Clamp for electric arc welding of metal products

Abstract

The invention relates to the technical field of intelligent welding equipment, and discloses a metal product electric arc welding clamp which comprises a rack, a main workpiece fixing module, an auxiliary workpiece fixing module, a state sensing module and a control module, the main workpiece fixing module comprises a distance adjusting unit and at least two fixing parts, and each fixing part is composed of a lateral clamping unit and a top pressing unit. The main workpiece fixing module, the auxiliary workpiece fixing module, the state sensing module and the control module form an intelligent clamping system, a traditional passive rigid welding clamp is changed, a simplified thermal-mechanical coupling finite element model is constructed and operated in real time, the workpiece deformation trend and the stress state in the welding thermal process are accurately predicted, the force and the position of a clamping mechanism are actively adjusted in advance, and the welding quality is improved. The posture of the main station is continuously and stably maintained; therefore, the welding precision and consistency are improved, and the thermal deformation and residual stress of the workpiece are inhibited.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent welding equipment, more particularly, it relates to a clamp for arc welding of metal products. BACKGROUND

[0002] Arc welding technology is widely used in the manufacturing process of metal products to connect parts, which melts the base material and welding material by high temperature generated by arc to achieve permanent combination of parts. At present, the welding operation of metal products is mostly completed automatically by intelligent welding equipment, in which the welding clamp is the key process equipment to ensure product quality and production efficiency. Its main function is to accurately and reliably position and fix the work to be welded, so as to ensure that the relative position between workpieces remains consistent before and after welding, thereby meeting the size and shape tolerance requirements of products.

[0003] However, the clamp used by the traditional intelligent welding equipment, especially the clamp used to fix the main workpiece and simultaneously weld multiple secondary workpieces, has basic automatic adjustment function, but in actual welding, the concentrated input of arc heat source will cause the main workpiece to experience uneven heating and cooling cycle, thereby causing significant thermal elastic-plastic deformation and internal stress. At this time, the rigid constraint of the traditional clamp will hinder the natural thermal expansion and contraction of the workpiece, and "lock" the huge stress inside the workpiece, which not only causes unpredictable warping deformation when the workpiece is released after welding, affecting the final accuracy, but also changes the preset weld gap between the secondary workpiece and the main workpiece during the welding process, and even causes micro cracks, thus being not conducive to the production of some high-precision metal products. SUMMARY

[0004] The present application aims to provide a clamp for arc welding of metal products to solve the above technical problems.

[0005] The present application solves the above technical problems by the following technical solutions: The present application provides a clamp for arc welding of metal products, comprising a rack, and a main workpiece fixing module, a secondary workpiece fixing module, a state sensing module and a control module arranged on the rack. The main workpiece fixing module comprises a spacing adjustment unit and at least two fixing parts, the fixing part is composed of a lateral clamping unit and a top pressing unit, and the lateral clamping unit, the top pressing unit and the spacing adjustment unit are all independent driving components controlled by the control module; the spacing adjustment unit drives the fixing parts to move synchronously to adjust the spacing therebetween; The secondary workpiece fixing module comprises at least one abutting unit for positioning and temporarily fixing the secondary workpiece at the preset welding position; The state sensing module is used to acquire the physical state parameters of the main workpiece in real time during the welding process. The control module is configured as follows: Based on physical state parameters, the deformation trend and stress state of the main workpiece are calculated in real time through a preset model, and control commands are dynamically generated accordingly. The control commands include at least the clamping force of the lateral clamping unit, the downward pressure of the top pressing unit, and the adjustment commands for the spacing of the spacing adjustment unit. Each independent drive component in the main workpiece fixing module is adaptively adjusted to counteract deformation and optimize stress state.

[0006] Preferably, the lateral clamping unit includes a slide mounted on the frame, two clamping plates symmetrically sliding on the slide, and a driving member for driving the two clamping plates to move synchronously in opposite directions.

[0007] Preferably, the driving component includes a drive motor fixedly mounted on the slide and a first bidirectional lead screw connected to the output end of the drive motor, and the sliding ends of the two clamping plates are respectively threaded to the two ends of the first bidirectional lead screw.

