Welding quality detection system and method

Abstract

The embodiment of the invention provides a welding quality detection system and method. The system comprises an excitation source, a welding assembly electrically connected with the excitation source and detection equipment electrically connected with the welding assembly. The excitation source is used for sending first electric signals to the welding assembly. The detection equipment is used for obtaining a second electric signal output by the welding assembly and determining the welding quality of the welding assembly based on gain information of the second electric signal and a preset frequency interval, and the second electric signal is used for indicating a response signal of the welding assembly to the first electric signal. According to the invention, the reliability of welding quality detection can be improved.

Description

Technical Field

[0001] The present application relates to the field of manufacturing, and in particular to a welding quality detection system and method. Background Art

[0002] Soldering technology is widely used in various connection situations. However, due to factors such as materials, environment, and process, cold solder joints may occur. Cold solder joints can cause functional and safety issues in components. Therefore, it is necessary to test the soldering quality of components.

[0003] In the related art, manual inspection or other equipment-assisted inspection is usually required. However, the above method has the problem of high detection error rate and poor reliability of welding quality detection. Summary of the Invention

[0004] The embodiments of the present application provide a welding quality detection system and method to improve the problems of high misjudgment rate and poor reliability in welding quality detection.

[0005] In a first aspect, an embodiment of the present application provides a welding quality detection system, the system comprising: an excitation source and a welding assembly electrically connected to the excitation source, the excitation source being used to send a first electrical signal to the welding assembly; a detection device electrically connected to the welding assembly, the detection device being used to obtain a second electrical signal output by the welding assembly, and determining the welding quality of the welding assembly based on gain information of the second electrical signal and a preset frequency range, wherein the second electrical signal is used to indicate a response signal of the welding assembly to the first electrical signal.

[0006] In a welding quality detection system provided in an embodiment of the present application, an excitation source is used to input a first electrical signal into a welding component, and based on the gain information of a second electrical signal output by the welding component and a preset frequency range, it is determined whether the frequency response information of the second electrical signal meets the preset frequency response characteristics, thereby detecting the welding quality of the welding component. The parallel resonant network constructed by the welding component itself can be used to detect the welding quality when the welding component is in an intact state, thereby reducing the misjudgment rate of the welding quality detection and improving the reliability of the welding quality detection.

[0007] In some embodiments, the welded assembly includes a weld and a weld, the weld and the weld are used to represent the parallel resonant network, and the second electrical signal is used to indicate a response signal of the parallel resonant network to the first electrical signal.

[0008] The embodiment of the present application uses welded parts and welds to characterize a parallel resonant network, and analyzes the frequency response information of the parallel resonant network's response signal to a first electrical signal (i.e., a second electrical signal). By analyzing whether the frequency response information of the second electrical signal conforms to a preset frequency response characteristic, the welding quality of the welded assembly is detected. The welding quality can be detected while the welded assembly is intact. Moreover, by detecting the welding quality by analyzing the electrical signal, the error rate of the welding quality detection can be reduced, thereby improving the reliability of the welding quality detection.

[0009] In some embodiments, the welding part includes a first metal layer, a first bending portion, a second metal layer and a second bending portion, the first metal layer is connected to the first bending portion, the second metal layer is connected to the second bending portion, the first metal layer and the second metal layer are arranged along the first direction, the first metal layer is connected to the second metal layer through a weld, and the first bending portion and the second bending portion are spaced apart along the second direction; the welding assembly includes multiple welds, and the multiple welds are spaced apart along the second direction; wherein the second direction is perpendicular to the first direction.

[0010] In an embodiment of the present application, the first metal layer and the second metal are connected through a plurality of welds arranged at intervals, so that the welding assembly can be used to characterize a parallel resonant network, thereby using the welding assembly itself to build a parallel resonant network, and realizing signal conversion through the parallel resonant network to detect the welding quality. On the one hand, the welding quality can be detected more accurately, and on the other hand, there is no need to set up other additional devices to convert the signal output by the excitation source; and the present application connects the first metal layer to the first bending portion, and the second metal layer to the second bending portion, the first metal layer and the second metal layer are arranged along the first direction, and the first bending portion and the second bending portion are spaced apart along the second direction. The above structure facilitates the electrical connection between the excitation source and the welding assembly, as well as the electrical connection between the detection equipment and the welding assembly, which can improve the stability of the electrical signal transmission, and thereby improve the accuracy of the welding quality detection.

[0011] In some embodiments, the excitation source includes a signal generator, a first signal line, a second signal line, a first signal terminal, and a second signal terminal; the signal generator, the first signal line, the first signal terminal, and the first metal layer are electrically connected in sequence; the second bend, the second signal terminal, the second signal line, and the signal generator are electrically connected in sequence, and the second bend is electrically connected to the ground terminal.

[0012] In this embodiment, the signal generator, first signal line, and first signal terminal serve as the transmission path for the first electrical signal, while the second bend, second signal terminal, and second signal line serve as the return path for the first electrical signal. By electrically connecting the second bend to the ground terminal, the first electrical signal can flow back smoothly, thereby improving the integrity of signal transmission.

[0013] In some embodiments, the detection equipment includes an oscilloscope, a third signal line, a fourth signal line, a first probe and a second probe; the first bending portion, the first probe, the third signal line and the oscilloscope are electrically connected in sequence; the second metal layer, the second probe, the fourth signal line and the oscilloscope are electrically connected in sequence, and the second probe is electrically connected to the ground end.

[0014] In this embodiment, the first bend, the first probe, and the third signal line serve as the receiving path for the second electrical signal, while the second metal layer, the second probe, and the fourth signal line serve as the return path for the second electrical signal. By electrically connecting the second probe to the ground terminal, the second electrical signal returns smoothly, thereby improving signal transmission integrity.

[0015] In some embodiments, the welding method of the welded part includes laser welding; the welded part includes a first electrode terminal and a second electrode terminal, the first electrode terminal includes a first metal layer and a first bending portion, and the second electrode terminal includes a second metal layer and a second bending portion.

[0016] The embodiment of the present application can improve the welding accuracy and welding speed of the first electrode terminal and the second electrode terminal by laser welding the first electrode terminal and the second electrode terminal, thereby improving the welding effect; and the welding part includes the first electrode terminal and the second electrode terminal, and by welding the first electrode terminal and the second electrode terminal, a current path is formed between multiple battery cells, thereby realizing high-power discharge of the battery; and the first electrode terminal of the present application includes a first metal layer and a first bending portion, and the second electrode terminal includes a second metal layer and a second bending portion. By overlapping the first electrode terminal and the second electrode terminal by bending, the strength of the welding assembly can be enhanced and the anti-peeling force can be improved; in addition, by providing the first metal layer and the first bending portion, as well as the second metal layer and the second bending portion, it is convenient to electrically connect the excitation source to the welding assembly, and the detection equipment to the welding assembly, thereby improving the stability of electrical signal transmission, and thereby improving the accuracy of welding quality detection.

[0017] In a second aspect, an embodiment of the present application provides a welding quality detection method, which is applied to any of the above-mentioned welding quality detection systems, and the method includes: an excitation source sends a first electrical signal to a welding component; the welding component responds to the first electrical signal and generates a second electrical signal; the detection device obtains the second electrical signal, and determines the welding quality of the welding component based on the gain information of the second electrical signal and a preset frequency range.

