A spot welding device capable of automatically assembling a weld

Abstract

This invention discloses a spot welding device capable of automatically assembling weld seams, belonging to the field of welding technology. It includes a frame and two scaffolds, A and B, mounted on the frame. A spot welding mechanism, mounted on scaffold A, is used to perform spot welding on the workpieces to be welded. A conveying mechanism, mounted on the frame, is used to convey the workpieces to be welded to the area below the spot welding mechanism. A positioning mechanism, mounted on the frame, is used to position the workpieces to be welded in conjunction with the conveying mechanism. Two limiting mechanisms, both mounted on the frame, are used to press and limit the position of the workpieces to be welded. This invention achieves full automation of plate assembly spot welding, effectively improving seam accuracy, welding quality, and production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of welding technology, and in particular relates to a spot welding device capable of automatically assembling weld seams. Background Technology

[0002] The outer panels of a shipping container (top, side, front, and bottom panels) are generally welded together from two or more sheet metal panels. Before welding, these panels need to be assembled and spot-welded together. Currently, manually assembling and spot-welding these panels is labor-intensive, inefficient, and produces unreliable quality.

[0003] Although similar automated splicing products exist on the market (such as the spot welding device disclosed in Chinese Patent Publication No. CN219131203U), they suffer from problems such as low efficiency, overlapping seams, and inaccurate seam positioning. Their low efficiency fails to meet production capacity requirements, thus limiting their application.

[0004] To address this, the present invention provides an automatic assembly and spot welding device that solves the problems of poor splicing quality and low efficiency. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a spot welding device capable of automatically assembling weld seams, thus solving the aforementioned problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a spot welding device capable of automatically assembling weld seams, comprising a frame and scaffolds A and B mounted on the frame, and further comprising:

[0007] The spot welding mechanism, installed on gantry A, is used to perform spot welding on the workpieces to be welded.

[0008] The conveying mechanism, mounted on the frame, is used to transport the workpiece to be welded to the area below the spot welding mechanism;

[0009] The positioning mechanism, mounted on the frame, is used in conjunction with the conveying mechanism to position the workpiece to be welded.

[0010] The limiting mechanism consists of two sets, both mounted on the frame, used to press and limit the workpiece to be welded.

[0011] The conveying mechanism has two sets of four components symmetrically mounted on the frame, including a motor, a slide rail B, and a mounting base C. The motor is detachably mounted on the slide rail B, and its output shaft is fixedly connected to a lead screw rotatably mounted on the slide rail B. The mounting base C is slidably engaged with the slide rail B and threadedly connected to the lead screw. A linear motion component B is fixedly connected to the mounting base C, and a push column is fixedly connected to the output shaft of the linear motion component B. The push column is slidably engaged with the mounting base C. Two sets of laser measuring instruments are mounted on the frame. The motor is a servo motor, and the frame is equipped with guide rails to facilitate the sliding of the workpiece to be welded.

[0012] Based on the above technical solutions, the present invention also provides the following optional technical solutions:

[0013] Further technical solution: The limiting mechanism includes a crossbeam B, and a pressure arm assembly can be detachably installed at the lower end of both crossbeams B. Mounting seats D can be detachably installed at both ends of the crossbeams B. One set of mounting seats D is fixedly connected to the output shaft of the linear motion component D fixedly connected to the frame. The mounting seats D are slidably engaged with the guide column A. The other set of mounting seats D is slidably engaged with the guide column B detachably installed on the frame B.

[0014] Further technical solution: The pressure arm assembly includes a pressure beam plate, pressure arm A, pressure arm B, and pressure arm C. The pressure beam plate is detachably mounted on the crossbeam B. Pressure arms A, B, and C are all hinged to connecting blocks detachably mounted on the pressure beam plate via connecting shafts. Pressure arms B and C are correspondingly arranged on the crossbeam B and are located between two sets of pressure arms A symmetrically arranged on it. A protrusion triangular protrusion is fixedly connected to the free end of pressure arm B. A pressure arm groove for avoiding the triangular protrusion is opened on the free end of pressure arm C.

[0015] Further technical solution: The positioning mechanism includes a crossbar, a positioning column, a rack, a mounting plate, and a connecting rod bracket. The crossbar is detachably mounted on the frame. A slide rail C is symmetrically and detachably mounted on the crossbar. A sliding seat B is slidably mounted on the slide rail C. The positioning column is detachably mounted on the sliding seat B. A spur gear is rotatably mounted between the two mounting plates. The lower mounting plate is fixedly connected to a pad block fixedly connected to the crossbar. Guide wheels are symmetrically arranged on both sides of the spur gear. The guide wheels are rotatably connected to the two spur gears. The two ends of the connecting rod bracket are fixedly connected to the sliding seat B and the rack, respectively. The two racks are symmetrically arranged about the central axis of the spur gear and both mesh with the spur gear. A connecting plate is fixedly connected to one rack. The connecting plate is fixedly connected to the output shaft of the linear motion component C detachably mounted on the crossbar. The two guide wheels correspondingly abut against the two racks.

[0016] Further technical solution: The spot welding mechanism includes spot welding machines and a crossbeam A. Several spot welding machines are mounted on the crossbeam A via a load-bearing component. Mounting seats A are detachably mounted at both ends of the crossbeam A. The mounting seats A are slidably engaged with guide columns A fixedly mounted on the frame A. The crossbeam A is fixedly connected to the output shaft of a linear motion component A detachably mounted on the frame A.

[0017] Further technical solution: The bearing component includes a slide rail A, a sliding seat A, and a mounting seat B. Several slide rails A are uniformly and detachably mounted on the crossbeam A. Several sliding seats A are uniformly and detachably mounted on the slide rails A and are fixed to the slide rails A by bolt assemblies. The mounting seat B is fixedly connected to a pressure sensor fixedly connected to the sliding seat A. The spot welding machine is detachably mounted on the mounting seat B.

[0018] Further technical solutions include a pressure optimization system for dynamically adjusting the pressure on the workpiece to be welded, including:

[0019] The pressure demand analysis module obtains the pressure demand coefficient based on the thickness and flatness of the workpiece to be welded through a pressure demand model.

[0020] The material property analysis module obtains material property coefficients based on the surface smoothness (arithmetic mean roughness) and elastic modulus of the workpiece through a material property model.

[0021] The pressure distribution analysis module obtains the pressure distribution coefficient based on the number of pressure arms and the distance between them using a pressure distribution model.

[0022] The dynamic process analysis module obtains dynamic process coefficients based on the real-time displacement of the pressure arm (the actual displacement value of the pressure arm from the moment the pressure arm contacts the workpiece surface until the set pressure is reached) and the thermal deformation force increment (the difference between the peak (or valley) value of the pressure arm pressure sensor reading and the reference clamping force at the start of welding during welding).

[0023] The pressure optimization module obtains the target clamping force based on the dynamic process coefficient, pressure distribution coefficient, and reference clamping force through a pressure optimization model.

[0024] A further technical solution: The pressure optimization model is expressed as follows:

[0025]

[0026] in, Indicates the target clamping force. Indicates the reference clamping force. Represents the coefficients of the dynamic process. This represents the pressure distribution coefficient.

