Manipulator welding equipment and welding method

Abstract

The invention relates to the field of mechanical arm welding, and discloses mechanical arm welding equipment and a welding method.The mechanical arm welding equipment comprises a workbench in the welding equipment, a welding gun is installed on the workbench, and a first pressing and holding mechanism is fixedly installed on the workbench; the second pressing and holding mechanism is installed on the workbench, a second sliding pipe is located under the welding gun and fixedly connected with the workbench through a U-shaped frame, and a first sliding pipe is slidably connected into the second sliding pipe. The adjusting mechanism is installed in the second sliding pipe and connected with the first sliding pipe through the back pressure assembly. The jacking mechanism is fixedly mounted at the top of the first sliding pipe; the pressing mechanism is matched with the first spring, so that the deformation force is counteracted; a thermistor in the adjusting mechanism dynamically adjusts the magnetic force of an electromagnet according to temperature changes, and a series of components are driven to enable the jacking mechanism to adaptively adjust jacking force; and the top pressure is enhanced in the melting stage, the original position is restored in the cooling stage, dynamic compensation of thermal expansion of the metal plate is achieved, and the metal plate is effectively prevented from being damaged due to thermal deformation in the welding process.

Description

Technical Field

[0001] The present invention relates to the technical field of robot welding, and more specifically, to a robot welding device and a welding method. Background Art

[0002] During the welding process, thin metal plates are very likely to expand and deform due to the heat generated by welding because of their thin thickness and small heat capacity. Once the metal plate is deformed, it will not only affect the quality of the welded joint, causing defects such as pores and cracks in the weld, reducing the strength and sealing of the welded structure, but also make it difficult to ensure the dimensional accuracy of the weldment, increasing the difficulty and cost of subsequent processing.

[0003] In order to deal with the problem of thermal expansion, some existing welding equipment is equipped with corresponding adjustment devices; one of the common adjustment methods is to use manual adjustment bolts to change the position of the top pressure mechanism to adjust the top pressure; before welding, the operator estimates the degree of thermal expansion of the metal plate based on experience, and manually rotates the bolts to make the top pressure mechanism apply a certain pressure in advance; however, this method has obvious limitations; on the one hand, manual estimation is difficult to be accurate, and the judgment standards of different operators are also different, which makes it difficult to maintain consistent top pressure for each welding; on the other hand, during the welding process, the thermal expansion of the metal plate is a dynamic process, and manual adjustment cannot be made in time according to the real-time thermal expansion situation, and cannot meet the precise requirements for top pressure in different welding stages.

[0004] Some other devices use a simple spring mechanism to adjust the top pressure. The spring is compressed in the initial state to provide a certain pressure for the top pressure mechanism. When the metal plate expands thermally, the spring will be further compressed, thereby increasing the top pressure. However, this spring adjustment method lacks flexibility, and the elastic coefficient of the spring is fixed. Once selected, the change law of the top pressure it provides during the entire welding process is difficult to change. Therefore, we designed a robot welding device and a welding method. Summary of the invention

[0005] The present invention provides a robot welding device and a welding method, which solve the technical problems that some welding devices in the related art use manually adjusted bolts or spring mechanisms to cope with thermal expansion; the former relies on manual estimation to adjust the top pressure, but it is difficult to make accurate judgments and cannot be adjusted in real time during welding, resulting in the top pressure being difficult to be consistent and difficult to meet precise requirements; the latter has a fixed spring elastic coefficient, lacks flexibility in adjustment, and the top pressure variation law is difficult to change.

[0006] The present invention provides a robot welding device, comprising a workbench with a welding gun installed, a first pressing mechanism, which is fixedly installed on the workbench; a second pressing mechanism, which is fixedly installed on the workbench and cooperates with the first pressing mechanism to fix a metal plate; a second sliding tube, which is located directly below the welding gun and is fixedly connected to the workbench through a U-shaped frame, and the first sliding tube is slidably connected therein; an adjusting mechanism, which is installed inside the second sliding tube and connected to the first sliding tube through a back pressure component; a top pressing mechanism, which is fixedly installed on the top of the first sliding tube; during the welding process of the welding gun on the metal plate, the adjusting component automatically offsets the deformation of the metal plate caused by thermal expansion; and during the melting stage and cooling stage of welding, the adjusting component adaptively adjusts the squeezing of the metal plate by the top pressing mechanism.

[0007] As a further optimization solution of the present invention, the first pressing mechanism includes a first pressing plate fixedly connected to the workbench; a first sliding rod fixedly installed on the first pressing plate, and a second pressing plate slidably connected thereto.

