Laser welding liquid cooling plate weld defect detection method and system

Abstract

The invention relates to the technical field of liquid cooling plate weld defect detection, and discloses a laser welding liquid cooling plate weld defect detection method and system. The welding seam height difference is obtained by subtracting the welding seam minimum height from the welding seam maximum height, if the welding seam height difference is smaller than or equal to the welding seam height difference threshold value, it is indicated that the distance difference between the highest position and the lowest position of the welding seam meets the standard, and welding seam detection is qualified; if the weld height difference is larger than the weld height difference threshold value, the distance difference between the highest position and the lowest position of the weld does not meet the standard, and weld detection is unqualified. The height difference of the weld joint reflects the flatness of the weld joint and the crack depth of the weld joint at the same time, and if the height difference of the weld joint is too large, the surface of the weld joint is not uniform, the flatness problem occurs, and the crack depth of the weld joint is large and potential safety hazards exist.

Description

Technical Field

[0001] The present invention relates to the technical field of weld defect detection of liquid cooling plates, and particularly to a method and system for detecting weld defects of laser-welded liquid cooling plates. Background Technique

[0002] A liquid cooling plate is a key device that uses liquid circulation heat transfer to achieve thermal management, and is widely used in the fields of new energy vehicle power battery cooling, electronic device heat dissipation, and industrial equipment temperature control. The liquid cooling plate usually has flow channels processed on a metal substrate. Coolant is introduced into the preset flow channels, and heat is absorbed by contacting the heat source. The coolant circulates in the flow channels, takes away the absorbed heat, and is cooled by a radiator, a heat exchanger, or an external heat dissipation device, finally realizing the temperature control of the entire system.

[0003] The manufacturing process of the liquid cooling plate usually includes numerical control machining, die stamping, laser welding, and surface treatment. Among them, to ensure the sealing performance and the integrity of the flow channels, the laser welding process is very important. After welding, it is necessary to conduct inspections to ensure that the welding meets the requirements. Summary of the Invention

[0004] Aiming at the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a method and system for detecting weld defects of laser-welded liquid cooling plates, so as to be able to detect the welds of the liquid cooling plates.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A method for detecting weld defects of laser-welded liquid cooling plates, including: Step 1, using an industrial camera with a light source to perform real-time imaging on the weld of the liquid cooling plate to obtain image features. After image processing, the maximum height and the minimum height of the weld from the table are obtained, which are respectively recorded as the weld maximum height and the weld minimum height. The weld height difference is obtained by subtracting the weld minimum height from the weld maximum height; Step 2, set a weld height difference threshold representing the standard value of the distance difference between the highest and the lowest points of the weld. The weld with a weld height difference exceeding the weld height difference threshold is a weld that does not meet the standard; Step 3, compare the weld height difference with the weld height difference threshold. If the weld height difference is less than or equal to the weld height difference threshold, it means that the distance difference between the highest and the lowest points of the weld meets the standard. In this case, the weld inspection is qualified; if the weld height difference is greater than the weld height difference threshold, it means that the distance difference between the highest and the lowest points of the weld does not meet the standard. In this case, the weld inspection is unqualified.

[0006] In some embodiments, when the weld height difference is greater than the weld height difference threshold, set a weld height difference proximity threshold greater than the weld height difference threshold, compare the weld height difference with the weld height difference proximity threshold, and obtain different responses according to the comparison results.

[0007] In some embodiments, if the weld height difference is less than or equal to the weld height difference approaching threshold, it represents that the distance gap between the highest and lowest points of the weld exceeds the standard to a low degree. In this case, the weld is further detected. If the weld height difference is greater than the weld height difference approaching threshold, it represents that the distance gap between the highest and lowest points of the weld exceeds the standard to a high degree. In this case, the weld detection is unqualified.

[0008] In some embodiments, when further detecting the weld, obtain the height of the liquid cooling plate, compare the height of the liquid cooling plate with the maximum weld height and the minimum weld height respectively, and take different responses according to the comparison results.