[0008] Preferably, the top pressing unit includes a first linear telescopic source and a pressing body fixedly installed on the telescopic end of the first linear telescopic source.

[0009] Preferably, the spacing adjustment unit includes a drive motor fixed on the frame and a second bidirectional lead screw rotatably mounted on the frame. The output end of the drive motor is connected to the second bidirectional lead screw via a pulley transmission component, and the two slide blocks are slidably connected to the two ends of the second bidirectional lead screw respectively.

[0010] Preferably, the clamping unit includes a second linear telescopic source and a clamping seat slidably mounted on the frame, wherein the clamping seat is connected to the telescopic end of the second linear telescopic source.

[0011] Preferably, the number of clamping units is three, with two clamping units symmetrically distributed on both sides of the body and the other clamping unit located on one side of the body.

[0012] Preferably, the state sensing module includes a temperature sensor matrix distributed on the rack, a laser displacement sensor located above the rack, and multiple force sensors distributed on the lateral clamping unit and the top pressing unit.

[0013] Preferably, the temperature sensor matrix consists of multiple non-contact infrared temperature sensors, which are concentrated on both sides of the weld axis, in front of and behind the welding heat source, and near the clamping point of the main workpiece fixing module.

[0014] Preferably, the preset model is a digital model that integrates a thermo-mechanical coupling algorithm, which includes a thermo-elastic-plastic stress sub-model and a structural response sub-model.

[0015] The beneficial effects of this invention are as follows: The present invention comprises a main workpiece fixing module, a secondary workpiece fixing module, a state sensing module, and a control module, forming an intelligent clamping system. This system changes the traditional passive rigid welding fixture by constructing and running a simplified thermo-mechanical coupling finite element model in real time. It accurately predicts the deformation trend and stress state of the workpiece during the welding process, proactively adjusts the clamping mechanism force and position in advance, and continuously and stably maintains the posture of the main workstation. This improves welding accuracy and consistency, suppresses workpiece thermal deformation and residual stress, reduces subsequent straightening processes and product scrap rate, enhances adaptability to different workpiece sizes and welding processes, enables efficient and high-quality welding of small batches of high-precision products, and improves production flexibility and economic benefits. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a clamp for arc welding of metal products according to the present invention; Figure 2 This is a schematic diagram of the structure between the main workpiece fixing module and the auxiliary workpiece fixing module in a fixture for arc welding of metal products according to the present invention; Figure 3 This is a schematic diagram of the main workpiece fixing module in a fixture for arc welding of metal products according to the present invention; Figure 4 This is a schematic diagram of the lateral clamping unit in a metal product arc welding fixture of the present invention; Figure 5 This is a block diagram showing the relationship between the various modules of a metal product arc welding fixture according to the present invention.

[0017] In the diagram: 10, frame; 20, spacing adjustment unit; 201, drive motor; 202, second bidirectional lead screw; 30, lateral clamping unit; 301, slide; 302, clamping plate; 303, drive motor; 304, first bidirectional lead screw; 40, top pressing unit; 401, first linear telescopic source; 402, pressing body; 50, pressing unit; 501, second linear telescopic source; 502, pressing seat; 60, temperature sensor matrix; 70, laser displacement sensor; 80, force sensor. Detailed Implementation

[0018] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0019] Please refer to the following: Figures 1 to 5A fixture for arc welding of metal products includes: a frame 10, and a main workpiece fixing module, a secondary workpiece fixing module, a status sensing module, and a control module disposed on the frame 10. The main workpiece fixing module includes a spacing adjustment unit 20 and at least two fixing parts. Each fixing part consists of a lateral clamping unit 30 and a top pressing unit 40, and the lateral clamping unit 30, the top pressing unit 40, and the spacing adjustment unit 20 are all independent driving components controlled by the control module. The spacing adjustment unit 20 drives the fixing parts to move synchronously to adjust their spacing.