[0008] As a further optimization scheme of the present invention, the second pressing mechanism includes a first screw rotatably connected to the workbench; a movable frame, rotatably mounted on the first screw and slidably connected to the workbench, and a slide groove is provided on it; a third pressure plate, located above the first screw and connected to the slider through a first support rod, and the slider is located inside the slide groove; a fourth pressure plate, located above the first screw and connected to the movable frame through a second support rod.

[0009] As a further optimization solution of the present invention, the second holding mechanism further includes a limiting frame fixedly connected to the third pressing plate, a sliding plate is slidably connected inside the limiting frame, and the sliding plate is fixedly connected to the second pressing plate.

[0010] As a further optimization scheme of the present invention, the adjustment mechanism includes a first connecting plate fixedly connected to the first sliding tube; a second connecting plate, slidably installed inside the second connecting plate and connected to the first connecting plate through a first spring; and an adjustment assembly, installed inside the second sliding tube and connected to the second connecting plate.

[0011] As a further optimization scheme of the present invention, the adjustment component includes a second screw rotatably connected to the second sliding tube, and the second screw is threadedly connected to the second connecting plate; a first gear is fixedly mounted on the second screw; a drive frame is slidably mounted on the second sliding tube, and a row of teeth is fixedly mounted inside it; a permanent magnet is fixedly mounted on the drive frame; an electromagnet is fixedly mounted on the drive frame; a rebound assembly is mounted inside the U-shaped frame; the top pressing mechanism includes a first mounting frame, and the first mounting frame is fixedly connected to the thermistor.

[0012] As a further optimization scheme of the present invention, the two ends of the U-shaped frame are respectively fixedly connected to the second sliding tube and the workbench, and the U-shaped frame is provided with a mounting groove; the rebound assembly includes a push plate fixedly connected to the driving frame, and the push plate is slidably connected to the mounting groove; the second slide rod is fixedly mounted on the push plate and is slidably connected to the U-shaped frame, and a second spring is sleeved on it, and the two ends of the second spring are respectively fixedly connected to the push plate and the U-shaped frame; and a ball is rollingly mounted on the bottom of the U-shaped frame.

[0013] As a further optimization scheme of the present invention, the pressing mechanism also includes a second mounting frame fixedly connected to the first mounting frame; a first rotating shaft, rotatably mounted on the second mounting frame, on which a driving roller and a driving belt are fixedly mounted, connecting the two driving rollers; and a rotating assembly, fixedly connected to the first sliding tube.

[0014] As a further optimization scheme of the present invention, the rotating assembly includes a second rotating shaft rotatably connected to the first sliding tube, and the second rotating shaft is fixedly connected to the second mounting frame; a toggle block, fixedly mounted on the second rotating shaft, and having a plurality of driving grooves thereon; a positioning plate, fixedly mounted on the first sliding tube, and having a third rotating shaft rotatably mounted thereon, and a driving disk, fixedly mounted on the driving disk, and having an auxiliary disk and a driving column fixedly mounted on the top thereof.

[0015] A welding method for a robot welding device comprises the following steps:

[0016] S1. Clamping the workpiece: Turn the first screw to drive the pressing plate to move up, place the metal plate, move the second pressing plate and use the limit frame to synchronize it with the third pressing plate to complete the clamping of the metal plate;

[0017] S2, pre-adjustment preparation: the top pressure mechanism presses the first spring to obtain a supporting force that matches the thickness of the metal plate, ensuring that the series circuit of the electromagnet and thermistor is normal;

[0018] S3, welding operation: the welding gun spot welds the seam, and the top pressure mechanism and the first spring buffer the thermal expansion deformation force during welding; in the melting stage, the temperature causes the thermistor to change the magnetic force of the electromagnet, driving the top pressure mechanism to increase the top pressure; when the welding gun moves, the second connecting plate is synchronized, and the top pressure mechanism is always directly below it; when reversing is required, the third shaft is rotated to switch the direction of the top pressure mechanism;

[0019] S4, restore to the original state: the welding gun spot welds into a seam, and the top pressure mechanism and the first spring buffer the thermal expansion deformation force during welding; in the melting stage, the temperature causes the thermistor to change the magnetic force of the electromagnet, driving the top pressure mechanism to increase the top pressure; when the welding gun moves, the second connecting plate is synchronized, and the top pressure mechanism is always directly below it; when reversing is required, the third shaft is rotated to switch the direction of the top pressure mechanism.

