Automatic welding station and welding method for angle seat

Abstract

The invention discloses an automatic welding station and a welding method for an angle seat. The automatic welding station comprises at least one base plate, and the base plate is provided with a welding station used for fixing an angle seat workpiece; the at least one welding robot is used for executing welding operation; each welding station is provided with a clamping device for positioning and clamping a workpiece; the control system comprises a robot control system and a PLC control system which are in communication connection and respectively control the track action of the welding robot and the logic action of each execution component of the work station. The welding method comprises the steps that an angle seat workpiece is fed to a welding station and initially positioned through a reference stop block, the clamping device is controlled to clamp the side direction and the end of the workpiece, the operation panel selects the workpiece model to call corresponding welding process parameters, the angle of a base plate is adjusted, and then the welding robot is controlled to conduct welding according to a preset track and parameters. And after welding is completed, the workpiece is loosened, the mechanism is reset, and discharging is conducted. A robot, a fixing tool and a digital system are integrated, and high-quality and high-efficiency automatic welding production of multi-specification angle seat workpieces is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding automation, in particular to an automatic welding station for corner seat and a welding method. BACKGROUND

[0002] In the field of mechanical manufacturing, especially in the production of automobile tooling fixtures, corner seat is a common welded structural part. The welding of traditional corner seat mainly relies on skilled welders holding welding guns for manual operation. This production method has the following obvious shortcomings:

[0003] Unstable quality: the welding quality is highly dependent on the personal skills and experience of the welder. When welding workpieces of different materials (such as carbon steel, stainless steel, aluminum alloy) or different thicknesses, the worker needs to have rich experience in parameter adjustment. Human factors can easily lead to uneven welds, porosity, slag inclusion, and false welding, affecting the connection strength and service life of the product.

[0004] Low production efficiency: manual welding is slow, and workers are prone to fatigue, making it difficult to maintain high efficiency. When faced with mass production tasks, multiple welders need to be equipped, which is high in labor cost and limited in single-shift output, restricting the improvement of production capacity.

[0005] Safety and environmental risk: the welding process produces arc light, smoke and noise, which poses a threat to the health of the operator. The open operation environment of manual welding makes protection more difficult.

[0006] Poor flexibility: when the product model changes, manual welding needs to retrain workers or adjust operation habits, making it difficult to quickly adapt to multi-variety and small-batch production demands.

[0007] In order to improve the level of welding automation, existing technologies have adopted industrial robots for welding. For example, a 6-axis articulated robot is used to carry a welding gun to complete welding through pre-programmed trajectories. However, when such general-purpose robot welding stations are applied to the production of specific fixture corner seats, there are still limitations: first, for a wide variety of corner seat specifications, there is a lack of efficient, precise and quick positioning and clamping fixtures, and the changeover time is long; second, the welding process parameter library is not perfect, making it difficult to intelligently adapt to changes in material and structure of different workpieces; third, the overall system integration is not high, and the parallel optimization of feeding and welding processes has not been realized, leaving room for improvement in production efficiency.

[0008] Therefore, there is an urgent need for an automatic welding solution designed specifically for fixture corner seats, with high flexibility, high precision and stable quality. SUMMARY

[0009] In view of the above-mentioned deficiencies of the prior art, the present application provides an automatic welding station and a welding method for corner seats, which realize high-quality, high-efficiency and high-flexibility automatic welding production of corner seat workpieces of multiple specifications.

[0010] To achieve the above-mentioned purpose, the first aspect of the present application provides an automatic welding station for corner seats, which comprises:

[0011] at least one base plate, which is provided with at least one welding station for fixing a corner seat workpiece;

[0012] at least one welding robot, which is used for performing welding work on the corner seat workpiece in the welding station;

[0013] a clamping device, which is arranged on each welding station and is used for positioning and clamping the workpiece before welding;

[0014] a control system, which comprises a robot control system and a PLC control system, and the two are communicatively connected through a communication bus, the robot control box is used for controlling the trajectory planning and action execution of the welding robot, and the PLC control box is used for controlling the logic action of the servo motor, the clamping device and each execution component of the work station.

[0015] In some embodiments of the first aspect of the present application, the clamping device comprises:

[0016] at least one reference block, which is used for transverse positioning of the workpiece;

[0017] a plurality of clamping cylinders, including a first cylinder and a second cylinder used for clamping the workpiece from both sides, and a third cylinder and a fourth cylinder used for clamping the workpiece from the end.

[0018] In some embodiments of the first aspect of the present application, the mounting position of the third cylinder and / or the fourth cylinder is adjustable to adapt to workpieces of different lengths.

[0019] In some embodiments of the first aspect of the present application, the welding station further comprises a welding gun cleaning device arranged within the working range of the welding robot, which is used for automatically cleaning the welding gun nozzle and the conductive nozzle.

[0020] In some embodiments of the first aspect of the present application, the welding gun cleaning device comprises a reamer assembly and a splash-proof agent spraying module, the reamer assembly is used for scraping off welding slag, and the spraying module is used for spraying splash-proof agent.

[0021] In some embodiments of the first aspect of the application, the robot control system integrates an intelligent welding process library, the welding process library pre-stores welding programs and welding process parameters corresponding to corner seat workpieces of different specifications, materials and thicknesses, the welding process parameters include motion trajectory, current and voltage parameters, wire feeding speed and protective gas flow setting values, and the PLC control system supports one-key calling through a workpiece model code.

[0022] In some embodiments of the first aspect of the application, the welding station further comprises a mixed protective gas tank and a welding wire barrel.

[0023] The mixed protective gas tank is connected with the welding torch through a gas supply pipeline, and the gas supply pipeline is integrated with a pressure reducing valve, a flow meter and an electromagnetic on-off valve.

[0024] The welding wire barrel is used for storing welding wire, and the welding robot has the ability to automatically identify the remaining amount of welding wire and perform welding wire replacement.

