Rapid welding-back method for long welding seam of metal structure based on automatic welding machine

Abstract

The invention relates to the field of welding, in particular to a rapid welding-back method for a long welding seam of a metal structure based on an automatic welding machine. Automatic welding adopted in the method comprises a rail and a trolley, and the trolley is sequentially provided with scanning equipment, heat treatment equipment, welding equipment and inspection equipment in the advancing direction. The equipment moves from one end of a weld joint to the other end of the weld joint in a sectional manner during operation, a scanning device maps and models a new section of the path when the equipment moves each time, and then a heat treatment device, a welding device and an inspection device respectively carry out pre-welding task heat treatment, welding and post-welding quality inspection on the weld joint in a task section where the heat treatment device, the welding device and the inspection device are located, any task segment can complete all welding procedures after three continuous task periods. And all the welding operations of the long welding seam comprising the N task sections can be completed only by N + 2 task periods. According to the technical scheme, the welding duration of the long weld joint can be effectively shortened, and the welding work efficiency and safety are improved.

Description

Technical Field

[0001] The invention relates to the field of welding, and in particular to a rapid de-welding method for a long weld of a metal structure based on an automatic welding machine. Background Art

[0002] Water conservancy and power engineering projects often involve the installation of large metal structures. For example, at hydropower stations, metal structures protect penstocks, gates, trash racks, and various opening and closing devices. With the exception of penstocks, which are often manufactured on-site, the majority of these components are factory-made and delivered as finished or semi-finished products, then assembled and installed on-site. Large metal structures are typically fabricated in assemblies at the factory and then welded together on-site for installation. Consequently, metal structure installation often involves numerous long welds.

[0003] During welding, the weld seam of metal structures is heated and then cooled back to room temperature. During this process, the material typically deforms due to thermal expansion and contraction. The amount of deformation in this local area is affected by the welding position, welding speed, and heat variations in the weld seam. Therefore, to prevent local deformation from affecting project quality during welding, welding operations on metal structures with long weld seams typically cannot be completed in a single pass. Instead, a segmented back-welding process is employed. This refers to a process whereby the weld seam is divided into several sections, each section welded separately, with each section welded in the opposite direction of the overall weld seam's growth.

[0004] Many engineering construction projects have strict construction cycle requirements. For example, some engineering nodes of certain water conservancy facilities need to be completed as soon as possible before the flood season, and so on. Therefore, the welding tasks of metal structures also need to improve work efficiency as much as possible and complete the tasks in a shorter time. However, the special requirements of the welding process for long welds in metal structures make it impossible for construction units to arrange multiple welders to perform synchronous welding at the same time to improve welding efficiency. In addition, the welding tasks of such large metal structures generally have the problems of high operational difficulty and limited operating environment. During the welding operation, it may also be necessary to perform workpiece heat treatment and insulation operations during the welding process. For the above reasons, the welding cycle of metal structures with a large number of long welds is often relatively long. How to effectively improve the welding efficiency of such welding tasks is becoming a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In order to solve the problems of great difficulty and low welding efficiency in welding metal structures with long welds, the present invention provides a rapid de-welding method for long welds of metal structures based on an automatic welding machine.

[0006] The technical solutions provided by the present invention are as follows:

[0007] A rapid desoldering method for long welds in metal structures using an automatic welding machine is described. The machine comprises a track extending along the weld seam and a trolley mounted on it. A scanning device is mounted in front of the trolley. The trolley contains three adjacent working chambers, each measuring a length ΔL along the track. Heat treatment equipment, welding equipment, and inspection equipment are installed in this three chambers, sequentially from front to back. The trolley, scanning device, heat treatment equipment, welding equipment, and inspection equipment are electrically connected to a host computer.

[0008] Using the above-mentioned automatic welding machine, the rapid desoldering method provided by the present invention comprises the following steps:

[0009] The automatic welding machine is mounted above the target area to be welded by a bracket, and the weld to be welded is divided into N task segments according to ΔL.

[0010] After each working cycle begins, the trolley is driven forward a distance of ΔL, and the i-th task segment of the path is scanned by the scanning equipment; the host computer analyzes the scanning data to generate the operating parameters of the heat treatment equipment, welding equipment and inspection equipment when processing the corresponding task segment, thereby completing the scanning task.

