Follow-up type flexible welding clamping device for heat exchanger plates and welding method

Abstract

The invention relates to the technical field of welding, in particular to a heat exchanger plate follow-up type flexible welding clamping device and welding method.The heat exchanger plate follow-up type flexible welding clamping device comprises a three-axis linkage mechanism which is provided with an X-axis moving module, a Y-axis moving module and a Z-axis moving module; the clamping mechanism is arranged at the execution tail end of the three-axis linkage mechanism; the clamping mechanism is provided with two clamping assemblies installed in a mirror image mode, the execution tail end of each clamping assembly overhangs outwards to be provided with a clamping body, and each clamping assembly is provided with a driver to drive the two clamping bodies to be opened and closed so as to clamp and loosen the edge of a to-be-welded plate set. The overhanging direction of the clamping body is perpendicular to the feeding direction of the three-axis linkage mechanism. The clamping bodies are driven to provide clamping force, the two clamping bodies are controlled to be opened and closed so as to clamp and loosen the edge of the plate sheet set, the clamping point can move along with a welding point of a worker or a welding robot, tension generated by local deformation of the plate sheet set is released, and it is guaranteed that all positions of the plate sheet set can be subjected to equal clamping force.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a flexible welding clamping device and welding method for heat exchanger plates. Background Technology

[0002] Plate heat exchangers are a type of high-efficiency heat exchanger composed of a series of metal plates with a certain corrugated shape, and are widely used in industrial fields. Due to the structural characteristics of plate heat exchanger plates, such as large area, thin thickness, significant plastic deformation during stamping, and diverse materials, when using a continuous pressing process for whole plates, the non-uniform stress distribution generated by the step-by-step stamping of the mold and the difference in material ductility result in the parabolic shape of the plate edge area. The gap between the plates near the two ends of the fully welded plate heat exchanger is smaller, while the gap near the middle is larger.

[0003] To ensure the gap between the plates meets welding requirements (gap less than 0.50mm), the plates need to be clamped. Currently, there are two types of clamping methods:

[0004] First, clamping with calipers is used. Workers use two or three calipers to clamp the edges of the sheet assembly, reducing the gap between the edges to a weldable distance. When workers use argon arc welding to weld the edges of the clamped sheet assembly, on the one hand, as the welding position changes, the clamping position of the calipers must be adjusted synchronously with the movement trajectory of the welding torch, making the operation cumbersome and significantly reducing welding efficiency; on the other hand, since the sheets are formed by stamping, residual stress concentration areas are generated during the stamping process, resulting in local deformation and causing the gap between the sheet assemblies to increase (which may lead to weldability issues or incomplete welds), often requiring multiple passes of repair welding to compensate.

[0005] Secondly, a clamping device is used. A prior art heat exchanger plate welding clamping device (Wang Neng, Yang Liyong, Xue Debo, et al. Design and experimental study of heat exchanger plate welding clamping device [J]. Modern Manufacturing Engineering, 2023, (06): 1-5+70.) uses two upper and lower serrated clamping plates to clamp the entire long-distance, large-format plate. Compared with manual clamping, the overall welding efficiency can be improved by about 40%. Since plate heat exchangers are formed by stacking and stamping metal sheets, and due to current process limitations, their dimensions may fluctuate within a reasonable range. Therefore, during the clamping process of the entire long-distance, large-format plate, the clamping of the entire strip can lead to the inability to release the local tension caused by the deformation of the plate assembly. There will always be one or more areas with poor clamping effect, resulting in differences in clamping effect and requiring workers to repeat welding. Summary of the Invention

[0006] The purpose of this invention is to provide a flexible welding clamping device and welding method for heat exchanger plates to solve the problems existing in the prior art. To achieve the above objective, this invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a heat exchanger plate follow-up flexible welding clamping device, comprising:

[0008] The three-axis linkage mechanism includes an X-axis movement module, a Y-axis movement module, and a Z-axis movement module;

[0009] A clamping mechanism is provided at the execution end of the three-axis linkage mechanism; the clamping mechanism has two mirror-mounted clamping components, each clamping component having a clamping body extending outward from its execution end, and each clamping component is equipped with a drive to drive the two clamping bodies to open and close to achieve clamping and releasing of the edge of the plate group to be welded, and the extension direction of the clamping body is perpendicular to the feed direction of the three-axis linkage mechanism.