[0009] In some embodiments, if the height of the liquid cooling plate is greater than the minimum weld height and greater than the maximum weld height, it represents that the local material fusion at the weld is incomplete and does not completely cover the area to be welded on the liquid cooling plate. In this case, the weld detection is unqualified. If the height of the liquid cooling plate is less than the maximum weld height and less than the minimum weld height, it represents that the weld protrudes from the original plane of the liquid cooling plate as a whole. In this case, the weld detection is qualified. If the height of the liquid cooling plate is greater than the minimum weld height but less than the maximum weld height, it represents that the height distribution of the weld is uneven and there is an obvious height difference locally. In this case, the weld detection is unqualified.

[0010] In some embodiments, subtract the minimum weld height from the height of the liquid cooling plate to obtain the weld gap height. At the same time, set the weld gap height threshold according to industry standards. When the height of the liquid cooling plate is greater than the minimum weld height but less than the maximum weld height, compare the weld gap height with the weld gap height threshold, and take different responses according to the comparison results.

[0011] In some embodiments, if the weld gap height is less than or equal to the weld gap height threshold, it represents that the gap between the minimum weld height and the height of the liquid cooling plate is within the allowable range. In this case, the weld detection is qualified. If the weld gap height is greater than the weld gap height threshold, it represents that the gap between the minimum weld height and the liquid cooling plate exceeds the allowable range. In this case, the weld detection is unqualified.

[0012] In some embodiments, the light sources equipped with the industrial camera include a backlight source, a side light source, and a laser illumination source. Among them, when imaging the weld of the liquid cooling plate, the side light source is used as the equipped light source.

[0013] The present invention also provides the following technical solutions: The present invention further provides a weld defect detection system for a laser welding liquid cooling plate, which is used to execute the method described above, and includes the following modules: an acquisition module, which is used to use an industrial camera with a light source to perform real-time imaging on the weld of the liquid cooling plate, obtain image features, and after image processing, obtain the maximum height and the minimum height of the weld from the tabletop, which are respectively recorded as the maximum weld height and the minimum weld height, and use the maximum weld height minus the minimum weld height to obtain the weld height difference; a setting module, which is used to set a weld height difference threshold representing the standard value of the distance gap between the highest and lowest points of the weld, and a weld with a weld height difference exceeding the weld height difference threshold is a weld that does not meet the standard; a comparison module, which is used to compare the weld height difference with the weld height difference threshold. If the weld height difference is less than or equal to the weld height difference threshold, it means that the distance gap between the highest and lowest points of the weld meets the standard. In this case, the weld inspection is qualified; if the weld height difference is greater than the weld height difference threshold, it means that the distance gap between the highest and lowest points of the weld does not meet the standard. In this case, the weld inspection is unqualified.

[0014] The present invention further provides a computer-readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the above-mentioned method for detecting weld defects of a laser welding liquid cooling plate.

[0015] The technical solution provided by the present invention has the following beneficial effects compared with the prior art: First, in the present invention, the weld height difference is obtained by subtracting the minimum weld height from the maximum weld height. If the weld height difference is less than or equal to the weld height difference threshold, it indicates that the distance gap between the highest and lowest points of the weld meets the standard, and the weld inspection is qualified; if the weld height difference is greater than the weld height difference threshold, it indicates that the distance gap between the highest and lowest points of the weld does not meet the standard, and the weld inspection is unqualified. The weld height difference reflects both the weld flatness and the weld crack depth at the same time. If the weld height difference is too large, it not only represents that the weld surface is uneven and there is a flatness problem, but also represents that the depth of the weld crack is relatively deep, posing a safety hazard.

[0016] Second, in the present invention, on the basis that the height difference of the weld does not exceed the weld height difference threshold by too much, the comparison between the height of the liquid cooling plate and the maximum height and the minimum height of the weld reflects three different situations. When the height of the liquid cooling plate is greater than the minimum height of the weld and greater than the maximum height of the weld, it means that the local material fusion at the weld is incomplete and does not completely cover the area on the liquid cooling plate that needs to be welded. In this case, the weld inspection is unqualified. When the height of the liquid cooling plate is less than the maximum height of the weld and less than the minimum height of the weld, it means that the whole weld protrudes from the original plane of the liquid cooling plate. In this case, the weld inspection is qualified. When the height of the liquid cooling plate is greater than the minimum height of the weld but less than the maximum height of the weld, it means that the height distribution of the weld is uneven and there is an obvious height difference locally. In this case, the weld inspection is unqualified.