[0025] In some embodiments of the first aspect of the application, the welding station is enclosed by a protective fence to form a closed working space.

[0026] The safety protection device of the protective fence includes a safety grating, an emergency stop button, an arc light protection curtain and an interlocked access door, the smoke dust capture efficiency of the ventilation and dust removal system is ≥95%, the working environment noise is ≤85dB, and the arc light intensity is reduced by ≥90%.

[0027] In some embodiments of the first aspect of the application, the PLC control system is built-in with a fault alarm and diagnosis module, which monitors the running parameters of the station in real time, triggers an audible and visual alarm and displays a fault code when the parameters deviate from the preset threshold, performs emergency shutdown when a serious fault occurs, and records the alarm event chain at the same time.

[0028] To achieve the above-mentioned purpose, the second aspect of the application provides an automatic welding method for a corner seat, the welding method comprising the following steps:

[0029] S1: loading the corner seat workpiece to the welding station and preliminarily positioning through a reference block;

[0030] S2: controlling the clamping device to clamp the workpiece laterally and at the end;

[0031] S3: selecting the workpiece model through the operation panel and calling the corresponding welding process parameters;

[0032] S4: adjusting the angle of the base plate according to the welding needs;

[0033] S5: controlling the welding robot to perform welding according to the preset trajectory and parameters;

[0034] S6: after the welding is completed, loosening the workpiece and resetting each actuator to unload.

[0035] In step S5:

[0036] During the welding process, an automatic cleaning program for the welding torch is triggered according to preset conditions, and welding is automatically resumed after cleaning is completed.

[0037] During the welding process, the PLC control system monitors the welding parameter data in real time and compares it with the preset process specifications. If the parameters deviate from the preset safety threshold or the logic is abnormal, a graded alarm will be triggered and preset protective operations will be executed.

[0038] The advantages of this invention are as follows: First, through the coordination of high-precision robot motion, high-rigidity tooling positioning, and digital welding power supply, the consistency of each weld seam formation and the penetration depth are ensured, fundamentally eliminating the quality fluctuations of manual welding and significantly improving the product qualification rate. Second, the automated welding speed is stable, and the multi-station parallel operation mode eliminates the time spent by the robot waiting for loading and unloading, resulting in a significant increase in equipment utilization and single-shift output compared to the traditional manual operation mode. Third, workers only need to complete simple loading and unloading actions and call the corresponding program on the operation interface, without needing to master welding skills, reducing the company's recruitment, training, and labor costs, and alleviating the pressure of a shortage of skilled welders. Fourth, the modular quick-change tooling design makes switching product models quick and easy, especially suitable for multi-variety, small-batch production modes, and can quickly respond to market changes and customer customization needs. Fifth, the fully enclosed design of the workstation effectively isolates arc light and spatter, and the integrated high-efficiency dust removal system significantly reduces the concentration of dust, ensuring that the overall working environment meets national occupational health standards and protecting the health of employees. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of the automated welding station described in this invention;

[0041] Figure 2 This is a schematic diagram of the welding station described in this invention;

[0042] Figure 3 This is a schematic diagram of the automated welding method described in this invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1:

[0045] Figure 1 A schematic diagram of the structure of an automated welding station according to the present invention is shown. Figure 1 As shown, the welding station integrates a welding robot 40, a robot control system, a PLC control system, an operation panel, and multiple welding machine stations.

[0046] Multiple welding stations are grouped and set on multiple base plates. Each base plate is positioned between two support frames. The PLC control system drives the base plate to rotate between the two support frames by controlling the servo motor to adjust the welding position, so that the welding robot 40 can complete the welding of the corner workpiece.

[0047] like Figure 1 As shown, the automated welding station of the present invention adopts a modular layout design with multiple substrates and multiple workstations, including multiple substrates arranged side by side around the workstation where the welding robot 40 is located. In this embodiment of the invention, the substrates include a first substrate 10, a second substrate 20, and a third substrate 30. The spacing between adjacent substrates can be set as needed to avoid interference between different substrates. At the same time, the spacing between the substrates and the corresponding welding robot 40 needs to be adapted to the working radius of the welding robot 40 to ensure that the corresponding welding robot 40 can cover virtually all workstations.

[0048] Each base plate is suspended and rotated by independent support frames on both sides. The support frames are made of high-strength carbon steel and are vertically fixed to the workshop floor by expansion bolts after being welded as a whole. The bottom is equipped with reinforcing ribs to ensure the rigidity and stability of the support structure.

[0049] In this embodiment of the invention, a first support frame 10a and a second support frame 10b are respectively mounted on the left and right sides of the first substrate 10. Deep groove ball bearings are embedded in the top of both support frames, and the rotating shafts at both ends of the substrate are interference-fitted with the inner rings of the bearings to achieve smooth rotation. A third support frame 20a and a fourth support frame 20b are respectively configured on both sides of the second substrate 20, with structures identical to those of the first substrate, ensuring consistent rotational accuracy across all substrates. A fifth support frame 30a and a sixth support frame 30b are respectively mounted on both sides of the third substrate 30. The height of all support frames is uniformly set to 1.2m, placing the working plane of the substrate at an ergonomic height of 800-1000mm, facilitating manual operation.

[0050] Servo motors serve as the power source for the substrate rotation, employing a one-to-one independent drive mode. Each motor is mounted on the outer side of the support frame on the corresponding substrate side to avoid interference with the substrate, workstation, and robot motion trajectory. The specific installation layout is as follows:

[0051] The first servo motor 10c is fixed to the outside of the first support frame 10a via a custom mounting base. The mounting base and the support frame are fastened together with high-strength bolts. The motor output shaft is coaxially connected to the left end shaft of the first substrate 10 via a flexible coupling, with a transmission efficiency of ≥98%. The second servo motor 20c is mounted on the outside of the third support frame 20a, and its installation method is the same as that of the first servo motor to ensure uniform drive performance. The third servo motor 30c is mounted on the outside of the fifth support frame 30a. All three servo motors are high-precision servo motors with a power of 1.5kW and a rated speed of 3000r / min. With the help of a planetary reducer, the substrate can be accurately rotated and positioned to meet the adjustment requirements of different welding angles.