[0011] After the scanning task is completed, the trolley remains in the brake state and performs the following actions simultaneously to complete the processing task:

[0012] A. Drive the heat treatment equipment to perform pre-weld heat treatment on the i-th task segment that has completed the scan according to the preset operating parameters.

[0013] B. Drive the welding equipment to weld the i-1th task segment that has completed pre-weld heat treatment in a direction opposite to the forward direction of the trolley according to preset operating parameters.

[0014] C. Drive the inspection equipment to perform flaw detection on the i-2th task segment that has completed welding according to the preset operating parameters.

[0015] The trolley is driven to move step by step along the starting point to the end point of the weld, and the above process is repeated, thereby completing the welding task after N+2 working cycles.

[0016] As a further improvement of the present invention, the scanning device adopts a depth camera; the scanning direction of the depth camera points to the area to be welded below the trolley.

[0017] The host computer obtains the point cloud data of the target area collected by the scanning device and performs spatial modeling of the target area based on the point cloud data. Alternatively, the host computer obtains a pre-established BIM model and obtains the spatial information of the target area based on the BIM model.

[0018] A weld seam recognition algorithm based on a depth image is running in the host computer; the weld seam recognition algorithm is used to identify the weld to be welded in the target area according to the depth image obtained by the scanning device, and to realize weld positioning in combination with the modeling information or spatial information of the target area.

[0019] As a further improvement of the present invention, in each scanning task, when the trolley fails to realize weld identification and positioning after reaching the end point from the starting point of the current working cycle, the trolley is driven back to the end point of the previous working cycle, and then the running speed of the trolley is reduced and the scanning is repeated.

[0020] As a further improvement of the present invention, the total duration T of any working cycle is equal to the sum of the scanning task duration Ta and the processing task duration Tb.

[0021] The processing task time Tb=max{t1, t2, t3}; wherein t1 represents the shortest heat treatment time of the current task segment; t2 represents the shortest welding time of the current task segment; and t3 represents the shortest flaw detection time of the current task segment.

[0022] As a further improvement of the present invention, the heat treatment apparatus includes a flame heater and a first actuator. The flame heater nozzle is a straight-line nozzle with multiple flame ports, arranged perpendicularly to the track within a trolley. Each flame port in the nozzle is controlled to be closed by a solenoid valve. The first actuator is used to drive the nozzle to move within a corresponding working chamber of the trolley in a direction parallel to the track.

[0023] The operating parameters of the heat treatment equipment generated by the host computer include: the switch status code of the flame nozzle, the movement trajectory and movement speed of the nozzle, the start time and end time of the heat treatment, and the opening of the gas valve on the supply side.

[0024] As a further improvement of the present invention, the first actuator in the heat treatment equipment is a linear slide; the nozzle of the flame heater is mounted on a trolley via the linear slide. The fuel tank of the flame heater is located outside the trolley and is connected to the nozzle via a pipeline and a gas valve.

[0025] As a further improvement of the present invention, the welding equipment includes a welding system and a second actuator, and the second actuator is used to drive the welding gun in the welding system to move freely in the corresponding working chamber in the trolley.

[0026] The operating parameters of the welding equipment generated by the host computer include: welding current, wire feeding speed, welding gun posture and moving speed.

[0027] As a further improvement of the present invention, the second actuator in the heat treatment equipment utilizes a bionic robotic arm or truss manipulator. The welding gun in the welding system is mounted within the trolley via the bionic robotic arm or truss manipulator. The welding machine, wire feeder, and shielding gas storage tank in the welding system are located outside the trolley. The welding machine is electrically connected to the welding gun via a cable, and the shielding gas storage tank is connected to the welding gun via a pipe. The wire feeder is used to deliver welding rods to the welding gun.

[0028] As a further improvement of the present invention, the inspection device includes a flaw detector and a third actuator, the third actuator being configured to drive a probe in the flaw detector to freely move within a corresponding working chamber in the trolley. The operating parameters of the inspection device generated by the host computer include the start and end times of the flaw detection operation, as well as the motion trajectory and movement speed of the probe.

[0029] As a further improvement of the present invention, the third actuator in the inspection equipment is a bionic robotic arm or truss manipulator; the probe in the flaw detector is mounted within the trolley via the bionic robotic arm or truss manipulator. The flaw detector's data processing equipment is mounted outside the trolley, and the probe and data processing equipment are connected via a cable.