[0018] In a welding quality detection method provided in an embodiment of the present application, an excitation source is used to input a first electrical signal into a welding component, and based on the gain information and a preset frequency range of a second electrical signal output by the welding component, it is determined whether the frequency response information of the second electrical signal meets the preset frequency response characteristics, thereby detecting the welding quality of the welding component. The welding quality can be detected when the welding component is in an intact state, reducing the misjudgment rate of the welding quality detection and improving the reliability of the welding quality detection.

[0019] In some embodiments, the welding quality of the welding component is determined based on the gain information of the second electrical signal and the preset frequency range, including: based on the gain information of the second electrical signal, taking the frequency range corresponding to the gain value greater than or equal to the gain threshold as the target frequency range; and determining the welding quality of the welding component based on the target frequency range and the preset frequency range.

[0020] The embodiment of the present application can accurately and quickly determine the frequency interval containing the resonant frequency by taking the frequency interval corresponding to the gain value greater than or equal to the gain threshold as the target frequency interval; compare the target frequency interval with the preset frequency interval to determine the welding quality of the welding component, thereby realizing the detection of welding quality in a non-destructive state, reducing the misjudgment rate of welding quality detection, and improving the reliability of welding quality detection.

[0021] In some embodiments, the welding quality of the welded component is determined based on the target frequency range and the preset frequency range, including: determining a first bandpass area corresponding to the target frequency range, and determining a second bandpass area corresponding to the preset frequency range; based on the first bandpass area and the second bandpass area, determining the welding quality of the welded component.

[0022] The embodiment of the present application evaluates the degree of overlap between the frequency response information of the welding component under specific frequency excitation and the preset frequency response characteristics based on the first bandpass area and the second bandpass area, thereby realizing the detection of welding quality in a non-destructive state, reducing the misjudgment rate of welding quality detection, and improving the reliability of welding quality detection.

[0023] In some embodiments, the welding quality of the welding assembly is determined based on the first bandpass area and the second bandpass area, including: determining the overlap ratio based on the first bandpass area and the second bandpass area; if the overlap ratio is greater than or equal to the ratio threshold, determining that the welding quality of the welding assembly is qualified.

[0024] The embodiment of the present application determines an overlap ratio based on the first and second bandpass areas, and evaluates the degree of similarity between the currently inspected welded assembly and the welded assembly with a qualified inspection result based on the overlap ratio. When the overlap ratio is greater than or equal to a ratio threshold, the currently inspected welded assembly is determined to be highly similar to the welded assembly with a qualified inspection result, thereby determining that the welding quality of the welded assembly is qualified. The above method can detect welding quality in a non-destructive state, reduce the false positive rate of welding quality inspection, and improve the reliability of welding quality inspection.

[0025] In some embodiments, the excitation source sends a first electrical signal to the welding component, including: inputting a first electrical signal of corresponding frequency into the welding component according to a preset frequency adjustment rule, and the preset frequency adjustment rule adjusts the frequency of the first electrical signal from a first frequency to a second frequency according to a preset step size.

[0026] In an embodiment of the present application, a first electrical signal is sent to a welding component through an excitation source, and the first electrical signal is adjusted from a first frequency to a second frequency according to a preset step size. By dynamically changing the frequency of the first electrical signal within a set range, continuous spectrum coverage is formed, thereby obtaining gain information of the response signal of the welding component to the first electrical signal in the entire frequency band, thereby improving the detection accuracy of welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of a welding quality detection system provided in an embodiment of the present application.

[0028] Figure 2 It is a structural schematic diagram of the welding assembly provided in an embodiment of the present application.

[0029] Figure 3 Schematic diagram of the structure of the parallel resonant network provided in the embodiment of the present application.

[0030] Figure 4 This is an application scenario diagram of the welding quality detection system provided in an embodiment of the present application.

[0031] Figure 5 It is a flow chart of the welding quality detection method provided in an embodiment of the present application.

[0032] Figure 6 This is a schematic diagram of the signal sending process of the excitation source provided in an embodiment of the present application.

[0033] Figure 7 It is a schematic diagram of the detection process of the detection equipment provided in the embodiment of the present application.

[0034] Figure 8 Schematic diagram of the structure of the oscilloscope provided in the embodiment of the present application.

[0035] Component Symbol Description: Welding quality inspection system 100, welding assembly 10, welding part 11, first electrode terminal 111, first metal layer 111a, first bend 111b, second electrode terminal 112, second metal layer 112a, second bend 112b, weld 12, air gap 13, excitation source 20, signal generator 21, first signal line 22, second signal line 23, first signal terminal 24, second signal terminal 25, inspection equipment 30, oscilloscope 31, memory 311, controller 312, communication bus 313, third signal line 32, fourth signal line 33, first probe 34, second probe 35, computer equipment 200. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of this application clearer, this application is described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] It should be noted that, in this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A alone, A and B together, and B alone, where A and B can be singular or plural. The terms "first," "second," "third," "fourth," and so on (if any) in the specification, claims, and drawings of this application are used to distinguish similar objects, not to describe a specific order or precedence.

[0038] In the embodiments of this application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplarily" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplarily" or "for example" is intended to present the relevant concepts in a concrete manner.

[0039] As a joining process, welding technology is widely used in various scenarios across multiple fields. For example, in automotive manufacturing, welding technology is used to splice body steel plates and connect chassis structural components. In electronics and precision manufacturing, welding technology is used for welding circuit boards and precision welding of medical devices such as scalpels and artificial joints. In the new energy sector, battery welding is also a key application. To meet these diverse joining needs, the main welding technologies used include laser welding, resistance welding, friction welding, and ultrasonic welding.

[0040] Among them, laser welding uses a high-energy-density laser beam as a heat source, acting on the welded part at the location to be welded. By adjusting the laser power, the material at the welded location is heated and melted, forming a molten pool that condenses to form a weld. It has the characteristics of fast welding speed, small welding deformation and high welding quality. Resistance welding uses the resistance heat generated by the current passing through the welded parts and the contact points as a heat source to locally heat the welded parts, while applying pressure for welding. Friction welding refers to the use of heat generated by friction between the contact surfaces of the workpieces as a heat source, causing the workpieces to undergo plastic deformation under pressure for welding. Ultrasonic welding uses high-frequency vibration waves to be transmitted to the surfaces of the two objects to be welded. Under pressure, the two surfaces of the objects rub against each other to form a fusion between the molecular layers.

[0041] Taking the application of laser welding technology in the battery field as an example, batteries (such as lithium-ion batteries) are core components in vehicles, unmanned aerial vehicles, power tools, and other equipment. A key performance requirement for batteries is high-power discharge. To meet this requirement, battery cells use wider electrode terminals (such as the cell tabs) to improve current handling. However, this design also places more stringent requirements on the laser welding process. On the one hand, the positive and negative tabs of multiple battery cells must be laser welded to achieve end-to-end connectivity, thus forming an effective current path between the multiple cells. On the other hand, the sampling terminals of the battery management system (BMS) must also be connected to the electrode terminals of the battery cells through the laser welding process.

[0042] However, the laser welding process can result in cold welds due to physical interference (e.g., welding jig obstruction or bent tabs). When different metal layers cannot achieve a good overlap, the laser energy may only form an effective weld in a portion of the metal layer (usually the upper layer), failing to penetrate to the underlying metal layer. This defect, where a weld is formed only in one metal layer without complete interlayer fusion, is called a cold weld.

[0043] Laser weld defects can cause performance and safety issues in batteries. For example, a defective weld between the positive and negative tabs can cause the battery pack to short circuit, leading to an unexpected power outage during driving and potentially causing a safety incident. Another example is a defective weld between the sampling terminal and the tab, which can cause the battery management system to misread the battery voltage and misjudge the battery voltage, potentially forcing an unmanned aerial vehicle to make an emergency landing or causing an unexpected halt in operations. Therefore, inspecting weld quality is crucial.