[0027] Further technical solution: The steps for obtaining the dynamic process coefficient based on the real-time displacement of the pressure arm (the actual displacement value of the pressure arm from the moment it contacts the workpiece surface until the set pressure is reached) and the thermal deformation force increment (the difference between the peak (or valley) value of the pressure arm pressure sensor reading and the reference clamping force at the start of welding) are as follows:

[0028] A dynamic expected displacement model is constructed using the basic displacement and pressure demand coefficient to output the dynamic expected displacement. The dynamic expected displacement model is expressed as follows:

[0029]

[0030] in, Indicates the expected dynamic displacement. Indicates the base displacement. This represents the displacement correction factor. Indicates the pressure demand coefficient;

[0031] The allowable thermal deformation force model is constructed by using the basic allowable thermal deformation force increment and material property coefficients to output the allowable thermal deformation force increment. The allowable thermal deformation force model is expressed as follows:

[0032]

[0033] in, This indicates the allowable increment of thermal deformation force. This indicates the allowable increase in thermal deformation force of the foundation. Indicates the correction factor for heat deformation force. Indicates the material property coefficient;

[0034] The dynamic process model is constructed by taking the real-time displacement of the pressure arm, the increment of thermal deformation force, the expected dynamic displacement, and the allowable increment of thermal deformation force, and outputting the dynamic process coefficients. The dynamic process model is expressed as follows:

[0035]

[0036] in, Represents the coefficients of the dynamic process. This indicates the real-time displacement of the pressure arm. Indicates the increment of thermal deformation force. Indicates the expected dynamic displacement. This indicates the allowable increment of thermal deformation force. Represents the weight coefficient and The ,when The process status matches expectations, requiring no dynamic adjustment of the clamping force. If the pressure is insufficient during the process, the clamping force needs to be increased positively. If the pressure is too high or there is an abnormality (thermal expansion causing jacking), it is necessary to reduce the pressure in the opposite direction.

[0037] Further technical solution: Based on the number of pressure arms and the distance between them, the steps to obtain the pressure distribution coefficient through a pressure distribution model are as follows:

[0038] The pressure arm quantity index is obtained by processing the ratio of the number of pressure arms to the maximum allowable number of pressure arms;

[0039] The absolute difference between the pressure arm spacing and the optimal spacing is then compared with the optimal spacing to obtain the spacing deviation index.

[0040] A pressure distribution model is constructed based on the number of pressure arms and the spacing deviation index, and the pressure distribution coefficient is output. The pressure distribution model is expressed as follows:

[0041]

[0042] in, Indicates the pressure distribution coefficient. Indicates the number of pressure arms index. This indicates that the spacing deviates from the index. Represents the attenuation coefficient, the Furthermore, the larger the value, the higher the pressure distribution efficiency.

[0043] Further technical solution: Based on the surface smoothness (arithmetic mean roughness) and elastic modulus of the workpiece, the steps for obtaining material property coefficients through a material property model are as follows:

[0044] The surface smoothness and elastic modulus are compared with the corresponding maximum allowable values ​​of the system to obtain the roughness index and elastic modulus index.

[0045] A material property model is constructed based on the roughness index and the elastic modulus index, and the material property coefficients are output. The material property model is expressed as follows:

[0046]

[0047] in, Represents the material property coefficient. Represents the roughness index. Indicates the elastic modulus index. Represents the weight coefficient and The The larger the value, the greater the required base clamping force.

[0048] Further technical solution: Based on the thickness and flatness of the workpiece to be welded, the steps to obtain the pressure demand coefficient through the pressure demand model are as follows:

[0049] The thickness and flatness are respectively compared with the corresponding maximum allowable values ​​of the system to obtain the thickness index and flatness index;

[0050] A pressure demand model is constructed based on the thickness index and the flatness index to output the pressure demand coefficient. The pressure demand model is expressed as follows:

[0051]

[0052] in, This represents the pressure demand coefficient. Indicates the thickness index. This indicates the smoothness index. Represents the weight coefficient and The The larger the value, the greater the required base clamping force.

[0053] This invention provides a spot welding device capable of automatically assembling weld seams, which has the following advantages compared with the prior art:

[0054] 1. This invention achieves full automation of the entire process from material loading and assembly to spot welding of the workpieces to be welded through the coordinated operation of conveying, positioning and limiting mechanisms, which significantly reduces labor intensity, improves production efficiency and can meet the requirements of large-scale production capacity.

[0055] 2. This invention utilizes the controllable displacement output of a servo motor combined with two sets of laser measuring devices to determine the initial value, thereby achieving precise distance pushing. By setting two sets of conveying mechanisms (each set consisting of two servo motors and a pushing mechanism), one mechanism pushes the welded plate to the limiting mechanism while the other pushes the plate to be welded, significantly improving efficiency compared to a single mechanism pushing back and forth.

[0056] 3. This invention utilizes a triangular protrusion fixedly connected to the free end of pressure arm B. Through an appropriate tilt angle design, the plates to be spliced, under the combined action of the thrust and the tilt angle of the triangular protrusion, ensure that the plates to be spliced ​​and the plates already pressed by pressure arm B are joined at the edges without overlapping. Furthermore, due to the thrust, there will be no gaps in the splicing. Combined with a centering and positioning function, misalignment during splicing is avoided, thus guaranteeing the quality of the seam.

[0057] 4. This invention uses several spot welding machines mounted on a crossbeam via a load-bearing component. Guide columns enable simultaneous down-welding / spot welding / lifting, further improving efficiency. In conjunction with a pressure sensor, it enhances welding quality and protects the welding torch.

[0058] 5. This invention can dynamically adjust the clamping force according to the characteristics of the workpiece, working conditions and real-time process, which solves the contradiction that excessive pressure hinders feeding or insufficient pressure affects flattening. It is suitable for workpieces of different materials, thicknesses and flatness, and ensures the best consistency of clamping effect.

[0059] 6. Based on real-time feedback from pressure and displacement sensors and compensation from a dynamic process model, the system can respond promptly to interferences such as welding thermal deformation, maintain the stability of the clamping force during the welding process, and thus obtain uniform and reliable weld quality. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the three-dimensional structure in this invention.

[0061] Figure 2 For the present invention Figure 1 Enlarged schematic diagram of part A in the diagram.

[0062] Figure 3 For the present invention Figure 1 Enlarged schematic diagram of section B in the diagram.

[0063] Figure 4 This is a schematic diagram of the structure of the carrier component in this invention.

[0064] Figure 5 This is a schematic diagram of the positioning mechanism in this invention.

[0065] Figure 6 This is a partial structural diagram of the limiting mechanism in this invention.

[0066] Figure 7 This is a schematic diagram of the pressure arm assembly of the present invention.

[0067] Figure 8 This is a schematic diagram of the working structure of the pressure arm assembly of the present invention.

[0068] Figure 9 This is a schematic diagram of the working principle of the pressure arm B in the conveying mechanism of the present invention.