[0010] As a further technical solution, the Y-axis moving module is disposed on the X-axis moving module, the Z-axis moving module is disposed on the Y-axis moving module, the X-axis moving module serves as the feeding direction, and the clamping mechanism is disposed on the Z-axis moving module.

[0011] As a further technical solution, the Z-axis moving module and the Y-axis moving module are both lead screw transmission mechanisms, and the X-axis moving module is a belt transmission mechanism.

[0012] As a further technical solution, the two clamping components are equipped with mounting bases, the mounting bases are equipped with guide rails and can slide up and down; the top and bottom of the mounting bases are each provided with springs and connected to one end of the springs, and the other end of the springs is provided with a limiting structure.

[0013] As a further technical solution, the clamping body is a rotatable rolling body.

[0014] As a further technical solution, each of the clamping components also includes a force guide plate and is connected to the drive. The force guide plate located at the upper part extends outward and bends vertically downward, and the force guide plate located at the lower part extends outward and bends vertically upward. The execution end of each force guide plate is provided with a support shaft, and the rolling element is mounted on the support shaft.

[0015] As a further technical solution, all of the clamping components are pneumatically driven.

[0016] In a second aspect, the present invention provides a welding method for heat exchanger plates, which employs a welding robot and a heat exchanger plate follow-up flexible welding clamping device as described in the first aspect, and includes the following steps:

[0017] The welding start point of the welding plate group is clamped by a follow-up flexible welding clamping device. When the welding robot is welding, the follow-up flexible welding clamping device follows the end of the welding robot to perform follow-up clamping until the welding end point. During the welding process, the laser vision sensor carried by the welding robot collects the weld features, and after identifying the weld features, it generates welding coordinates. Then the welding robot completes the welding.

[0018] As a further technical solution, weld seam feature recognition is performed using a deep learning model. The deep learning model is built based on the object detection model YOLOv10: the FasterNet Block module, which is constructed with partial convolution and pointwise convolution as its core, is integrated into the original YOLOv10 architecture cross-stage local network for backbone network reconstruction; a detection head based on the DWR module is set up, the DWRconv module is added, and the 3x3 convolution is deleted, leaving only the conv2d module; the original loss function in the object detection model YOLOv10 is replaced with the MPDIoU loss function.

[0019] As a further technical solution, when the follow-up flexible welding clamping device clamps the plate group to be welded, it has a 2-3mm safety distance between the clamping body and the edge of the plate group to be welded.

[0020] The beneficial effects of the present invention are as follows:

[0021] (1) The clamping mechanism of the present invention has two clamping components and a clamping body that extends outwards. The clamping body is driven to provide clamping force, and the opening and closing of the two clamping bodies is controlled to achieve clamping and releasing of the edge of the plate group. It changes from the existing caliper clamping and surface clamping to follow-up point clamping, and is fed under the drive of the three-axis linkage mechanism. This allows the clamping point to move together with the welding point of the worker or welding robot, releasing the tension generated by the local deformation of the plate group, ensuring that all parts of the plate group are subjected to equal clamping force, and solving the problem that the local clamping effect of existing welding clamping devices or manual clamping is not ideal, resulting in low welding efficiency and unstable welding quality.

[0022] (2) In this invention, the mounting bases of the two clamping components cooperate with the guide rails, allowing the two clamping components to float up and down after clamping the plate group. This eliminates the support reaction force against the deformation of the plate group, thus adapting to the irregular deformation of the plate group. A set of springs in this invention provides vertical support for the clamping components, solving the positioning problem along the radial direction of the plate group. While providing support, the clamping components can still move up and down along the guide rails. In summary, this embodiment introduces a degree of freedom along the radial direction of the plate group, allowing the clamping structure to float with the irregular deformation of the plate group, achieving flexible clamping of the plate heat exchanger.

[0023] (3) The present invention designs the clamping body as a rotatable rolling body. When the rolling body clamps the plate group and feeds, the rolling body can move along the plate group in a rolling state, reducing the friction between the clamping body and the plate group during the clamping and feeding process, and ensuring the clamping effect of the clamping mechanism.