[0052] To enable batch welding operations, four independent welding stations are evenly distributed along the length of each substrate. The structural dimensions of each station can be set as needed, forming a large-scale operation layout with a total of twelve stations. Specifically, the four stations on the first substrate 10 are defined from left to right as the first welding station 101, the second welding station 102, the third welding station 103, and the fourth welding station 104, with a center-to-center distance of 500mm between adjacent stations. This distance is compatible with the maximum external dimensions (350mm) of the corner bracket workpiece, ensuring that the workpieces do not collide between stations. The second substrate 20 has corresponding fifth welding stations 201, sixth welding stations 202, seventh welding stations 203, and eighth welding stations 204, with the same spacing as the first substrate. The third substrate 30 has ninth welding stations 301, tenth welding stations 302, eleventh welding stations 303, and twelfth welding stations 304.

[0053] As can be seen from the above, this invention, through the collaborative design of three base plates, six sets of support frames, three servo motors, and twelve welding stations, not only meets the production capacity requirements for parallel welding of multiple workpieces, but also ensures the equipment's versatility and ease of maintenance through modular and standardized structural design, providing a solid structural foundation for the efficient and stable operation of automated welding stations. It should be noted that the welding robot 40, the base plates, and the number of welding stations on each base plate can all be specifically set according to production capacity requirements; this invention does not impose any special limitations on these aspects.

[0054] like Figure 1 Of the twelve welding stations shown (first welding station 101 to twelfth welding station 304), each station is equipped with [equipment / facilities]. Figure 2The corner bracket shown is a dedicated fixing device that precisely matches the workpiece structure, ensuring accurate positioning and no loosening of the workpiece during welding and substrate flipping.

[0055] like Figure 2 As shown, the corner seat workpiece to be welded is a typical three-plate splicing structure, consisting of a left plate 1001, a right plate 1002, and a middle stiffening plate 1003. The welding process requires that the left plate 1001 and the right plate 1002 be tightly fitted to the two end faces of the stiffening plate 1003, and the weld seam must be continuously formed along the mating surface. Therefore, the core function of the fixing device is to ensure the fitting accuracy and clamping stability of the three plates.

[0056] In this embodiment of the invention, the fixing device adopts a combined design of reference positioning and multi-directional cylinder clamping. The reference positioning structure consists of multiple reference blocks 1004 made of wear-resistant alloy material. The reference blocks 1004 are vertically fixed to preset mounting holes at the welding station by fastening screws. Anti-loosening washers are added to the bottom of the screws to prevent positioning misalignment due to long-term vibration. The positioning surface of the reference blocks 1004 is precision ground, with a flatness error ≤0.01mm. During loading, one edge of the left side plate 1001 must be tightly pressed against the positioning surface of the reference blocks 1004 to achieve lateral reference positioning of the workpiece at the station, ensuring consistent placement of each batch of workpieces.

[0057] The clamping structure consists of four high-performance cylinders, divided into two functional modules: side clamping and end clamping. The side clamping module comprises a first cylinder 1005 and a second cylinder 1006, symmetrically arranged on both sides of the workstation. Their stroke can be set as needed, and the working pressure is adjustable from 0.3 to 0.6 MPa. The operation is independently controlled by a PLC control system via an electromagnetic reversing valve. After loading, the first and second cylinders 1005 and 1006 drive the piston rods to synchronously push the right side plate 1002, ensuring a tight fit between the inner end faces of the two side plates and the two sides of the reinforcing rib 1003, with a fit gap ≤0.03 mm, meeting the welding process requirements for plate fit. The end clamping module consists of a third cylinder 1007 and a fourth cylinder 1008, symmetrically arranged at both ends of the workstation along the workpiece length. Its function is to apply clamping force from both axial ends of the workpiece, preventing axial displacement due to thermal deformation during welding. The clamping response time is ≤0.5 seconds, ensuring rapid clamping without affecting the production cycle.

[0058] To accommodate six marked dimensions (100mm, 150mm, 200mm, 250mm, 300mm, and 350mm) for angle-mounted workpieces, the end clamping module features an adjustable positioning structure. Six evenly distributed positioning holes (12mm diameter, 50mm center-to-center spacing, corresponding to the six workpiece dimensions) are pre-set on the mounting base of the third cylinder 1007. The fourth cylinder 1008 is fixedly mounted on a reference base at the other end of the workstation. Before operation, the operator can insert the positioning pin 1009 into the corresponding numbered positioning hole according to the actual length of the workpiece to be welded, thereby locking the installation position of the third cylinder 1007 and ensuring precise matching of the clamping distance between the two end cylinders to the workpiece length. This adjustment structure eliminates the need to disassemble the cylinders; size switching is achieved simply by inserting and removing the positioning pins.

[0059] It should be noted that the welding station of the present invention can also have positioning holes set on the mounting base plates of the third cylinder 1007 and the fourth cylinder 1008 simultaneously to achieve bidirectional adjustment at both ends; or a servo motor can be used to replace the positioning pin for positioning, and the servo motor can be driven by the PLC control system to drive the cylinder to move along the length direction of the station, with a translation accuracy of ±0.02mm, which can adapt to more customized workpieces of non-standard sizes; in addition, a mode in which only one cylinder is driven to move and the other cylinder is fixed can be selected, which can be flexibly switched according to production needs.