[0044] There are three main methods for detecting cold welds in laser welding: First, manual physical inspection, such as using a pick tool to peel the tab to visually inspect the weld continuity. Second, resistance testing, based on the principle that a cold weld reduces the conductive cross-sectional area and increases resistance, measures the resistance of the solder joint and compares it to a preset acceptance threshold to identify defects. Third, multispectral imaging testing, using a multi-band light source to illuminate the solder joint and capture reflectance images at different spectra. By analyzing features such as reflectivity and texture compared to normal solder joints, it can identify oxidation, porosity, or areas of incomplete fusion caused by cold welds. However, existing detection methods all have significant limitations. For example, manual inspection with a pick tool relies on operator experience and is highly subjective, and peeling the tab with a tool carries the risk of damaging the battery. While resistance testing can identify cold welds with significantly increased resistance, it is insensitive to hidden defects such as microscopic internal pores that do not significantly increase resistance. Multispectral imaging testing is prone to missed detections due to feature blurring or interference. These limitations collectively increase the detection error rate, making it difficult to ensure the reliability of weld quality inspections.

[0045] In view of the above problems, the present application provides a welding quality detection system and method, which uses an excitation source to input a first electrical signal into a welding component, and determines whether the frequency response information of the second electrical signal output by the welding component meets the preset frequency response characteristics based on the gain information and the preset frequency range, thereby detecting the welding quality of the welding component. It can detect the welding quality when the welding component is in an intact state, reduce the misjudgment rate of the welding quality detection, and improve the reliability of the welding quality detection.

[0046] The following will describe some embodiments with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0047] Figure 1 Schematic diagram of a welding quality detection system provided by some embodiments of the present application. Figure 1 As shown, the welding quality detection system 100 may include a welding assembly 10, an excitation source 20, and a detection device 30, wherein the welding assembly 10 is electrically connected to the excitation source 20 and the detection device 30 respectively. Optionally or additionally, the welding assembly 10 may represent an assembly that needs to be subjected to welding quality detection. The excitation source 20 is used to send a first electrical signal to the welding assembly 10, referring to Figure 1 In the direction of the arrow in FIG, the first electrical signal is responded to by welding assembly 10, resulting in a second electrical signal. Detection device 30 is used to obtain the second electrical signal output by welding assembly 10 and determine the welding quality of welding assembly 10 by analyzing the second electrical signal. The second electrical signal is used to indicate the response signal of welding assembly 10 to the first electrical signal.

[0048] In some embodiments, the welding assembly 10 may include a welding structure formed by welding multiple battery cells. Figure 2 A schematic diagram illustrating the structure of a welded assembly, Figure 2 The embodiment is a welded assembly formed by welding two battery cells. It is understandable that the welded assembly 10 in other embodiments of the present application can also be a welded structure formed by welding more than two battery cells. Figure 2 As shown, the welding assembly 10 includes a welding part 11 and a weld 12. The welding part 11 may represent a metal component to be welded, and the weld 12 may represent a metal connection structure formed by the welding part 11 being melted by heat during the laser welding process.

[0049] Alternatively or additionally, in some embodiments, the welding member 11 may include multiple electrode terminals. Electrode terminals can represent metal conductors in a battery that connect the internal electrode material of the battery to an external circuit. For example, in a pouch cell battery, the electrode terminals may include tabs, sampling terminals for collecting battery voltage, and the like. The number of electrode terminals can be two, or more than two, such as three, four, or five, without limitation. In the present embodiment, the welding member 11 includes a first electrode terminal 111 and a second electrode terminal 112, each of which belongs to a different battery cell. For example, in a battery comprising cell c1 and cell c2, the first electrode terminal 111 may represent the positive tab of cell c1, and the second electrode terminal 112 may represent the negative tab of cell c2. The first electrode terminal 111 and the second electrode terminal 112 are welded to connect cells c1 and c2 in series. The welding method may include laser welding. In this embodiment of the present application, laser welding is performed on first electrode terminal 111 and second electrode terminal 112, thereby improving the welding accuracy and speed of first electrode terminal 111 and second electrode terminal 112, thereby enhancing the welding effect. Alternatively, first electrode terminal 111 and second electrode terminal 112 may both be positive electrode tabs. In this case, welding first electrode terminal 111 and second electrode terminal 112 connects battery cell c1 and battery cell c2 in parallel.

[0050] Illustratively, during laser welding, the first electrode terminal 111 and the second electrode terminal 112 are arranged in a bent manner, with the first electrode terminal 111 being the upper metal layer and the second electrode terminal 112 being the lower metal layer. The laser beam irradiates the first electrode terminal 111 to generate a thermal effect, causing the metal to melt and form a molten pool. The molten metal flows toward the second electrode terminal 112 under the action of gravity, and the laser irradiates the second electrode terminal 112 through the molten pool cavity to melt it. The molten metal of the first electrode terminal 111 and the second electrode terminal 112 are connected together to form a weld 12. In the laser welding process, the molten pool cavity refers to an unfilled cavity or bubble formed inside the molten metal due to violent vaporization of the metal or gas retention.

[0051] like Figure 2 As shown, the first electrode terminal 111 includes a first metal layer 111a and a first bent portion 111b, and the second electrode terminal 112 includes a second metal layer 112a and a second bent portion 112b. Thus, the weldment 11 includes the first metal layer 111a, the first bent portion 111b, the second metal layer 112a, and the second bent portion 112b. The weldment 11 of the present embodiment includes the first electrode terminal 111 and the second electrode terminal 112. By welding the first electrode terminal 111 and the second electrode terminal 112, a current path is formed between multiple battery cells, enabling high-power discharge of the battery.

[0052] The first electrode terminal 111 includes a first metal layer 111a and a first bending portion 111b, and the second electrode terminal 112 includes a second metal layer 112a and a second bending portion 112b. Overlapping the first electrode terminal 111 and the second electrode terminal 112 by bending can enhance the strength of the welding component 10 and improve the anti-peeling force; in addition, by providing the first metal layer 111a and the first bending portion 111b, as well as the second metal layer 112a and the second bending portion 112b, it is convenient to electrically connect the excitation source 20 to the welding component 10, and to electrically connect the detection equipment 30 to the welding component 10, thereby improving the stability of electrical signal transmission and thereby improving the accuracy of welding quality detection.