[0017] Third, in the present invention, when the height of the liquid cooling plate is greater than the minimum height of the weld but less than the maximum height of the weld, the key lies in the size of the gap between the minimum height of the weld and the height of the liquid cooling plate. Only when this gap exceeds a certain degree will it pose a substantial threat to the structural performance. If the gap is not large, it can be considered that the inspection is qualified because the local height exceeding standard problem caused by the protrusion of the highest part of the weld can be removed by mechanical grinding or precision machining methods to restore the weld surface to an ideal flat state, thus not having a substantial impact on the overall performance of the liquid cooling plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic flow chart of the steps of the present invention; Figure 2 is a schematic module structure diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] It can be understood that the term "one" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of the element can be multiple. The term "one" cannot be understood as a limitation on the number.

[0021] The method for detecting weld defects of a laser-welded liquid cooling plate provided by the present invention, as Figure 1 and Figure 2 shown, includes the following steps: First step: Place the liquid cooling plate flat on the tabletop. Use a high-resolution industrial camera with a light source to perform real-time imaging on the weld of the liquid cooling plate to obtain the image features of the weld. The obtained image features are processed using an image processing algorithm, such as a convolutional neural network, to extract features. Obtain the distance between the highest point of the weld and the tabletop, denoted as the maximum weld height. At the same time, obtain the distance between the lowest point of the weld and the tabletop, denoted as the minimum weld height. After obtaining the maximum weld height and the minimum weld height, subtract the minimum weld height from the maximum weld height to obtain the weld height difference. It is worth mentioning that the light sources are of three forms: backlight, side light, and laser illumination. When backlight illumination is used, the weld edge will appear clearer, facilitating the precise positioning of the overall weld contour; side light can emphasize the texture and subtle unevenness of the weld surface, making local defects more obvious; the high brightness and local focusing of laser illumination will magnify hidden defects such as microcracks or pores. Based on this, in this step, when obtaining the maximum and minimum weld heights, the high-resolution industrial camera is equipped with side light.

[0022] Second step: Set the weld height difference threshold according to industry standards. The weld height difference threshold represents the standard value of the distance gap between the highest and lowest points of the weld. Welds with a weld height difference exceeding the weld height difference threshold do not meet the standards.

[0023] In the third step, compare the weld height difference with the weld height difference threshold, and different responses are obtained according to the comparison results. If the weld height difference is less than or equal to the weld height difference threshold, it indicates that the distance difference between the highest and lowest points of the weld meets the standard. In this case, the weld defect detection of the liquid cooling plate is qualified. If the weld height difference is greater than the weld height difference threshold, it indicates that the distance difference between the highest and lowest points of the weld does not meet the standard. In this case, the weld defect detection of the liquid cooling plate is unqualified. Because the weld height difference is actually a multi-dimensional index, it not only reflects the flatness of the weld as a whole, but also indirectly reveals the possible crack depth inside the weld. When the distance between the highest and lowest points of the weld is too large, it indicates that there are obvious unevenness on the weld surface. This unevenness may be caused by factors such as uneven heat input, different metal solidification speeds, or abnormal molten pool flow during the welding process, and there may also be deeper cracks. Because during the welding process, once cracks appear, it will not only cause local material failure, but also significantly reduce the weld height at that position, thereby increasing the overall height difference. Therefore, the exceeding of the weld height difference can be regarded as a signal of unqualified weld flatness and also a warning of a larger crack depth. By detecting and analyzing this height difference, two kinds of defect information can be captured simultaneously, providing a scientific basis for immediate adjustment during the production process and subsequent maintenance, and ensuring that the welding structure meets the standard requirements in terms of safety and reliability. For example, assume that the maximum weld height is 8 mm and the minimum weld height is 6 mm, then the weld height difference is 8 mm minus 6 mm which equals 2 mm. Assume that the weld height difference threshold is 2.5 mm, and the weld height difference of 2 mm is less than the weld height difference threshold of 2.5 mm. Therefore, the distance difference between the highest and lowest points of the weld meets the standard, and the weld defect detection of the liquid cooling plate is qualified.