[0024] (4) The deep learning-based FBDM-YOLOv10 model designed in this invention incorporates a detection head based on a dynamically weighted residual module, which enhances the model's robustness and improves convergence speed during training. Furthermore, the original model's backbone is reconstructed by integrating FasterNet Block modules, and the MPDIoU loss function is introduced to improve the perception of small target features, reduce model size, and enhance real-time performance. This model addresses the problem of real-time and accurate weld seam identification when using low-computing-power, low-cost equipment to address the accumulation of errors caused by shrinkage, warping, and deformation resulting from heat input during the welding of large-format, long-distance plates. Attached Figure Description

[0025] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute a limitation thereof. It should also be understood that these drawings are for simplicity and clarity and are not necessarily drawn to scale. The invention will now be described and explained with additional features and details using the drawings, wherein:

[0026] Figure 1 A schematic diagram of the use of the follower-type flexible welding clamping device in an embodiment of the present invention is shown;

[0027] Figure 2 A schematic diagram of the heat exchanger plate to be welded in an embodiment of the present invention is shown;

[0028] Figure 3 A schematic diagram of the follow-up flexible welding clamping device in an embodiment of the present invention is shown.

[0029] Figure 4 A schematic diagram of the clamping mechanism in an embodiment of the present invention is shown;

[0030] Figure 5 A schematic diagram of the X-axis movement module in an embodiment of the present invention is shown;

[0031] Figure 6 A schematic diagram of the Y-axis movement module in an embodiment of the present invention is shown;

[0032] Figure 7 A schematic diagram of the Z-axis movement module in an embodiment of the present invention is shown;

[0033] Figure 8A schematic diagram of the welding robot structure in an embodiment of the present invention is shown;

[0034] Figure 9 The diagram shows the FBDM-YOLOv10 network structure in an embodiment of the present invention.

[0035] Figure 10 A schematic diagram of the DWR module structure in an embodiment of the present invention is shown;

[0036] Figure 11 A schematic diagram showing the safe distance reserved between the clamping device and the edge of the plate group in an embodiment of the present invention is shown.

[0037] In the diagram: 100, heat exchanger plate to be welded; 110, plate assembly; 120, clamping plate; 130, weld seam; 200, follow-up flexible welding clamping device; 210, clamping mechanism; 211, bearing; 212, support shaft; 213, guide plate; 214, gripper; 215, first guide rail; 216, spring; 217, mounting base; 218, second guide rail; 219, first mounting plate; 220, X-axis moving module; 221, second mounting plate; 222, belt drive mechanism; 223, first drive; 230, Y-axis moving module; 231, third guide rail; 232. 233 Y-axis lead screw; 234 Y-axis moving module; 235 First support plate; 236 Second support plate; 237 Third support plate; 238 Second drive; 249 Third mounting plate; 240 Z-axis moving module; 241 Fourth guide rail; 242 Z-axis lead screw; 243 Z-axis moving module; 244 Fourth support plate; 245 Fifth support plate; 246 Sixth support plate; 247 Third drive; 300 Welding robot; 310 Welding torch; 320 Laser vision sensor; 330 First welding arm; 340 Second welding arm; 350 Base. Detailed Implementation

[0038] The technical solutions in typical embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0039] Example 1

[0040] like Figure 1 and Figure 3 As shown, this embodiment provides a heat exchanger plate follow-up flexible welding clamping device 200, including a three-axis linkage mechanism and a clamping mechanism 210. The clamping mechanism 210 is responsible for realizing the follow-up clamping of the plate heat exchanger plates, while the three-axis linkage mechanism is responsible for carrying the clamping mechanism 210 to realize rapid three-axis movement and positioning to the clamping position of the plate heat exchanger plates.

[0041] The clamping mechanism 210 is located at the execution end of the three-axis linkage mechanism. The clamping mechanism 210 has two mirror-mounted clamping components. Each clamping component has a clamping body extending outward from its execution end. Each clamping component is equipped with a drive to drive the two clamping bodies to open and close, thereby clamping and releasing the edge of the plate assembly 110 to be welded. The extension direction of the clamping body is perpendicular to the feed direction of the three-axis linkage mechanism.

[0042] In this embodiment, the clamping mechanism 210 has two clamping components with overhanging clamping bodies. The clamping bodies are driven to provide clamping force, and the opening and closing of the two clamping bodies is controlled to clamp and release the edges of the plate assembly. This changes the existing caliper clamping and surface clamping to a follow-up point clamping, and is fed under the drive of a three-axis linkage mechanism. This allows the clamping point to move together with the welding point of the worker or welding robot, releasing the tension caused by the local deformation of the plate assembly, ensuring that all parts of the plate assembly are subjected to equal clamping force, and solving the problem of unsatisfactory local clamping effect of existing welding clamping devices or manual clamping, which leads to low welding efficiency and unstable welding quality.