[0030] The present invention has the following beneficial effects:

[0031] The technical solution provided by the present invention divides the long weld into multiple sections, and then uses an automatic welding machine that includes heat treatment equipment, welding equipment and inspection equipment to perform parallel processing on each task segment in the long weld through a pipeline parallel strategy. When the automatic welding machine moves from one end of the long weld to the other end, within each task cycle, the automatic welding machine can synchronously perform pre-weld heat treatment, welding and post-weld quality inspection on three adjacent different task segments. Then, after the automatic welding reaches the end of the long weld, the heat treatment, welding and quality inspection operations of all task segments can be completed. Compared with the operating mode of the conventional segmented de-welding process, the new method provided by the present invention can greatly improve the work efficiency of the welding operation and shorten the overall task time while ensuring the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a flowchart of the steps of the method for rapid desoldering of a long weld of a metal structure based on an automatic welding machine provided in Example 1 of the present invention.

[0033] Figure 2 Schematic diagram of the structure of the automatic welding machine in Example 1 of the present invention.

[0034] Figure 3 This is a schematic diagram of the welding process of a welding machine task including four task segments in Example 1 of the present invention.

[0035] Figure 4This is a schematic structural diagram of the heat treatment equipment in the automatic welding machine according to Example 1 of the present invention.

[0036] Figure 5 This is an assembly diagram of the welding equipment in the automatic welding machine according to embodiment 1 of the present invention.

[0037] The following are marked in the figure:

[0038] 1. Track; 2. Trolley; 3. Scanning device; 41. Flame heater; 42. First actuator; 51. Welding gun; 52. Second actuator; 61. Probe; 62. Third actuator. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] Example 1

[0042] This embodiment provides a method for rapidly de-welding long welds on metal structures using an automatic welding machine. This method can utilize a newly designed automatic welding machine to rapidly de-weld metal structures with long welds in sections, significantly improving the welding efficiency of such metal structures while ensuring welding quality. Traditionally, welding long welds on metal structures requires welders to weld each section of the weld sequentially. Each section requires not only high-quality welding but also pre-weld heat treatment and post-weld quality inspection, which is time-consuming and labor-intensive.

[0043] In the technical solution provided by this embodiment, construction workers can use automatic welding machines to replace manual work to complete welding tasks, and use assembly line processes to process different links in the welding operation in parallel, thereby significantly shortening the welding operation time of long weld metal structures. Figure 1 As shown, the rapid desoldering method provided in this embodiment includes the following process:

[0044] First, the construction personnel can use the bracket to set up the automatic welding machine above the target area to be welded. Figure 2 As shown, the automatic welding machine includes a track 1 extending along the weld seam and a trolley 2 mounted thereon. A scanning device 3 is mounted in front of trolley 2. Trolley 2 contains three adjacent working chambers, each measuring ΔL along the track 1. Heat treatment equipment, welding equipment, and inspection equipment are installed in these chambers, sequentially from front to back. Trolley 2, scanning device 3, heat treatment equipment, welding equipment, and inspection equipment are electrically connected to a host computer.

[0045] In actual application, the trolley 2 can move along the track 1. During the movement of the trolley 2, the scanning device 3 can perform a spatial scan of the area below the path, thereby identifying the welds that need to be welded and determining the spatial position and morphological distribution of the weld area relative to the equipment coordinate system of the automatic welding machine. Next, when the trolley 2 moves to the corresponding position, the heat treatment equipment can perform heat treatment on the area around the weld; the welding equipment can automatically weld the weld after heat treatment based on the known spatial position and morphology of the weld; finally, the inspection equipment is used to perform quality inspection on the weld after completion of welding.

[0046] In particular, the automatic welding machine provided in this embodiment sequentially installs the heat treatment equipment, welding equipment, and inspection equipment in three different working chambers along the forward direction of the trolley 2. This ensures that each time the trolley 2 advances a distance equal to the length of the working chamber, the heat treatment equipment arrives at a new area, the welding equipment arrives at the area previously occupied by the heat treatment equipment, and the inspection equipment arrives at the area previously occupied by the welding equipment.

[0047] Based on the aforementioned characteristics of the automatic welding machine, this embodiment further draws on pipeline technology in processor design to redesign the equipment's procedures for the segmented desoldering process of long weld metal structures. Before welding, technicians can divide the weld to be welded into N task segments according to ΔL and send the corresponding welding tasks to the automatic welding machine's host computer. After receiving the corresponding tasks, the host computer can process each task end according to the four procedures of "scanning-heat treatment-welding-quality inspection". In the operating logic of the automatic welding machine designed in this embodiment, the scanning, heat treatment, welding, and quality inspection procedures required for each task segment are implemented in different task cycles. Within the same task cycle, the automatic welding machine can simultaneously perform heat treatment, welding, and quality inspection operations on three different adjacent task segments. This parallel pipeline operation strategy shortens the overall welding time of long welds and improves the execution efficiency of the segmented desoldering process for long welds.