[0024] Step 4: When the weld height difference is greater than the weld height difference threshold, set the weld height difference to be close to the threshold. The weld height difference close to the threshold is greater than the weld height difference threshold, but does not exceed the weld height difference threshold by much, but is close to the weld height difference threshold. For example, the weld height difference threshold is 2.5 mm, and the weld height difference close to the threshold is 2.8 mm. On this basis, compare the weld height difference with the weld height difference close to the threshold, and different responses are obtained according to the comparison results. If the weld height difference is less than or equal to the weld height difference close to the threshold, it means that although the distance difference between the highest and lowest points of the weld exceeds the standard, the degree of exceeding is not high. In this case, further detect the weld defects. If the weld height difference is greater than the weld height difference close to the threshold, it means that the distance difference between the highest and lowest points of the weld not only exceeds the standard, but also the degree of exceeding is relatively high. In this case, the weld defect detection of the liquid cooling plate remains unqualified. During the further detection process, obtain the height of the liquid cooling plate, and compare the height of the liquid cooling plate with the maximum weld height and the minimum weld height respectively, and different responses are made according to the comparison results. If the height of the liquid cooling plate is greater than the maximum weld height and the maximum weld height is greater than the minimum weld height, it means that the overall local welding area formed at the weld does not reach the top plane of the liquid cooling plate, and the filling of the weld on the entire welding surface is significantly insufficient. This indicates that there are problems with the heat input or molten pool control during the laser welding process, resulting in incomplete local metal fusion and thus unable to achieve the expected self-closure phenomenon. In other words, this situation reflects the incomplete fusion of local materials, which does not completely cover the area to be welded on the liquid cooling plate, thus causing a decrease in structural strength or local stress concentration, and there is a potential risk of failure during subsequent use or service. Therefore, this weld is judged to be unqualified. If the height of the liquid cooling plate is less than the minimum weld height and the minimum weld height is less than the maximum weld height, it means that the actually formed weld area exceeds the range of the top plane of the liquid cooling plate, and the weld as a whole protrudes from the original plane of the liquid cooling plate. Although this phenomenon indicates that the local metal has been fully or even overly melted and fused under the action of the laser, it appears relatively firm from the perspective of pure welding technology, but the excessive metal accumulation may form irregular protrusions in appearance. In subsequent production and processing, the protruding weld profile can be trimmed to be consistent with the plane of the liquid cooling plate through mechanical grinding or finishing processes. Therefore, in this case, although there is an excessive fusion phenomenon in the weld, it does not directly affect the welding connection strength and safety, so the final weld defect detection can be judged to be qualified. If the height of the liquid cooling plate is greater than the minimum weld height but less than the maximum weld height, it reflects that the height distribution of the weld is uneven, and there is an obvious phenomenon of height difference locally. This weld non-uniformity may be the result of a series of process factors such as improperly controlled laser power, welding speed, and workpiece positioning error, directly indicating that the fusion of local metal on the liquid cooling plate fluctuates.Welds with uneven heights not only fail to meet the quality requirements in terms of appearance but also affect the stress resistance and sealing performance of the connection area to a certain extent. Especially in application scenarios with harsh working conditions or high requirements for heat transfer and sealing performance, such uneven welds are extremely likely to become potential failure hazards. Therefore, the test results should be judged as unqualified. In summary, by comparing the height of the liquid cooling plate with the maximum and minimum heights of the weld, the fusion situation of local metal during the laser welding process can be judged more meticulously. If the overall height of the weld is lower than the top of the liquid cooling plate, it indicates insufficient welding and incomplete fusion. If the overall height of the weld exceeds the top of the liquid cooling plate, it indicates a moderate over-fusion problem, but it can be rectified by subsequent surface treatment. Uneven weld heights directly reflect the instability of process control. For example, assume the maximum height of the weld is 8 mm, the minimum height of the weld is 5.4 mm, and the height difference of the weld is 2.6 mm. The height difference of the weld, 2.6 mm, is greater than the weld height difference threshold of 2.5 mm but less than the weld height difference approaching threshold of 2.8 mm. Therefore, further testing is carried out. During the further testing process, if the height of the liquid cooling plate is 10 mm, then the height of the liquid cooling plate, 10 mm, is greater than the minimum height of the weld, 5.4 mm, and greater than the maximum height of the weld, 8 mm. In this case, the local metal fails to fuse sufficiently and the weld is unqualified. If the height of the liquid cooling plate is 5 mm, the height of the liquid cooling plate, 5 mm, is less than the maximum height of the weld, 8 mm, and less than the minimum height of the weld, 5.4 mm. In this case, the local metal is over-fused and the weld is qualified. If the height of the liquid cooling plate is 6 mm, the height of the liquid cooling plate, 6 mm, is greater than the minimum height of the weld, 5.4 mm but less than the maximum height of the weld, 8 mm. In this case, the local metal fusion is uneven and the weld is unqualified. Present it in tabular form as shown in Table 1 below:.

