application.

Fig. 2 is a schematic flow chart of an example of a method for detecting battery welding quality using vibration signals according to an embodiment of the present application.

Fig. 3 is a schematic view of a structure of a welded component to be tested in a battery according to an embodiment of the present application.

Fig. 4 is a schematic view showing a welded structure of a welded member of a battery according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of another example of a detection system for detecting welding quality of a battery using a vibration signal according to an embodiment of the present application.

Fig. 6 is a schematic diagram of a detection system for continuously detecting whether a tab on a battery pole piece has a cold joint or an overseld.

Detailed Description

The technical solutions in the present application will be described below with reference to the accompanying drawings.

In the description of the embodiments of the present application, unless otherwise indicated, "/" means or, for example, a/B may represent a or B; "and/or" herein is merely an association relationship describing an association object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, in the description of the embodiments of the present application, "plurality" means two or more than two.

The terms "first" and "second" are used below for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present embodiment, unless otherwise specified, the meaning of "plurality" is two or more.

With the development of technology, various terminal devices (e.g., mobile phones, computers, tablets, various wearable devices, etc.) play an important role in the life of people, and batteries of these electronic devices are particularly important. In the production of batteries for terminal equipment, it is often necessary to weld together the different components. For example: in the production process of the battery, the tab of the battery needs to be welded to the current collector. In addition, when battery pack is processed, need weld shaping nickel piece on the finished battery casing, if welding operation is improper, lead to rosin joint or overseld easily, seriously reduced the quality and the life-span of battery, cause battery trouble to appear in the user's use, influence user's use experience to, still probably cause the influence to user's safety.

In order to check the welding effect, a welding tension test, or a method of testing the voltage and internal resistance of the battery is generally used to detect the welding effect. However, the welding tension test is a destructive test, and the method can only perform spot check test when the battery starts to be produced or ends to be produced, cannot monitor the welding effect of all the welding parts in real time, cannot find the false welding or overselding condition in the welding process in time, cannot find the defective products caused by the false welding or overselding in time, so that the defective products may flow out to a post-process, and the like, may be a batch problem when found, and cause huge loss.

To intercept the cold solder joint product with a maximum probability, the battery factory may test the voltage and internal resistance of the battery before shipment. But not all dummy bonds or overspray can be screened by the test voltage and internal resistance. For example: taking laser welding as an example, assuming that there are four welding spots under normal conditions, if two of the welding spots are cold welds, the other two welding spots are normal, and at this time, the internal resistance of the test battery may be normal. Therefore, the method cannot completely and effectively screen out defective welding products, and the battery may malfunction when used in the terminal equipment.

In view of the above, the present application provides a method and system for detecting welding quality of a battery using a vibration signal, applying the vibration signal to a welding member to be detected in the battery, detecting vibration parameters generated at a detection position and a reference detection position, respectively, of the welding member to be detected after excitation of the vibration signal, and comparing a difference value of the vibration parameters corresponding to the detection position and the reference detection position, respectively, with a parameter range determined by a welding member that is well welded to determine the welding quality of the welding member to be detected. According to the method, except for the vibration condition of the reference detection position, the vibration condition (vibration parameter) of the reference detection position is deducted, namely, the vibration parameter of the welding component to be detected caused by external vibration is deducted, the interference caused by the external vibration to the welding component to be detected is reduced, the detection precision is improved, the welding quality of the welding component to be detected can be accurately and timely detected, the welding defective products can be effectively screened, and nondestructive (or nondestructive) detection of the welding component to be detected can be realized. And moreover, the welding condition of the part to be detected can be continuously detected on line, so that the welding effect of all the welding parts can be monitored in real time, the welding quality of the battery is ensured, the occurrence of false welding or overselding defects is avoided, the quality and the service life of the battery are improved, and the user experience of a user when using terminal equipment provided with the battery is improved.

The method for detecting the welding quality of the battery using the vibration signal provided in the present application is described below with reference to specific examples.

Fig. 1 is a schematic diagram of an example of a system for detecting welding quality of a battery by using a vibration signal according to an embodiment of the present application, where the method for detecting welding quality of a battery by using a vibration signal provided in the present application may be applied to a detection system shown in fig. 1, and as shown in fig. 1, the detection system includes:

a signal generator 101, a welded component to be measured 102, a laser probe 103, a signal converter 104 and a display 105.

The signal generator 101 is configured to generate a vibration signal (e.g., a first vibration signal or a second vibration signal), and the vibration frequency, the vibration amplitude, or the like of the vibration signal is fixed. For example, in the embodiment of the present application, the vibration signal may be an acoustic wave signal or a vibration wave signal, or the like. It should be understood that in other embodiments of the present application, the signal generator 101 may generate other forms of vibration signals, and the form of the specific signal generated by the signal generator 101 is not limited in the present application, so long as the generated signal is a vibration signal.

The vibration signal generated by the signal generator 101 is applied to the welding member 102 to be measured. In this embodiment of the present application, the welding manner of the to-be-welded component 102 may include: laser welding, ultrasonic welding, resistance welding, or the like; moreover, the to-be-welded component 102 may include welding between two or more workpieces made of metal, and the metal materials of different workpieces may be the same material or different materials. The embodiment of the present application is not limited to the welding manner of the to-be-welded component 102 and whether the to-be-welded component is formed by welding two or more workpieces.

The laser probe 103 is used to detect vibration information of the welding member 102 to be measured after the vibration signal is applied, for example, the vibration information includes: at least one of vibration displacement information, vibration velocity information, vibration acceleration information, vibration frequency information, vibration amplitude information, vibration energy information, vibration waveform information, and the like. It should be understood that in embodiments of the present application, the vibration information may also include other forms of vibration information, and embodiments of the present application are not limited herein.

In the embodiment of the present application, the number of the laser probes 103 may be one or may be plural, which is not limited herein.

The signal converter 104 is connected to the laser probe 103, and is configured to convert vibration information detected by the laser probe 103 into vibration parameters. For example, the signal converter 104 may convert the vibration information detected by the laser probe 103 into an acoustic signal, a digital signal, or the like, so as to present the vibration information detected by the laser probe in a data or digital manner.

The display 105 is used for displaying the signal converted by the signal converter 104, that is, displaying the vibration parameters of the welding component 102 to be tested after the vibration signal is applied. For example: the converted data can be displayed in a chart or digital form on the display 105, so that the vibration condition of different components can be conveniently compared and analyzed.

It should be appreciated that in the system shown in fig. 1, the display 105 is optional. In other words, in embodiments of the present application, the detection system may not include a display.

Optionally, in the system shown in fig. 1, a processor may further include a processor, where the processor is configured to calculate the vibration parameter obtained by the signal converter 104 to obtain a first value, and compare the first value with a predetermined range of values to determine the welding quality of the welded component to be measured.