[0069] Figure reference numerals: 1. Frame; 2. Axle A; 3. Axle B; 4. Spot welding mechanism; 401. Spot welding machine; 402. Crossbeam A; 403. Mounting base A; 404. Guide column A; 405. Linear motion component A; 406. Load-bearing assembly; 4061. Slide rail A; 4062. Sliding seat A; 4063. Mounting base B; 5. Conveying mechanism; 501. Motor; 502. Slide rail B; 503. Mounting base C; 504. Linear motion component B; 505. Push column; 506. Laser measuring instrument; 6. Positioning mechanism; 601. Crossbar; 602. Positioning column 603. Sliding seat B; 604. Slide rail C; 605. Linear motion component C; 606. Rack; 607. Connecting plate; 608. Linkage bracket; 609. Flat gear; 610. Mounting plate; 611. Pad; 7. Limiting mechanism; 701. Linear motion component D; 702. Mounting seat D; 703. Crossbeam B; 704. Pressure arm assembly; 7041. Pressure beam plate; 7042. Connecting block; 7043. Pressure arm A; 7044. Pressure arm B; 70441. Triangular protrusion; 7045. Pressure arm C; 70451. Pressure arm groove; 7046. Connecting shaft. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0071] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0072] Please see Figures 1 to 8 According to one embodiment of the present invention, a spot welding device capable of automatically assembling weld seams includes a frame 1 and scaffolds A2 and B3 mounted on the frame 1, and further includes:

[0073] Spot welding mechanism 4 is installed on frame A2 and is used to spot weld the workpieces to be welded.

[0074] The conveying mechanism 5 is installed on the frame 1 and is used to convey the workpiece to be welded to the area below the spot welding mechanism 4.

[0075] Positioning mechanism 6 is installed on frame 1 and is used in conjunction with conveying mechanism 5 to position the workpiece to be welded.

[0076] The limiting mechanism 7 has two sets, both of which are installed on the frame 1, and is used to press and limit the workpiece to be welded.

[0077] Please see Figure 1 , Figure 2 as well as Figure 4Preferably, the spot welding mechanism 4 includes spot welding machines 401 and a crossbeam A402. Several spot welding machines 401 are mounted on the crossbeam A402 via a bearing assembly 406. Mounting seats A403 are detachably mounted at both ends of the crossbeam A402. The mounting seats A403 are slidably engaged with guide columns A404 fixedly mounted on the frame A2. The crossbeam A402 is fixedly connected to the output shaft of a linear motion component A405 detachably mounted on the frame A2. The purpose of this arrangement is to use the linear motion component A405 to push the crossbeam A402 to drive the spot welding machines 401 mounted on the crossbeam A402 via the bearing assembly 406 to perform linear motion in the vertical direction, thereby causing the spot welding machines 401 to contact the workpiece to be welded and perform spot welding on the workpiece.

[0078] Preferably, the bearing assembly 406 includes a slide rail A4061, a sliding seat A4062, and a mounting base B4063. Several slide rails A4061 are uniformly and detachably mounted on the crossbeam A402, and several sliding seats A4062 are uniformly and detachably mounted on the slide rails A4061 and fixed to the slide rails A4061 by bolt assemblies. The mounting base B4063 is fixedly connected to a pressure sensor fixedly connected to the sliding seat A4062. The spot welding machine 401 is detachably mounted on the mounting base B4063. The purpose of this arrangement is to install and place the spot welding machine 401, and at the same time use the pressure sensor to detect the contact pressure between the spot welding machine 401 and the workpiece to be welded.

[0079] Please see Figure 1 as well as Figure 3The conveying mechanism 5 has two sets symmetrically mounted on the frame 1, including a motor 501, a slide rail B502, and a mounting base C503. The motor 501 is detachably mounted on the slide rail B502, and its output shaft is fixedly connected to a lead screw (not shown in the figure) rotatably mounted on the slide rail B502. The mounting base C503 is slidably engaged with the slide rail B502 and threadedly connected to the lead screw. A linear motion component B504 is fixedly connected to the mounting base C503, and a push column 505 is fixedly connected to the output shaft of the linear motion component B504. The push column 505 is slidably engaged with the mounting base C503. Two sets of laser measuring instruments 506 for measuring the moving distance of the workpiece to be welded are mounted on the frame 1. The motor 501 is a servo motor. A guide rail (not shown in the figure) is mounted on the frame 1 to facilitate the sliding of the workpiece to be welded. The purpose of this arrangement is to first start the workpiece located at... A set of linear motion components B504 on the inner or outer side causes the push column 505 to extend. At this time, the motor 501 drives the mounting base C503 through the lead screw to drive the push column 505 to move horizontally linearly along the length of the slide rail B502. At this time, the two push columns 505 push one workpiece to be welded to the welding area A away from the motor 501. Then, another set of conveying mechanisms 5 is activated to move another workpiece to the welding area B close to the motor 501. At this time, the two workpieces to be welded are located on both sides of the center line of the spot welding head of the spot welding machine 401, and the distance and parallelism between them can be measured by an infrared distance sensor. Since the conveying mechanism 5 is driven by two sets of four motors, it can accurately adjust the position of the workpiece to be welded in the horizontal position to prevent the workpiece from tilting. The moving distance of the workpiece is measured by two sets of laser measuring instruments 506.

[0080] Please see Figure 1 , Figure 2 , Figure 6 , Figure 7 as well as Figure 8 Preferably, the limiting mechanism 7 includes a crossbeam B703, and a pressure arm assembly 704 is detachably mounted on the lower end of each of the two crossbeams B703. Mounting seats D702 are detachably mounted on both ends of the crossbeams B703. One set of mounting seats D702 is fixedly connected to the output shaft of the linear motion component D701 fixedly connected to the frame 1. The mounting seats D702 are slidably engaged with the guide column A404. The other set of mounting seats D702 is slidably engaged with the guide column B (not shown in the figure) detachably mounted on the frame B3. The purpose of this arrangement is to use the linear motion component D701 to push the crossbeams B703 to drive the pressure arm assembly 704 to press and limit the workpiece to be welded.

[0081] The pressure arm assembly 704 includes a pressure beam plate 7041, pressure arms A 7043, B 7044, and C 7045. The pressure beam plate 7041 is detachably mounted on the crossbeam B 703. Pressure arms A 7043, B 7044, and C 7045 are all hinged to a connecting block 7042 detachably mounted on the pressure beam plate 7041 via a connecting shaft 7046. Pressure arms B 7044 and C 7045 are correspondingly arranged on the crossbeam B 703 and are located between two sets of pressure arms A 7043 symmetrically arranged on 703. A triangular protrusion 70441 is fixedly connected to the free end of pressure arm B 7044. A pressure arm groove 70451 for avoiding the triangular protrusion 70441 is provided on the free end of pressure arm C 7045. The purpose of this arrangement is to ensure that when the conveying mechanism... 5. When the workpiece to be welded is pushed to the welding area A, the linear motion component D701 pushes the pressure beam plate 7041, which is equipped with the pressure arm B7044, to move linearly in the vertical direction, pressing against the workpiece to be welded in the welding area A. At this time, the conveying mechanism 5 is started to transport another workpiece to the welding area B. During this period, the other workpiece first abuts against the triangular protrusion 70441, and under the guidance of the triangular protrusion 70441, its end abuts against the end of the workpiece to be welded in the welding area A. The triangular protrusion 70441 can guide the workpiece to be welded into the welding area B and prevent the two workpieces from overlapping. At this time, another set of linear motion components D701 is started to push the corresponding crossbeam B703 to move linearly, pressing and limiting the workpiece to be welded in the welding area B, thereby completing the assembly of the two workpieces.