[0025] Step 5: When the height of the liquid cooling plate is greater than the minimum weld height but less than the maximum weld height, subtract the minimum weld height from the height of the liquid cooling plate to obtain the height by which the minimum weld height is lower than the liquid cooling plate, denoted as the weld height difference. At the same time, set a threshold for the weld height difference according to industry standards. The threshold for the weld height difference represents the maximum height difference allowed between the weld and the liquid cooling plate when the weld is lower than the liquid cooling plate height without affecting the structural performance. Based on this, compare the weld height difference with the threshold for the weld height difference and obtain different responses according to the comparison results. If the weld height difference is less than or equal to the threshold for the weld height difference, it means that the difference between the minimum weld height and the liquid cooling plate height is within the allowable range. In this case, the weld inspection is qualified. If the weld height difference is greater than the threshold for the weld height difference, it means that the difference between the minimum weld height and the liquid cooling plate exceeds the allowable range. In this case, the weld inspection is unqualified. Because when the height of the liquid cooling plate is greater than the minimum weld height but less than the maximum weld height, although it reflects the uneven height distribution of the weld and there is an obvious phenomenon of high and low differences locally. However, if the height of the liquid cooling plate is close to the minimum weld height, that is, the minimum weld height is not much less than the liquid cooling plate height, they can be regarded as close. On this premise, it can be considered that the minimum weld height does not affect the structural performance. As long as the minimum weld height does not affect the structural performance, since the maximum weld height protrudes from the liquid cooling plate, it can also be ground off. That is to say, although when the height of the liquid cooling plate is greater than the minimum weld height but less than the maximum weld height, it reflects the unevenness of the weld height, but this unevenness is mainly due to the minimum weld height affecting the structural performance, rather than the maximum weld height. For example, assume that the maximum weld height is 8 mm, the minimum weld height is 5.4 mm, and the height of the liquid cooling plate is 6 mm. The height of the liquid cooling plate 6 mm is greater than the minimum weld height 5.4 mm but less than the maximum weld height 8 mm. In this case, subtract the minimum weld height 5.4 mm from the height of the liquid cooling plate 6 mm to obtain a weld height difference of 0.6 mm. Assume that the threshold for the weld height difference is 1 mm. The weld height difference of 0.6 mm is less than the threshold for the weld height difference of 1 mm. Therefore, the difference between the minimum weld height of 5.4 mm and the liquid cooling plate height of 6 mm is within the allowable range, and this difference hardly affects the structural performance of the liquid cooling plate. For the protruding maximum weld height of 8 mm, it can be ground off. Therefore, in this case, the weld inspection is qualified. Generally speaking, in the case where the height of the liquid cooling plate is greater than the minimum weld height but less than the maximum weld height, a refined detection method is used to evaluate the actual impact of the weld on the overall structural performance. First, at this time, the height of the liquid cooling plate is between the two poles of the weld, reflecting an obvious unevenness in the height of the weld, and this unevenness is mainly manifested as the difference in the height by which the minimum weld height is lower than the top surface of the liquid cooling plate. To quantitatively describe this phenomenon, define the weld height difference as the value obtained by subtracting the minimum weld height from the height of the liquid cooling plate. This value indicates the deficiency of the lowest part of the weld compared to the top surface of the liquid cooling plate.According to industry standards, a threshold value for the weld gap height is further set. This threshold represents the maximum allowable height difference between the weld and the liquid cooling plate on the premise that the weld does not affect the structural performance. If the actually measured weld gap height is less than or equal to this weld gap height threshold, it indicates that although there is a relatively obvious uneven distribution of high and low in the local weld, the distance from the lowest point of the weld to the top surface of the liquid cooling plate is still within the allowable range, and it will not have a significant adverse impact on the overall mechanical properties, sealing performance or heat dissipation performance of the liquid cooling plate. At this time, the weld inspection can be considered qualified; on the contrary, if the weld gap height is greater than the preset weld gap height threshold, it indicates that the defect degree between the liquid cooling plate and the lowest part of the weld has exceeded the safe allowable range, which may lead to excessive local stress concentration and is prone to fracture or seal failure under long-term service, and then the weld inspection result is judged as unqualified. It should be emphasized that although in this case, the highest point of the weld protrudes significantly above the top surface of the liquid cooling plate, if this protrusion is only the result of excessive melting of the material, the local height exceeding standard problem formed can be removed by mechanical grinding or precision machining methods to restore the weld surface to an ideal flat state, thus not having a substantial performance impact on the overall liquid cooling plate. That is to say, the key lies in the size of the gap between the minimum height of the weld and the height of the liquid cooling plate. Only when this gap exceeds a certain degree will it pose a substantial threat to the structural performance.