[0043] like Figure 3 As shown, the three-axis linkage mechanism includes an X-axis moving module 220, a Y-axis moving module 230, and a Z-axis moving module 240; the Y-axis moving module 230 is mounted on the X-axis moving module 220, and the Z-axis moving module 240 is mounted on the Y-axis moving module 230.

[0044] The X-axis moving module 220 serves as the main feed direction, driving the clamping mechanism 210 to clamp the plate assembly 110 to be welded during welding, so that the clamping point moves together with the welding point of the worker or welding robot. The clamping mechanism 210 is mounted on the Z-axis moving module 240. The Y-axis moving module 230 is used for adjusting the clamping mechanism 210 in the Y direction, and the Z-axis moving module 240 is used for adjusting the clamping mechanism 210 in the Z direction (i.e., adjusting in the height direction).

[0045] like Figure 5 As shown, the X-axis moving module 220 is a belt drive mechanism 222, specifically a synchronous belt drive. Because a linear module with an effective stroke of 1400mm would experience vibration due to an excessively long leadscrew, affecting transmission accuracy, a synchronous belt module was chosen. Furthermore, since the primary requirement for follow-up clamping is stable movement of the clamping point after clamping, a three-phase stepper motor was selected for the first drive 223. Compared to a two-phase stepper motor, it offers more stable operation and higher power output.

[0046] The second mounting plate 221 of the X-axis moving module 220 is used to support the mounting of the Y-axis moving module 230.

[0047] like Figure 6As shown, the Y-axis moving module 230 screw transmission mechanism includes a third guide rail 231 and a Y-axis moving module 233 mounted on the third guide rail 231. The Y-axis moving module 233 cooperates with the Y-axis screw 232. The third guide rail 231 has a second support plate 235 and a third support plate 236 at both ends, and a first support plate 234 on the third guide rail 231. The first support plate 234 and the third support plate 236 support the Y-axis screw 232. A second drive 237, which is also a motor drive, is mounted on the second support plate 235.

[0048] The Y-axis moving module 230 is mounted on the second mounting plate 221 via the bottom of the third guide rail 231. The top of the Y-axis moving module 233 of the Y-axis moving module 230 is provided with a third mounting plate 238 for mounting the Z-axis moving module 240.

[0049] like Figure 7 As shown, the Z-axis movement module 240 is also a lead screw drive mechanism, including a fourth guide rail 241 and a Z-axis movement module 243 mounted on the fourth guide rail 241. The Z-axis movement module 243 is coupled with a Z-axis lead screw 242. The fourth guide rail 241 has a fifth support plate 245 and a sixth support plate 246 at both ends, and a fourth support plate 244 on the fourth guide rail 241. The fourth support plate 244 and the sixth support plate 246 support the Z-axis lead screw 242. A third drive 247 is mounted on the fifth support plate 245, and the third drive 247 is also a motor drive.

[0050] The Z-axis moving module 240 is mounted on the third mounting plate 238 via the fourth guide rail 241. The clamping mechanism 210 is mounted on the Z-axis moving module 243 on the fourth guide rail 241 via the first mounting plate 219.

[0051] While the follow-up clamping design solves the problem of local tension caused by the deformation of the plate assembly 110, it also introduces the characteristic of irregular deformation of the plate assembly 110. Furthermore, the introduction of thermal deformation during welding results in the plate assembly 110 not being a horizontal straight line after clamping. If the clamping structure moves linearly along the plate assembly 110 under the action of the X-axis moving module 220 after clamping, it will generate a support reaction force against the deformation of the plate assembly 110, which will act directly on the clamping structure 210, leading to problems such as poor clamping effect and structural failure.

[0052] like Figure 4 As shown, the two clamping components are equipped with mounting bases 217, which are equipped with guide rails and can slide up and down; springs 216 are provided at the top and bottom of the mounting base and connected to one end of the springs 216, and the other end of the springs 216 is provided with a limiting structure.

[0053] Specifically, a vertical plate is fixed to the first mounting plate 219, with extensions at the top and bottom. A second guide rail 218 is mounted on the vertical plate and slides in cooperation with the mounting base 217. In this embodiment, the upper and lower parts of the mounting base 217 are connected to one end of a spring 216, and the other end is connected to the extensions of the vertical plate at the top and bottom.