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

[0021] 1. A robot welding device and a welding method described in the present invention cooperate with each other through the top pressure mechanism and the first spring to initially offset the deformation force; the thermistor in the adjustment mechanism dynamically adjusts the magnetic force of the electromagnet according to temperature changes, and drives a series of components to enable the top pressure mechanism to adaptively adjust the top pressure; the top pressure is enhanced in the melting stage and restored to its original position in the cooling stage, thereby realizing dynamic compensation for the thermal expansion of the metal plate, effectively avoiding damage to the metal plate due to thermal deformation during the welding process, and improving the welding quality.

[0022] 2. The robot welding equipment and welding method described in the present invention realize clamping by rotating the first screw to drive the relevant pressure plate to rise. Since the position of the first pressure plate is fixed, the thickness of the metal plate will automatically match the initial jacking pressure of the jacking mechanism and the adjustment mechanism, so that it has a reasonable jacking pressure to avoid damage to the metal plate. The design of the limit frame and the slide plate ensures the synchronous movement of the second and third pressure plates to avoid affecting the clamping effect due to misalignment of the position, thereby improving the stability and efficiency of metal plate clamping.

[0023] 3. The robot welding equipment and welding method described in the present invention, when the workbench drives the welding gun to move during the process of spot welding to form a weld, the U-shaped frame ensures that the top pressure mechanism is always directly below the welding gun, and continuously and effectively constrains the metal plate; the top pressure mechanism uses a driving belt to contact the metal plate, which not only reduces the movement friction and facilitates movement, but also avoids the scratching of the metal plate by the traditional top block, thereby further protecting the metal plate; in addition, the rotating assembly can flexibly switch the movement direction of the top pressure mechanism, so that it can better adapt to the different movement paths of the welding gun, thereby improving welding efficiency and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0026] Figure 3 yes Figure 1 Rear view of

[0027] Figure 4 is a structural schematic diagram of the second pressing mechanism of the present invention;

[0028] Figure 5 is a schematic diagram of the internal structure of the second sliding tube of the present invention;

[0029] Figure 6 yes Figure 5 Enlarged view of point B in the middle;

[0030] Figure 7 It is a structural schematic diagram of the top pressing mechanism of the present invention;

[0031] Figure 8 It is a schematic diagram of the structure of the rotating assembly of the present invention;

[0032] Fig. 9 It is a structural schematic diagram of the U-shaped frame of the present invention;

[0033] Fig.10 yes Fig. 9 Enlarged view of point C in the middle;

[0034] Fig.11 It is a schematic diagram of the connection between the U-shaped frame and the ball bearing of the present invention;

[0035] Fig.12 It is a flow chart of the welding method of the present invention.

[0036] In the figure: 1, workbench; 2, welding gun; 301, first pressing plate; 302, moving frame; 303, first supporting rod; 304, sliding block; 305, limiting frame; 306, third pressing plate; 307, first sliding rod; 308, second pressing plate; 309, sliding plate; 310, first screw rod; 311, second supporting rod; 312, fourth pressing plate; 401, U-shaped frame; 402, first sliding tube; 403, second sliding tube; 404, first connecting plate; 405, first spring; 406, second connecting plate; 407, second screw rod; 408, electromagnet; 409, permanent magnet; 410, drive frame; 411, first gear; 412, latch; 413, push plate; 414, drive belt; 415, thermistor; 416, drive roller; 417, first mounting frame; 418, first rotating shaft; 419, second mounting frame; 420, toggle block; 421, second rotating shaft; 422, auxiliary disk; 423, drive disk; 424, drive column; 425, third rotating shaft; 426, positioning plate; 427, ball bearing; 428, second spring; 429, second slide bar. DETAILED DESCRIPTION

[0037] The subject matter described herein will now be discussed with reference to example implementations. It should be understood that the discussion of these implementations is only to enable those skilled in the art to better understand and implement the subject matter described herein, and the functions and arrangements of the elements discussed may be changed without departing from the scope of protection of the contents of this specification. Various examples may omit, replace, or add various processes or components as needed. In addition, the features described in some examples may also be combined in other examples.