[0020] Specifically, the lateral clamping unit 30 includes a slide block 301 slidably mounted on the frame 10, two clamping plates 302 symmetrically sliding on the slide block 301, and a driving component for driving the two clamping plates 302 to move synchronously in opposite directions. The driving component includes a drive motor 303 fixedly mounted on the slide block 301 and a first bidirectional lead screw 304 connected to the output end of the drive motor 303. The sliding ends of the two clamping plates 302 are threadedly connected to both ends of the first bidirectional lead screw 304. The top pressing unit 40 includes a first linear telescopic source 401 and a pressing body 402 fixedly mounted on the telescopic end of the first linear telescopic source 401. The first linear telescopic source 401 can be a servo cylinder. The spacing adjustment unit 20 includes a drive motor 201 fixedly mounted on the frame 10 and a second bidirectional lead screw 202 rotatably mounted on the frame 10. The output end of the drive motor 201 is connected to the second bidirectional lead screw 202 via a pulley transmission component. The two slide blocks 301 are slidably connected to both ends of the second bidirectional lead screw 202.

[0021] The auxiliary workpiece fixing module includes three clamping units 50 for positioning and temporarily holding the auxiliary workpiece in a preset welding position. Two clamping units 50 are symmetrically distributed on both sides of the machine body, and the other clamping unit 50 is located on one side of the machine body. The clamping unit 50 includes a second linear telescopic source 501 and a clamping seat 502 slidably mounted on the frame 10. The clamping seat 502 is connected to the telescopic end of the second linear telescopic source 501. The second linear telescopic source 501 can be a servo cylinder or an electric push rod.

[0022] The state sensing module is used to acquire the physical state parameters of the main workpiece in real time during the welding process. The state sensing module includes a temperature sensor matrix 60 distributed on the frame 10, a laser displacement sensor 70 located above the frame 10, and force sensors 80 distributed on multiple lateral clamping units 30 and top pressing units 40.

[0023] It should be noted that, to achieve comprehensive and high-precision sensing of the main workpiece's status during the welding process, the status sensing module integrates multiple sensors, forming a distributed monitoring network. The specific configuration, function, and collaborative working method of each sensor are as follows: The temperature sensor matrix 60 consists of multiple non-contact infrared temperature sensors, which are fixedly mounted on the frame 10 in a grid-like distribution and precisely aligned with pre-defined key monitoring points on the main workpiece. The layout strategy aims to cover the entire welding heat-affected zone, with particular focus on: both sides of the weld axis for monitoring the lateral temperature gradient; in front of and behind the welding heat source for predicting the heat source's movement effect and cooling rate; and near the clamping points of the main workpiece fixing module for assessing the local thermal state of the clamping point area. The core function of this matrix is ​​to collect temperature values ​​at multiple locations on the surface of the main workpiece in real time and synchronously. The control module uses this data and a spatial interpolation algorithm to internally reconstruct the dynamic two-dimensional temperature field of the main workpiece during the welding process. This temperature field is one of the most critical input data for the preset model to perform thermal deformation prediction calculations, and it directly determines the accuracy of the prediction.

[0024] A laser displacement sensor 70 is mounted on a crossbeam above the frame 10. Its laser beam is vertically downward and aimed at the upper surface of the main workpiece, pointing to one or more key points on the workpiece that are prone to deformation and are representative, such as the center point between two fixed parts or the cantilever end. The sensor accurately measures the real-time normal displacement (i.e., deformation) of the key points of the main workpiece relative to their initial position in a high-frequency (typically higher than 1kHz) and non-contact manner. Its high-precision displacement signal output serves as a feedback signal: used to verify and calibrate the deformation trend predicted by the preset model, forming a closed-loop control; when the measured deformation exceeds the preset safety threshold, it can directly trigger the control module to execute an emergency adjustment strategy.