[0082] Preferably, the pressure arms A7043, B7044 and C7045 are all made of mold steel and their pressing ends are provided with buffer rubber pads.

[0083] Preferably, pressure sensors and displacement sensors are integrated on the pressure arms A7043, B7044 and C7045.

[0084] Please see Figure 1 as well as Figure 5Preferably, the positioning mechanism 6 includes a crossbar 601, a positioning post 602, a rack 606, a mounting plate 610, and a connecting rod bracket 608. The crossbar 601 is detachably mounted on the frame 1. A slide rail C604 is symmetrically and detachably mounted on the crossbar 601. A sliding seat B603 is slidably disposed on the slide rail C604. The positioning post 602 is detachably mounted on the sliding seat B603. A spur gear 609 is rotatably mounted between the two mounting plates 610. The lower mounting plate 610 is fixedly connected to a pad 611 fixedly connected to the crossbar 601. Guide wheels (not shown in the figure) are symmetrically arranged on both sides of the spur gear 609. The guide wheels are rotatably connected to the two spur gears 609. The two ends of the connecting rod bracket 608 are fixedly connected to the sliding seat B603 and the rack 606, respectively. The centers of the two racks 606 about the central axis of the spur gear 609 are aligned. The racks 606 are symmetrically arranged and mesh with the spur gear 609. A connecting plate 607 is fixedly connected to one of the racks 606. The connecting plate 607 is fixedly connected to the output shaft of the linear motion component C605, which is detachably mounted on the crossbar 601. The two guide wheels abut against the two racks 606. The purpose of this arrangement is to use the linear motion component C605 to push the connecting plate 607 to perform linear motion. At this time, the connecting plate 607 pushes the racks 606 to drive the sliding seat B603 to perform synchronous motion. The positioning pins 602 follow the sliding seat B603 to perform linear motion. Since the two racks 606 are symmetrically arranged and mesh with the spur gear 609, the two racks 606 can perform linear motion in opposite directions. That is, it causes the two positioning pins 602 to perform linear motion in opposite directions, thereby realizing the center positioning of the workpiece by using the two positioning pins 602 to move in opposite directions.

[0085] Specific work process:

[0086] First, a set of linear motion components B504 located on the inner or outer side is activated. The linear motion components B504 cause the push column 505 to extend. At this time, the motor 501 pushes the mounting base C503 through the lead screw, which drives the push column 505 to move linearly in the horizontal direction along the length of the slide rail B502. At this time, the two push columns 505 push one workpiece to be welded to the welding area A away from the motor 501. Then, another set of conveying mechanisms 5 is activated to cause another workpiece to be welded to move to the welding area B close to the motor 501. At this time, the two workpieces to be welded are located on both sides of the center line of the spot welding head of the spot welding machine 401, and the distance and parallelism between them can be measured by an infrared distance sensor. Since the conveying mechanism 5 is driven by two sets of four motors, it can accurately adjust the position of the workpiece to be welded in the horizontal position to prevent the workpiece to be welded from tilting. The moving distance of the workpiece to be welded is measured by two sets of laser measuring instruments 506.

[0087] Secondly, the linear motion component C605 is used to drive the connecting plate 607 to perform linear motion. At this time, the connecting plate 607 drives the rack 606 to drive the sliding seat B603 to perform synchronous motion. The positioning column 602 follows the sliding seat B603 to perform linear motion. Since the two racks 606 are centrally symmetrically arranged and both mesh with the spur gear 609, the two racks 606 can perform linear motion in opposite directions, which causes the two positioning columns 602 to perform linear motion in opposite directions. Thus, the two positioning columns 602 are used to perform opposing motion to center the workpiece to be welded.

[0088] Next, when the conveying mechanism 5 pushes the workpiece to be welded to the welding area A, the linear motion component D701 pushes the pressure beam plate 7041, which is equipped with the pressure arm B7044, to move linearly in the vertical direction, pressing against the workpiece to be welded in the welding area A. At this time, the conveying mechanism 5 is started to transport another workpiece to the welding area B. During this period, the other workpiece first abuts against the triangular protrusion 70441, and under the guidance of the triangular protrusion 70441, its end abuts against the end of the workpiece to be welded in the welding area A. The triangular protrusion 70441 can guide the workpiece to be welded into the welding area B, preventing the two workpieces from overlapping. At this time, another set of linear motion components D701 is started to push the corresponding crossbeam B703 to move linearly, pressing and limiting the workpiece to be welded in the welding area B, thereby completing the assembly of the two workpieces to be welded.

[0089] Finally, the linear motion component A405 pushes the crossbeam A402 to drive the spot welding machine 401, which is mounted on the crossbeam A402 via the bearing component 406, to make linear motion in the vertical direction, thereby causing the spot welding machine 401 to come into contact with the workpiece to be welded and perform spot welding on the workpiece.

[0090] Repeat the above steps until the preset number of welding plates are welded into a whole, and use a conveyor to transport it to the next process on the production line, and then start welding the next plate again.

[0091] As one embodiment of the present invention, it further includes a pressure optimization system for dynamically adjusting the pressure of the workpiece to be welded, including:

[0092] The pressure demand analysis module obtains the pressure demand coefficient based on the thickness and flatness of the workpiece to be welded through a pressure demand model.

[0093] The material property analysis module obtains material property coefficients based on the surface smoothness (arithmetic mean roughness) and elastic modulus of the workpiece through a material property model.

[0094] The pressure distribution analysis module obtains the pressure distribution coefficient based on the number of pressure arms and the distance between them using a pressure distribution model.

[0095] The dynamic process analysis module obtains dynamic process coefficients based on the real-time displacement of the pressure arm (the actual displacement value of the pressure arm from the moment the pressure arm contacts the workpiece surface until the set pressure is reached) and the thermal deformation force increment (the difference between the peak (or valley) value of the pressure arm pressure sensor reading and the reference clamping force at the start of welding during welding).

[0096] The pressure optimization module obtains the target clamping force based on the dynamic process coefficient, pressure distribution coefficient, and reference clamping force through a pressure optimization model.

[0097] Through the above technical solutions, this application solves the problem of unstable welding quality caused by fixed or inaccurate pressure adjustment in traditional spot welding devices. Specifically, it achieves this by: adapting to differences in workpiece thickness and flatness through dynamic pressure adjustment to avoid insufficient or overload pressure; matching different surface roughness and elastic modulus through material property analysis to prevent material deformation or slippage; improving the synergistic efficiency of the multi-arm system through pressure distribution optimization; and ensuring the stability of the welding process by timely compensating for pressure fluctuations through real-time monitoring of thermal deformation force increments.

[0098] Preferably, the step of obtaining the pressure demand coefficient based on the thickness and flatness of the workpiece using a pressure demand model is as follows:

[0099] The thickness and flatness are respectively compared with the corresponding maximum allowable values ​​of the system to obtain the thickness index and flatness index;

[0100] A pressure demand model is constructed based on the thickness index and the flatness index to output the pressure demand coefficient. The pressure demand model is expressed as follows:

[0101]

[0102] in, This represents the pressure demand coefficient. Indicates the thickness index. This indicates the smoothness index. Represents the weight coefficient and The The larger the value, the greater the required base clamping force.