It should be understood that the example shown in fig. 1 is merely an example of the structure of the detection system provided in the present application, and is not meant to limit the structure of the detection system, and in other embodiments of the present application, the detection system may include more or less components than those illustrated, or may combine certain components, or different components, etc. The application is not limited herein.

An example of a method for detecting battery welding quality using vibration signals is provided in the embodiment of the present application shown in fig. 2. The method shown in fig. 2 may be applied in the detection system shown in fig. 1. As shown in fig. 2, the method includes: s210 to S240.

S210, a vibration signal (or may be referred to as a first vibration signal) generated by the signal generator is applied to a first position of a first welding workpiece included in a welding component to be measured, the welding component to be measured including the first welding workpiece and a second welding workpiece, and a ratio of a volume of the second welding workpiece to a volume of the first welding workpiece is greater than or equal to 2.

Fig. 3 is a schematic view showing an example of the structure of a welded member to be measured in a battery. As shown in fig. 3, the welded component to be measured includes: a welding workpiece 1 (the welding workpiece 1 may also be referred to as a first welding workpiece) and a welding workpiece 2 (the welding workpiece 2 may also be referred to as a second welding workpiece), the welding workpiece 1 and the welding workpiece 2 are welded together, and the combined whole of the welding workpiece 1 and the welding workpiece 2 may be referred to as a part to be welded. The volume of the welding workpiece 2 is twice or more the volume of the welding workpiece 1.

A vibration signal application position 3 (the vibration signal application position may also be referred to as a first position) is present on the welding workpiece 1, and a first vibration signal generated by a signal generator is applied to the vibration signal application position 3, and the first vibration signal frequency and amplitude are known. The first vibration signal generated by the signal generator propagates on the welding workpiece 1 and the welding workpiece 2. There are a plurality of welding spots on the welding areas of the welding workpiece 1 and the welding workpiece 2. For example, as shown in fig. 3, there are four welding spots, in which the welding spot 4 and the welding spot 5 are normal welding spots that are well welded, and the welding spot 6 and the welding spot 7 are dummy welding or over-welding spots.

S220, detecting vibration information by using a laser probe on at least one detection position and at least one reference detection position on the welding component to be detected, wherein at least one first detection position exists on the first welding workpiece, at least one second detection position exists on the second welding workpiece, and a welding area on the welding component to be detected is positioned between the first position and the at least one first detection position and comprises at least one welding spot.

For example, with continued reference to the example shown in fig. 3, the position 8 represents a detection position of the laser probe (the detection position is a first detection position), and the position 9 represents a reference detection position of the laser probe (the reference detection position is a second detection position), which corresponds to the reference detection position. Vibration information is detected by a laser probe at the detection position 8 and the reference detection position 9, respectively. For example: the laser probe comprises a first laser probe and a second laser probe, and vibration information is detected by the first laser probe at a detection position 8; at the reference detection position 9, vibration information is detected by the second laser probe.

As shown in fig. 3, the detection position 8 is located on the welding workpiece 1, and the reference detection position 9 is located on the welding workpiece 2.

Alternatively, in the embodiment of the present application, if the welding workpiece 1 and the welding workpiece 2 differ greatly in size, for example: the volume of the welding workpiece 2 is twice or more as large as the welding workpiece 1, in which case the detection position 8 and the vibration signal applying position 3 may both be provided on the welding workpiece 1 of a smaller size, and the reference detection position 9 may be provided on the welding workpiece 2 of a larger size. For example: the welding workpiece 2 is a pole piece, and the welding workpiece 1 is a pole lug. Alternatively, the welding workpiece 2 is a battery case, and the welding workpiece 1 is a nickel plate.

Alternatively, in the embodiment of the present application, as shown in fig. 3, the welding area 10 needs to be located between the vibration signal applying position 3 and the detecting position 8, and many welding spots (for example, welding spots 4 to 7) are included in the welding area 10, and among these welding spots, welding spots that are well welded, and welding spots that are cold or overselded are included. The welding region 13 is arranged between the vibration signal applying position 3 and the detection position 8, and after the first vibration signal is applied to the vibration signal applying position 3, the first vibration signal is attenuated by the welding region 10 and then transmitted to the detection position 8, so that the attenuated first vibration signal can be detected at the detection position 8 by the laser probe.

In the embodiment of the application, when determining the reference detection position, it is required to ensure that the reference detection position and the detection position are substantially consistent with each other in the case of external disturbance vibration, and the reference detection position is less affected by the applied vibration signal.

In the embodiment of the present application, since: the ratio of the volume of the welding workpiece 2 to the volume of the welding workpiece 1 is greater than or equal to 2, and the application position (i.e., the first position) and the detection position (i.e., the first detection position) of the first vibration signal are both located on the welding workpiece 1 with the smaller volume, and the vibration caused by the first vibration signal is larger at the detection position. The reference detection position (i.e. the second detection position) is located on the welding workpiece 2 with larger volume, the vibration caused by the first vibration signal is smaller in the reference detection position (i.e. the second detection position), and meanwhile, the vibration caused by the external interference exists in both the detection position and the reference detection position, so that the vibration information in the detection position mainly reflects the vibration condition of the welding part to be detected caused by the excitation of the vibration signal and the external interference, and the vibration information in the reference detection position mainly reflects the vibration condition of the welding part to be detected caused by the external interference.

For example, as shown in fig. 3, the reference detection position 9 may be provided around the welding region 10, and illustratively, the reference detection position 9 may be provided in the welding region surrounding region 11 shown in fig. 3.

Illustratively, the reference detection position 9 needs to be located as close as possible to the welding workpiece 1 (i.e., the part where the vibration signal is applied) and at a position less affected by the applied vibration signal. For example, as shown in fig. 3, the reference detection position 9 is located on the welding workpiece 2 (i.e., the part where the non-vibration signal application position is located), and is located in the region 11 around the welding region.

For example, in connection with the example shown in fig. 3, vibration signals are measured with two laser probes at the detection position 8 and the reference detection position 9, respectively, which vibration signals may comprise, for example: the vibration signal includes: at least one of a vibration displacement signal, a vibration velocity signal, a vibration acceleration signal, a vibration frequency signal, a vibration amplitude signal, a vibration energy signal, a vibration waveform signal, and the like.

After the application of the vibration signal, the welding workpiece 1 and the welding workpiece 2 vibrate, the vibration wave propagates along the solid, and there is also vibration at the detection position 8 and the reference detection position 9, and the vibration signal of the vibration wave can be detected by the laser probe.