[0025] The force sensors 80 are specifically miniature strain gauge force sensors 80 or piezoelectric force sensors 80, which are directly integrated into the clamping plates 302 in each lateral clamping unit 30 and the piston rod end of the first linear telescopic source 401 in each top pressing unit 40. This integration method ensures that the sensors can directly and without interference measure the actual clamping force applied to the main workpiece, avoiding measurement errors caused by factors such as friction in the transmission mechanism. These distributed force sensors 80 monitor the magnitude of the force at each clamping point in real time. By collecting data from all these force sensors 80, the control module can grasp the distribution of clamping force in real time, ensuring uniform clamping force and avoiding local overpressure or insufficient pressure. The system accurately calculates the constraint reaction force and resultant torque of the entire clamping system on the main workpiece, which is the direct basis for evaluating whether the system is in an "over-constrained" state and making force optimization adjustments accordingly. It provides accurate boundary condition loads for the mechanical equilibrium equations in the preset model, greatly improving the reliability of stress state calculation.

[0026] In summary, the temperature sensor matrix 60, laser displacement sensor 70, and distributed force sensor 80 configured in this invention do not operate in isolation. Instead, they synchronously transmit the collected multi-physical field data, such as temperature, displacement, and force, to the control module. The control module, through data fusion technology, inputs these parameters into a preset thermo-mechanical coupling model, thereby achieving comprehensive perception, accurate prediction, and intelligent control of the welding state of the main workpiece. This detailed sensor configuration description fully ensures that those skilled in the art can understand and implement this state perception module.

[0027] The control module is configured to: calculate in real time the deformation trend and real-time stress state of the main workpiece caused by welding heat input and internal stress based on the physical state parameters obtained by the state perception module and through preset mechanical and thermal deformation models; dynamically generate and output control commands to counteract the deformation trend and optimize the stress state based on the above calculation results; the control commands include at least: the clamping force of the lateral clamping unit 30, the downward pressure of the top pressing unit 40, and the adjustment command of the spacing of the spacing adjustment unit 20; drive each unit of the main workpiece fixing module to execute the control commands so as to implement dynamic and adaptive clamping force and constraint position adjustment of the main workpiece during the welding process.

[0028] It should be noted that the mechanical and thermal deformation models relied upon by the control module are a "simplified real-time thermo-mechanical coupled finite element model" optimized for real-time control. This model includes a heat conduction sub-model, a thermo-elastic-plastic stress sub-model, and a structural response sub-model. The core objective is to achieve millisecond-level rapid computation while maintaining calculation accuracy through reasonable simplification, thus meeting the real-time control requirements of the welding process. Details are as follows: 1. Model Establishment and Initialization Geometric modeling and mesh generation: During system initialization, the control module automatically generates a simplified "beam-shell hybrid model" based on the user-input basic dimensions of the main workpiece (such as length, cross-sectional width and height). The main body of the main workpiece is simplified into a one-dimensional beam element, which inherits the cross-sectional properties of the workpiece (such as moment of inertia and cross-sectional area). The local areas used for welding the sub-workpiece are refined using two-dimensional shell elements to more accurately calculate the local heat concentration effect. Material property library: The model has a built-in material property database. When the operator inputs the material type of the workpiece (such as "Q235"), the model automatically loads the temperature-related properties of the material, which mainly include: elastic modulus E(T), coefficient of thermal expansion α(T), yield strength σs(T), specific heat capacity C(T) and thermal conductivity λ(T).

[0029] 2. The specific calculation process of the model The model's calculations are performed cyclically within each control cycle (e.g., 100ms), and consist of two core parts: Part 1: Transient Heat Transfer Calculation This section is used to calculate the temperature field distribution T(x,y,z,t) on the workpiece based on the welding heat input.

[0030] Control equations (simplified): The model solves the following simplified three-dimensional unsteady heat conduction equations: ; Where: ρ is the material density, C p λ is the specific heat capacity, and λ is the thermal conductivity. The welding heat source term is a key input to the model.

[0031] The Goldak double-ellipsoidal heat source model is used for description. This model can accurately simulate the molten pool morphology of arc welding. Its formula is: First half-ellipsoid: ; Posterior hemispheric: ; Where Q=ηUI is the welding heat input, η is the thermal efficiency coefficient, and U and I are the welding voltage and current acquired in real time; a f a r b, c, f f f r Characteristic parameters related to welding methods and materials are pre-calibrated and stored in a database.