[0053] Optionally or additionally, in some embodiments, the first metal layer 111a is connected to the first bend portion 111b, and the second metal layer 112a is connected to the second bend portion 112b. The first metal layer 111a and the second metal layer 112a are arranged along the first direction, and the first bend portion 111b and the second bend portion 112b are spaced apart along the second direction. During laser welding, the laser beam irradiates the first metal layer 111a to produce a thermal effect, causing the metal to melt and form a molten pool. The molten metal flows toward the second metal layer 112a under the action of gravity, and the laser irradiates the second metal layer 112a through the molten pool cavity to melt it. The molten metal of the first metal layer 111a and the second metal layer 112a are connected together to form a weld 12. In this way, the first metal layer 111a is connected to the second metal layer 112a through the weld 12. The welding assembly 10 includes a plurality of welds 12, Figure 2 Taking the number of welds 12 as 4 as an example, multiple welds 12 are arranged at intervals along the second direction. The second direction is perpendicular to the first direction. The first direction can be Figure 2 The X-axis direction shown, the second direction can be Figure 2 The Y-axis direction is shown. In the embodiment of the present application, the first metal layer 111a and the second metal layer 112a are connected by a plurality of welds 12 arranged at intervals, so that the welding assembly 10 can be used to characterize the parallel resonant network, thereby using the welding assembly 10 itself to build a parallel resonant network, and realizing signal conversion through the parallel resonant network to detect the welding quality. On the one hand, the welding quality can be detected more accurately, and on the other hand, no additional devices are required to convert the signal output by the excitation source 20; and the present application connects the first metal layer 111a to the first bending portion, and the second metal layer 112a to the second bending portion 112b. The first metal layer 111a and the second metal layer 112a are arranged along the first direction, and the first bending portion 111b and the second bending portion 112b are spaced apart along the second direction. The above structure facilitates the electrical connection between the excitation source 20 and the welding assembly 10, and the electrical connection between the detection device 30 and the welding assembly 10, which can improve the stability of the electrical signal transmission and thus improve the accuracy of the welding quality detection.

[0054] Alternatively or additionally, in some embodiments, air gaps 13 exist between adjacent welds 12. Air gaps 13 can represent portions of the circuit where the first electrode terminal 111 and the second electrode terminal 112 are not connected. While welds 12 can form current pathways, air gaps 13 between adjacent welds 12 cannot. Thus, welds 12 can be considered resistors, and air gaps 13 can be considered capacitors. Based on this, welds 11 and welds 12 can be characterized as a circuit topology comprising resistors and capacitors, i.e., a parallel resonant network.

[0055] As an example of this application, Figure 3 The schematic diagram of the parallel resonant network is shown below. Figure 3As shown, the number of capacitors in the parallel resonant network is 2 and the number of resistors is 2. The resistance of the resistor is determined by the resistivity of the first metal layer 111a and / or the second metal layer 112a and the shape of the weld 12. Under specific design and production parameters, its resistance fluctuates within a very small range and can be regarded as unchanged in theory. In this application, R is used to replace the resistance of the weld 12. The capacitance of the capacitor is determined by the thickness of the air gap 13 and the shape of the first metal layer 111a and / or the second metal layer 112a. Its capacitance conforms to the capacitance theorem of a parallel plate capacitor, that is, the capacitance of the capacitor is proportional to the facing area of ​​the first metal layer 111a and the second metal layer 112a, and inversely proportional to the distance between the first metal layer 111a and the second metal layer 112a. In this application, C is used to replace the capacitance of the capacitor.

[0056] In some embodiments, when the weld 11 and the weld 12 are used to characterize a parallel resonant network, a sinusoidal AC signal with an angular frequency of ω (for ease of description, this application also refers to it as the "first electrical signal") is input into the parallel resonant network (i.e., the welding assembly 10) to obtain the frequency domain impedance shown in Formula 1.

[0057] Formula 1: .

[0058] The sinusoidal AC signal can represent a voltage signal that changes periodically over time according to a sinusoidal law, and the frequency domain impedance can be a complex parameter used to describe the response characteristics of a linear time-invariant system (such as a parallel resonant network) to different frequency signals in the frequency domain. In Formula 1, and Indicates the capacitance of different capacitors. and Indicates the resistance value of different resistors, represents an imaginary number, L represents the parasitic inductance in the parallel resonant network, ω represents the angular frequency, In formula 1, the number of C is the number of air gaps 13, and the number of R is the number of welds 12. As can be seen from formula 1, when the capacitance and value of multiple capacitors are equal to the parasitic inductance, The imaginary part of the parallel resonant network is 0, and the entire parallel resonant network behaves as a pure resistor. When the welding material and process are determined, the capacitance, resistance and parasitic inductance of the parallel resonant network are also determined. In this way, there is a unique angular frequency ω that makes the imaginary part of the frequency domain impedance Z equal to 0. The frequency corresponding to this angular frequency ω is f It is called the resonant frequency. The relationship between frequency and angular frequency can be expressed as ω=2π f .

[0059] Thus, a sinusoidal AC signal (i.e., a first electrical signal) within a specific frequency range is input to the parallel resonant network. For example, if the first electrical signal is a voltage signal, the signal output by the parallel resonant network is called a second electrical signal, which indicates the parallel resonant network's response to the first electrical signal. The second electrical signal has a low-passband impedance in the frequency domain, manifested by an increase in the voltage amplitude near the resonant frequency, a peak voltage amplitude at the resonant frequency, and a decrease in the voltage amplitude away from the resonant frequency. Thus, the second electrical signal forms a resonant peak at the resonant frequency. In other words, when the welding material and process are determined, the frequency response characteristics of the parallel resonant network are fixed. Based on this, the process level of the weld 12, or in other words, the weld quality, can be analyzed using the frequency response information of the weld assembly 10. In the embodiment of the present application, the welding part 11 and the weld 12 are used to characterize the parallel resonant network, and the frequency response information of the response signal (i.e., the second electrical signal) of the parallel resonant network to the first electrical signal is analyzed. By analyzing whether the frequency response information of the second electrical signal meets the preset frequency response characteristics, the welding quality of the welding assembly 10 is detected, and the welding quality can be detected when the welding assembly 10 is in an intact state. Moreover, by detecting the welding quality by analyzing the electrical signal, the error rate of the welding quality detection can be reduced, and the reliability of the welding quality detection can be improved.

[0060] Alternatively or additionally, in some embodiments, the excitation source 20 is configured to transmit a first electrical signal to the welding assembly 10. The first electrical signal may include a voltage signal. The excitation source 20 includes a signal generator 21, a first signal line 22, a second signal line 23, a first signal terminal 24, and a second signal terminal 25. The signal generator 21, the first signal line 22, the first signal terminal 24, and the first metal layer 111a are electrically connected in sequence. The second bend 112b, the second signal terminal 25, the second signal line 23, and the signal generator 21 are electrically connected in sequence, with the second bend 112b being electrically connected to ground. Thus, the signal generator 21 transmits the first electrical signal, which reaches the first metal layer 111a via the first signal line 22 and the first signal terminal 24. By electrically connecting the second bend 112b to ground, the first electrical signal flows back to the signal generator 21 via the second bend 112b, the second signal terminal 25, and the second signal line 23. In this embodiment, the signal generator 21, first signal line 22, and first signal terminal 24 serve as the transmission path for the first electrical signal, while the second bent portion 112b, second signal terminal 25, and second signal line 23 serve as the return path for the first electrical signal. By electrically connecting the second bent portion 112b to the ground terminal, the first electrical signal can flow back smoothly, thereby improving the integrity of signal transmission.

[0061] Optionally or additionally, the detection device 30 is used to obtain a second electrical signal output by the welding assembly 10 and determine the welding quality of the welding assembly 10 based on the gain information and a preset frequency range of the second electrical signal, wherein the second electrical signal is used to indicate the response signal of the welding assembly 10 to the first electrical signal. The detection device 30 includes an oscilloscope 31, a third signal line 32, a fourth signal line 33, a first probe 34, and a second probe 35. The first bend 111b, the first probe 34, the third signal line 32, and the oscilloscope 31 are electrically connected in sequence. The second metal layer 112a, the second probe 35, the fourth signal line 33, and the oscilloscope 31 are electrically connected in sequence, and the second probe 35 is electrically connected to the ground terminal. In this way, the signal generator 21 and the oscilloscope 31 are in a common ground state. The second electrical signal is transmitted to the oscilloscope 31 via the first bend 111b, the first probe 34, and the third signal line 32. The second probe 35 is electrically connected to the ground terminal, allowing the second electrical signal to flow back to the oscilloscope 31 via the second metal layer 112a, the second probe 35, and the fourth signal line 33. In this embodiment of the present application, the first bend 111b, the first probe 34, and the third signal line 32 serve as the receiving path for the second electrical signal, and the second metal layer 112a, the second probe 35, and the fourth signal line 33 serve as the return path for the second electrical signal. By electrically connecting the second probe 35 to the ground terminal, the second electrical signal flows back smoothly, thereby improving the integrity of signal transmission.