[0048] Specifically, when the entire welding task consists of N task segments, the aforementioned newly designed automatic welding machine and the operational logic for multi-task parallel processing of the welding process provided in this embodiment can be used to drive the trolley 2 from the starting point of the weld and move in sections along the track 1 from one end of the weld to the other. When the automatic welding machine leaves the end point of the weld, the welding operation of the entire long weld is completed. In the operating logic of this embodiment, the entire welding operation is divided into multiple continuous work cycles, each of which includes two subtasks: a scanning task and a processing task, which need to be completed independently within different time sequences.

[0049] Among them, after each working cycle starts, the host computer first drives the trolley 2 to move forward a distance of ΔL. During the forward process, the scanning device 3 installed at the front of the vehicle will pass through a completely new task segment that has not been reached before. In this process, the i-th task segment of the path can be scanned by the scanning device 3. The purpose of the scanning action in this embodiment is to enable the host computer to accurately model the working environment of the current task segment and identify the position coordinates and spatial distribution of the welds that need to be welded in the current working environment. Based on the relevant information obtained by the host computer from analyzing the scanning data, the host computer can further generate the operating parameters of the heat treatment equipment, welding equipment and inspection equipment when processing the corresponding task segment.

[0050] For example, the host computer can determine the location distribution of the area around the weld that requires heat treatment based on information such as the weld's location, and then plan the treatment area of ​​the heat treatment equipment. The trajectory of the welding gun 51 during welding is determined based on information such as the weld's location and shape. Different weld widths require different welding methods. Finally, the host computer needs to determine the area that requires weld quality inspection after welding is completed based on information such as the weld's location and shape, and use this information to control the flaw detector to completely scan the entire area along the corresponding trajectory.

[0051] After the scanning task is completed, trolley 2 remains in the brake state. At this time, assuming that the area previously scanned by trolley 2 is the i-th task segment, the first working chamber in trolley 2 is located in the i-th task segment, the second working chamber is located in the i-1-th task segment, and the third working chamber is located in the i-2-th task segment. Next, the automatic welding machine synchronously performs the following actions to complete the processing task:

[0052] A. Drive the heat treatment equipment to perform pre-weld heat treatment on the i-th task segment that has completed the scan according to the preset operating parameters.

[0053] B. Drive the welding equipment to weld the i-1th task segment that has completed pre-weld heat treatment in a direction opposite to the forward direction of the trolley 2 according to preset operating parameters.

[0054] C. Drive the inspection equipment to perform flaw detection on the i-2th task segment that has completed welding according to the preset operating parameters.

[0055] The trolley 2 is driven to move along the starting point of the weld to the end point, and the above process is repeated, thereby completing the welding task of the long weld containing N task segments after N+2 working cycles.

[0056] In order to more clearly demonstrate the advantages of the rapid de-welding method for long welds of metal structures based on an automatic welding machine provided in this embodiment, a welding task including four task segments (denoted as L1, L2, L3, and L4) is taken as an example. Figure 3 The execution process of the solution of this embodiment is described in detail:

[0057] In the first task cycle, the automatic welding machine can scan and heat treat the L1 segment.

[0058] In the second task cycle, the automatic welding machine can scan and heat treat the L2 segment and weld the L1 segment.

[0059] In the third task cycle, the automatic welding machine can scan and heat treat the L3 segment, weld the L2 segment, and perform quality inspection on the L1 segment.

[0060] During the fourth task cycle, the automatic welding machine can scan and heat treat the L4 segment, weld the L3 segment, and perform quality inspection on the L2 segment.

[0061] During the fifth task cycle, the automatic welding machine can weld the L4 segment and perform quality inspection on the L3 segment.

[0062] During the sixth task cycle, the automatic welding machine was able to perform quality inspection on segment L4. At this point, all segments had completed the four processes of scanning, heat treatment, welding, and quality inspection, and the welding task was successfully completed.