[0032] Boundary conditions: The model considers convection and radiation heat dissipation between the workpiece and the environment, and its boundary conditions are expressed as follows: ; Among them, h c ε is the convective heat transfer coefficient, σ is the Stefan-Boltzmann constant, ϵ is the emissivity, and T0 is the ambient temperature.

[0033] Part Two: Calculation of Thermal Stress Field This section uses the calculated temperature field to solve for the stress and deformation of the workpiece.

[0034] Constitutive relation: The model adopts a thermo-elastic-plastic constitutive model, and its incremental stress-strain relationship is as follows: ; in: For stress increment, This is the elastoplastic matrix, whose value depends on the current stress state and temperature. This represents the total strain increment. For thermal strain increment, .

[0035] Mechanical equilibrium equations and solutions: The mechanical equilibrium equations of the model are as follows: ; Where: [K] is the global stiffness matrix, whose elements are related to the material property E(T) at the current temperature; {δ} is the nodal displacement vector to be determined, and the trend of this vector is the "deformation trend" in the claim; {F th} represents the thermal load vector, caused by the non-uniform temperature field T(x,y,z,t), {F clamp} represents the clamp constraint reaction force vector, the value of which is provided by the real-time measurement value of the force sensor in the state perception module.

[0036] Real-time stress state output: After solving for the displacement field {δ}, the internal stress field {σ} of the workpiece can be calculated using constitutive relations. The model will output the distribution of equivalent stress in real time and mark the region where the stress exceeds 60% of the material's yield strength σs(T) at that temperature as a "high stress risk zone". Simultaneously, for {F... clamp The resultant moment of} was analyzed, and the constraint risk index was calculated.

[0037] 3. Real-time calibration of the model To ensure model accuracy, the preset model incorporates a sensor-based real-time calibration mechanism: Temperature field calibration: The measured values ​​of the temperature sensor matrix are compared with the predicted values ​​at the corresponding locations in the model. The Kalman filter algorithm is used to fine-tune the heat source parameters (such as thermal efficiency η) in the model so that the predicted temperature field approximates the measured values.

[0038] Deformation calibration: The actual deformation measured by the laser displacement sensor is compared with the displacement field {δ} predicted by the model. If the deviation continues to exceed the tolerance, the boundary conditions (such as the contact friction coefficient) in the mechanical model are corrected in reverse.

[0039] The specific usage process of the fixture provided by this invention is as follows: S100, System Preparation and Initialization: Workpiece and parameter input: The operator places the main workpiece (such as a square tube) on the main workpiece fixing module and installs the auxiliary workpiece (such as a foot) on the clamping unit 50 of the auxiliary workpiece fixing module; then, the operator inputs the key parameters of the current workpiece through the human-machine interface, including: length L, width W, height H, wall thickness t, and material type (such as Q235 steel). System self-check and model initialization: When the control module starts, it first performs a system self-check to confirm that the status of each sensor and actuator is normal. Then, according to the input workpiece parameters, the control module calls the corresponding material properties (thermal expansion coefficient α, elastic modulus E, etc.) from the internal material database and instantiates the preset simplified real-time thermo-mechanical coupling finite element model. This model automatically generates a mesh based on the workpiece geometry and sets the initial displacement, stress, and strain fields to zero. Calculating the initial clamping scheme: Based on the workpiece weight, geometric dimensions, and material properties, the control module calculates the optimal initial clamping parameters using an internal algorithm. Spacing between fixed parts: Based on the length L, the optimal distance between the two fixed parts is calculated using the empirical formula Spacing = L × 0.65, and this distance is sent as an instruction to the spacing adjustment unit 20; Initial clamping force: Based on the cross-sectional dimensions and wall thickness, calculate the basic clamping force (e.g., lateral clamping force F) that can prevent workpiece movement while avoiding crushing deformation. side = 150N, downward pressure at the top F top = 80N); Automatic positioning and clamping: After the calculation is completed, the control module drives the drive motor 201 in the spacing adjustment unit 20, so that the drive motor 201 drives the second bidirectional lead screw 202 to rotate, so that the two fixed parts can move synchronously to the calculated spacing; then, the drive motor 303 in each side clamping unit 30 and the first linear telescopic source 401 in the top pressing unit 40 are controlled to operate, so as to clamp the front and rear sides and the top of the main workpiece with the calculated initial force value. At the same time, the auxiliary workpiece to be welded is installed on the corresponding clamping seat 502. The second linear telescopic source 501 drives the clamping seat 502 to move closer to the main workpiece, so that the auxiliary workpiece and the main workpiece are in corresponding contact and the positioning of the main workpiece and the auxiliary workpiece is completed.