Optionally, in this embodiment, the distance between the first position (i.e. the vibration signal applying position) and the welding spot is between 0.5mm and 50mm, the distance between the first detection position (i.e. the detection position) and the welding spot is between 0.5mm and 10mm, and the distance between the second detection position (i.e. the reference detection position) and the welding spot is between 0.5mm and 10mm. In this way, the accuracy and repeatability of the test results can be ensured.

In the embodiment of the present application, if there are a plurality of welding spots (for example, welding spots 4, 5, 6, and 7 shown in fig. 3) in the welding area, and the detection position and the reference detection position are each a plurality of, in this case, the distance between the first position (for example, vibration signal application position 3 shown in fig. 3) and each welding spot is between 0.5mm and 50mm, the distance between any one of the first detection positions (i.e., detection positions) and any one of the welding spots is between 0.5mm and 10mm, and the distance between any one of the second detection positions (i.e., reference detection positions) and any one of the welding spots is between 0.5mm and 10mm. In other words, there are a plurality of different distances between the different first detection positions and the different welding spots, each of the plurality of different distances being between 0.5mm and 10 mm; there are also a plurality of different distances between the different second detection positions and the different welding spots, each of the plurality of different distances being between 0.5mm and 10mm.

S230, determining difference values of vibration parameters corresponding to the at least one detection position and the at least one reference detection position respectively.

For example, in connection with the example shown in fig. 3, the signal converter converts vibration information detected by the two laser probes, respectively, into vibration parameters. Assume that: the vibration parameter (or may be referred to as a first vibration parameter) corresponding to the detection position 8 is B1, the vibration parameter (or may be referred to as a second vibration parameter) corresponding to the reference detection position 9 is B2, and the difference obtained by subtracting B2 from B1 is the difference between the vibration parameters corresponding to the detection position and the reference detection position, respectively, and the difference between the vibration parameters may be referred to as a first value or a vibration quality parameter. The difference value of the vibration parameters can reflect the welding quality of the welding part to be detected, and the vibration condition (namely the vibration parameters) of the reference detection position is deducted, namely the vibration parameters caused by external vibration of the welding part to be detected are deducted, so that the interference caused by the external vibration of the welding part to be detected is reduced, and the accuracy of detecting the welding quality of the welding part to be detected is improved. The welding quality of the welded component to be measured can be determined by comparing the difference in vibration parameters corresponding to the detected position and the reference detected position, respectively, with a parameter range (or may also be referred to as a vibration quality parameter range) determined by a plurality of welded components that are well welded.

For example, in the example shown in fig. 3, the volume of the welding workpiece 2 is twice or more the volume of the welding workpiece 1, and the vibration signal applying position 3 and the detecting position 8 are both located on the welding workpiece 1, and the reference detecting position 9 is located on the welding workpiece 2. The detection position 8 and the reference detection position 9 are relatively independent positions, the vibration information detected by the laser probe at the reference detection position 9 reflects the vibration information caused by external interference on the welding part to be detected, and the vibration information detected by the laser probe at the detection position 8 reflects the vibration information caused by external interference on the welding part to be detected and the applied vibration signal. The difference obtained by subtracting the vibration parameter corresponding to the reference detection position 9 from the vibration parameter corresponding to the detection position 8 is the vibration information actually caused by the vibration signal applied by the signal generator. In the example shown in fig. 3, the vibration signal applying position 3 and the detecting position 8 are located on the same welding workpiece 1, the reference detecting position 9 is located on the welding workpiece 2, both the detecting position 8 and the reference detecting position 9 are affected by external disturbance, and when the vibration signal is applied to the vibration signal applying position 3, the detecting position 8 is vibrated by the influence of the vibration signal, whereas the reference detecting position 9 is located on the welding workpiece 2 having a large volume and is hardly vibrated by the influence of the vibration signal. The difference obtained by subtracting the vibration parameter corresponding to the reference detection position 9 from the vibration parameter corresponding to the detection position 8 reflects the vibration influence of the welding part to be detected due to the application of the additional vibration signal.

It should be understood that in the above examples, only one detection position and one reference detection position are described, and in other embodiments of the present application, the detection position and the reference detection position may be plural, respectively.

For example: the number of detection positions is plural, and the reference detection position may be one, in which case one possible implementation is: calculating an average value (the average value may also be referred to as an average value of the first vibration parameter) of the plurality of vibration parameters obtained at the plurality of detection positions, using the average value as the vibration parameter corresponding to the detection position, and using a difference value (in this case, the vibration parameter corresponding to the reference detection position corresponds to an average value of the second vibration parameter) of the vibration parameter corresponding to each of the detection position and the reference detection position as a difference value (the difference value of the vibration parameter may also be referred to as a first value) of the vibration parameter corresponding to the detection position; another possible implementation is: first, the difference between the vibration parameter corresponding to the reference detection position and the vibration parameter corresponding to each detection position is calculated, a plurality of differences are obtained, and an average value of the plurality of differences is calculated as the difference between the vibration parameters corresponding to the detection position and the reference detection position, respectively (the difference between the vibration parameters may also be referred to as a first value).

Also for example: the detection positions are one, the reference detection positions can be a plurality, in which case one possible implementation is: calculating an average value (the average value may also be referred to as an average value of the second vibration parameter) of the plurality of vibration parameters obtained at the plurality of reference detection positions, using the average value as the vibration parameter corresponding to the reference detection position, and using a difference between the average value and the vibration parameter corresponding to the detection position (in this case, the vibration parameter corresponding to the detection position corresponds to the first vibration parameter) as a difference between the vibration parameters corresponding to the detection position and the reference detection position (the difference between the vibration parameters may also be referred to as the first value); another possible implementation is: firstly, calculating the difference value of the vibration parameter corresponding to the detection position and the vibration parameter corresponding to each reference detection position to obtain a plurality of difference values, calculating the average value of the plurality of difference values, and taking the average value as the difference value of the vibration parameter corresponding to the detection position and the reference detection position respectively.

Also for example: the number of the detection positions may be plural, and the number of the detection positions may be different from the number of the reference detection positions, in which case vibration parameters corresponding to the plural reference detection positions may be obtained, respectively, and an average value of the plural vibration parameters (the average value may also be referred to as an average value of the second vibration parameters) may be calculated; and obtaining vibration parameters corresponding to the plurality of detection positions, and calculating an average value (the average value may also be referred to as an average value of the first vibration parameters) of the plurality of vibration parameters; a difference between the average value of the first vibration parameter and the average value of the second vibration parameter is calculated, and the difference is used as a difference between vibration parameters corresponding to the detection position and the reference detection position, respectively (the difference between vibration parameters may also be referred to as a first value).