[0060] The welding station of this invention supports two flexible loading modes, which can be freely selected according to the production scenario and capacity requirements: one is manual loading, where the operator places the assembled corner seat workpiece (left side plate 1001, right side plate 1002 and stiffening plate 1003 initially spliced) stably on one side of the reference block 1004 of the welding station to ensure that the workpiece is placed in accordance with the positioning reference; the other is automated loading, where a robotic arm accurately grabs the pre-assembled workpiece from the loading basket and moves it to the corresponding welding station according to the preset trajectory, realizing unmanned operation of the loading process and adapting to the needs of large-scale batch production.

[0061] After the loading action is completed, the workpiece can be fixed in two ways: manual and automatic. First, the PLC control system directly outputs control signals to drive the first cylinder 1005 and the second cylinder 1006 on the side to move. The piston rods extend synchronously and apply a stable clamping force to firmly press the left side plate 1001 and the right side plate 1002 against the two sides of the stiffener 1003, thus laying a solid positioning foundation for subsequent welding. Then, the end clamping stage begins. In this embodiment of the invention, the third cylinder 1007 and the fourth cylinder 1008 at the end adopt a manual triggering mode. The operator drives the piston rods of the two cylinders to extend by pulling the corresponding first operating handle 1010 (adapted to the third cylinder 1007) and the second operating handle 1011 (adapted to the fourth cylinder 1008), applying a clamping force from both ends of the workpiece's axial direction to complete the full-dimensional fixation of the workpiece and prevent displacement caused by thermal deformation or substrate flipping during the welding process.

[0062] If a higher level of automation is required in the production scenario, the end cylinders can be replaced with an electric drive mode: at this time, there is no need for manual operation of the handle. After the material is loaded and the side cylinders are clamped, the PLC control system will automatically send drive commands to precisely control the extension and retraction strokes of the third cylinder 1007 and the fourth cylinder 1008, realizing automated clamping from both ends of the workpiece. The entire clamping process does not require manual intervention, further improving the production cycle and ease of operation.

[0063] The welding robot 40 of this invention is a 6-axis articulated industrial robot, which is the welding execution component of the workstation. The body can be integrally formed from high-strength aluminum alloy, which has the advantages of structural rigidity and lightweight. The load capacity is 10-20kg, the repeatability of positioning accuracy is ±0.05mm, and the working radius is ≥1500mm. It can cover twelve welding stations on three substrates in all directions and flexibly adapt to the welding requirements of different angles and positions such as planar welds and right-angle welds of corner seat workpieces.

[0064] The robot adopts a column-mounted installation method, with its bottom fixed to the workshop floor by expansion bolts, maintaining a reasonable distance from the protective fence and each welding station, which avoids movement interference and provides sufficient space for equipment maintenance; its end flange fixes the welding gun through a customized connector, is compatible with digital pulse MIG / MAG welding power supply, can stably adapt to welding wires with diameters of 0.8 to 1.2 mm, and integrates a welding wire guide tube fixing structure to reduce welding wire transport resistance and wear.

[0065] In addition, the robot body has an IP67 protection rating, which can withstand the fumes, spatter, and slight corrosion in the welding environment, and adapt to workshop working conditions from -5℃ to 45℃. The joint motors have built-in temperature sensors and overload protection modules. Through program adjustment and component adaptation, it can cover the welding of corner workpieces of different sizes and specifications from 100mm to 350mm, and can also be extended to welding processes of various materials such as carbon steel, stainless steel, and aluminum alloy, with extremely strong adaptability and reliability.

[0066] The robot station of the present invention can be equipped with multiple welding robots 40. These robots can work individually or collaboratively, and the work scope can be flexibly allocated according to the production task and workpiece specifications. When working individually, each robot can dock with different substrates or welding stations and process multiple batches of corner seat workpieces of the same or different specifications in parallel to achieve multi-line synchronous production. When working collaboratively, they can cooperate according to weld type, position or process.

[0067] The welding station of this invention is also equipped with a welding torch cleaning device 70. This device is fixedly installed within the working radius of the welding robot 40, using an independent bracket to fix it to the ground. Its overall protection level reaches IP54, allowing it to withstand fumes and spatter in the welding environment. This device consists of a reamer assembly, an anti-spatter agent spraying module, a drive unit, and a control interface. It is specifically designed to solve the problem of spatter adhering to the welding torch nozzle and contact tip during the welding process, ensuring welding continuity and weld quality.

[0068] The reamer assembly is made of wear-resistant alloy and precision-ground. Its diameter is precisely matched to the inner diameter of the welding torch nozzle. It can be driven by a stepper motor and, during cleaning, can extend coaxially into the nozzle along the welding torch axis to thoroughly scrape away the spatter from the inner wall of the nozzle and around the contact tip through a rotating motion. The anti-spatter spray module has a built-in high-pressure spray head and a sealed reservoir. It can be filled with special welding anti-spatter agent. After cleaning, the spray head is precisely aligned with the welding torch tip and sprays the anti-spatter agent evenly in an atomized form to form a protective film, reducing the adhesion of welding slag during subsequent welding.

[0069] Meanwhile, the cleaning device is linked with the PLC control system and the robot control system through the control interface. The cleaning timing can be preset through the operation panel, supporting triggering based on the number of welded workpieces or a fixed time interval, or the welding robot 40 can actively request cleaning during the welding interval; when the cleaning command is triggered, the PLC control system sends a signal to the robot control system, driving the welding robot 40 to move the welding torch precisely to the positioning position of the cleaning device. After the welding torch is in place, the drive unit starts the reamer assembly to perform the slag removal action. After the slag removal is completed, the anti-spatter agent is immediately triggered for spraying. After completion, the robot automatically returns to the welding position to continue working without affecting the production cycle.

[0070] In addition, the device is equipped with a liquid level sensor and a fault detection module. When the anti-spatter agent is insufficient or the reamer is stuck, it sends an alarm signal to the PLC control system in real time, prompting the operator to replenish the agent or perform maintenance through the operation panel. This ensures stable operation of the device, effectively reduces the frequency of manual cleaning of the welding torch, and improves the automation level and work efficiency of the workstation.