[0103] The thickness index is the ratio of the thickness of the workpiece to be welded to the system's preset maximum allowable thickness. This is achieved by dividing the actual thickness measured by a thickness sensor by the system's stored maximum allowable thickness, quantifying the impact of material thickness on clamping force. The flatness index is the ratio of the surface deformation of the workpiece to the system's preset maximum allowable deformation. This is achieved by measuring the surface contour using laser scanning or a contact displacement sensor, calculating the deformation, and then dividing it by the system's stored maximum allowable deformation, reflecting the compensation requirement of sheet flatness for clamping force. The weighting coefficient is a pre-set parameter used to adjust the influence of thickness and flatness on pressure requirements, ensuring a reasonable allocation of influencing factors in different scenarios where thickness or flatness is dominant. The pressure requirement model is a mathematical relationship that generates a pressure requirement coefficient through a linear combination of the thickness and flatness indices. This can be achieved by using an embedded controller to perform a weighted summation operation and limit the output range, enabling unified quantification of clamping force requirements under different material properties.

[0104] Specifically, the thickness of the workpiece to be welded is measured in real time using a thickness sensor and compared with the maximum allowable thickness stored in the system to generate a thickness index ranging from 0 to 1. Simultaneously, the surface contour of the workpiece is scanned by a displacement sensor, and its maximum deformation is calculated and compared with the maximum allowable deformation of the system to generate a flatness index ranging from 0 to 1. The thickness index and flatness index are multiplied by their respective weighting coefficients and then linearly superimposed. The superposition result is limited to within 1 by a min function, ultimately outputting a pressure demand coefficient. When the thickness of the workpiece is close to the maximum allowable value, the thickness index approaches 1. At this point, if the flatness is good, the pressure demand coefficient will primarily reflect the thickness's requirement for clamping force. When the workpiece exhibits significant deformation, the flatness index increases, and the pressure demand coefficient will automatically increase to compensate for the clamping force loss caused by surface unevenness. The normalization constraint of the weighting coefficients ensures that the combined influence of thickness and flatness remains within a controllable range, avoiding the risk of overpressure or underpressure caused by abnormalities in a single parameter.

[0105] Compared to existing technologies, traditional methods rely on manual experience to adjust the clamping force, failing to quantify the combined effects of thickness and flatness in real time, leading to clamping force mismatch during welding. This solution establishes a mathematical model to transform the physical parameters of thickness and flatness into calculable exponents, and combines this with a weighting mechanism to achieve adaptive adjustment of the clamping force.

[0106] Through the above technical solution, this application solves the problem of insufficient clamping force adaptation caused by differences in the thickness and flatness of the workpieces to be welded. By converting thickness and flatness parameters into standardized indices and combining them with a weighting mechanism, the system can automatically identify the changes in clamping force requirements due to differences in material properties. When processing thicker or uneven workpieces, the system automatically increases the reference clamping force to effectively suppress workpiece displacement during welding; when processing thinner or flat workpieces, the system reduces the clamping force to avoid excessive deformation. This solution eliminates the subjective error of manual adjustment, ensures the positioning accuracy of the joints of different specifications of plates, and avoids welding quality defects caused by improper clamping force.

[0107] Preferably, the step of obtaining material property coefficients through a material property model based on the surface smoothness (arithmetic mean roughness) and elastic modulus of the workpiece to be welded is as follows:

[0108] The surface smoothness and elastic modulus are compared with the corresponding maximum allowable values ​​of the system to obtain the roughness index and elastic modulus index.

[0109] A material property model is constructed based on the roughness index and the elastic modulus index, and the material property coefficients are output. The material property model is expressed as follows:

[0110]

[0111] in, Represents the material property coefficient. Represents the roughness index. Indicates the elastic modulus index. Represents the weight coefficient and The The larger the value, the greater the required base clamping force.

[0112] Among them, surface smoothness refers to the flatness of the micro-geometry of the surface of the workpiece to be welded, characterized by the arithmetic mean roughness. This can be achieved using a contact or non-contact roughness measuring instrument, used to quantify the influence of surface friction resistance on the clamping force. Elastic modulus refers to the ratio of stress to strain in a material during elastic deformation, specifically achieved through tensile testing or a dynamic mechanical analyzer, used to reflect the material's ability to resist elastic deformation. Ratio processing involves normalizing the measured values ​​of surface smoothness and elastic modulus with the system's preset maximum allowable values, specifically using linear proportional conversion, to eliminate interference from different dimensional parameters in the model calculation. The material property model refers to a mathematical relationship between the roughness exponent and the elastic modulus exponent through a weighted summation, limiting the output range. This can be achieved using a linear combination and threshold truncation algorithm, used to comprehensively evaluate the material properties' demand intensity on the reference clamping force.

[0113] Specifically, surface smoothness and elastic modulus are converted into dimensionless roughness index and elastic modulus index, respectively. The roughness index reflects the additional demand on clamping force due to surface friction, while the elastic modulus index reflects the basic demand on clamping force due to material rigidity. By adjusting the weighting coefficients, the influence weights of these two factors can be assigned to different welding scenarios. For example, when welding highly elastic materials, the weight of the elastic modulus index is set to a higher value to prioritize meeting the material's resistance to deformation. The coefficients output by the material property model are restricted to the [0,1] range. When the measured value exceeds the system's maximum allowable value, the coefficient is forcibly truncated to 1 to prevent uncontrolled clamping force due to abnormal material parameters.

[0114] Compared to existing technologies, which typically employ fixed clamping forces or adjust clamping forces solely based on thickness, neglecting the coupling effect of material surface roughness and elastic modulus, this approach can easily lead to insufficient clamping force on smooth surfaces or redundant clamping force on highly elastic materials. This solution establishes a quantitative relationship between material properties and clamping force, achieving dynamic adaptation of the clamping force and resolving the problem of clamping force mismatch caused by differences in material properties.

[0115] Through the above technical solution, this application can automatically adjust the reference clamping force according to the surface condition and material rigidity of the workpiece to be welded, avoiding insufficient friction caused by an overly smooth surface or insufficient deformation resistance caused by excessive material elasticity, thereby ensuring that the clamping force is precisely matched with the material properties and improving the forming quality and consistency of the welded joint.

[0116] Preferably, the step of obtaining the pressure distribution coefficient through the pressure distribution model based on the number of pressure arms and the distance between the pressure arms is as follows:

[0117] The pressure arm quantity index is obtained by processing the ratio of the number of pressure arms to the maximum allowable number of pressure arms;

[0118] The absolute difference between the pressure arm spacing and the optimal spacing is then compared with the optimal spacing to obtain the spacing deviation index.

[0119] A pressure distribution model is constructed based on the number of pressure arms and the spacing deviation index, and the pressure distribution coefficient is output. The pressure distribution model is expressed as follows:

[0120]

[0121] in, Indicates the pressure distribution coefficient. Indicates the number of pressure arms index. This indicates that the spacing deviates from the index. Represents the attenuation coefficient, the Furthermore, the larger the value, the higher the pressure distribution efficiency.