For another example: the number of detection positions is plural, the number of reference detection positions may be plural, and the number of detection positions is the same as the number of reference detection positions, in which case one possible implementation is: vibration parameters corresponding to a plurality of reference detection positions can be obtained respectively, and an average value of the plurality of vibration parameters (the average value can also be called as an average value of a second vibration parameter) is calculated; and obtaining vibration parameters corresponding to the plurality of detection positions, and calculating an average value (the average value may also be referred to as an average value of the first vibration parameters) of the plurality of vibration parameters; and calculating a difference value between the average value corresponding to the plurality of detection positions and the average value corresponding to the plurality of reference detection positions (namely, a difference value between the average value of the first vibration parameter and the average value of the second vibration parameter), and taking the difference value as a difference value between the vibration parameters corresponding to the detection positions and the reference detection positions respectively (the difference value of the vibration parameters can be also called as a first value). Another possible implementation is: first, the difference between the vibration parameter corresponding to one detection position and the vibration parameter at the reference detection position corresponding to the detection position is calculated, so that a plurality of differences can be obtained, and the average value of the plurality of differences is calculated as the difference between the vibration parameters corresponding to the detection position and the reference detection position, respectively (the difference between the vibration parameters may also be referred to as a first value). In this way, the correspondence relationship between the detection position and the reference detection position, that is, the one-to-one correspondence relationship between the detection position and the reference detection position can be set in advance.

It should also be appreciated that in the above examples, reference is merely made to the case where the reference detection position is one or more points and the detection position is one or more points. In other embodiments of the present application, the reference detection region (or may also be referred to as a second detection region) and the detection region (or may also be referred to as a first detection region) may also be set in advance, without being limited to setting one or more detection points. In this case, the detection of multiple points may be performed in the reference detection area and the detection area, respectively, the vibration information corresponding to each detection point may be obtained, and the vibration parameters obtained after the conversion by the signal converter may be obtained, so that the vibration parameters corresponding to the multiple detection points may be obtained, the average value of the vibration parameters corresponding to the reference detection area and the average value of the vibration parameters corresponding to the detection area may be calculated, and the difference between the two average values may be used as the first value.

Illustratively, in the embodiments of the present application, the vibration parameters may be: any one of vibration displacement, vibration velocity, vibration acceleration, vibration frequency, vibration amplitude, vibration energy, and the like. The specific form of the vibration parameter is not limited in the embodiments of the present application.

S240, comparing the difference value of the vibration parameters with a predetermined range of the difference value of the vibration parameters to determine the welding quality of the welding parts to be measured.

Wherein S230 and S240 may be performed by a processor.

The following describes a determination process of a range of predetermined differences, which may also be referred to as a predetermined numerical range in the present embodiment.

In the embodiment of the present application, before S210, a plurality of well-welded welding parts are first selected manually. The plurality of welded parts that are well welded and the welded part to be detected that is actually detected are the same, and the structure, the size, the welding position, the welding process, and the like are the same, for example, each welded part that is well welded includes a first welded part and a second welded part. In other words, a plurality of well-welded parts are identical to those to be welded except that the parts to be welded have poor welding points (e.g., cold welding, overselding, etc.).

After obtaining a plurality of well-welded parts, the vibration signal (or also referred to as a second vibration signal) generated by the signal generator is applied to each well-welded part, and at least one detection position (the detection position on the well-welded part may also be referred to as a third detection position) and at least one reference detection position (the reference detection position on the well-welded part may also be referred to as a fourth detection position) are present on each well-welded part. Vibration information is detected at a third detection position and a fourth detection position on each welded component which are well welded by using a laser probe (for example, a plurality of laser probes), and the vibration information detected by the laser probe of the signal converter is converted into vibration parameters. The vibration parameter corresponding to each third detection position on the welded component that is well welded may also be referred to as a third vibration parameter, and the vibration parameter corresponding to each fourth detection position on the welded component that is well welded may also be referred to as a fourth vibration parameter. And further determining the difference value of the vibration parameters (i.e., the difference value of the third vibration parameter and the fourth vibration parameter) respectively corresponding to the detection position and the reference detection position. In other words, the steps S210 to S230 are performed for each welded component that is well welded, resulting in a difference in the corresponding vibration parameter for each welded component that is well welded (the difference in the vibration parameter may also be referred to as the vibration quality parameter for each welded component that is well welded).

It should be understood that the vibration frequency or vibration amplitude of the vibration signal applied to the plurality of welded good components is the same, in other words, the magnitude, form, application position, etc. of the second vibration signal applied to each welded good component is the same. The magnitude, form, application position, etc. of the second vibration signal applied to each welded component that is well welded are also the same as the magnitude, form, application position of the first vibration signal applied to the welded component to be measured, that is, the same vibration signal is applied to each of the welded components that are well welded and the welded component to be measured.

It should also be appreciated that the number, position, etc. of probe locations (third probe location) and reference probe locations (fourth probe location) are the same for different well-welded components.

It should also be understood that the number, position, etc. of the detected positions (third detected positions) on each of the welded parts that are well welded are the same as the number, position, etc. of the detected positions (first detected positions) on the welded parts to be measured; the number, position, etc. of reference detection positions (fourth detection positions) on each welded component that is well welded are also the same as the number, position, etc. of reference detection positions (second detection positions) on the welded component to be measured.

For example, in connection with the example shown in fig. 3, fig. 3 is a schematic view of the structure of a welded component to be measured, fig. 4 is a schematic view of the structure of a welded component with good welding corresponding to the welded component to be measured, and as shown in fig. 4, the welded component with good welding also includes: the welding workpiece 1a and the welding workpiece 2a, the welding workpiece 1a and the welding workpiece 2a are welded together, the whole of the welding workpiece 1a and the welding workpiece 2a can be called a welding part, a vibration signal applying position 3a is arranged on the welding workpiece 1a, a vibration signal generated by a signal generator is applied to the vibration signal applying position 3a, and a plurality of welding spots are arranged on a welding area of the welding workpiece 1a and the welding workpiece 2 a. For example, as shown in fig. 4, there are four welding spots, namely, a welding spot 4a, a welding spot 5a, a welding spot 6a, and a welding spot 7a, which are all normal welding spots that are good welding.

The welding workpiece 1a shown in fig. 4 and the welding workpiece 2a, the detection position 8a, the vibration signal application position 3a, the reference detection position 9a, the welding region 10a, the welding region surrounding region 11a, and the welding workpiece 1 shown in fig. 3 and the welding workpiece 2 detection position 8, the vibration signal application position 3, the reference detection position 9, the welding region 10, the welding region surrounding region 11 positions are all the same. In other words, the structure shown in fig. 3 and 4 is identical except for the presence of defective solder joints 6 and 7 in fig. 3 (including structure, size, solder position, solder process, etc.). The second vibration signal applied to the vibration signal application position 3a by the signal generator and the vibration signal of the first vibration signal applied to the vibration signal application position 3 are identical in magnitude, form (for example, amplitude, frequency, etc.).