[0071] The robot control system and PLC control system of the present invention are equipped with independent robot control box 60 and PLC control box 50 respectively. The two adopt a modular design, each undertaking core control functions, and deeply cooperating through a high-speed communication bus to form a stable and reliable control core for the workstation.

[0072] The robot control box 60 can be made of cold-rolled steel plate with IP54 protection rating. It has a built-in high-precision motion controller and servo drive module, which supports trajectory planning, motion execution and program storage of 6-axis articulated robots. The box integrates a heat dissipation system and electromagnetic shielding structure, which can withstand electromagnetic interference and temperature fluctuations in the welding environment. It has reserved teaching pendant interface, welding torch cleaning device 70 linkage interface and fault alarm output interface on the outside, which can receive and execute welding commands in real time, and at the same time provide feedback on the robot's operating status (such as welding in progress, torch cleaning in progress, fault).

[0073] The PLC control box 50 also adopts an IP54 protection-rated enclosed structure. Internally, it is equipped with an industrial-grade high-performance PLC controller, digital / analog signal acquisition module, bus communication module, and power supply module. The modular layout facilitates maintenance and expansion. Externally, it is equipped with a standardized aviation plug interface, which can be connected to servo motors, cylinder magnetic switches, operation panels, safety light curtains, emergency stop buttons, and other workstation execution components and detection elements. It is responsible for the entire process logic control, including material loading confirmation, workpiece clamping, substrate rotation, welding triggering, and safety interlocking.

[0074] The robot control system and PLC control system establish a real-time communication link via the Profinet bus, with a communication latency of ≤10ms, enabling high-speed interaction of commands and status. Based on the workstation readiness signal (workpiece clamped in place), the PLC control system sends a welding start command, welding parameters corresponding to the workpiece specifications (such as current, voltage, and speed), and the current angle information of the substrate to the robot control system. Upon receiving the command, the robot control system drives the welding robot 40 to perform the welding operation along a preset trajectory, providing real-time feedback on welding progress, welding torch position, and abnormal statuses (such as wire exhaustion or welding torch malfunction). When the PLC control system detects a safety hazard (such as a safety light curtain being triggered) or a workstation abnormality (such as a cylinder not clamping), it immediately sends a stop command to the robot control system. Both systems work together to cut off the welding action and drive circuit, ensuring operational safety. Furthermore, the robot control system transmits welding completion signals, welding duration, and other data back to the PLC control system, which then synchronizes them to the digital management system, enabling visualized traceability and unified scheduling of the production process. It also supports centralized setting and status monitoring of parameters for both control boxes via the operation panel, offering convenient operation and robust control logic, providing dual guarantees for the automated and high-precision operation of the workstation.

[0075] The operation panel of this invention serves as the human-machine interface unit for the welding station. It employs a combination of an industrial-grade touchscreen and physical buttons, and is installed on the outside of the protective fence for easy observation and operation. The operation panel communicates in real-time with the PLC control box 50 via industrial Ethernet or fieldbus, primarily achieving four functions: 1) Status monitoring and visualization, dynamically displaying the rotation angle of each substrate, the clamping status of the workstation, the robot's working mode, real-time curves of welding current and voltage, system alarm information, and production counts; 2) Process parameter retrieval and management, with a built-in graphical program selection interface, allowing operators to access the corresponding robot welding program, tooling control parameters, and welding process specifications with a single click on the workpiece model icon; 3) Manual operation and debugging, providing dedicated buttons for axis jogging, cylinder single-action, and mode switching, facilitating equipment debugging, maintenance, and emergency intervention; 4) Production data management, allowing viewing of historical output and pass rate statistical reports, and featuring access control functionality to support controlled modification of process parameters. This operation panel is dustproof, waterproof, and resistant to electromagnetic interference. Its intuitive interactive design significantly lowers the technical barrier for operators, making it a key interface for achieving flexible and intelligent production in the welding station.

[0076] The welding station of the present invention is also equipped with a mixed protective gas tank 80, which is connected to the welding gun gas supply system of the welding robot 40 through a dedicated gas supply pipeline, and is used to provide a continuous and stable inert gas protective environment to the arc area during the welding process.

[0077] The gas tank stores a precisely premixed mixture of argon (Ar) and carbon dioxide (CO2), or other mixed gases as required by the welding materials (such as an argon (Ar) and helium (He) mixture suitable for aluminum alloys). The gas supply line integrates a pressure reducing valve, flow meter, and solenoid on / off valve. A PLC control system automatically controls the gas flow and adjusts the gas supply based on welding start / stop signals, ensuring appropriate gas protection at different welding stages (arc initiation, welding, and arc termination). This effectively isolates the weld from air, prevents weld oxidation and nitriding, reduces porosity and spatter, and significantly improves weld quality, mechanical properties, and corrosion resistance.

[0078] Meanwhile, the gas tank is also equipped with a pressure sensor and a low pressure alarm device. When the pressure inside the tank is lower than the set threshold, the system will automatically remind you to replace the gas tank to ensure the continuity and stability of the welding process.

[0079] The welding station of the present invention is also equipped with a welding wire hopper 90, which serves as a centralized storage and supply unit for welding wire and is fixedly installed on a dedicated bracket or workshop floor within the reach of the welding robot 40. The hopper contains a large-capacity coil of welding wire, the specifications of which (e.g., diameter 1.0mm, 1.2mm) can be changed according to the current welding process requirements.