[0062] In some embodiments, the welding quality inspection system 100 can be used to inspect the weld quality between multiple battery cells in a battery, or to sample the weld quality between a terminal and a tab of a battery cell. This embodiment of the present application illustrates the use of the welding quality inspection system 100 to inspect the weld quality between multiple battery cells in a battery. A battery comprises multiple battery cells, which are connected in series via welding. This creates a current path between the previously independent cells, enabling high-power discharge of the battery. Batteries can be used in a variety of devices. For example, batteries can be used in electric vehicles (electric vehicles, electric motorcycles, electric bicycles), aircraft (agricultural drones, manned drones, consumer drones), power tools (electric drills, lawn mowers), cleaning tools (vacuum cleaners, sweepers), and industrial robots, among other electrical devices. They can also be used in mobile energy storage devices, household energy storage devices, industrial and commercial energy storage devices, uninterruptible power supplies, and other electronic devices requiring batteries, such as personal computers, tablet computers, smartphones, and digital cameras, without limitation.

[0063] In the welding quality detection system 100 provided in the above embodiment of the present application, an excitation source 20 is used to input a first electrical signal into the welding component 10, and based on the gain information of the second electrical signal output by the welding component 10 and a preset frequency range, it is determined whether the frequency response information of the second electrical signal meets the preset frequency response characteristics, thereby detecting the welding quality of the welding component 10. The parallel resonant network constructed by the welding component 10 itself can be used to detect the welding quality when the welding component 10 is in an intact state, thereby reducing the misjudgment rate of the welding quality detection and improving the reliability of the welding quality detection.

[0064] Figure 4 This is an application scenario diagram of the welding quality detection system provided in the embodiment of the present application. Figure 4 As shown, welding quality inspection system 100 is communicatively connected to computer device 200. Computer device 200 may include an electronic product with data processing and interaction capabilities, such as a personal computer, tablet computer, smartphone, etc. Communication connections may include wired connections and wireless connections. Wired connections may be through data cables, etc., while wireless connections may be through Wi-Fi, Bluetooth, cellular networks, near-field communication, etc.

[0065] In some embodiments, the computer device 200 is communicatively connected to the excitation source 20 in the welding quality inspection system 100. The computer device 200 is configured to control the frequency of the first electrical signal transmitted by the excitation source 20. For example, the computer device 200 transmits a preset frequency adjustment rule to the excitation source 20, and the excitation source 20, in accordance with the preset frequency adjustment rule, inputs the first electrical signal of the corresponding frequency to the welding assembly 10. The preset frequency adjustment rule is configured based on actual needs. For example, the preset frequency adjustment rule indicates the minimum frequency (referred to herein as the "first frequency") and the maximum frequency (referred to herein as the "second frequency") of the first electrical signal, and instructs the frequency of the first electrical signal to be adjusted from the first frequency to the second frequency according to a preset step size. The first frequency, the second frequency, and the preset step size can be configured based on actual needs. For example, the first frequency can be 1 kHz, 2 kHz, or 3 kHz, and the second frequency can be 99 MHz or 100 MHz. The preset step size can be 1 kHz, 2 kHz, or 3 kHz, without limitation.

[0066] Exemplarily, the computer device 200 is connected to the excitation source 20 via a physical cable. Before sending the preset frequency adjustment rules to the excitation source 20, the computer device 200 initializes serial communication and configures the communication parameters, hardware interface, and communication protocol to ensure stable and reliable data exchange between the two communicating parties. Subsequently, the computer device 200 sends the preset frequency adjustment rules to the excitation source 20. In response to the preset frequency adjustment rules, the excitation source 20 sends a first electrical signal of a corresponding frequency to the welding assembly 10. The welding assembly 10 responds to the first electrical signal and generates a second electrical signal. The detection device 30 acquires the second electrical signal and determines the weld quality of the welding assembly 10 by analyzing the frequency response information of the second electrical signal.

[0067] Optionally, in other embodiments, the excitation source 20 may have data processing and interaction capabilities. For example, a user may configure a preset frequency adjustment rule in the excitation source 20 to implement frequency control of the first electrical signal transmitted by the excitation source 20. This embodiment of the present application uses the example of a computer device 200 communicating with the welding quality inspection system 100.

[0068] In the above application scenario, the computer device 200 is communicatively connected to the welding quality detection system 100, and the computer device 200 is used to control the signal frequency of the excitation source 20 in the welding quality detection system 100, so that the excitation source 20 does not require a complex control circuit, thereby reducing hardware costs; and the computer device 200 can be communicatively connected with multiple excitation sources 20 to realize welding quality detection of multiple welding components 10, thereby improving the welding quality detection efficiency.

[0069] Figure 5 This is a flow chart of the welding quality detection method provided by the embodiment of the present application. The welding quality detection method can be applied to a welding quality detection system (such as Figure 1 Welding quality detection system 100 in FIG. Figure 5 As shown, the welding quality detection method may include the following steps. The order of the steps in the flowchart may be changed according to different requirements.

[0070] S11, the excitation source sends a first electrical signal to the welding assembly.

[0071] In some embodiments, the excitation source 20 transmits a first electrical signal to the welding assembly 10 according to a preset frequency adjustment rule. The first electrical signal may include a voltage signal. The first electrical signal may be a dynamic signal whose frequency continuously changes over time, manifesting as a continuous frequency change from low to high or from high to low within a certain frequency range. Exemplarily, the excitation source 20 transmits the first electrical signal to the welding assembly 10 by inputting the first electrical signal of a corresponding frequency into the welding assembly 10 according to the preset frequency adjustment rule. The preset frequency adjustment rule adjusts the frequency of the first electrical signal from a first frequency to a second frequency according to a preset step size.

[0072] The first frequency may be greater than the second frequency, that is, the frequency of the first electrical signal gradually decreases. The first frequency may also be less than the second frequency, that is, the frequency of the first electrical signal gradually increases. In the embodiment of the present application, the first frequency is less than the second frequency as an example. The first frequency is used to describe the lowest frequency of the first electrical signal, and the second frequency is used to describe the highest frequency of the first electrical signal. The first electrical signal is gradually adjusted from the first frequency to the second frequency based on a preset step size.

[0073] Among them, the preset step size, the first frequency and the second frequency can be set according to actual needs. For example, the preset step size can be 1KHz, 2KHz, 3KHz, the first frequency can be 1KHz, 2KHz, 3KHz, and the second frequency can be 99MHz, 100MHz, and there is no limitation here. The embodiment of the present application takes the first frequency as 1KHz, the second frequency as 100MHz, and the preset step size as 1KHz as an example. Figure 6 The signal transmission process of the excitation source provided in the embodiment of the present application is described as follows: Figure 6 As shown, the computer device 200 sends a frequency instruction to the excitation source 20, instructing the excitation source 20 to send a first electrical signal to the welding assembly 10. The excitation source 20 generates the first electrical signal of the corresponding frequency at a preset time interval (for example, the preset time interval is 50 milliseconds or 60 milliseconds), and gradually increases the frequency from the first frequency of 1 kHz, increasing by 1 kHz each time, until the frequency reaches 100 MHz, and then stops sending the first electrical signal.