[0026] Embodiments disclosed by the present invention. The processes described above with reference to the flowcharts can be implemented as computer software programs. Embodiments disclosed by the present invention include a computer program product, which includes a computer program carried on a computer-readable medium. The computer program contains program codes for executing the methods shown in the flowcharts. In such an embodiment, the computer program can be downloaded and installed from a network through a communication part, and / or installed from a removable medium. When the computer program is executed by a central processing unit, the above-mentioned functions defined in the methods of the present application are executed. It should be noted that the above-mentioned computer-readable medium in the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of a computer-readable storage medium can include, but are not limited to: an electrical connection with one or more wire segments, a portable computer disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical fiber, a portable compact disk read-only memory, an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or combined with an instruction execution system, apparatus, or device. In the present application, a computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries computer-readable program codes. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, and the computer-readable medium can send, propagate, or transmit a program for use by or combined with an instruction execution system, apparatus, or device. The program codes contained on the computer-readable medium can be transmitted by any appropriate medium, including but not limited to: wireless segments, wire segments, optical cables, RF, etc., or any suitable combination of the above.

[0027] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a part of code that contains one or more executable instructions for implementing a specified logical function. It should also be noted that, in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, may be implemented by a dedicated hardware-based system that performs the specified functions or operations, or may be implemented by a combination of dedicated hardware and computer instructions.

[0028] Those skilled in the art should understand that the above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application.

Claims

1. A method for detecting weld defects of a laser welding liquid cooling plate, characterized in that, Including: Step 1: Use an industrial camera with a light source to perform real-time imaging on the weld of the liquid cooling plate to obtain image features. After image processing, the maximum height and minimum height of the weld from the tabletop are obtained, denoted as the maximum weld height and the minimum weld height respectively. The weld height difference is obtained by subtracting the minimum weld height from the maximum weld height; Step 2: Set a weld height difference threshold representing the standard value of the distance gap between the highest and lowest points of the weld. Welds with a weld height difference exceeding the weld height difference threshold are non-compliant welds; Step 3: Compare the weld height difference with the weld height difference threshold. If the weld height difference is less than or equal to the weld height difference threshold, it means that the distance gap between the highest and lowest points of the weld meets the standard. In this case, the weld inspection is qualified. If the weld height difference is greater than the weld height difference threshold, it means that the distance gap between the highest and lowest points of the weld does not meet the standard. In this case, the weld inspection is unqualified.