[0038] like Figures 1 to 11As shown, a manipulator welding device of an embodiment of the present invention includes a workbench 1 with a welding gun 2 installed; a first pressing mechanism is fixedly installed on the workbench 1; a second pressing mechanism is fixedly installed on the workbench 1, and cooperates with the first pressing mechanism to fix the metal plate; the second sliding tube 403 is located directly below the welding gun 2, and is fixedly connected to the workbench 1 through a U-shaped frame 401, and the first sliding tube 402 is slidably connected therein; the adjusting mechanism is installed inside the second sliding tube 403, and is connected to the first sliding tube 402 through a back pressure component; the top pressing mechanism is fixedly installed on the top of the first sliding tube 402; during the welding process of the welding gun 2 on the metal plate, the adjusting component automatically offsets the deformation of the metal plate caused by thermal expansion; and in the melting stage and cooling stage of welding, the adjusting component adaptively adjusts the extrusion of the metal plate by the top pressing mechanism.

[0039] It should be noted that the workbench 1 is not only used to place metal sheets, but also can move the welding gun 2 back and forth and left and right so that the welding gun 2 can weld straight welds. The main structure for controlling the movement of the welding gun 2 is that the second motor controls the moving block on the moving frame to move back and forth. The welding gun 2 is installed on the moving block. The first motor controls the reciprocating screw rod to rotate, and the reciprocating screw rod moves the moving frame left and right. After the function of the workbench 1 is determined, the placement of the metal plate can be described. The metal plate is a thin metal plate, which is easily changed due to thermal expansion during the welding process. The metal plate is first placed on the second holding mechanism, and the second holding mechanism is controlled by part of the second holding mechanism. The structure is moved upward to match it with the first pressing mechanism, which can fix the metal plate to facilitate subsequent welding. The top pressing mechanism is located below the metal plate, and its center is aligned with the center of the welding gun 2, so that the weld point welded by the welding gun 2 acts on the metal plate, and the force applied by the metal plate to the top pressing mechanism is in the center and can be effectively dispersed. The top pressing mechanism is installed on the second sliding tube 403, and the bottom height of the second sliding tube 403 is fixed. The top of the top pressing mechanism is normally on the same plane as the ground of the first pressing mechanism. In this way, the thickness of the placed metal plate can effectively self-adapt to the squeezing force of the absolute top pressing mechanism on the metal plate.

[0040] After the metal plate is placed, when the welding gun 2 is used for welding, spot welding is adopted, and multiple spot weldings are used to form a weld. This is because the metal plate is thin, and direct, rapid and continuous welding will cause excessive heat, which will cause the metal plate to be penetrated. When the metal plate is welded, the top pressure of the top pressure mechanism itself on the metal plate can be aligned to offset, and the welding process is divided into a melting stage and a cooling stage. The higher the temperature, the greater the extrusion constraint is required, so the adjustment mechanism can dynamically adjust the pressure of the top pressure mechanism on the metal plate. When the welding is completed and enters the cooling mechanism, the adjustment mechanism will dynamically adjust the top pressure mechanism to gradually restore it to its original state.

[0041] Please refer to Figure 1 and Figure 2The first pressing mechanism includes a first pressing plate 301 fixedly connected to the workbench 1; a first sliding rod 307 is fixedly installed on the first pressing plate 301, and a second pressing plate 308 is slidably connected thereto.

[0042] Please refer to Figure 3 and Figure 4 The second pressing mechanism includes a first screw 310 rotatably connected to the workbench 1; the movable frame 302 is rotatably mounted on the first screw 310 and is slidably connected to the workbench 1, and a slide groove is opened on it; the third pressing plate 306 is located above the first screw 310, and is connected to the slider 304 through the first support rod 303, and the slider 304 is located inside the slide groove; the fourth pressing plate 312 is located above the first screw 310, and is connected to the movable frame 302 through the second support rod 311.

[0043] When the metal plate needs to be clamped and fixed, the first screw 310 can be rotated first. The first screw 310 drives the movable frame 302 to move upward. The upward movement of the movable frame 302 will drive the fourth pressure plate 312 and the third pressure plate 306 to move upward through the second support rod 311 and the first support rod 303. In this way, the metal plate can be clamped by the fourth pressure plate 312, the third pressure plate 306, the first pressure plate 301, and the second pressure plate 308, and thus fixed well.

[0044] The second pressing mechanism further includes a limiting frame 305 fixedly connected to the third pressing plate 306 , a slide plate 309 is slidably connected inside the limiting frame 305 , and the slide plate 309 is fixedly connected to the second pressing plate 308 .