In the structure shown in fig. 4, after the steps S210 to S230 are performed, a difference value of vibration parameters (i.e., a difference value of a third vibration parameter and a fourth vibration parameter) corresponding to a detection position (i.e., a third detection position) and a reference detection position (i.e., a fourth detection position) on each of the welded parts that are well welded may be calculated, and the difference value of the third vibration parameter and the fourth vibration parameter corresponding to each of the welded parts that are well welded may also be referred to as a vibration quality parameter of each of the welded parts that are well welded. Thus, the difference values (vibration mass parameters) of the vibration parameters corresponding to the plurality of welded parts having good welding are obtained, and the difference values (vibration mass parameters) of the vibration parameters are calculated, thereby obtaining a predetermined difference range.

For example, assuming that 32 welded parts are used, after S210 to S230 are performed for each welded part, a difference in vibration parameters corresponding to each welded part can be obtained, in the example shown in fig. 4, a difference in vibration quality parameters corresponding to each welded part can also be referred to as a third vibration parameter and a fourth vibration parameter, namely, 32 pieces of data (namely, 32 vibration quality parameters) are obtained, and after eliminating abnormal data for the obtained 32 pieces of data, the remaining data is taken as basic data, normal distribution is made, and an average value (denoted as X ₁ ) And standard deviation sigma, select average value X ₁ The values of the standard deviation of 3 times up and down are taken as a1 and a2, so that the normal range of the vibration parameter difference value corresponding to the welding parts which are well welded is (a 1, a 2), namely [ X ] ₁ -3×σ,X ₁ +3×σ]I.e. the predetermined difference range is [ X ] ₁ -3×σ,X ₁ +3×σ]。

It should be understood that if there are multiple probe positions and reference probe positions for each of the plurality of well-welded parts, the method of calculating the difference in vibration parameters corresponding to the different welded parts is the same for the different welded parts.

For example, assuming that there are two detection positions (i.e., two third detection positions) and two reference detection positions (i.e., two fourth detection positions) on each welded component that is well welded, in this case, for any one welded component that is well welded, two vibration parameters (i.e., two third vibration parameters) corresponding to the two detection positions may be calculated as an average value of the two vibration parameters corresponding to the two detection positions (the average value of the vibration parameters corresponding to the two detection positions, respectively, may also be referred to as an average value of the third vibration parameters). Similarly, two vibration parameters (i.e., two fourth vibration parameters) corresponding to the two reference detection positions may be calculated to obtain an average value of the two vibration parameters corresponding to the two reference detection positions (the average value of the vibration parameters corresponding to the two reference detection positions may also be referred to as an average value of the fourth vibration parameter), and a difference between the average value of the third vibration parameter and the average value of the fourth vibration parameter is used as the vibration quality parameter of the welded component having good welding.

It will also be appreciated that the method of calculating the difference in vibration parameters separately for each of the welded component that is well welded and the welded component that is to be measured is the same.

In the above manner, a range of differences predetermined by the welded parts that are well welded can be obtained.

The difference value (i.e., the first value) of the vibration parameters of the welded component to be measured calculated in S230 is compared with the predetermined difference range.

If the difference value of the vibration parameters of the to-be-measured welding component is within the predetermined difference value range, the quality of the to-be-measured welding component is proved to be good, and the to-be-measured welding component is qualified to be welded;

if the difference value of the vibration parameters of the welded component to be detected is not in the predetermined difference value range, the quality of the welded component to be detected is poor, and the welded component with unsuitable welding quality is proved to have the defects of cold joint, overseld and the like.

The method for detecting the welding quality of the battery by utilizing the vibration signal applies the vibration signal (namely, a first vibration signal) to a vibration signal application position (namely, a first position) of a welding workpiece 1 (namely, a first welding workpiece) of a welding part to be detected in the battery, after the vibration signal is excited, the welding part to be detected generates vibration information on a detection position (namely, a first detection position) on the welding workpiece 1 and a reference detection position (namely, a second detection position) on a welding workpiece 2 (namely, a second welding workpiece) respectively, after the vibration information is detected by a laser probe (a first laser probe and a second laser probe), the vibration information is converted into vibration parameters (the detection position corresponds to the first vibration parameter, the reference detection position corresponds to the second vibration parameter), comparing the difference value of vibration parameters (namely, the difference value of the first vibration parameter and the second vibration parameter) corresponding to the detection position and the reference detection position with the parameter range determined by the welding component with good welding quality to determine the welding quality of the welding component to be detected, subtracting the vibration condition of the reference detection position, namely subtracting the vibration parameter of the welding component to be detected caused by external vibration, reducing the interference caused by the external vibration to the welding component to be detected, improving the detection precision, accurately detecting the welding quality of the welding component to be detected, effectively screening out welding defective products, realizing nondestructive (or nondestructive) detection of the welding component to be detected, being applicable to the welding quality of the welding component with complex detection mechanism, having better universality, the welding condition of the part to be detected can be continuously detected on line, and the welding effect of all the welded parts can be monitored in real time, so that the welding quality of the battery is ensured, and the occurrence of the defects of cold joint or over-welding is avoided.

Alternatively, in other embodiments of the present application, an optical fiber may be used in conjunction with the laser probe in order to further increase the useful life of the laser probe. For example, a fiber optic sensor may be placed in series before the laser probe. For example, fig. 5 is a schematic diagram of another system for detecting welding quality of a battery by using a vibration signal according to an embodiment of the present application, and the method for detecting welding quality of a battery by using a vibration signal according to the present application may also be applied to the detection system shown in fig. 5. As shown in fig. 5, the system includes:

a signal generator 501, a welding part 502 to be measured, a fiber optic sensor 506, a rheostat 507, a laser probe 503, a signal converter 504, a display 505, and a power supply 508.

The descriptions of the signal generator 501, the to-be-measured welding component 502, the laser probe 503, the signal converter 504, and the display 505 may refer to the corresponding specific descriptions of fig. 1, and for brevity, the descriptions are omitted here.

The power supply 508 is used to supply power to the optical fiber sensor 506, the varistor 507, and the laser probe 503, where the optical fiber sensor 506 and the laser probe 503 are connected to the to-be-measured welding component 502, and the optical fiber sensor 506 can sense an application region (for example, a pole piece application region (the pole piece application region may also be referred to as a current collector application region) and a non-application region (for example, a pole piece non-application region (the pole piece non-application region may also be referred to as a current collector)) of the to-be-measured welding component 502 (when the optical fiber sensor 506 detects the non-application region on the to-be-measured welding component 502, the internal resistance of the varistor 507 is reduced, the current in the circuit is increased, and the current in the circuit is reduced, so that the power of the laser probe 503 is reduced to a smaller power value).