[0054] In this embodiment, spring 216 is a compression flat wire mold spring, model TL10×50 with a limit compression rate of 40% and a limit pressure of 98N, which can ensure the stable installation of the pneumatic gripper while allowing for vertical floating space.

[0055] In this embodiment, the mounting bases 217 of the two clamping components cooperate with the guide rail, allowing the two clamping components to float up and down after clamping the plate group 110. This eliminates the support reaction force against the deformation of the plate group 110, adapting to the irregular deformation of the plate group 110. A set of springs 216 in this embodiment provides vertical support for the clamping components, solving the positioning problem along the radial direction of the plate group 110. While providing support, the clamping components can still move up and down along the guide rail. In summary, this embodiment introduces a degree of freedom along the radial direction of the plate group 110, allowing the clamping structure to float with the irregular deformation of the plate group 110, achieving flexible clamping of the plate heat exchanger.

[0056] Each clamping assembly also includes a force guide plate 213 connected to the drive. Each clamping assembly is pneumatically driven; therefore, the clamping device should also be equipped with an air compressor to provide pneumatic clamping force to the clamping assembly. The upper force guide plate 213 extends outward and bends vertically downward, while the lower force guide plate 213 extends outward and bends vertically upward. Each force guide plate 213 has a support shaft 212 at its actuating end, and rolling elements are mounted on the support shaft 212. The force guide plate 213 is mounted on a gripper 214, which cooperates with a first guide rail 215 (the first guide rail 215 is mounted on a mounting base 217). Under pneumatic drive, clamping force is applied through the gripper 214.

[0057] The pneumatic gripper uses the MHZ2-32D finger cylinder as the core clamping actuator, with a maximum clamping force of 158N, which meets the design requirement of 110N (maximum required clamping force 73.2N × 1.5 times safety factor).

[0058] The guide plate 213 is made of Q235 steel plate laser cutting, with a thickness of 8mm. The surface is nickel-plated to improve wear resistance. Its arc structure design can effectively disperse clamping stress.

[0059] The clamping body is a rotatable rolling element. In this embodiment, the rolling element is bearing 211, which is a high-temperature bearing. The high-temperature full ball bearing of model 686 is used, with a temperature range of 0℃ to 600℃, to ensure stable operation in the high-temperature welding environment.

[0060] In this embodiment, the clamping body is designed as a rotatable rolling body. When the rolling body clamps the plate group 110 and feeds, the rolling body can move along the plate group 110 in a rolling state, which reduces the friction between the clamping body and the plate group 110 during the clamping and feeding process, and ensures the clamping effect of the clamping mechanism 210.

[0061] Example 2

[0062] This embodiment provides a welding method for heat exchanger plates, which uses a welding robot 300 and a heat exchanger plate follow-up flexible welding clamping device 200 as described in Embodiment 1.

[0063] like Figure 8 As shown, the welding robot 300 includes a base 350, a first welding arm 330, a second welding arm 340, and a welding torch 310 located at the front end of the first welding arm 330. A laser vision sensor 320 is also arranged at the front end of the first welding arm 330 along with the welding torch 310. The laser vision sensor 320 consists of a RealSense D435i depth camera and a 650n006D line laser sensor, and is capable of acquiring weld feature images in real time.

[0064] like Figure 1 As shown, the placement direction of the heat exchanger plate 100 to be welded is consistent with the layout direction of the X-axis moving module 220.

[0065] The heat exchanger plate 100 to be welded is composed of several plate groups 110 stacked together, and the two ends are positioned by clamping plates 120, with the weld seam 130 to be welded exposed laterally.

[0066] The welding method for heat exchanger plates includes the following steps:

[0067] The flexible welding clamping device 200 is used to clamp the welding start point of the welding plate group. When the welding robot 300 is welding, the flexible welding clamping device 200 follows the welding robot 300 to perform follow-up clamping at the end of the welding process until the welding end point. During the welding process, the laser vision sensor 320 carried by the welding robot 300 collects the weld features and generates welding coordinates after identifying the weld features. Then the welding robot 300 completes the welding.

[0068] When the laser vision sensor 320 acquires weld seam images, the first step is camera calibration, the second is camera correction, the third is the camera taking pictures of the weld seam, and the fourth is preprocessing the captured images such as grayscale conversion, noise reduction, and binarization.

[0069] Weld seam feature recognition is performed using a deep learning model; the deep learning model is built upon the YOLOv10 object detection model, specifically the FasterNet Block-DWR-MPDIoU-YOLOv10 (FBDM-YOLOv10) model, such as... Figure 9 As shown.