[0122] The pressure arm quantity index is the ratio of the current number of pressure arms to the maximum allowable number of pressure arms in the system. This is achieved by dividing the current number of pressure arms by the preset maximum number in real-time, reflecting whether the pressure arm configuration meets the welding area coverage requirements. The spacing deviation index is the ratio of the absolute difference between the actual pressure arm spacing and the optimal spacing to the optimal spacing itself. This is achieved by obtaining actual spacing data from a laser rangefinder and calculating and normalizing the difference with the preset optimal spacing, quantifying the degree to which the pressure arm layout deviates from the ideal state. The attenuation coefficient is a weighted parameter used to adjust the impact of spacing deviation on pressure distribution efficiency. It is obtained as a fixed value through preset empirical values, experimental calibration, or historical data fitting, controlling the negative attenuation magnitude of the spacing deviation index.

[0123] Specifically, the pressure arm quantity index reflects the redundancy of pressure arms through ratio calculation. When the number of pressure arms is close to the maximum allowable value of the system, the index approaches 1, indicating that there are sufficient pressure arm resources, providing more adjustment space for pressure distribution. The spacing deviation index measures the rationality of the pressure arm distribution through normalized difference calculation. When the difference between the actual spacing and the optimal spacing increases, the index rises, leading to a more severe decay of the pressure distribution coefficient. The pressure distribution model uses the pressure arm quantity index as the base of the exponential function and the spacing deviation index as the negative power term of the exponential function, achieving nonlinear coupling between the two through exponential calculation. When the number of pressure arms is sufficient and the spacing distribution is reasonable, the model output coefficient approaches 1, and the system maintains an efficient pressure distribution state; when the number of pressure arms is insufficient or the spacing distribution is deviated, the model output coefficient decays towards 0, and the system automatically reduces the expected pressure distribution efficiency to prevent welding deformation caused by local pressure overload or underload.

[0124] Compared to existing technologies, traditional pressure distribution methods rely on manual experience to adjust the layout of the pressure arms, lacking quantitative analysis of the coupling effect between the number and spacing of pressure arms, which easily leads to uneven pressure distribution and weld misalignment. This solution establishes a mathematical relationship model, transforming the parameters of the number and spacing of pressure arms into a calculable exponential form, and uses an exponential function to dynamically adjust the pressure distribution efficiency, achieving autonomous optimization of pressure distribution during the welding process.

[0125] Through the above technical solution, this application can automatically adjust the pressure distribution strategy according to the real-time layout characteristics of the number and spacing of the pressure arms, eliminate local pressure imbalance caused by insufficient or unreasonable pressure arm configuration, ensure that the plate joint position remains stable during the welding process, improve the weld formation quality and positioning accuracy, and avoid efficiency loss and operation error caused by manual intervention.

[0126] Preferably, the steps for obtaining the dynamic process coefficient based on the real-time displacement of the pressure arm (the actual displacement value of the pressure arm from the moment it contacts the workpiece surface until the set pressure is reached) and the thermal deformation force increment (the difference between the peak (or valley) value of the pressure arm pressure sensor reading and the reference clamping force at the start of welding) are as follows:

[0127] A dynamic expected displacement model is constructed using the basic displacement and pressure demand coefficient to output the dynamic expected displacement. The dynamic expected displacement model is expressed as follows:

[0128]

[0129] in, Indicates the expected dynamic displacement. Indicates the base displacement. This represents the displacement correction factor. Indicates the pressure demand coefficient;

[0130] The allowable thermal deformation force model is constructed by using the basic allowable thermal deformation force increment and material property coefficients to output the allowable thermal deformation force increment. The allowable thermal deformation force model is expressed as follows:

[0131]

[0132] in, This indicates the allowable increment of thermal deformation force. This indicates the allowable increase in thermal deformation force of the foundation. Indicates the correction factor for heat deformation force. Indicates the material property coefficient;

[0133] The dynamic process model is constructed by taking the real-time displacement of the pressure arm, the increment of thermal deformation force, the expected dynamic displacement, and the allowable increment of thermal deformation force, and outputting the dynamic process coefficients. The dynamic process model is expressed as follows:

[0134]

[0135] in, Represents the coefficients of the dynamic process. This indicates the real-time displacement of the pressure arm. Indicates the increment of thermal deformation force. Indicates the expected dynamic displacement. This indicates the allowable increment of thermal deformation force. Represents the weight coefficient and The ,when The process status matches expectations, requiring no dynamic adjustment of the clamping force. If the pressure is insufficient during the process, the clamping force needs to be increased positively. If the pressure is too high or there is an abnormality (thermal expansion causing jacking), it is necessary to reduce the pressure in the opposite direction.

[0136] The real-time displacement of the pressure arm refers to the actual displacement value of the pressure arm from the moment it contacts the workpiece surface until the set pressure is reached. This can be measured using a displacement sensor and reflects the deviation between the actual movement trajectory and the expected state of the pressure arm. The thermal deformation force increment refers to the difference between the peak or trough value of the pressure arm pressure sensor reading during welding and the reference clamping force at the start of welding. This can be calculated in real-time using a pressure sensor and is used to quantify the dynamic impact of welding heat on the clamping force. The dynamic expected displacement refers to the displacement reference value adjusted based on the basic displacement and pressure demand coefficient. This can be calculated by combining preset basic displacement parameters with the output results of the pressure demand model and is used to adapt to the displacement requirements of workpieces with different thicknesses and flatnesses. The allowable thermal deformation force increment refers to the threshold value for thermal deformation force variation adjusted according to material properties. This can be calculated by combining the coefficients output by the material property model with preset basic values ​​and is used to prevent pressure runaway due to material thermal expansion.

[0137] Specifically, the dynamic expected displacement model introduces a pressure demand coefficient, transforming the workpiece's thickness and flatness parameters into displacement correction factors, allowing different workpiece specifications to correspond to different displacement reference values. The permissible thermal deformation force model combines material roughness and elastic modulus parameters to dynamically adjust the permissible range of thermal deformation force variation, avoiding excessive thermal deformation due to differences in material properties. The dynamic process model collects displacement deviation and thermal deformation force increments in real time, normalizing their influence to the [-1,1] interval using weighting coefficients. When the displacement deviation exceeds the dynamic expectation or the thermal deformation force exceeds the permissible range, it automatically generates positive or negative adjustment signals, triggering a clamping force compensation mechanism.

[0138] Compared to existing technologies, traditional methods only perform clamping operations based on preset pressure values, failing to detect pressure fluctuations caused by material thermal expansion or assembly errors during welding. This solution establishes a multi-parameter coupled mathematical model, transforming displacement deviation and thermal deformation force increments into quantifiable adjustment coefficients, thus achieving closed-loop control of the clamping force.

[0139] Through the above technical solution, this application can detect the dynamic changes of the pressure arm displacement and thermal deformation force in real time, and automatically correct the clamping force reference value according to the material properties and workpiece parameters. When the material is pushed up by thermal expansion or the pressure arm displacement is insufficient during the welding process, the system triggers clamping force compensation through a dynamic process coefficient to eliminate pressure mismatch caused by thermal deformation or assembly errors, ensuring that the clamping force is always within a reasonable range during the welding process, thereby improving the weld assembly accuracy and welding quality stability.