Optionally, the laser probe shown in fig. 5 includes: the laser probes whose detection positions and reference detection positions correspond respectively, that is, the laser probe shown in fig. 5 includes a plurality of laser probes, in which case the varistor and the plurality of laser probes are in a serial relationship.

Optionally, in the system shown in fig. 5, a processor may further include a processor, where the processor is configured to calculate the vibration parameter obtained by the signal converter 504 to obtain a first value, and compare the first value with a predetermined range of values to determine the welding quality of the welded component to be measured. In other words, the processor is mainly used for calculating and processing the vibration parameters, and comparing the processed data (namely, the difference value of the vibration parameters corresponding to the detection position and the reference detection position) with a predetermined numerical range to determine the welding quality of the welding component to be detected.

It should be appreciated that in the system shown in fig. 5, the display 505 is optional.

Fig. 6 is a schematic diagram of a detection system for continuously detecting whether there is a cold joint or an overseld in a tab on a battery pole piece. As shown in fig. 6, the detection system includes:

Signal generator 601, welded part 602 to be tested, optical fiber sensor 603, rheostat 604, laser probe 605, signal converter 606, display 607, power supply 608.

Wherein, the welding part 602 to be measured comprises: tab 602a, a pole piece non-dressing region (or non-dressing region that may be referred to as a current collector) 602b, and a pole piece dressing region (or dressing region that may be referred to as a current collector) 602c.

The power supply 608 is used to power the fiber sensor 603, the varistor 604 and the laser probe 605, and the fiber sensor 603, the laser probe 605 and the welding member 602 to be measured are not in contact.

Alternatively, in the embodiment of the present application, the signal generator 601 and the to-be-welded component 602 may or may not be in contact.

Optionally, in the embodiment of the present application, the distance between the optical fiber sensor 603 and the laser probe 605 is less than 2mm, so as to ensure that the optical fiber sensor and the laser probe detect the same non-dressing area or the same dressing area.

In the present embodiment, if the laser probe 605 includes a plurality of laser probes, the distance between the fiber sensor and each laser probe is less than 2mm.

In the inspection system shown in fig. 6, a signal generator 601 generates a vibration signal that is transmitted to a part 602 to be welded, and a fiber sensor 603, a varistor 604, and a laser probe 605 are connected in series. The part 602 to be soldered can be moved relative to the fiber sensor 603, the varistor 604 and the laser probe 605. In other words, the part 602 to be welded can move in one direction, and the positions of the optical fiber sensor 603, the rheostat 604 and the laser probe 605 are relatively unchanged, so that the welding condition of the part 602 to be welded can be continuously measured on line.

When the optical fiber sensor 603 detects that the electrode piece on the to-be-detected welding part 602 is not arranged on the dressing area 602b, the internal resistance of the rheostat 604 is reduced, the current in the circuit is increased, and the power of the laser probe 605 is increased to a normal working value. When the fiber sensor 603 detects that the electrode pad dressing area 602c on the to-be-measured welding part 602, the internal resistance of the rheostat 604 increases, the current in the circuit decreases, and the power of the laser probe 605 is reduced to a smaller power value. The method can reduce the power of the laser probe during operation and prolong the service life of the laser probe.

The laser probe 605 can detect vibration information at the detection position on the welding member 602 and the reference detection position, respectively. After the signal converter 606 acquires the vibration information detected by the laser probes 605, the vibration information is converted into vibration parameters, for example, the signal converter 606 may convert the vibration information detected by the laser probes 605 into acoustic signals or digital signals. Further, according to the vibration parameters converted by the signal converter 606, the difference between the vibration parameters corresponding to the detection position and the reference detection position may be determined by the step in S230. Then, by comparing the difference value of the vibration parameter with a predetermined range of the difference value of the vibration parameter, the welding quality of the welding member 602 to be measured can be determined by the step in S240 described above. The display 607 may display the signals converted by the display signal converter 606, that is, the vibration parameters of the to-be-measured welding member 602 after the vibration signals are applied. For example: the converted data can be displayed in a chart or digital form on the display 607, so that the vibration condition of different components can be conveniently compared and analyzed.

According to the method for detecting the welding quality of the battery by using the vibration signal, the vibration signal (namely, the first vibration signal) is applied to the welding workpiece 1 (namely, the first welding workpiece) of the welding component to be detected in the battery, after the vibration signal is excited, the vibration information is generated on the detection position (namely, the first detection position) on the welding workpiece 1 and the reference detection position (namely, the second detection position) on the welding workpiece 2 (namely, the second welding workpiece) respectively, after the vibration information is detected by the laser probe (the first laser probe and the second laser probe), the vibration information is converted into the vibration parameters (the detection position corresponds to the first vibration parameter and the reference detection position corresponds to the second vibration parameter), the difference value (namely, the difference value between the first vibration parameter and the second vibration parameter) of the vibration parameters) respectively corresponding to the detection position and the parameter range determined by the welding component with good welding performance are compared, so as to determine the welding quality of the welding component to be detected, the vibration condition (vibration parameter) of the reference detection position is deducted, namely, the vibration parameter caused by the welding component to be detected is subtracted, the vibration condition (vibration parameter) to be detected, the welding component to be detected is detected, the interference caused by the welding component to be detected, the welding component to be detected is reduced, the welding component to be detected is detected, the real-time is detected, the welding quality is improved, or the welding component to be detected continuously, the welding quality can be detected, or the welding component to be detected, and has no real-time, and can be detected, and the welding component is detected, the occurrence of the cold joint or the overselding defect is avoided. And the optical fiber sensor is arranged in front of the laser probe to control the power of the laser probe, so that the service life of the laser probe can be prolonged.

The embodiment of the application also provides a system for detecting the welding quality of the battery by using the vibration signal, which comprises a signal generator, a laser probe, a signal converter and a display.

Wherein the signal generator is used for generating a vibration signal, and the vibration frequency, the vibration amplitude and the like of the vibration signal are fixed.

The vibration signal (i.e., the first vibration signal) generated by the signal generator is applied to the welded component to be measured. The laser probe (including, for example, a first laser probe and a second laser probe) is used to detect vibration information generated at a detection position (first detection position) and a reference detection position (second detection position), respectively, of a welding member to be measured after a vibration signal is applied, and the vibration information includes, for example: at least one of a vibration displacement, a vibration velocity, a vibration acceleration, a vibration frequency, a vibration amplitude, a vibration energy, a vibration waveform, and the like. The signal converter is connected with the laser probe and is used for converting vibration information detected by the laser probe into vibration parameters (the detection position corresponds to the first vibration parameter, and the reference detection position corresponds to the second vibration parameter). For example, the signal converter may convert vibration information detected by the laser probe into an acoustic signal or a digital signal, etc., so as to present the vibration information detected by the laser probe in a data or digital manner. The display is used for displaying the signals converted by the signal converter, namely, the vibration parameters of the welding component to be tested after the vibration signals are applied. For example: the converted data can be displayed in a chart or digital form on a display, so that the vibration conditions of different components can be conveniently compared and analyzed. For example, the structure of the system for determining battery welding quality using vibration signals provided herein may be as shown in fig. 1.