[0074] In the embodiment of the present application, a first electrical signal is sent to the welding component 10 through an excitation source 20, and the first electrical signal is adjusted from a first frequency to a second frequency according to a preset step size. By dynamically changing the frequency of the first electrical signal within a set range, a continuous spectrum coverage is formed, thereby obtaining the gain information of the response signal of the welding component 10 in the entire frequency band, thereby improving the detection accuracy of the welding quality.

[0075] S12, the welding component responds to the first electrical signal and generates a second electrical signal.

[0076] In some embodiments, the welding assembly 10 is used to represent a parallel resonant network. The parallel resonant network generates a second electrical signal in response to a first electrical signal. The second electrical signal is a voltage signal.

[0077] S13, the detection device obtains the second electrical signal, and determines the welding quality of the welded assembly based on the gain information and the preset frequency range of the second electrical signal.

[0078] The welding quality of the welding component 10 affects the frequency response information of the second electrical signal. Therefore, the detection device 30 obtains the second electrical signal and analyzes the second electrical signal to determine the welding quality of the welding component 10, for example, to determine whether there is a cold weld in the weld 12.

[0079] Optionally or additionally, in some embodiments, the detection device 30 processes the second electrical signal based on Fourier transform, converts the second electrical signal from the time domain to the frequency domain, and obtains a frequency domain response diagram. In the frequency domain response diagram, the horizontal axis can be used to represent the frequency, and the vertical axis can be used to represent the gain information. The frequency domain response diagram includes a gain curve, which is used to represent the characteristics of the gain information of the second electrical signal changing with frequency. The gain information is used to describe the degree to which the amplitude of the first electrical signal is enhanced after passing through the parallel resonant network, reflecting the amplification ability of the parallel resonant network for electrical signals of a specific frequency. The gain information may include voltage gain. The type of gain information is related to the signal type of the first electrical signal. When the first electrical signal is a voltage signal, the gain information is voltage gain. Taking the gain information as voltage gain as an example, the voltage gain is determined based on the ratio of the voltage amplitude of the second electrical signal to the voltage amplitude of the first electrical signal.

[0080] In some embodiments, the embodiments of the present application are described by taking the first electrical signal as a voltage signal and the second electrical signal as a voltage signal as an example. When the welding material and process are determined, the frequency response characteristics of the parallel resonant network are certain. Based on this, the process level of the weld 12, that is, the welding quality, can be analyzed by the frequency response information of the welding assembly 10. Taking the first electrical signal as a voltage signal as an example, the second electrical signal output by the parallel resonant network has a low-resistance bandpass in the frequency domain, which is manifested as the voltage amplitude of the second electrical signal increasing near the resonant frequency, and the voltage amplitude at the resonant frequency reaching a peak value, and the voltage amplitude of the second electrical signal decreasing away from the resonant frequency. In this way, the second electrical signal forms a resonant peak at the resonant frequency.

[0081] Based on the gain information of the second electrical signal and the preset frequency range, the welding quality of the welding component 10 is determined, including: based on the gain information of the second electrical signal, taking the frequency range corresponding to the gain value greater than or equal to the gain threshold as the target frequency range; based on the target frequency range and the preset frequency range, determining the welding quality of the welding component 10.

[0082] Among them, taking the gain information as voltage gain as an example, in the frequency domain response diagram of the second electrical signal, the second electrical signal will have a significant resonance peak at the resonant frequency, and the voltage gain at the corresponding resonant frequency is the maximum value. Based on this, a gain threshold is set to obtain a frequency interval containing the resonant frequency, that is, a target frequency interval. Optionally or additionally, the frequency interval corresponding to the gain value greater than or equal to the gain threshold is used as the target frequency interval. The gain threshold is related to the resonant frequency, and the gain threshold can be set according to actual needs. Exemplarily, the number of gain thresholds can be multiple, for example, the number of gain thresholds is 2, namely the first gain threshold and the second gain threshold, and the first gain threshold and the second gain threshold can be the same or different. According to the frequency domain response diagram of the second electrical signal, the frequency corresponding to the maximum voltage gain is determined, which is recorded as f 1. Based on frequency f 1. Determine the first low-frequency cutoff frequency and the first high-frequency cutoff frequency. For example, the first low-frequency cutoff frequency is recorded as 1 / 2 f 1, the first high frequency cutoff frequency is recorded as 2 f 1. The gain value corresponding to the first low-frequency cutoff frequency is used as the first gain threshold, and the gain value corresponding to the first high-frequency cutoff frequency is used as the second gain threshold. In this way, the target frequency interval is the frequency interval corresponding to the gain value greater than or equal to the gain threshold (for example, the first gain threshold and the second gain threshold), that is, the frequency interval corresponding to the first low-frequency cutoff frequency and the first high-frequency cutoff frequency. For example, the target frequency interval is [1 / 2 f 1, 2 f 1].

[0083] The preset frequency range is a pre-set frequency range used to assist in evaluating the welding quality of the welded assembly 10. Before welding the welded component 11, welding parameters are determined. These parameters guide the welding process. Welding parameters may include, but are not limited to, weld length, weld width, distance between weld points, welding speed, and the frequency of the excitation source 20. Based on the welding parameters, a theoretical frequency can be determined. The theoretical frequency is a theoretical value representing the frequency corresponding to the maximum voltage gain of the welded assembly 10 under theoretical conditions. Based on the welding parameters, multiple welded components 11 are welded to obtain multiple welded assemblies 10. Welded assemblies 10 with acceptable welding quality are selected from the multiple welded assemblies 10 and are referred to as preset welded assemblies. Methods for testing welding quality can refer to relevant technologies, such as manual physical inspection, resistance testing, and multispectral imaging testing, and are not described in detail here. The number of preset welded assemblies is set based on actual needs. For example, the number of preset welded assemblies may be 3, 5, or 8, etc., without limitation. The frequency corresponding to the maximum voltage gain is determined based on the frequency domain response graph of the second electrical signal passing through the preset welded assemblies. The preset frequency can be determined based on the theoretical frequency and the frequencies corresponding to the plurality of preset welding components. For example, the theoretical frequency is adjusted based on the frequencies of the plurality of preset welding components, and the adjusted frequency is used as the preset frequency, which is recorded as f . According to the preset frequency f , determine the second low-frequency cutoff frequency and the second high-frequency cutoff frequency. For example, considering the influencing factors such as design error (such as design error of weld length and design error of weld width) and system interference (such as power fluctuation of excitation source 20), the second low-frequency cutoff frequency is recorded as 1 / 2 f , the second high frequency cutoff frequency is recorded as 2 f The gain value corresponding to the second low-frequency cutoff frequency is used as the third gain threshold, and the gain value corresponding to the second high-frequency cutoff frequency is used as the fourth gain threshold. In this way, the preset frequency interval is the frequency interval corresponding to the gain value greater than or equal to the gain threshold (for example, the third gain threshold and the fourth gain threshold), that is, the frequency interval corresponding to the second low-frequency cutoff frequency and the second high-frequency cutoff frequency. For example, the preset frequency interval is [1 / 2 f , 2 f ].