2. The method for detecting weld defects of the laser welding liquid cooling plate according to claim 1, characterized in that When the weld height difference is greater than the weld height difference threshold, set a weld height difference close to the threshold that is greater than the weld height difference threshold, and compare the weld height difference with the weld height difference close to the threshold, and different responses are obtained according to the comparison results.

3. The method for detecting weld defects of the laser welding liquid cooling plate according to claim 2, wherein, If the weld height difference is less than or equal to the weld height difference close to the threshold, it means that the degree of the distance gap between the highest and lowest points of the weld exceeding the standard is low. In this case, the weld is further inspected. If the weld height difference is greater than the weld height difference close to the threshold, it means that the degree of the distance gap between the highest and lowest points of the weld exceeding the standard is high. In this case, the weld inspection is unqualified.

4. The method for detecting weld defects of the laser welding liquid cooling plate according to claim 3, characterized in that, When further inspecting the weld, obtain the height of the liquid cooling plate, compare the height of the liquid cooling plate with the maximum weld height and the minimum weld height respectively, and different responses are made according to the comparison results.

5. The method for detecting weld defects of the laser welding liquid cooling plate according to claim 4, characterized in that If the height of the liquid cooling plate is greater than the minimum weld height and greater than the maximum weld height, it means that the local material fusion at the weld is incomplete and does not completely cover the area to be welded on the liquid cooling plate. In this case, the weld inspection is unqualified. If the height of the liquid cooling plate is less than the maximum weld height and less than the minimum weld height, it means that the weld protrudes from the original plane of the liquid cooling plate as a whole. In this case, the weld inspection is qualified. If the height of the liquid cooling plate is greater than the minimum weld height but less than the maximum weld height, it means that the height distribution of the weld is uneven and there is an obvious height difference locally. In this case, the weld inspection is unqualified.

6. The method for detecting weld defects of the laser welding liquid cooling plate according to claim 5, wherein, Obtain the weld gap height by subtracting the minimum weld height from the height of the liquid cooling plate. At the same time, set a weld gap height threshold according to industry standards. When the height of the liquid cooling plate is greater than the minimum weld height but less than the maximum weld height, compare the weld gap height with the weld gap height threshold, and different responses are obtained according to the comparison results.

7. The laser welding liquid cooling plate weld defect detection method according to claim 6, characterized in that: If the weld gap height is less than or equal to the weld gap height threshold, it means that the gap between the minimum weld height and the height of the liquid cooling plate is within the allowable range. In this case, the weld inspection is qualified. If the weld gap height is greater than the weld gap height threshold, it means that the gap between the minimum weld height and the liquid cooling plate exceeds the allowable range. In this case, the weld inspection is unqualified.

8. The method for detecting weld defects of the laser welding liquid cooling plate according to claim 1, characterized in that, The light sources paired with the industrial camera include backlight sources, side light sources, and laser illumination sources. Among them, when imaging the weld of the liquid cooling plate, the paired light source is the side light source.

9. A laser welding liquid cooling plate weld defect detection system, which is used to execute the method described in any one of claims 1-8, and is characterized in that, It includes the following modules: An acquisition module, which is used to use the light source paired with the industrial camera to perform real-time imaging on the weld of the liquid cooling plate, obtain image features, and after image processing, obtain the maximum height and minimum height of the weld from the tabletop, which are respectively recorded as the maximum weld height and the minimum weld height, and obtain the weld height difference by subtracting the minimum weld height from the maximum weld height; A setting module, which is used to set a weld height difference threshold representing the standard value of the distance gap between the highest and lowest points of the weld. A weld with a weld height difference exceeding the weld height difference threshold is a non-compliant weld; A comparison module, which is used to compare the weld height difference with the weld height difference threshold. If the weld height difference is less than or equal to the weld height difference threshold, it means that the distance gap between the highest and lowest points of the weld meets the standard. In this case, the weld inspection is qualified; if the weld height difference is greater than the weld height difference threshold, it means that the distance gap between the highest and lowest points of the weld does not meet the standard. In this case, the weld inspection is unqualified.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement a method for detecting weld defects of a laser-welded liquid cooling plate described in any one of the above claims 1-8.

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