It should be appreciated that in the system shown in fig. 1, the display 105 is optional. In other words, the system provided in embodiments of the present application may also not include a display.

Optionally, in the system shown in fig. 2, a processor may further include a processor, where the processor is configured to calculate the vibration parameter obtained by the signal converter, obtain a difference value (which may also be referred to as a vibration quality parameter or a first value) of the vibration parameter corresponding to each of the detected position and the reference detected position, and compare the first value with a predetermined range of values (which may also be referred to as a predetermined range of values) to determine the welding quality of the welded component to be measured.

Alternatively, the system for determining the welding quality of a battery using vibration signals provided by the present application may not include the welded component to be measured in fig. 1.

It should be understood that in the embodiment of the present application, the number of the laser probes may be one, or may be plural.

The process of detecting the welding quality of the to-be-detected welding component by using the system for detecting the welding quality of the battery by using the vibration signal provided by the application can refer to the corresponding descriptions of fig. 1 and fig. 2, and for brevity, the description is omitted here.

According to the system for detecting the welding quality of the battery by using the vibration signal, the vibration signal (namely, the first vibration signal) is generated through the signal generator, the vibration signal is applied to the welding workpiece 1 (namely, the first welding workpiece) of the welding part to be detected, the vibration information is generated on the detection position (namely, the first detection position) of the welding workpiece 1 and the reference detection position (namely, the second detection position) of the welding workpiece 2 (namely, the second welding workpiece) respectively, after the vibration information is detected through the laser probe, the vibration information detected by the laser probe is converted into the vibration parameter (the detection position corresponds to the first vibration parameter, the reference detection position corresponds to the second vibration parameter), the difference value (namely, the difference value of the first vibration parameter and the first vibration parameter) of the vibration parameter) respectively corresponding to the detection position and the parameter range determined by the welding part with good welding performance are compared, so that the welding quality of the welding part to be detected is determined, the vibration condition of the welding part to be detected is deducted, namely, the vibration parameter caused by external vibration to the welding part to be detected is deducted, interference of the detection result caused by the external vibration is reduced, the detection result is detected through the laser probe, the detection position corresponds to the first vibration parameter, the detection position corresponds to the second vibration parameter, the difference value corresponds to the first vibration parameter, the difference value is different from the first vibration parameter, the welding part is different from the first vibration parameter, the welding quality is detected by the welding part, and the welding quality is different from the welding part. And moreover, the welding condition of the part to be detected can be continuously detected on line, so that the welding effect of all the welded parts can be monitored in real time, the welding quality of the battery is ensured, and the occurrence of false welding or over-welding defects is avoided.

Alternatively, in another possible implementation manner, on the basis of the system for detecting the welding quality of the battery by using the vibration signal provided by the application, the system may further include an optical fiber sensor, where the optical fiber sensor is connected in series before the laser probe, for example, the structure of the system for detecting the welding quality of the battery by using the vibration signal provided by the application may be as shown in fig. 5, for example: when the welding quality of the pole piece and the pole lug is detected on line, as the welding area is positioned in the non-coating area of the pole piece, when the optical fiber sensor detects the non-coating area of the pole piece, the power of the laser probe is increased to a normal working value; when the optical fiber sensor detects the coating area of the pole piece, the power of the laser probe is reduced to a smaller power value, so that the power of the laser probe in operation can be reduced, and the service life of the laser probe is prolonged.

Optionally, in an embodiment of the present application, a distance between the optical fiber sensor and the laser probe is less than 2mm, so as to ensure that the optical fiber sensor and the laser probe detect the same non-dressing area or the same dressing area.

In an embodiment of the present application, if the system comprises a plurality of laser probes, the distance between the fiber optic sensor and each laser probe is less than 2mm.

It should be appreciated that in the system shown in fig. 5, the display 505 is optional. In other words, the system provided in embodiments of the present application may also not include a display.

Optionally, in the system shown in fig. 5, a processor may further include a processor, where the processor is configured to calculate the vibration parameter obtained by the signal converter 504, obtain a difference value (which may also be referred to as a vibration quality parameter or a first value) of the vibration parameter corresponding to each of the detected position and the reference detected position, and compare the first value with a predetermined range of values (which may also be referred to as a predetermined range of values) to determine the welding quality of the welded component to be measured.

It should be understood that the example shown in fig. 5 is merely an example of the structure of the detection system provided in the present application, and is not meant to limit the structure of the detection system, and in other embodiments of the present application, the detection system may include more or less components than those shown, for example, may not include the power source and/or the welding component to be measured in fig. 5, or may combine some components, or different components, etc. The application is not limited herein.

According to the system for detecting the welding quality of the battery by using the vibration signal, the vibration signal (namely, the first vibration signal) is generated through the signal generator, the vibration signal is applied to the welding workpiece 1 (namely, the first welding workpiece) of the welding part to be detected, vibration information is generated on the detection position (namely, the first detection position) of the welding workpiece 1 and the reference detection position (namely, the second detection position) of the welding workpiece 2 (namely, the second welding workpiece) respectively, after the vibration information is detected through the laser probe, the vibration information detected by the laser probe is converted into the vibration parameter (the detection position corresponds to the first vibration parameter, the reference detection position corresponds to the second vibration parameter), and the difference value (namely, the difference value between the first vibration parameter and the first vibration parameter) of the vibration parameter corresponding to the detection position and the parameter range determined by the welding part with good welding is compared, so that the welding quality of the welding part to be detected is determined. The optical fiber sensor is connected in series before the laser probe, so that the power of the laser probe during operation can be reduced, the service life of the laser probe is prolonged, and the service life and the stability of the system are improved. In addition, the vibration condition of the reference detection position is deducted, namely, the vibration parameters caused by external vibration to the to-be-detected welding part are deducted, the interference of the external vibration to the detection result is reduced, the detection precision is improved, the welding quality of the to-be-detected welding part can be accurately detected, the welding defective products are effectively screened out, the nondestructive (or nondestructive) detection of the to-be-detected welding part is realized, the welding condition of the to-be-detected part can be continuously detected on line, the welding effect of all the welding parts in the battery can be monitored in real time is realized, the occurrence of false welding or overselding defects is avoided, and the service life and the stability of the system are improved.