[0080] Under the control system's scheduling, the welding robot 40 has the ability to automatically identify the remaining welding wire and perform welding wire replacement. When the welding wire is about to run out or the type of welding wire needs to be changed, the robot can autonomously move to the welding wire spool 90 and, through a dedicated clamping mechanism on its end effector, complete the disassembly of the old welding wire spool and the grasping, positioning, and installation of the new welding wire spool. This process can be assisted by the robot's vision system or sensors for positioning, and the PLC control system coordinates the timing of the actions. This design eliminates the need for traditional long-distance wire feeding pipelines, simplifies the system structure, reduces wire feeding failure points, and gives the workstation greater flexibility. That is, by changing the wire spool, it can quickly adapt to the needs of welding wires of different materials and specifications, making the switching between multiple welding tasks more convenient and efficient.

[0081] The welding machine workstation of this invention adopts a fully enclosed protective fence, which is constructed by splicing a modular galvanized square steel frame with high-strength steel mesh to form a completely enclosed and independent working space. The fence is no less than 2.2 meters high and is equipped with an interlocked maintenance door with a safety lock, and integrates multiple safety protection devices. The protective devices include a safety light curtain at the entrance, an emergency stop button, an arc light protection curtain, and a viewing window.

[0082] Meanwhile, the top and sides of the enclosure are equipped with a high-efficiency ventilation and dust removal system. Through a combination of top and side suction, it ensures that the welding fume capture efficiency is no less than 95%, and the purified air meets the GBZ 2.1 standard. Furthermore, the interior of the enclosure uses sound-absorbing materials and an arc-absorbing coating to control ambient noise below 85dB and reduce arc intensity by more than 90%. This fully enclosed protective design not only provides a physical safety barrier for automated welding but also creates a working environment that meets modern industrial hygiene standards, achieving an organic combination of production safety, occupational health, and environmental protection.

[0083] The PLC control system of this invention has a built-in fault alarm and diagnostic module. This module can monitor the operating status and key parameters of the robot, welding power supply, servo positioner, pneumatic unit, safety devices and auxiliary systems in real time. These parameters include current, voltage, servo feedback, air pressure, grating signal, etc.

[0084] During welding, if any parameter deviates from the preset safety threshold or a logical anomaly is detected, the system will immediately initiate a multi-level response: First, an alarm window will pop up in a prominent color and text on the user interface of the operation panel, accurately displaying the fault code, location, and possible cause; simultaneously, an audible and visual alarm will be triggered for on-site warning. For serious faults that may cause equipment damage or safety risks, the system will perform an emergency shutdown and lock the relevant equipment.

[0085] Meanwhile, the module also has preliminary fault diagnosis and historical data recording functions, which can store recent alarm event chains to help maintenance personnel quickly locate the root cause, reduce unplanned downtime, and thus significantly improve the maintainability and overall operating efficiency of the equipment.

[0086] The robot control system of the present invention integrates an intelligent welding process library, which pre-stores welding programs and welding process parameters optimized for different materials (such as carbon steel, stainless steel, and aluminum alloy), different plate thicknesses, and various typical corner seat structures. The welding process parameters include motion trajectory, current and voltage parameters, wire feeding speed, and shielding gas flow rate settings.

[0087] During operation, operators only need to select the corresponding program through the operation panel of the PLC control system according to the workpiece model code to call it with one click. No manual adjustment is required, which greatly reduces the dependence on the operator's experience and ensures the standardization and repeatability of the welding process.

[0088] Example 2:

[0089] Figure 3 A schematic flowchart of an automated welding method according to the present invention is shown. For example... Figure 3 As shown, the welding method includes the following steps:

[0090] S1: Loading the workpiece.

[0091] Operators or automated feeding devices place the pre-assembled corner bracket workpieces, including the left side plate, right side plate, and middle stiffener plate, stably at the designated welding station.

[0092] When placing the workpiece, it is necessary to ensure that its side edge is in close contact with the pre-set wear-resistant alloy reference block on the workstation to achieve lateral reference positioning and ensure the consistency of the position of all workpieces before welding.

[0093] In manual loading, workers need to gently push the workpiece to the stop positioning surface; in automated mode, a robotic arm grabs the workpiece from the loading area and accurately places it at the workstation.

[0094] S2: Workpiece positioning and clamping.

[0095] First, the PLC control system drives the first and second cylinders, which are symmetrically arranged on both sides of the workpiece, to move synchronously. Their piston rods push the right side plate with adjustable pressure (0.3–0.6MPa), so that the inner end faces of the left and right side plates are tightly fitted with the two sides of the stiffener plate, ensuring that the fitting gap is ≤0.03mm, which meets the core requirements of the welding process for the assembly accuracy of the plate.

[0096] Subsequently, the end-fixing stage begins, which can be performed manually or automatically depending on the production configuration. In manual mode, the operator operates the first and second operating handles at both ends of the workstation, driving the third and fourth cylinders to apply clamping force from both ends of the workpiece along the axial direction, with a clamping response time of ≤0.5 seconds. In automatic mode, the PLC directly controls the movement of the cylinders at both ends, achieving rapid clamping without human intervention.

[0097] In addition, to accommodate workpieces of different lengths, the end clamping module is equipped with an adjustable positioning mechanism (such as a positioning pin hole or a servo translation mechanism), which can quickly adjust the clamping distance when switching workpiece sizes. This effectively suppresses the displacement of the workpiece that may be caused by thermal deformation or substrate flipping during the entire welding process, providing a stable and reliable clamping foundation for robotic welding.

[0098] S3: Welding parameter configuration.

[0099] Operators can directly select or input the model code of the corner bracket workpiece to be welded through the graphical interface of the control panel outside the protective fence; the system then calls up the optimized process package that is perfectly matched to the model from its integrated intelligent welding process library with one click, including the robot's motion trajectory, welding speed, multi-layer and multi-pass welding sequence, precise current, voltage and wire feed speed parameters, as well as the corresponding welding torch oscillation mode and shielding gas flow rate setting value.

[0100] Meanwhile, the PLC control system performs closed-loop monitoring of the entire station's readiness status. It confirms the workpiece is clamped in place by real-time acquisition of magnetic switch signals from the cylinders at each workstation, and verifies the accuracy of the substrate angle positioning by reading feedback from the servo encoder. Simultaneously, the robot control system determines whether the welding robot 40 is in standby mode, and the pressure sensor monitors that the mixed protective gas pressure is within the set range.