[0140] Preferably, the pressure optimization model is expressed as:

[0141]

[0142] in, Indicates the target clamping force. Indicates the reference clamping force. Represents the coefficients of the dynamic process. This represents the pressure distribution coefficient.

[0143] The target clamping force refers to the final clamping force dynamically adjusted based on real-time operating conditions. This can be achieved through collaborative calculations using pressure sensors and a controller, and is used to address material deformation or joint misalignment caused by insufficient or excessive pressure during welding. The reference clamping force is the initial clamping force preset based on material properties and welding requirements. This can be determined through experimental data or experience and serves as a benchmark for pressure adjustment. The dynamic process coefficient reflects the impact of clamping arm displacement deviation and thermal deformation force increment on pressure demand during welding, and is used to dynamically correct the reference clamping force. The pressure distribution coefficient adjusts the pressure distribution efficiency based on the number and spacing of clamping arms, and is used to optimize pressure distribution under the coordinated action of multiple clamping arms.

[0144] Specifically, the pressure optimization model generates the target clamping force by multiplying the baseline clamping force, the dynamic process coefficient, and the pressure distribution coefficient. The baseline clamping force serves as the initial pressure reference. The dynamic process coefficient determines whether to increase or decrease the pressure by monitoring the displacement of the clamping arms and the increment of thermal deformation force in real time. For example, when the real-time displacement of the clamping arms exceeds the expected dynamic displacement, the dynamic process coefficient increases, triggering a positive adjustment of the clamping force; when the increment of thermal deformation force exceeds the allowable range, the dynamic process coefficient decreases or even becomes negative, triggering a reverse adjustment of the clamping force. The pressure distribution coefficient constrains the impact of the clamping arm layout on the pressure distribution efficiency through the exponential decay relationship between the clamping arm number index and the spacing deviation index. When the number of clamping arms is close to the maximum allowable value and the spacing deviation is small, the pressure distribution coefficient approaches 1, indicating optimal pressure distribution efficiency; conversely, when the spacing deviation is large, the pressure distribution coefficient decays, reducing pressure distribution efficiency to avoid local overload. Thus, the model can dynamically adjust the target clamping force according to real-time operating conditions and clamping arm layout, ensuring that the pressure during welding is always adapted to the material properties and process requirements.

[0145] Compared to existing technologies, where the clamping force is typically fixed or adjusted only based on static parameters, it cannot adapt to dynamic changes such as material thermal deformation and clamp arm displacement deviation during welding, leading to misalignment of the joint or unstable welding quality. This solution uses a dynamic process coefficient to capture changes in displacement and thermal deformation force in real time, and combines this with a pressure distribution coefficient to optimize the synergistic effect of multiple clamping arms, achieving dynamic closed-loop control of the clamping force and significantly improving the stability and adaptability of the welding process.

[0146] Through the above technical solution, this application can dynamically adjust the target clamping force based on the real-time displacement deviation, thermal deformation force increment, and pressure arm layout parameters during the welding process, thereby effectively avoiding misalignment of the joint due to insufficient pressure or material deformation due to excessive pressure. Simultaneously, by introducing a pressure distribution coefficient, the uniformity of pressure distribution under the synergistic action of multiple pressure arms is optimized, further improving the consistency of welding quality.

[0147] As one embodiment of the present invention, the output speed of the conveying mechanism 5 is controlled to save conveying time and improve efficiency. Specifically, when the conveying mechanism 5 conveys the plates, if the number of plates to be welded together is small, the force required to push the workpieces is low and easily handled by the servo motor. In this case, a two-stage running trajectory of "uniform acceleration-uniform deceleration" is adopted. However, if the number of plates to be welded together is large, the weight is high, the friction is high, and the force required to accelerate them is also high. In this case, a two-stage running trajectory of "uniform acceleration-uniform speed-uniform deceleration" is adopted.

[0148] The acceleration during uniform acceleration and uniform deceleration currently uses constant values ​​based on field tests. This is primarily to prevent inertial forward lurch after the conveyor stops, which could cause deviation from the predetermined position. During deceleration, the acceleration of the pushing block is slightly greater than the measured acceleration of the plate without thrust (i.e., ensuring a small thrust between the pushing block and the plate during deceleration to prevent impact and inertial forward lurch). The maximum speed during the "uniform acceleration-uniform speed-uniform deceleration" process is the rated power output of the servo motor (during acceleration, power ≈ (friction force F + force ma providing acceleration) * speed). Therefore, controlling the servo motor power to increase proportionally with time during acceleration achieves the uniform acceleration target. After reaching the rated power, maintaining the rated power for a certain period before uniform deceleration occurs. The duration of maintaining the transport motion can be calculated using parameters such as the predetermined distance of movement, the acceleration during uniform acceleration and deceleration, and the rated power.

[0149] In practice, parameters such as motor parameters, acceleration during uniform acceleration and deceleration, and the distance from the laser rangefinder to the welding point remain almost unchanged after equipment debugging. Subsequent operations only require inputting the mass of a single board and the number of boards to be welded together. Based on the basic motion formula, the system can determine whether to use a "uniform acceleration-uniform deceleration" or "uniform acceleration-uniform speed-uniform deceleration" motion trajectory and the duration of the uniform speed process. Efficiency is further improved by shortening the board conveying time.

[0150] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0151] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A spot welding device capable of automatically assembling a weld, comprising a frame and a row frame A and a row frame B mounted on the frame, characterized in that, Also includes: The spot welding mechanism, installed on gantry A, is used to perform spot welding on the workpieces to be welded. The conveying mechanism, mounted on the frame, is used to transport the workpiece to be welded to the area below the spot welding mechanism; The positioning mechanism, mounted on the frame, is used in conjunction with the conveying mechanism to position the workpiece to be welded. The limiting mechanism consists of two sets, both mounted on the frame, used to press and limit the workpiece to be welded. The conveying mechanism has two sets of four components symmetrically mounted on the frame, including a motor, a slide rail B, and a mounting base C. The motor is detachably mounted on the slide rail B, and its output shaft is fixedly connected to a lead screw rotatably mounted on the slide rail B. The mounting base C is slidably fitted with the slide rail B and threadedly connected to the lead screw. A linear motion component B is fixedly connected to the mounting base C, and a push column is fixedly connected to the output shaft of the linear motion component B. The push column is slidably fitted with the mounting base C. Two sets of laser measuring instruments are mounted on the frame. The motor is a servo motor. The frame is equipped with guide rails to facilitate the sliding of the workpiece to be welded. The limiting mechanism includes a crossbeam B, and a pressure arm assembly can be detachably installed at the lower end of both crossbeams B. The pressure arm assembly includes a pressure beam plate, pressure arm A, pressure arm B, and pressure arm C. The pressure beam plate is detachably installed on the crossbeam B. Pressure arms A, B, and C are all hinged to a connecting block detachably installed on the pressure beam plate via a connecting shaft. Pressure arms B and C are correspondingly arranged on the crossbeam B and are located between two sets of pressure arms A symmetrically arranged on the crossbeam. A protrusion triangular protrusion is fixedly connected to the free end of pressure arm B, and a pressure arm groove for avoiding the triangular protrusion is opened at the free end of pressure arm C.