[0045] Since different metal plates have different lengths and widths, the second pressure plate 308 needs to be moved first according to the size of the metal plate. Since the second pressure plate 308 and the third pressure plate 306 are limited by the limit frame 305, they can move synchronously. This can avoid the second pressure plate 308 and the third pressure plate 306 from being misaligned and affecting the clamping of the metal plate. The synchronous movement also eliminates the process of multiple distributed alignment movements, thereby improving work efficiency.

[0046] Please refer to Figure 5 The adjustment mechanism includes a first connecting plate 404 fixedly connected to the first sliding tube 402; the second connecting plate 406 is slidably installed inside the second connecting plate 406 and is connected to the first connecting plate 404 through the first spring 405; the adjustment component is installed inside the second sliding tube 403 and is connected to the second connecting plate 406.

[0047] When the metal plate is fixed, the pressing mechanism will press the first spring 405 according to the thickness of the metal plate. The first spring 405 is pressed, so that it can react on the pressing mechanism, so that the pressing mechanism gives a supporting force to the metal plate. In this way, the supporting force will be determined by the thickness of the metal plate, realizing synchronous adjustment.

[0048] Please refer to Figure 6 and Figure 7 The adjusting component includes a second screw rod 407 rotatably connected to the second sliding tube 403, and the second screw rod 407 is threadedly connected to the second connecting plate 406; the first gear 411 is fixedly mounted on the second screw rod 407; the driving frame 410 is slidably mounted on the second sliding tube 403, and a row of latch teeth 412 is fixedly mounted inside the driving frame 410; the permanent magnet 409 is fixedly mounted on the driving frame 410; the electromagnet 408 is fixedly mounted on the driving frame 410; the rebound component is mounted inside the U-shaped frame 401; the pressing mechanism includes a first mounting frame 417, and the first mounting frame 417 is fixedly connected to the thermistor 415; when the metal plate is fixed and needs to be welded, the welding gun 2 is spot welded. When the welding gun 2 welds the metal plate, the metal plate will undergo thermal expansion, and the thermal expansion will act on the pressing mechanism, so that the pressing mechanism acts on the first spring 405. Since the pressing mechanism is supported by the first spring 405, they can offset each other, thereby avoiding deformation of the metal plate.

[0049] Since the electromagnet 408 and thermistor 415 are connected in series, and the thermistor 415 is an NTC thermistor 415, when the temperature rises, the resistance decreases, so that more current will flow into the electromagnet 408. The more current flows into the electromagnet 408, the greater the magnetic force of the electromagnet 408 will be, so that the permanent magnet 409 can be better acted on, and the permanent magnet 409 and the electromagnet 408 magnetically repel each other.

[0050] The welding process is divided into two stages: melting and cooling. In this way, when in the welding melting stage, the temperature is high and a strong constraint is required. The high temperature will act on the thermistor 415, causing the resistance of the thermistor 415 to decrease, thereby increasing the magnetic force of the electromagnet 408. Then the electromagnet 408 will be able to act on the permanent magnet 409, causing the permanent magnet 409 to drive the drive frame 410 and the latch 412 to move. The movement of the drive frame 410 and the latch 412 will cause the first gear 411 to rotate. The rotation of the first gear 411 will drive the second screw 407 to rotate. The rotation of the second screw 407 will cause the second connecting plate 406 to move upward. In this way, the first spring 405, the first connecting plate 404, and the first sliding tube 406 are 02 and the top pressure mechanism will move up, thereby providing a greater top pressure. Since the thermistor 415 can change with the temperature, dynamic adjustment can be effectively achieved. When welding is completed and it is in the cooling stage, the temperature sensed by the thermistor 415 will drop. As the temperature drops, the resistance of the thermistor 415 will increase, so that the magnetic force of the electromagnet 408 on the permanent magnet 409 will continue to decay. At this time, the rebound component can make the drive frame 410 gradually return to its original position, thereby making the second connecting plate 406 return to its original position, constantly adapting to the thermal expansion of the metal plate due to the welding heat, realizing dynamic compensation for the metal plate, and avoiding damage to the metal plate during the welding process.

[0051] Please refer to Figures 9 to 11 The two ends of the U-shaped frame 401 are respectively fixedly connected to the second sliding tube 403 and the workbench 1, and a mounting groove is provided on the U-shaped frame 401; the rebound component includes a push plate 413 fixedly connected to the driving frame 410, and the push plate 413 is slidably connected to the mounting groove; the second sliding rod 429 is fixedly installed on the push plate 413 and is slidably connected to the U-shaped frame 401, and a second spring 428 is sleeved thereon, and the two ends of the second spring 428 are respectively fixedly connected to the push plate 413 and the U-shaped frame 401; the ball 427 is rollingly installed at the bottom of the U-shaped frame 401.