[0070] The YOLOv10 network structure can be divided into three parts: Backbone, Neck, and Head. The Backbone is the main network for feature extraction, primarily aiming to extract multi-level features from the input image for subsequent processing. The Neck connects the Backbone and the Head, responsible for feature fusion, combining features from different levels to enhance the model's ability to detect targets at different scales. The Head performs target detection based on the fused features, generating outputs such as bounding boxes and class confidence scores. Each Head is responsible for processing targets at different scales to improve detection accuracy.

[0071] YOLOv10 employs depthwise separable convolution, which decomposes standard convolution into two independent stages: channel-wise spatial convolution and pointwise convolution. This reduces the number of parameters while improving computational efficiency. However, it suffers from several problems: First, the separation of depthwise and pointwise convolution may sever the correlation between spatial and channel features, leading to a decrease in the model's ability to fuse multi-level semantic information in complex scenes. Second, adjustments to the network topology alter the gradient flow path during backpropagation, potentially slowing down convergence or causing the model to get stuck in local optima. Third, depthwise separable convolution is less effective at representing subtle features, making it prone to false positives or false negatives when dealing with densely distributed small targets. Although the modular design reduces the number of parameters per layer, the multiple convolutional blocks stacked to compensate for performance losses actually increase the complexity of the network architecture, making hyperparameter tuning and model compression more challenging.

[0072] To solve the above problems, such as Figure 9As shown, the FasterNet Block module, built around Partial Convolution (PConv) and Pointwise Convolution (PWConv) as its core, is integrated into the YOLOv10 Cross-Stage Partial Network (CSPNet) architecture for backbone network reconstruction, constructing a feature extraction system that balances efficiency and accuracy. Partial Convolution (PConv) employs a channel-selective activation mechanism, performing spatial convolution operations only on channels with high information entropy in the input feature map, while the remaining channels retain their original values. This strategy preserves core spatial features while reducing computational complexity to less than 25% of traditional convolutions, and avoids the information decay effect caused by the decoupling of spatial and channel features in depthwise separable convolutions. Pointwise Convolution (PWConv), an optimized version of 1×1 convolution, is deployed after the PConv layer. Through a learnable weight matrix, it dynamically reorganizes and nonlinearly maps cross-channel features, effectively enhancing the diversity and discriminative power of feature representation.

[0073] The PConv module represents an efficient convolution technique that performs convolution operations only on selected portions of the input feature map, that is, it only processes the active regions in the input channels, thereby significantly reducing the number of floating-point operations (FLOPs) without sacrificing the ability to capture spatial features.

[0074] like Figure 9 and Figure 10 As shown, this embodiment designs a detection head structure based on Dynamic Weighted Residual (DWR) modules. Through a multi-stage feature enhancement mechanism, it significantly improves the perception capability of small targets. Based on the bounding box regression and category prediction branches, a DWRconv convolutional module is added before each branch, and the 3x3conv module in each branch is removed, retaining only the conv2d module. Through Region Residualization (RR) and Semantic Residualization (SR), multiple feature maps are concatenated and processed to construct a more powerful and comprehensive feature representation, effectively improving detection accuracy. Compared to the original detection head, this structure has better adaptability to welding scenarios and makes a significant contribution to improving the accuracy of small target recognition and reducing data volume.

[0075] To better adapt to the need for small-scale target detection in automated welding, this embodiment uses the MPDIoU (Maximum Possible DIoU) loss function instead of the original loss function. The MPDIoU loss function simplifies the comparison process of bounding box similarity by reducing the distance between the top-left and bottom-right corners of the predicted bounding box and the actual bounding box, making it adaptable to both overlapping and non-overlapping bounding boxes. The core of MPDIoU lies in using the corner distance of the bounding boxes to measure similarity, avoiding the complex overlapping calculation of IoU (Intersection over Union, or Cross-Rounding). By minimizing the corner distance between these two boxes, MPDIoU can more quickly optimize the accuracy of target detection. This approach not only enhances the model's robustness to targets of different scales and shapes but also simplifies the computation process to some extent and improves the convergence speed during training.

[0076] The laser emitter projects two bright areas onto the plate. After being processed by the FBDM-YOLOv10 model, the accurate bounding box position can be obtained, and the coordinate position of the welding coordinate point can be generated.