[0063] By analyzing the above process, it can be found that the rapid desoldering method provided in this embodiment can complete the rapid segmented desoldering of a long weld containing N segments through N+2 cycles. Assuming that the work efficiency values ​​obtained by completing the heat treatment, welding and quality inspection of each task segment are all 1, then in the technical solution provided in this embodiment, the heat treatment task of the first segment can be completed in the first cycle; the total work efficiency value is 1. The second cycle can complete the heat treatment of the first segment and the welding task of the second segment; the total work efficiency value is 2. The last cycle can only complete the quality inspection of the last segment, and the total work efficiency value is 1. The second to last cycle can only complete the welding of the first to last segment and the quality inspection task of the second to last segment; the total work efficiency value is 2. In the remaining cycles, the heat treatment, welding and quality inspection tasks can be performed in three consecutive different segments at the same time. The total work efficiency value is 3.

[0064] In the segmented back-welding process of long welds, heat treatment, welding, and post-weld quality inspection are necessary processes, and in theory, each process must be performed in a specified order. Therefore, assuming that the theoretical shortest task duration of the three processes is T1, T2, and T3, for a task consisting of 4 segments, the total task duration required for manual welding using the traditional process is T total T total =4×(T1+T2+T3).

[0065] In the solution provided by this embodiment, after adopting the aforementioned parallel pipeline operation mode, the total duration T of any working cycle is equal to the sum of the scanning task duration Ta and the processing task duration Tb. When multiple tasks need to be processed in parallel, the corresponding processing cycle is equal to the longest task among them. Therefore, the processing task duration Tb = max{t1, t2, t3}; where t1 represents the shortest heat treatment duration of the current task segment; t2 represents the shortest welding duration of the current task segment; and t3 represents the shortest flaw detection duration of the current task segment.

[0066] Therefore, the total task duration T required for the above four working cycles is total for:

[0067] T total =4×Ta+T1+max{T1,T2}+max{T1,T2,T3}+max{T1,T2,T3}+max{T2,T3}+T3.

[0068] In practical applications, the time required for heat treatment, welding, and quality inspection usually meets the following relationship:

[0069] T2>T1>T3,

[0070] Therefore, in this embodiment,

[0071] T total =4×Ta+T1+4×T2+T3,

[0072] Compared with the total task duration of the traditional process, the solution of this embodiment can shorten the process duration ΔT by:

[0073] △T=3×T1+3×T3-4×Ta.

[0074] Among them, this embodiment only needs to obtain and process the relevant data collected by the scanning device 3 when the trolley 2 is running to perform the scanning task. The time consumed by this process is much less than the time consumed by operations such as welding and heat treatment, so the duration Ta can be regarded as 0.

[0075] In summary, assuming that a long weld needs to be divided into N segments during welding, the solution of this embodiment can shorten the process time of the traditional process by (N-1)T1+(N-1)T3. In addition, it should be additionally explained that when comparing the process time of the present invention with that of the traditional process, the above content assumes that the shortest time consumed by the two in performing heat treatment, welding and quality inspection is the same. In practice, this embodiment uses an automatic welding machine instead of manual labor to perform related operations, and the operating efficiency of an automatic welding machine is generally higher than that of manual labor. Therefore, the rapid desoldering method provided in this embodiment actually shortens the process time even more than the results of the theoretical analysis above.

[0076] In this embodiment, the scanning, heat treatment, welding, and quality inspection operations described above are performed on each task segment using the scanning device 3, heat treatment equipment, welding equipment, and inspection equipment in the automatic welding machine. In actual applications, the scanning device 3 can be a depth camera; the depth camera's scanning direction is directed toward the area to be welded below the trolley 2.

[0077] In this embodiment, the function of the scanning device 3 is to scan the target area to obtain relevant spatial and image information, thereby assisting the host computer in spatially modeling the target area and identifying and locating the weld. Therefore, the host computer can choose to obtain point cloud data of the target area collected by the scanning device 3 and perform spatial modeling of the target area based on the point cloud data. In other solutions, considering that the design unit of the metal structure to be welded in the engineering project typically provides the construction unit with a BIM model related to the metal structure, the host computer can also directly obtain a pre-established BIM model of the metal structure to be welded, and then obtain the spatial information of the target area based on the BIM model.

[0078] In addition, a weld recognition algorithm based on a depth image is also running in the host computer of this embodiment; the weld recognition algorithm is used to identify the weld to be welded in the target area according to the depth image obtained by the scanning device 3, and realize weld positioning in combination with the modeling information or spatial information of the target area.