[0084] By analyzing the target frequency range and the preset frequency range of the welded assembly 10 to be inspected, the weld quality of the welded assembly 10 can be determined. For example, if the target frequency range and the preset frequency range do not overlap in the frequency domain, the weld quality of the welded assembly 10 can be determined to be unqualified. If the target frequency range and the preset frequency range overlap in the frequency domain, further analysis can be performed to inspect the weld quality of the welded assembly 10.

[0085] The embodiment of the present application can accurately and quickly determine the frequency interval containing the resonant frequency by taking the frequency interval corresponding to the gain value greater than or equal to the gain threshold as the target frequency interval; the target frequency interval is compared with the preset frequency interval to determine the welding quality of the welding component 10, thereby realizing the detection of welding quality in a non-destructive state, reducing the misjudgment rate of welding quality detection, and improving the reliability of welding quality detection.

[0086] Alternatively or additionally, in some embodiments, if the target frequency region and the preset frequency interval overlap in the frequency domain, further analysis is performed to detect the welding quality of the welding assembly 10. Exemplarily, determining the welding quality of the welding assembly 10 based on the target frequency interval and the preset frequency interval includes: determining a first bandpass area corresponding to the target frequency interval, and determining a second bandpass area corresponding to the preset frequency interval; and determining the welding quality of the welding assembly 10 based on the first bandpass area and the second bandpass area.

[0087] Among them, taking the first electrical signal and the second electrical signal as voltage signals as an example, the first bandpass area can be represented by the geometric area enclosed by the gain curve and the frequency axis (i.e., the horizontal axis) within the target frequency range, and the second bandpass area can be represented by the geometric area enclosed by the gain curve and the frequency axis (i.e., the horizontal axis) within the preset frequency range.

[0088] In some embodiments, the embodiments of the present application are described by taking the first electrical signal and the second electrical signal as voltage signals as an example. The first bandpass area and the second bandpass area can be calculated by integration. For example, when determining the first bandpass area corresponding to the target frequency interval, the first low-frequency cutoff frequency and the first high-frequency cutoff frequency corresponding to the target frequency interval are determined. For example, the minimum value corresponding to the target frequency interval is used as the first low-frequency cutoff frequency of the target frequency interval, and the maximum value corresponding to the target frequency interval is used as the first high-frequency cutoff frequency of the target frequency interval. The difference between the first high-frequency cutoff frequency and the first low-frequency cutoff frequency is calculated as the first bandpass width. The gain function corresponding to the gain curve in the target frequency interval is determined as the first gain function. The first bandpass area is determined by processing the first bandpass width and the first gain function by integration.

[0089] As another example, when determining the second passband area corresponding to the preset frequency interval, the second low-frequency cutoff frequency and the second high-frequency cutoff frequency corresponding to the preset frequency interval are determined. For example, the minimum value corresponding to the preset frequency interval is used as the second low-frequency cutoff frequency of the preset frequency interval, and the maximum value corresponding to the preset frequency interval is used as the second high-frequency cutoff frequency of the preset frequency interval. The difference between the second high-frequency cutoff frequency and the second low-frequency cutoff frequency is calculated as the second passband width. The gain function corresponding to the gain curve in the preset frequency interval is determined as the second gain function. The second passband width and the second gain function are processed by integration to determine the second passband area. Among them, the method of determining the passband area by integration can refer to the relevant technology and will not be described here.

[0090] The embodiment of the present application evaluates the degree of overlap between the frequency response information of the welding component 10 under specific frequency excitation and the preset frequency response characteristics based on the first bandpass area and the second bandpass area, thereby realizing the detection of welding quality in a non-destructive state, reducing the misjudgment rate of welding quality detection, and improving the reliability of welding quality detection.

[0091] In some embodiments, the degree of overlap between the frequency response information of the welded assembly 10 under a specific frequency excitation and a preset frequency response characteristic is evaluated based on the first bandpass area and the second bandpass area. For example, determining the weld quality of the welded assembly 10 based on the first bandpass area and the second bandpass area includes: determining an overlap ratio based on the first bandpass area and the second bandpass area; if the overlap ratio is greater than or equal to a ratio threshold, determining that the weld quality of the welded assembly 10 is acceptable; and if the overlap ratio is less than the ratio threshold, determining that the weld quality of the welded assembly 10 is unacceptable.

[0092] The ratio threshold can be set according to actual needs. For example, the ratio threshold can be 80%, 85%, 90%, etc., and is not limited here.

[0093] In some embodiments, determining the overlap ratio based on the first passband area and the second passband area includes: determining the overlapping frequency interval based on the first passband area and the second passband area, and determining a third passband width corresponding to the overlapping frequency interval; determining multiple gain values ​​corresponding to the overlapping frequency interval; processing the third passband width and the multiple gain values ​​by integration to obtain the overlapping area; and determining the ratio of the overlapping area to the second passband area as the overlap ratio. The first low-frequency cutoff frequency of the target frequency interval corresponding to the first passband area is recorded as f 1L , the first high frequency cutoff frequency of the first bandpass area corresponding to the target frequency range is recorded as f 1H The second low-frequency cutoff frequency of the second bandpass area corresponding to the preset frequency range is recorded as f 2L, the second high frequency cutoff frequency corresponding to the preset frequency range of the second bandpass area is recorded as f 2H . Select f 1L and f 2L The maximum value in is used as the low-frequency cutoff frequency of the overlapping frequency interval, and the f 1H and f 2H The minimum value in is used as the high-frequency cutoff frequency of the overlapping frequency interval. In this way, the overlapping frequency interval can be determined, and the multiple gain values ​​corresponding to the overlapping frequency interval can be determined through the gain function corresponding to the target frequency interval and the gain function corresponding to the preset frequency interval.

[0094] The embodiment of the present application determines an overlap ratio based on the first and second bandpass areas, and assesses the degree of similarity between the currently inspected welded assembly 10 and the welded assembly 10 with a qualified inspection result based on the overlap ratio. When the overlap ratio is greater than or equal to a ratio threshold, it is determined that the currently inspected welded assembly 10 has a high degree of overlap with the welded assembly 10 with a qualified inspection result, thereby determining that the weld quality of the welded assembly 10 is qualified. The above method can detect welding quality in a non-destructive manner, reduce the false positive rate of welding quality inspection, and improve the reliability of welding quality inspection.

[0095] Combine Figure 7 The detection process of the detection device provided in the embodiment of the present application is described as follows: Figure 7 As shown, detection device 30 invokes a Fourier transform algorithm within oscilloscope 31, using the Fourier transform algorithm to convert the second electrical signal from the time domain to the frequency domain, thereby obtaining a frequency domain response graph. Oscilloscope 31 analyzes the frequency domain response graph to determine a target frequency range and compares the overlap ratio between the first bandpass area corresponding to the target frequency range and the second bandpass area corresponding to the preset frequency range. If the overlap ratio is greater than or equal to a ratio threshold, the weld quality of welded assembly 10 is determined to be acceptable. If the overlap ratio is less than the ratio threshold, the weld quality of welded assembly 10 is determined to be unacceptable, and a prompt may be output to indicate a high risk of defective solder joints in welded assembly 10.

[0096] In a welding quality detection method provided in an embodiment of the present application, an excitation source 20 is used to input a first electrical signal into a welding component 10, and based on the gain information and a preset frequency range of a second electrical signal output by the welding component 10, it is determined whether the frequency response information of the second electrical signal meets the preset frequency response characteristics, thereby detecting the welding quality of the welding component 10. The welding quality can be detected when the welding component 10 is in an intact state, thereby reducing the misjudgment rate of the welding quality detection and improving the reliability of the welding quality detection.