It should be understood that the foregoing is only intended to assist those skilled in the art in better understanding the embodiments of the present application and is not intended to limit the scope of the embodiments of the present application. It will be apparent to those skilled in the art from the foregoing examples that various equivalent modifications or variations can be made, for example, in which some steps of the methods described above are not required, or in which some steps are newly added, etc. Or a combination of any two or more of the above. Such modifications, variations, or combinations are also within the scope of embodiments of the present application.

It should also be understood that the various numbers referred to in the embodiments of the present application are merely descriptive convenience and are not intended to limit the scope of the embodiments of the present application. The sequence numbers of the above-mentioned processes do not mean the sequence of execution sequence, and the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

It is also to be understood that in the various embodiments of the application, terms and/or descriptions of the various embodiments are consistent and may be referenced to one another in the absence of a particular explanation or logic conflict, and that the features of the various embodiments may be combined to form new embodiments in accordance with their inherent logic relationships.

It will be clear to those skilled in the art that, for convenience and brevity of description, the specific working procedures of the systems, apparatuses and units described above may refer to the corresponding procedures in the foregoing embodiments, and are not repeated here.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of detecting a welding quality of a battery using a vibration signal, the battery including a welding component to be measured, the welding component to be measured including a first welding workpiece and a second welding workpiece, a ratio of a volume of the second welding workpiece to a volume of the first welding workpiece being greater than or equal to 2, the method comprising:

applying a first vibration signal to a first location on the first weld workpiece;

detecting vibration information on at least one first detection location on the first welded workpiece with a first laser probe;

Vibration information at least one second detection location on the second welded workpiece using a second laser probe;

converting the vibration information at the at least one first detection position into a first vibration parameter;

converting the vibration information at the at least one second detection location into a second vibration parameter;

determining a first value according to the first vibration parameter and the second vibration parameter;

when the first numerical value is in a predetermined numerical value range, determining that the welding quality of the to-be-welded part is good;

when the first numerical value is not in a predetermined numerical value range, determining that welding defects exist in the to-be-welded component;

wherein a welding area on the part to be welded is positioned between the first position and the at least one first detection position, and the welding area comprises at least one welding spot;

the predetermined numerical range is determined according to vibration parameters corresponding to a plurality of welding components with good welding, and the structure, the size, the welding position and the welding process of each welding component with good welding are the same as those of the welding component to be detected.

2. The method of claim 1, wherein determining a first value based on the first vibration parameter and the second vibration parameter comprises:

determining an average value of the first vibration parameters corresponding to the at least one first detection position according to the first vibration parameters corresponding to each first detection position;

determining an average value of the second vibration parameters corresponding to the at least one second detection position according to the second vibration parameters corresponding to each second detection position;

and taking the difference between the average value of the first vibration parameter and the average value of the second vibration parameter as the first numerical value.

3. The method according to claim 1 or 2, characterized in that the distance between the first position and the welding spot is 0.5-50 mm, the distance between the first detection position and the welding spot is 0.5-10 mm, and the distance between the second detection position and the welding spot is 0.5-10 mm.

4. A method according to claim 3, characterized in that the method further comprises:

detecting non-coating areas and coating areas on the to-be-welded component by using an optical fiber sensor, wherein the optical fiber sensor is connected in series before the first laser probe and the second laser probe;

When the optical fiber sensor detects a non-coating area on the welding part to be detected, the first laser probe and the second laser probe detect vibration information of the non-coating area after the first vibration signal is applied by using first power;

when the optical fiber sensor detects that the optical fiber sensor detects the coating area on the welding part to be detected, the first laser probe and the second laser probe detect vibration information of the coating area after the first vibration signal is applied by using second power;

the second power is less than the first power, and the welding region is located in the non-coated region.

5. The method according to claim 1 or 2, wherein the vibration information comprises: at least one of vibration displacement information, vibration velocity information, vibration acceleration information, vibration frequency information, vibration amplitude information, vibration energy information, and vibration waveform information;

the vibration parameters include: at least one of vibration displacement parameter, vibration speed parameter, vibration acceleration parameter, vibration frequency parameter, vibration amplitude parameter, vibration energy parameter, and vibration waveform parameter.

6. A method according to claim 3, wherein the predetermined range of values is obtained by:

Applying a second vibration signal to the plurality of welded parts, wherein the amplitudes and frequencies of the first vibration signal and the second vibration signal are the same, and the second vibration signal is the same at the application positions and the first positions of the plurality of welded parts;

detecting vibration information of each welding-good welding component after the second vibration signal is applied on a third detection position and a fourth detection position on each welding-good welding component, wherein the number and the positions of the third detection positions on different welding-good welding components are the same, the number and the positions of the fourth detection positions on different welding-good welding components are the same, the number and the positions of the third detection positions on each welding-good welding component are the same as those of the first detection positions on the welding component to be detected, and the number and the positions of the fourth detection positions on each welding-good welding component are the same as those of the second detection positions on the welding component to be detected;

converting vibration information at a third detection position on the plurality of welded parts with good welding performance into a third vibration parameter;

Converting vibration information at a fourth detection position on the plurality of welded parts with good welding performance into a fourth vibration parameter;

and obtaining the predetermined numerical range according to the third vibration parameter and the fourth vibration parameter.

7. The method of claim 6, wherein said deriving said predetermined range of values from said third vibration parameter and said fourth vibration parameter comprises:

determining an average value of the third vibration parameter corresponding to each well-welded part;

determining an average value of the fourth vibration parameter corresponding to each well-welded part;

determining a difference value between the average value of the third vibration parameter and the average value of the fourth vibration parameter corresponding to each welding component with good welding as a vibration quality parameter of each welding component with good welding;

determining an average value X of vibration quality parameters corresponding to the plurality of welded parts according to the vibration quality parameters of each welded part ₁ And standard deviation sigma;

the predetermined range of values is:

[X ₁ -3×σ,X ₁ +3×σ]。

8. a method according to claim 3, wherein the first welded workpiece is a tab and the second welded workpiece is a pole piece.

9. A system for detecting battery weld quality using a vibration signal, the system comprising: the system comprises a signal generator, a laser probe, a signal converter and a processor, wherein the laser probe comprises a first laser probe and a second laser probe, the battery comprises a to-be-detected welding component, the to-be-detected welding component comprises a first welding workpiece and a second welding workpiece, the ratio of the volume of the second welding workpiece to the volume of the first welding workpiece is greater than or equal to 2, and the system is used for executing the method for detecting the welding quality of the battery by using the vibration signal.

10. The system of claim 9, wherein the system further comprises: the optical fiber sensor is connected in series before the first laser probe and the second laser probe;

the optical fiber sensor is used for: detecting non-coating areas and coating areas on the welding part to be detected;

the second power is less than the first power, the welding region being in the non-coated region;

the distance between the optical fiber sensor and the first laser probe is less than or equal to 2mm;

the distance between the optical fiber sensor and the second laser probe is less than or equal to 2mm.