2. The spot welding device capable of automatically assembling a weld according to claim 1, characterized by, The two ends of the crossbeam B are detachably mounted with mounting seats D. One set of mounting seats D is fixedly connected to the output shaft of the linear motion component D fixedly connected to the frame. The mounting seats D are slidably engaged with the guide column A. The other set of mounting seats D is slidably engaged with the guide column B detachably mounted on the frame B.

3. The spot welding device capable of automatically assembling a weld according to claim 1, characterized by, The positioning mechanism includes a crossbar, a positioning column, a rack, a mounting plate, and a connecting rod bracket. The crossbar is detachably mounted on the frame. A slide rail C is symmetrically and detachably mounted on the crossbar. A sliding seat B is slidably mounted on the slide rail C. The positioning column is detachably mounted on the sliding seat B. A spur gear is rotatably mounted between the two mounting plates. The lower mounting plate is fixedly connected to a pad block fixedly connected to the crossbar. Guide wheels are symmetrically arranged on both sides of the spur gear. The guide wheels are rotatably connected to the two spur gears. The two ends of the connecting rod bracket are fixedly connected to the sliding seat B and the rack, respectively. The two racks are symmetrically arranged about the central axis of the spur gear and both mesh with the spur gear. A connecting plate is fixedly connected to one rack. The connecting plate is fixedly connected to the output shaft of the linear motion component C detachably mounted on the crossbar. The two guide wheels correspondingly abut against the two racks.

4. The spot welding device capable of automatically assembling a weld according to claim 1, characterized by, The spot welding mechanism includes spot welding machines and a crossbeam A. Several spot welding machines are mounted on the crossbeam A via a load-bearing assembly. Mounting seats A are detachably mounted at both ends of the crossbeam A. The mounting seats A are slidably engaged with guide columns A fixedly mounted on the frame A. The crossbeam A is fixedly connected to the output shaft of a linear motion component A detachably mounted on the frame A.

5. The spot welding device capable of automatically assembling a weld according to claim 4, characterized by The load-bearing component includes a slide rail A, a sliding seat A, and a mounting base B. Several slide rails A are uniformly and detachably mounted on the crossbeam A. Several sliding seats A are uniformly and detachably mounted on the slide rails A and are fixed to the slide rails A by bolt assemblies. The mounting base B is fixedly connected to a pressure sensor that is fixedly connected to the sliding seat A. The spot welding machine is detachably mounted on the mounting base B.

6. The spot welding device capable of automatically assembling a weld seam according to any one of claims 1 to 5, characterized in that, It also includes a pressure optimization system for dynamically adjusting the pressure on the workpiece to be welded, including: The pressure demand analysis module obtains the pressure demand coefficient based on the thickness and flatness of the workpiece to be welded through a pressure demand model. The material property analysis module obtains material property coefficients based on the surface smoothness and elastic modulus of the workpiece through a material property model. The pressure distribution analysis module obtains the pressure distribution coefficient based on the number of pressure arms and the distance between them using a pressure distribution model. The dynamic process analysis module obtains dynamic process coefficients based on the real-time displacement of the pressure arm and the increment of thermal deformation force. The pressure optimization module obtains the target clamping force based on the dynamic process coefficient, pressure distribution coefficient, and reference clamping force through a pressure optimization model.

7. The spot welding device capable of automatically assembling a weld seam according to claim 6, characterized by The pressure optimization model is expressed as follows: in, Indicates the target clamping force. Indicates the reference clamping force. Represents the coefficients of the dynamic process. This represents the pressure distribution coefficient.

8. The spot welding device capable of automatically assembling a weld according to claim 7, characterized by The steps for obtaining the dynamic process coefficients based on the real-time displacement of the pressure arm and the increment of thermal deformation force are as follows: A dynamic expected displacement model is constructed using the basic displacement and pressure demand coefficient to output the dynamic expected displacement. The dynamic expected displacement model is expressed as follows: wherein, represents a dynamic expected displacement, represents a base displacement, represents a displacement correction factor, represents a pressure demand factor; The allowable thermal deformation force model is constructed by using the basic allowable thermal deformation force increment and material property coefficients to output the allowable thermal deformation force increment. The allowable thermal deformation force model is expressed as follows: wherein, represents an allowable thermal deformation force increment, represents a base allowable thermal deformation force increment, represents a thermal deformation force correction coefficient, represents a material characteristic coefficient; The dynamic process model is constructed by taking the real-time displacement of the pressure arm, the increment of thermal deformation force, the expected dynamic displacement, and the allowable increment of thermal deformation force, and outputting the dynamic process coefficients. The dynamic process model is expressed as follows: in, Represents the coefficients of the dynamic process. This indicates the real-time displacement of the pressure arm. Indicates the increment of thermal deformation force. Indicates the expected dynamic displacement. This indicates the allowable increase in thermal deformation force. Represents the weight coefficient and The ,when The process status matches expectations, requiring no dynamic adjustment of the clamping force. If the pressure is insufficient during the process, the clamping force needs to be increased positively. If the pressure during the process is too high or there is an abnormality, it is necessary to reduce the pressure in the opposite direction.

9. The spot welding device capable of automatically assembling a weld according to claim 8, characterized by The steps to obtain the pressure distribution coefficient using a pressure distribution model based on the number of pressure arms and the distance between them are as follows: The pressure arm quantity index is obtained by processing the ratio of the number of pressure arms to the maximum allowable number of pressure arms; The absolute difference between the pressure arm spacing and the optimal spacing is then compared with the optimal spacing to obtain the spacing deviation index. A pressure distribution model is constructed based on the number of pressure arms and the spacing deviation index, and the pressure distribution coefficient is output. The pressure distribution model is expressed as follows: in, Indicates the pressure distribution coefficient. Indicates the number of pressure arms index. This indicates that the spacing deviates from the index. Represents the attenuation coefficient, the Furthermore, the larger the value, the higher the pressure distribution efficiency.

10. The spot welding device capable of automatically assembling a weld according to claim 8, characterized by, Based on the surface smoothness and elastic modulus of the workpiece, the steps for obtaining material property coefficients using a material property model are as follows: The surface smoothness and elastic modulus are compared with the corresponding maximum allowable values ​​of the system to obtain the roughness index and elastic modulus index. A material property model is constructed based on the roughness index and the elastic modulus index, and the material property coefficients are output. The material property model is expressed as follows: in, Represents the material property coefficient. Represents the roughness index. Indicates the elastic modulus index. Represents the weight coefficient and The The larger the value, the greater the required base clamping force.

11. The spot welding device capable of automatically assembling a weld according to claim 8, characterized by, Based on the thickness and flatness of the workpiece to be welded, the steps to obtain the pressure demand coefficient using the pressure demand model are as follows: The thickness and flatness are respectively compared with the corresponding maximum allowable values ​​of the system to obtain the thickness index and flatness index; A pressure demand model is constructed based on the thickness index and the flatness index to output the pressure demand coefficient. The pressure demand model is expressed as follows: wherein, represents a pressure demand coefficient, represents a thickness index, represents a flatness index, represents a weight coefficient and , the and the greater the value the greater the required reference compaction force.

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