[0101] Once all detection conditions meet the preset safety and process thresholds, the PLC control system will send a welding start command to the robot control system, thereby ensuring that each welding operation begins under conditions of precise parameters and controlled status, thus ensuring high-quality welding.

[0102] S4: Substrate angle adjustment.

[0103] This step is optional and aims to adjust the weld to the robot's optimal welding space posture. The PLC control system drives the servo motor on the corresponding side of the substrate to rotate precisely according to the weld position information preset in the current welding program, so that the workpiece mounted on the substrate, along with its weld interface, is adjusted to the ideal welding angle.

[0104] This rotation process relies on a rigid rotating structure supported by deep groove ball bearings on a high-strength support frame at both ends of the substrate. With the feedback of the high-resolution encoder of the servo system, the angular positioning accuracy can reach ±0.02°, ensuring that the robot welding gun can perform welding in an optimal posture such as near-flat welding or boat-shaped welding. This effectively improves the weld formation quality, reduces welding defects, and significantly enhances the process adaptability of welds in different positions.

[0105] S5: The robot performs welding operations.

[0106] After receiving the welding start command and corresponding process parameters sent by the PLC control system, the welding robot 40 begins to move according to the optimized trajectory program pre-stored in the intelligent process library.

[0107] Driven by a digital pulsed MIG / MAG welding power source, the welding torch mounted on the robot's end effector performs continuous and stable arc welding at the workpiece joint based on real-time current, voltage, wire feed speed, and torch oscillation mode.

[0108] During the welding process, the robot control system monitors the weld position and molten pool status in real time through its built-in sensor module, and dynamically fine-tunes the welding torch posture and welding parameters to ensure uniform weld formation, adequate penetration, and the absence of defects such as undercut and porosity. Simultaneously, the shielding gas system precisely controls the on / off state and flow rate of the mixed gas at each stage of arc initiation, welding, and arc termination according to programmed settings, effectively isolating air and ensuring welding metallurgical quality. The wire feeding system stably delivers the welding wire in coordination with the welding speed, ensuring a continuous and reliable process.

[0109] The entire welding process is completed automatically within a fully enclosed protective space. Operators only need to monitor the real-time welding curve and status prompts through the control panel to achieve high-quality, highly repeatable unmanned welding operations.

[0110] S6: Welding completed and reset.

[0111] After completing the predetermined trajectory, the welding robot 40 sends a welding completion signal to the PLC control system and automatically raises the welding torch to a safe height, returning to the set standby position along the optimized path to avoid interference with the workpiece or tooling.

[0112] Subsequently, the PLC controls the operation of each clamping cylinder according to a preset sequence: first, the end clamping cylinders (the third and fourth cylinders) are released to remove the axial constraint; then, the side clamping cylinders (the first and second cylinders) retract synchronously, and the workpiece is completely released. At the same time, if the substrate has been angled during the welding process, the PLC will drive the corresponding servo motor to precisely rotate the substrate back to the initial zero position or the preparatory angle required for the next workpiece, ensuring that the workstation returns to a ready state.

[0113] Once all actuators are reset, the system records and uploads key data from this welding operation (such as welding duration, actual parameters, and completion time) to the production management system. This provides a basis for quality traceability and capacity statistics, thereby ensuring the safe and orderly completion of a welding cycle and preparing for subsequent continuous operations.

[0114] After welding is completed and the workpiece is released from its fixed position, the operator or unloading robot removes the formed corner bracket from the workstation. In manual mode, workers can remove the workpiece with the help of auxiliary lifting tools or manual handling tools; in automatic mode, a collaborative robotic arm or gantry-type gripper performs precise picking and transfer. After simple surface cleaning, the removed workpiece is transferred to the next process or directly sent to the finished product inspection area via conveyor belt, material trolley, or AGV automated guided vehicle.

[0115] The above describes the specific process of an automated welding method according to the present invention.

[0116] During the welding operation (step S5), the PLC control system triggers the welding torch cleaning program based on preset rules (such as the cumulative number of welded workpieces or fixed time intervals) or by the welding robot 40 actively requesting it during the welding interval. During cleaning, the PLC control system sends instructions to the robot control system, driving the welding robot 40 to precisely move the welding torch to the fixed position of the dedicated welding torch cleaning device 70. After positioning, the drive unit of the cleaning device starts, and its wear-resistant alloy reamer assembly, driven by a stepper motor, extends coaxially into the nozzle along the welding torch axis, thoroughly scraping away the spatter adhering to the conductive tip and the inner wall of the nozzle through high-speed rotation. After slag removal, the device's built-in anti-spatter agent spraying module is activated, and the high-pressure spray head evenly sprays a special welding anti-spatter agent onto the surface of the welding torch head in atomized form, forming a protective film that significantly reduces slag adhesion during subsequent welding. The entire cleaning process is fully automated, controlled collaboratively by the PLC and robot control systems. After completion, the robot automatically returns to the welding station with the welding torch to continue operation.

[0117] Meanwhile, during welding, the PLC control system collects and records key welding parameters in real time (such as actual welding current, voltage, wire feeding speed, gas flow rate, robot motion trajectory deviation, and welding time during the welding process), and compares them with the preset process specifications in real time. Once any parameter deviates from the preset safety threshold or logic abnormality is detected, the system will immediately trigger a graded alarm and execute preset protective operations.

[0118] Specifically: First, the welding power supply is immediately stopped, and the robot stops moving and removes the welding torch. Second, the alarm type and abnormal parameters are displayed on the human-machine interface with prominent visual and audible signals. Finally, the system automatically records complete abnormal time segment data and generates a fault report containing possible cause analysis to guide maintenance personnel to quickly locate and troubleshoot problems, thereby effectively preventing the generation of batch quality defects and ensuring the reliability of the production process and the traceability of product quality.