[0079] In each scanning task of the scheme of this embodiment, when the trolley 2 reaches the end point from the starting point of the current working cycle, if the weld recognition and positioning cannot be achieved, the trolley 2 can be driven back to the end point of the previous working cycle, and then the running speed of the trolley 2 can be reduced and rescanned.

[0080] In this embodiment, the function of the heat treatment equipment is to preheat the metal around the weld before welding, thereby reducing the cooling rate of the weld joint, avoiding the formation of hardened structure and reducing welding stress and deformation, and preventing welding cracks. In practical applications, this embodiment uses flame heating to heat treat the weldment. The heat treatment equipment includes a flame heater 41 and a first actuator 42, wherein, as shown in FIG. Figure 4 As shown, the nozzle of the flame heater 41 is a straight-line nozzle with multiple flame outlets. It is arranged in a direction perpendicular to the track 1 within the trolley 2. Each nozzle in the nozzle is controlled to be closed or turned off by a solenoid valve. The first actuator 42 is used to drive the nozzle to move within the corresponding working chamber of the trolley 2 in a direction parallel to the track 1. The operating parameters of the heat treatment equipment generated by the host computer include: the on / off state code of the flame outlet, the movement trajectory and movement speed of the nozzle, the start and end time of the heat treatment, and the opening degree of the gas valve on the supply side.

[0081] In the typical solution provided in this embodiment, the first actuator 42 in the heat treatment equipment can be a linear slide; the nozzle of the flame heater 41 is installed inside the trolley 2 via the linear slide. The fuel tank of the flame heater 41 is located outside the trolley 2 and is connected to the nozzle via a pipeline and a gas valve.

[0082] Taking into account that the duration of heat treatment in each task cycle is usually shorter than the duration of welding, the host computer needs to flexibly allocate the timing of starting the heat treatment equipment according to the working time of the welding equipment, so as to ensure that when the current task cycle ends and enters the next task cycle, the temperature of the corresponding task segment is just at the target temperature suitable for welding. In actual applications, the range of heat treatment areas corresponding to welds of different widths is different. In response to this problem, the present embodiment can control the switching state of each jet nozzle in the nozzle through the host computer, and cooperate with the linear slide to drive the nozzle to reciprocate along the extension direction of the weld, thereby realizing heating of the area of ​​specified width. When the number of jet nozzles opened changes, the host computer also needs to synchronously switch the opening of the gas invention so that the fuel supply is adapted to the heating demand.

[0083] In this embodiment, the function of the welding equipment is to weld the preheated weldment and connect the weldments on both sides of the weld. In traditional processes, welding requires the use of a welding system, such as carbon dioxide shielded welding or an argon arc welder. Such a welding system includes a welding gun 51, a welding machine, a wire feeder, and a shielding gas storage tank. The wire feeder is used to continuously supply welding wire to the welding gun 51. The welding machine is electrically connected to the welding gun 51, and then provides a large current during the welding process to instantly achieve a molten connection between the welding wire and the weldment; the shielding gas storage tank is used to deliver shielding gases such as carbon dioxide and argon to the welding area when the welding gun 51 is started to avoid local oxidation of the material.

[0084] In this embodiment, if Figure 5 As shown, the welding equipment includes a welding system and a second actuator 52. The second actuator 52 is used to drive the welding gun 51 in the welding system to move freely within the corresponding working chamber in the trolley 2. In actual applications, the second actuator 52 in the heat treatment equipment can adopt a bionic robotic arm or a truss robot; the welding gun 51 in the welding system is installed in the trolley 2 via the bionic robotic arm or truss robot. The welder, wire feeder, and shielding gas storage tank in the welding system are located outside the trolley 2. The welding body is electrically connected to the welding gun 51 via a cable, and the shielding gas storage tank is connected to the welding gun 51 via a pipeline. The wire feeder is used to deliver welding rods to the welding gun 51.

[0085] At this point, the host computer can adaptively plan the movement trajectory and spatial posture that the welding gun 51 needs to go through when performing the welding task based on the spatial information of the area to be welded that has been obtained in the scanning task, and then issue corresponding control instructions to the bionic robotic arm or truss manipulator. At the same time, the host computer also coordinates the control of the shielding gas switch on the welding machine, wire feeder, and welding gun 51, thereby automatically completing the corresponding welding task instead of manual labor. Typically, the operating parameters of the welding equipment generated by the host computer include: welding current, wire feed speed, posture and movement speed of the welding gun 51, etc. The relevant technical solutions for using robotic arms to replace manual labor to perform welding tasks are already very mature in the fields of automobile processing, equipment manufacturing, etc., and the technical details of this part will not be elaborated in this embodiment.