[0077] This embodiment designs a deep learning-based FBDM-YOLOv10 model, which incorporates a DWR-based detection head, enhancing the model's robustness and improving convergence speed during training. Furthermore, the original model undergoes backbone reconstruction incorporating FasterNet Block modules, and an MPDIoU loss function is introduced to improve the ability to perceive small target features, reduce model size, and enhance real-time performance. This model addresses the challenge of achieving real-time and accurate weld seam identification when using low-computing-power, low-cost equipment to handle the cumulative errors caused by shrinkage, warping, and deformation resulting from heat input during the welding of large-format, long-distance plates.

[0078] like Figure 11 As shown, when the follow-up flexible welding clamping device clamps the plate group to be welded, its clamping body has a 2-3mm safety distance reserved between the edge of the plate group to be welded, which can effectively avoid the risk of the clamping device accidentally welding together with the plate group, which seriously affects the production process and product quality.

[0079] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A flexible welding clamping device for heat exchanger plates, characterized in that, include: The three-axis linkage mechanism includes an X-axis movement module, a Y-axis movement module, and a Z-axis movement module; A clamping mechanism is located at the end of the actuator of the three-axis linkage mechanism; The clamping mechanism has two mirror-mounted clamping components. Each clamping component has a clamping body extending outward from its actuating end. Each clamping component is equipped with a drive to drive the two clamping bodies to open and close, thereby clamping and releasing the edges of the plate group to be welded. The extension direction of the clamping body is perpendicular to the feed direction of the three-axis linkage mechanism.

2. The heat exchanger plate follow-up flexible welding clamping device as described in claim 1, characterized in that, The Y-axis moving module is mounted on the X-axis moving module, the Z-axis moving module is mounted on the Y-axis moving module, the X-axis moving module serves as the feed direction, and the clamping mechanism is mounted on the Z-axis moving module.

3. The heat exchanger plate follow-up flexible welding clamping device as described in claim 2, characterized in that, The Z-axis moving module and the Y-axis moving module are both ball screw drive mechanisms, and the X-axis moving module is a belt drive mechanism.

4. The heat exchanger plate follow-up flexible welding clamping device as described in claim 1, characterized in that, Both clamping components are equipped with mounting bases, which are equipped with guide rails and can slide up and down; the top and bottom of the mounting bases are each provided with springs and connected to one end thereto, and the other end of the springs is provided with a limiting structure.

5. The heat exchanger plate follow-up flexible welding clamping device as described in claim 1, characterized in that, The clamping body is a rotatable rolling body.

6. The heat exchanger plate follow-up flexible welding clamping device as described in claim 5, characterized in that, Each of the clamping assemblies further includes a force guide plate and is connected to the drive. The upper force guide plate extends outward and bends vertically downward, while the lower force guide plate extends outward and bends vertically upward. Each force guide plate has a support shaft at its actuating end, and the rolling element is mounted on the support shaft.

7. The heat exchanger plate follow-up flexible welding clamping device as described in claim 1, characterized in that, All of the clamping components are pneumatically driven.

8. A method for welding heat exchanger plates, characterized in that, The welding process, employing a welding robot and a heat exchanger plate follow-up flexible welding clamping device as described in any one of claims 1-7, includes the following steps: The welding start point of the welding plate group is clamped by a follow-up flexible welding clamping device. When the welding robot is welding, the follow-up flexible welding clamping device follows the end of the welding robot to perform follow-up clamping until the welding end point. During the welding process, the laser vision sensor carried by the welding robot collects the weld features, and after identifying the weld features, it generates welding coordinates. Then the welding robot completes the welding.

9. The welding method for heat exchanger plates as described in claim 8, characterized in that, Weld seam feature recognition is performed using a deep learning model. The deep learning model is built based on the object detection model YOLOv10: the FasterNet Block module, which is constructed with partial convolution and pointwise convolution as its core, is integrated into the original YOLOv10 architecture for cross-stage local network reconstruction of the backbone network; a detection head based on the dynamically weighted residual module is set up, the DWRconv module is added, and the 3x3 convolution is deleted, leaving only the conv2d module; the original loss function in the object detection model YOLOv10 is replaced with the MPDIoU loss function.

10. The welding method for heat exchanger plates as described in claim 8, characterized in that, When the follow-up flexible welding clamping device clamps the plate group to be welded, a safety distance of 2~3mm is reserved between the clamping body and the edge of the plate group to be welded.

Images