[0119] After welding is completed, online visual inspection of weld formation, weld width, and reinforcement height can be performed using machine vision systems or infrared thermal imaging devices, or welding stability can be indirectly assessed using technologies such as acoustic emission and arc sensing. All collected data (including time-series curves, abnormal events, and quality judgment results) are uploaded in real time to the workshop-level production management system (MES) or cloud database, forming a traceable electronic process archive and automatically generating welding process reports and statistical charts. If the system detects parameters exceeding tolerance or quality abnormalities, it can trigger audible and visual alarms in real time, output non-conforming marks, and pause the process when necessary, supporting rapid intervention and adjustment by process personnel, thereby achieving digital control, continuous optimization, and full lifecycle traceability of welding quality.

[0120] The advantages of this invention are as follows: First, through the coordination of high-precision robot motion, high-rigidity tooling positioning, and digital welding power supply, the consistency of each weld seam formation and the penetration depth are ensured, fundamentally eliminating the quality fluctuations of manual welding and significantly improving the product qualification rate. Second, the automated welding speed is stable, and the multi-station parallel operation mode eliminates the time spent by the robot waiting for loading and unloading, resulting in a significant increase in equipment utilization and single-shift output compared to the traditional manual operation mode. Third, workers only need to complete simple loading and unloading actions and call the corresponding program on the operation interface, without needing to master welding skills, reducing the company's recruitment, training, and labor costs, and alleviating the pressure of a shortage of skilled welders. Fourth, the modular quick-change tooling design makes switching product models quick and easy, especially suitable for multi-variety, small-batch production modes, and can quickly respond to market changes and customer customization needs. Fifth, the fully enclosed design of the workstation effectively isolates arc light and spatter, and the integrated high-efficiency dust removal system significantly reduces the concentration of dust, ensuring that the overall working environment meets national occupational health standards and protecting the health of employees.

[0121] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An automated welding station for corner brackets, characterized in that, The welding station includes: At least one base plate, wherein at least one welding station for fixing the corner bracket workpiece is provided on the base plate; At least one welding robot is used to perform welding operations on the corner bracket workpiece at the welding station; A clamping device is provided at each of the welding stations to position and clamp the workpiece before welding. The control system includes a robot control system and a PLC control system, which are connected via a communication bus. The robot control box is used to control the trajectory planning and motion execution of the welding robot, and the PLC control box is used to control the logical actions of the servo motor, clamping device and various execution components of the workstation.

2. The automated welding station according to claim 1, characterized in that, The clamping device includes: At least one reference stop is used for lateral positioning of the workpiece; Multiple clamping cylinders, including a first cylinder and a second cylinder for clamping the workpiece from both sides, and a third cylinder and a fourth cylinder for clamping the workpiece from the end.

3. The automated welding station according to claim 2, characterized in that, The mounting positions of the third and / or fourth cylinders are adjustable to accommodate workpieces of different lengths.

4. The automated welding station according to claim 1, characterized in that, The welding station also includes a welding torch cleaning device, which is located within the working range of the welding robot and is used to automatically clean the welding torch nozzle and conductive tip.

5. The automated welding station according to claim 4, characterized in that, The welding torch cleaning device includes a reamer assembly and an anti-spatter spraying module. The reamer assembly is used to scrape off welding slag, and the spraying module is used to spray anti-spatter agent.

6. The automated welding station according to claim 1, characterized in that, The robot control system integrates an intelligent welding process library, which pre-stores welding programs and welding process parameters corresponding to corner bracket workpieces of different specifications, materials, and plate thicknesses. The welding process parameters include motion trajectory, current and voltage parameters, wire feeding speed, and protective gas flow rate settings. The PLC control system supports one-click recall via workpiece model code.

7. The automated welding station according to claim 1, characterized in that, The welding station also includes a mixed protective gas cylinder and a welding wire drum; The mixed protective gas tank is connected to the welding torch via a gas supply pipeline, which integrates a pressure reducing valve, a flow meter, and a solenoid on / off valve. The welding wire hopper is used to store welding wire, and the welding robot has the ability to automatically identify the remaining welding wire and perform welding wire replacement.

8. The automated welding station according to claim 1, characterized in that, The welding station is enclosed by a protective fence to form a closed working space; The safety protection devices of the protective fence include safety light curtains, emergency stop buttons, arc light protection curtains and interlocked maintenance doors. The smoke and dust capture efficiency of the ventilation and dust removal system is ≥95%, the noise level in the working environment is ≤85dB, and the arc light intensity is reduced by ≥90%.

9. The automated welding station according to claim 1, characterized in that, The PLC control system has a built-in fault alarm and diagnosis module that monitors the operating parameters of the workstation in real time. When the parameters deviate from the preset threshold, it triggers an audible and visual alarm and displays a fault code. In case of a serious fault, it performs an emergency shutdown and records the alarm event chain.

10. An automatic welding method for corner brackets, characterized in that, The welding method includes: S1: Load the corner bracket workpiece to the welding station and perform preliminary positioning using the reference block; S2: Control the clamping device to clamp the workpiece laterally and at the end; S3: Select the workpiece model through the operation panel and call up the corresponding welding process parameters; S4: Adjust the substrate angle according to welding requirements; S5: Controls the welding robot to perform welding according to preset trajectories and parameters; S6: After welding is completed, release the workpiece and reset each actuator to proceed with unloading; In step S5: During the welding process, an automatic cleaning program for the welding torch is triggered according to preset conditions, and welding is automatically resumed after cleaning is completed. During the welding process, the PLC control system monitors the welding parameter data in real time and compares it with the preset process specifications. If the parameters deviate from the preset safety threshold or the logic is abnormal, a graded alarm will be triggered and preset protective operations will be executed.

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