[0086] In this embodiment, the function of the inspection equipment is to perform a post-weld quality inspection on the corresponding task section after the welding is completed, and then identify possible welding defects such as pores, slag inclusions, incomplete penetration, lack of fusion and cracks. In practical applications, this embodiment can adopt a non-destructive testing solution based on X-ray or ultrasonic waves. The inspection equipment includes a flaw detector and a third actuator 62. The third actuator 62 is used to drive the probe 61 in the flaw detector to move freely in the corresponding working chamber in the trolley 2. Similar to the welding equipment, the third actuator 62 in the inspection equipment of this embodiment can also adopt a bionic robot arm or a truss robot; the probe 61 in the flaw detector is installed in the trolley 2 through the bionic robot arm or the truss robot. The data processing equipment of the flaw detector is installed outside the trolley 2, and the probe 61 and the data processing equipment are connected by a cable communication.

[0087] In practice, the host computer flexibly controls the third actuator 62 to move the flaw detector to the appropriate position based on the distribution of the weld seam after welding, completing the flaw detection task according to the inspection path planned by the host computer. Furthermore, since the processing time of the inspection task in each task segment is shorter than that of the welding task, the host computer can flexibly select the start time of the flaw detection task within each task cycle based on the duration of the task cycle. Therefore, the operating parameters of the inspection equipment generated by the host computer include the start and end times of the flaw detection operation, as well as the motion trajectory and movement speed of the probe 61.

[0088] In practice, when flaw detector results indicate weld quality defects in a specific section, the higher-level control team records this information and generates a quality inspection report after welding. After welding, the relevant technicians verify the contents of the quality inspection report and make decisions based on the actual situation and take appropriate measures.

[0089] Finally, it's important to emphasize that the rapid segmented annealing method using parallel assembly line technology provided in this embodiment can be applied not only to the automatic welding machine described above to achieve rapid automatic welding, but can also be applied to manual welding operations. For example, a construction team could divide the construction personnel into three teams: heat treatment, welding, and quality inspection. They could then divide a long weld into multiple task segments, and then employ a similar strategy to arrange for the three teams to perform joint operations on different task segments of the long weld to improve work efficiency. Of course, compared to machines, manual joint operations are still subject to numerous limitations, such as worker efficiency and operational safety, which can affect the feasibility and efficiency of the solution. However, the solution based on the automatic welding machine provided in this embodiment is not subject to these limitations.

[0090] The above-described embodiment merely represents one embodiment of the present invention. While the description is relatively specific and detailed, it should not be construed as limiting the scope of the invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of the present invention. Therefore, the scope of the present invention shall be determined by the appended claims.

Claims

1. A rapid desoldering method for long welds of metal structures based on an automatic welding machine, characterized in that: The automatic welding machine includes a track extending along the weld seam and a trolley mounted thereon, with a scanning device installed in front of the trolley. The trolley contains three adjacent working chambers, each with a length ΔL along the track. The three working chambers are sequentially installed with heat treatment equipment, welding equipment, and inspection equipment in order from front to back. The trolley, scanning device, heat treatment equipment, welding equipment, and inspection equipment are electrically connected to the host computer. Rapid desoldering methods include: The automatic welding machine is mounted above the target area to be welded by a bracket; the weld to be welded is divided into N task segments according to ΔL; After each working cycle begins, the trolley is driven forward a distance of ΔL, and the scanning equipment is used to scan the topography of the i-th task segment along the path. The host computer analyzes the scanning data to generate the operating parameters of the heat treatment equipment, welding equipment, and inspection equipment when processing the corresponding task segment, thereby completing the scanning task. After the scanning task is completed, the trolley remains in the brake state and performs the following actions simultaneously to complete the processing task: A. Drive the heat treatment equipment to perform pre-weld heat treatment on the i-th task segment that has completed the scan according to the preset operating parameters; B. driving the welding equipment to weld the i-1th task segment that has completed pre-weld heat treatment in a direction opposite to the forward direction of the trolley according to preset operating parameters; C. Drive the inspection equipment to perform flaw detection on the i-2th task section that has completed welding according to the preset operating parameters; The trolley is driven to move step by step along the starting point to the end point of the weld, and the above process is repeated, thereby completing the welding task after N+2 working cycles.