[0040] S200, Real-time adaptive control of the welding process: This stage begins after the welding arc is ignited and continues cyclically until the welding is completed. Simultaneously, the temperature sensor matrix 60 collects the temperature values ​​of multiple points on the main workpiece in real time, the laser displacement sensor 70 accurately measures the real-time deformation data of key points on the workpiece, the force sensor 80 collects the current clamping force data in real time, and the welding current I and voltage U data are obtained from the welding power source in real time. The control module filters and fuses these data to internally reconstruct the real-time temperature field and mechanical state field of the workpiece. The control module inputs the real-time welding torch position (from the robot controller) and welding parameters (I, U) as a moving heat source into the preset model. The model first performs transient heat conduction calculations to predict the temperature field changes on the workpiece within the next 1-2 seconds. Subsequently, based on the predicted temperature field, the model performs thermal stress field calculations, which comprehensively consider the thermal expansion effect of the material and the constraint reaction force of the current fixture, and outputs two key results: Deformation trend vector: predicts the direction and magnitude of the workpiece's displacement at future moments; Real-time stress state: including over-constraint risk index (obtained by analyzing the fluctuation of the resultant torque of each clamping force) and high-stress region (marking the region where the equivalent stress is close to the material yield strength). Based on the above calculation results, the control module performs intelligent decision-making and command generation. The core decision-making logic of the control module is a priority-based expert system, specifically including: Priority 1: Release over-constraint. If the calculated over-constraint risk index exceeds the threshold (e.g., 0.8), the system immediately generates an instruction to synchronously reduce the force of all lateral clamping units 30 (e.g., reduce it to 70% of the original force) in order to release the locked stress. Priority 2: Counteracting predicted deformation. This is the most frequent adjustment. For example, if the model predicts that the right end of the workpiece will warp upward by 0.5mm due to welding heat input, the control module will generate an instruction to increase the downward pressure of the right top pressing unit 40 by 10% to counteract the warping trend. Or, if it is predicted that the middle of the workpiece will bend to one side due to thermal expansion, an instruction will be generated to fine-tune the spacing adjustment unit 20, moving the corresponding side fixing part outward by 0.1mm to provide space for thermal expansion, thereby reducing stress at the source. Priority 3: Maintain stability. After all compensation adjustments, ensure that the clamping force is always maintained at the minimum value required to prevent workpiece movement. The generated control command set is immediately sent to the corresponding independent drive components (servo motors of the lateral clamping unit 30, the top pressing unit 40, and the spacing adjustment unit 20); these components execute fine-tuning actions precisely and synchronously; after the actions are completed, the state perception module immediately collects a new round of data and feeds it back to the control module; the control module compares the new measured data (especially deformation data) with the model's predicted values, and fine-tunes the model parameters (such as heat source efficiency) through the Kalman filter algorithm to achieve model self-calibration, thereby making more accurate predictions in subsequent cycles.

[0041] S300, Welding Completed and System Reset: After welding is completed, the control module controls all clamping units to execute a "stress release sequence". First, all clamping forces are slowly reduced to zero, allowing the workpiece to complete its final free contraction in an unconstrained state, avoiding secondary deformation caused by sudden release. Then, all clamps are retracted; while the spacing adjustment unit 20 drives the fixing part to return to the default width position, and the end clamping mechanism retracts, ready to welcome the next work cycle.