[0097] Continuing from the previous article Figure 1 Description of oscilloscope 31, combined with Figure 8 The structure of the oscilloscope provided in the embodiments of the present application is described below. In some embodiments, the oscilloscope 31 includes a memory 311 , a controller 312 , and at least one communication bus 313 . The controller 312 is coupled to the memory 311 via the communication bus 313 .

[0098] In some embodiments, the memory 311 is used to store one or more computer programs. The one or more computer programs are configured to be executed by the controller 312. The one or more computer programs include multiple instructions. When the multiple instructions are executed by the controller 312, the welding quality detection method executed on the oscilloscope 31 can be implemented.

[0099] In some embodiments, the controller 312 provides computing and control capabilities. For example, the controller 312 is configured to execute a computer program stored in the memory 311 to implement the aforementioned welding quality detection method. For example, the controller 312 obtains the second electrical signal and determines the welding quality of the welding assembly 10 based on the gain information of the second electrical signal and a preset frequency range.

[0100] In some embodiments, the oscilloscope 31 is a device that can automatically perform numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessors, application-specific integrated circuits, programmable gate arrays, digital processors, and embedded devices.

[0101] Although not shown, the power supply connected to the oscilloscope 31 may include any of one or more DC or AC power supplies, a recharging device, a power failure detection circuit, a power converter or inverter, a power status indicator, and the like. The oscilloscope 31 may also include various sensors, a Bluetooth module, a Wi-Fi module, and the like, which are not described in detail here.

[0102] In some embodiments, a computer program is stored in the memory 311, and when the computer program is executed by at least one controller 312, all or part of the steps in the welding quality detection method are implemented. The memory 311 includes a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0103] In some embodiments, the embodiments of the present application also provide a computer-readable storage medium, which may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function, etc.; the data storage area may store data created according to the use of the oscilloscope 31, etc.

[0104] In some embodiments, at least one controller 312 is the control core (Control Unit) of the oscilloscope 31. It utilizes various interfaces and circuits to connect the various components of the entire oscilloscope 31. It executes or runs programs or modules stored in the memory 311 and calls data stored in the memory 311 to perform various functions of the oscilloscope 31 and process data. For example, when the at least one controller 312 executes the computer program stored in the memory 311, it implements all or part of the steps of the welding quality inspection method in the embodiments of the present application. The at least one controller 312 can be composed of an integrated circuit, such as a single packaged integrated circuit or multiple packaged integrated circuits with the same or different functions, including one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and a combination of various control chips.

[0105] The above-mentioned integrated unit implemented in the form of a software function module can be stored in a computer-readable storage medium. The above-mentioned software function module is stored in a storage medium and includes a number of instructions for causing the oscilloscope 31 or a processor to execute parts of the methods of various embodiments of the present application.

[0106] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the module division is only a logical function division, and other division methods may be used in actual implementation.

[0107] Modules described as separate components may or may not be physically separate, and components shown as modules may or may not be physical units, and may be located in one place or distributed across multiple network elements. Some or all of these modules may be selected to achieve the objectives of this embodiment based on actual needs.

[0108] In addition, the functional modules in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0109] It is obvious to those skilled in the art that the present application is not limited to the details of the above-mentioned exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or basic characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present application. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "including" does not exclude other units or, and the singular does not exclude the plural. Multiple units or devices stated in the specification may also be implemented by one unit or device through software or hardware. Words such as first, second, etc. are used to indicate names and do not indicate any particular order.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A welding quality detection system, characterized in that: The system comprises: an excitation source and a welding assembly electrically connected to the excitation source, wherein the excitation source is used to send a first electrical signal to the welding assembly; A detection device is electrically connected to the welding assembly, the detection device is used to obtain a second electrical signal output by the welding assembly, and determine the welding quality of the welding assembly based on gain information and a preset frequency range of the second electrical signal, The second electrical signal is used to indicate a response signal of the welding component to the first electrical signal.

2. The welding quality detection system according to claim 1, characterized in that: The welding assembly includes a welding part and a welding seam, the welding part and the welding seam are used to represent a parallel resonant network, and the second electrical signal is used to indicate a response signal of the parallel resonant network to the first electrical signal.

3. The welding quality detection system according to claim 2, characterized in that: The welding part includes a first metal layer, a first bending portion, a second metal layer and a second bending portion, The first metal layer is connected to the first bending portion, the second metal layer is connected to the second bending portion, the first metal layer and the second metal layer are arranged along a first direction, the first metal layer is connected to the second metal layer via the weld, and the first bending portion and the second bending portion are spaced apart along a second direction; The welding assembly includes a plurality of welds, and the plurality of welds are spaced apart along the second direction; The second direction is perpendicular to the first direction.

4. The welding quality detection system according to claim 3, wherein: The excitation source includes a signal generator, a first signal line, a second signal line, a first signal terminal and a second signal terminal; The signal generator, the first signal line, the first signal terminal and the first metal layer are electrically connected in sequence; The second bending portion, the second signal terminal, the second signal line, and the signal generator are electrically connected in sequence, and the second bending portion is electrically connected to a ground end.

5. The welding quality detection system according to claim 3 or 4, characterized in that: The detection device includes an oscilloscope, a third signal line, a fourth signal line, a first probe and a second probe; The first bending portion, the first probe, the third signal line, and the oscilloscope are electrically connected in sequence; The second metal layer, the second probe, the fourth signal line, and the oscilloscope are electrically connected in sequence, and the second probe is electrically connected to a ground terminal.

6. The welding quality detection system according to any one of claims 3 to 5, characterized in that: The welding method of the welded parts includes laser welding; The welding member includes a first electrode terminal and a second electrode terminal. The first electrode terminal includes the first metal layer and a first bending portion. The second electrode terminal includes the second metal layer and a second bending portion.

7. A welding quality detection method, applied to the welding quality detection system according to any one of claims 1 to 6, characterized in that: The method comprises: The excitation source sends a first electrical signal to the welding assembly; The welding assembly responds to the first electrical signal and generates a second electrical signal; The detection device acquires the second electrical signal, and determines the welding quality of the welding assembly based on gain information and a preset frequency range of the second electrical signal.

8. The welding quality detection method according to claim 7, wherein: The determining the welding quality of the welding assembly based on the gain information of the second electrical signal and the preset frequency range includes: Based on the gain information of the second electrical signal, taking a frequency interval corresponding to a gain value greater than or equal to a gain threshold as a target frequency interval; The welding quality of the welding component is determined according to the target frequency range and the preset frequency range.

9. The welding quality detection method according to claim 8, wherein: The determining of the welding quality of the welded components according to the target frequency range and the preset frequency range includes: Determining a first bandpass area corresponding to the target frequency interval, and determining a second bandpass area corresponding to the preset frequency interval; The welding quality of the welding assembly is determined based on the first bandpass area and the second bandpass area.

10. The welding quality detection method according to claim 9, wherein: The determining the welding quality of the welding assembly based on the first bandpass area and the second bandpass area includes: determining an overlap ratio based on the first bandpass area and the second bandpass area; If the overlap ratio is greater than or equal to the ratio threshold, it is determined that the welding quality of the welded assembly is qualified.

11. The welding quality detection method according to claim 7, wherein: The excitation source sends a first electrical signal to the welding assembly, comprising: According to a preset frequency adjustment rule, a first electrical signal of a corresponding frequency is input to the welding component, and the preset frequency adjustment rule adjusts the frequency of the first electrical signal from a first frequency to a second frequency according to a preset step size.

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