2. The rapid desoldering method for long welds of metal structures based on an automatic welding machine according to claim 1, characterized in that: The scanning device uses a depth camera; the scanning direction of the depth camera points to the area to be welded under the trolley; The host computer obtains point cloud data of the target area collected by the scanning device; and performing spatial modeling of the target area based on the point cloud data; or, the host computer obtains a pre-established BIM model and obtains spatial information of the target area based on the BIM model; A weld recognition algorithm based on a depth image is running in the host computer; the weld recognition algorithm is used to identify the weld to be welded in the target area according to the depth image obtained by the scanning device, and realize weld positioning in combination with the modeling information or spatial information of the target area.

3. The rapid desoldering method for long welds of metal structures based on an automatic welding machine according to claim 1, characterized in that: In each scanning task, when the trolley fails to identify and locate the weld after reaching the end point from the starting point of the current working cycle, the trolley is driven back to the end point of the previous working cycle, and then the trolley's running speed is reduced and the scan is repeated.

4. The rapid desoldering method for long welds of metal structures based on an automatic welding machine according to claim 1, characterized in that: The total duration T of any working cycle is equal to the sum of the scanning task duration Ta and the processing task duration Tb; The processing task duration Tb=max{t1, t2, t3}; wherein t1 represents the shortest heat treatment duration of the current task segment; t2 represents the shortest welding duration of the current task segment; and t3 represents the shortest flaw detection duration of the current task segment.

5. The rapid desoldering method for long welds of metal structures based on an automatic welding machine according to claim 1, characterized in that: The heat treatment equipment includes a flame heater and a first actuator. The flame heater nozzle is a straight-line nozzle with multiple flame ports, which are arranged in a direction perpendicular to the track in a trolley. Each flame port in the nozzle is controlled to be turned off by a solenoid valve. The first actuator is used to drive the nozzle to move in a corresponding working chamber in the trolley in a direction parallel to the track. The operating parameters of the heat treatment equipment generated by the host computer include: the switch status code of the flame nozzle, the movement trajectory and movement speed of the nozzle, the start time and end time of the heat treatment, and the opening of the gas valve on the supply side.

6. The rapid desoldering method for long welds of metal structures based on an automatic welding machine according to claim 5, characterized in that: The first actuator in the heat treatment equipment adopts a linear slide; the nozzle of the flame heater is installed in the trolley through the linear slide; the fuel tank of the flame heater is located outside the trolley and is connected to the nozzle through a pipeline and a gas valve.

7. The rapid desoldering method for long welds of metal structures based on an automatic welding machine according to claim 1, characterized in that: The welding device includes a welding system and a second actuator, wherein the second actuator is used to drive a welding gun in the welding system to move freely in a corresponding working chamber in the trolley; The operating parameters of the welding equipment generated by the host computer include: welding current, wire feeding speed, welding gun posture and moving speed.

8. The rapid desoldering method for long welds of metal structures based on an automatic welding machine according to claim 7, characterized in that: The second actuator in the heat treatment equipment adopts a bionic robotic arm or a truss robot; the welding gun in the welding system is installed in the trolley through a bionic robotic arm or a truss robot; the welder, wire feeder and shielding gas storage tank in the welding system are located outside the trolley, the welding body is electrically connected to the welding gun through a cable, and the shielding gas storage tank is connected to the welding gun through a pipe; the wire feeder is used to transport welding rods to the welding gun.

9. The rapid desoldering method for a long weld of a metal structure based on an automatic welding machine according to claim 1, characterized in that: The inspection equipment includes a flaw detector and a third actuator, wherein the third actuator is used to drive a probe in the flaw detector to move freely in a corresponding working chamber in the trolley; The operating parameters of the inspection equipment generated by the host computer include: the start time and end time of the flaw detection operation, and the motion trajectory and moving speed of the probe.

10. The rapid desoldering method for a long weld of a metal structure based on an automatic welding machine according to claim 9, characterized in that: The third actuator in the inspection equipment adopts a bionic robotic arm or a truss robotic arm; the probe in the flaw detector is installed in the trolley through the bionic robotic arm or the truss robotic arm; the data processing device of the flaw detector is installed outside the trolley, and the probe and the data processing device are connected through a cable communication.

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