[0042] As described above, the metal product arc welding fixture provided by this invention, by setting up a main workpiece fixing module, a secondary workpiece fixing module, a state sensing module, and a control module, constitutes an intelligent clamping system capable of proactive sensing, intelligent decision-making, and dynamic adaptation. This changes the traditional passive and rigid fixing tool welding fixture. By constructing and running a simplified thermo-mechanical coupling finite element model in real time, it can accurately predict the workpiece deformation trend and stress state caused by the welding thermal process, and proactively adjust the force and position of each clamping mechanism accordingly. This continuously and stably maintains the posture of the main workstation during the welding process, significantly improving welding accuracy and consistency, fundamentally suppressing workpiece thermal deformation and residual stress, greatly reducing subsequent straightening processes and product scrap rates, and greatly enhancing adaptability to different workpiece sizes and welding processes. This achieves efficient and high-quality welding of small-batch, high-precision products, comprehensively improving production flexibility and economic benefits.

[0043] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. A fixture for arc welding of metal products, characterized in that, include: The frame, and the main workpiece fixing module, the auxiliary workpiece fixing module, the status sensing module and the control module mounted on the frame; The main workpiece fixing module includes a spacing adjustment unit and at least two fixing parts. Each fixing part consists of a lateral clamping unit and a top pressing unit. The lateral clamping unit, the top pressing unit, and the spacing adjustment unit are all independent driving components controlled by the control module. The spacing adjustment unit drives the fixing parts to move synchronously to adjust their spacing. The auxiliary workpiece fixing module includes at least one clamping unit for positioning and temporarily fixing the auxiliary workpiece at a preset welding position; The state sensing module is used to acquire the physical state parameters of the main workpiece in real time during the welding process; The control module is configured as follows: Based on physical state parameters, the deformation trend and stress state of the main workpiece are calculated in real time through a preset model, and control commands are dynamically generated accordingly. The control commands include at least the clamping force of the lateral clamping unit, the downward pressure of the top pressing unit, and the adjustment commands for the spacing of the spacing adjustment unit. Each independent drive component in the main workpiece fixing module is adaptively adjusted to counteract deformation and optimize stress state.

2. The clamp for arc welding of metal products according to claim 1, characterized in that, The lateral clamping unit includes a slide mounted on the frame, two clamping plates symmetrically sliding on the slide, and a drive unit for driving the two clamping plates to move synchronously towards each other.

3. A fixture for arc welding of metal products according to claim 2, characterized in that, The driving component includes a drive motor fixedly mounted on the slide and a first bidirectional lead screw connected to the output end of the drive motor. The sliding ends of the two clamps are respectively threaded to the two ends of the first bidirectional lead screw.

4. A fixture for arc welding of metal products according to claim 1, characterized in that, The top pressing unit includes a first linear telescopic source and a pressing body fixedly installed on the telescopic end of the first linear telescopic source.

5. A fixture for arc welding of metal products according to claim 2, characterized in that, The spacing adjustment unit includes a drive motor fixed on the frame and a second bidirectional lead screw rotatably mounted on the frame. The output end of the drive motor is connected to the second bidirectional lead screw via a pulley transmission component, and the two slide blocks are slidably connected to the two ends of the second bidirectional lead screw respectively.

6. A fixture for arc welding of metal products according to claim 1, characterized in that, The clamping unit includes a second linear telescopic source and a clamping seat slidably mounted on the frame. The clamping seat is connected to the telescopic end of the second linear telescopic source.

7. A fixture for arc welding of metal products according to claim 1, characterized in that, The number of clamping units is three, with two clamping units symmetrically distributed on both sides of the body and the other clamping unit located on one side of the body.

8. A fixture for arc welding of metal products according to claim 1, characterized in that, The state sensing module includes a temperature sensor matrix distributed on the rack, a laser displacement sensor located above the rack, and multiple force sensors distributed on the lateral clamping unit and the top pressing unit.

9. A fixture for arc welding of metal products according to claim 8, characterized in that, The temperature sensor matrix consists of multiple non-contact infrared temperature sensors, which are concentrated on both sides of the weld axis, in front of and behind the welding heat source, and near the clamping point of the main workpiece fixing module.

10. A fixture for arc welding of metal products according to claim 1, characterized in that, The preset model is a digital model that integrates a thermo-mechanical coupling algorithm, which includes a thermo-elastic-plastic stress sub-model and a structural response sub-model.

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