[0052] In the melting stage mentioned above, the magnetic force of the electromagnet 408 is greater than the spring force of the second spring 428, which can compress the second spring 428, thereby moving the second connecting plate 406 upward. When in the cooling stage, the magnetic force of the electromagnet 408 continues to decrease until it disappears, so that the spring force of the second spring 428 will continue to be greater than the magnetic force of the electromagnet 408, thereby causing the second connecting plate 406 to continuously return to its original position, realizing reciprocating motion, and it is in its original state after each use, which is convenient for continued use next time.

[0053] Since the welding of the metal plate by the welding gun 2 is not just a single spot welding, but a weld is formed through multiple spot weldings, when the welding gun 2 completes a spot welding of the metal plate, the welding gun 2 will be controlled by the workbench to move to the side of the previous spot welding to continue spot welding. Since the U-shaped frame 401 connects the workbench with the second connecting plate 406, when the welding gun 2 moves, the second connecting plate 406 will also move synchronously, so that the top pressing mechanism can always be located directly below the welding gun 2, which is convenient for restraining each spot welding and avoiding deformation and damage of the metal plate due to thermal expansion; and the ball bearing 427 is arranged at the bottom of the U-shaped frame 401 to better assist the movement.

[0054] Please refer to Figure 7 The pressing mechanism also includes a second mounting frame 419 fixedly connected to the first mounting frame 417; the first rotating shaft 418 is rotatably mounted on the second mounting frame 419, on which a driving roller 416 is fixedly mounted, and a driving belt 414 connects the two driving rollers 416; the rotating assembly is fixedly connected to the first sliding tube 402.

[0055] Since the contact surface between the driving belt 414 and the metal plate is a square, the center point is the welding point, which can disperse the force caused by thermal expansion very well. Spot welding is performed continuously during welding, which requires the entire pressing mechanism to move together. By utilizing the driving belt 414, the friction between the contact and the metal plate can be used to move. Compared with the traditional top block, it can not only reduce the friction between the two movements and facilitate movement, but also reduce the scratching of the metal plate by the traditional top block due to friction during movement, thereby further protecting the metal plate.

[0056] Please refer to Figure 8The rotating assembly includes a second rotating shaft 421 rotatably connected to the first sliding tube 402, and the second rotating shaft 421 is fixedly connected to the second mounting frame 419; the toggle block 420 is fixedly mounted on the second rotating shaft 421, and a plurality of driving grooves are provided on it; the positioning plate 426 is fixedly mounted on the first sliding tube 402, and a third rotating shaft 425 is rotatably mounted on it, and the driving disk 423 is fixedly mounted on the driving disk 423, and an auxiliary disk 422 and a driving column 424 are fixedly mounted on the top thereof.

[0057] When welding metal plates, the welding gun 2 not only moves horizontally but also vertically, and the position of the pressing mechanism can normally only move in one direction, horizontally or vertically. When it is necessary to move in the other direction, the third rotating shaft 425 needs to be rotated, so that the third rotating shaft 425 drives the driving disk 423 to rotate, and the driving disk 423 drives the driving column 424 to rotate. The driving column 424 acts on the toggle block 420 to rotate the second rotating shaft 421 by ninety degrees. In this way, the pressing mechanism will also rotate by ninety degrees, so that it can change from horizontal to vertical, or from vertical to horizontal, which is convenient for adapting to more convenient welding.

[0058] Please refer to Fig.12 , a welding method of a robot welding device, comprising the following steps:

[0059] S1. Clamping the workpiece: Turn the first screw to drive the pressing plate to move up, place the metal plate, move the second pressing plate and use the limit frame to synchronize it with the third pressing plate to complete the clamping of the metal plate;

[0060] S2, pre-adjustment preparation: the top pressure mechanism presses the first spring to obtain a supporting force that matches the thickness of the metal plate, ensuring that the series circuit of the electromagnet and thermistor is normal;

[0061] S3, welding operation: the welding gun spot welds the seam, and the top pressure mechanism and the first spring buffer the thermal expansion deformation force during welding; in the melting stage, the temperature causes the thermistor to change the magnetic force of the electromagnet, driving the top pressure mechanism to increase the top pressure; when the welding gun moves, the second connecting plate is synchronized, and the top pressure mechanism is always directly below it; when reversing is required, the third shaft is rotated to switch the direction of the top pressure mechanism;

[0062] S4, restore to the original state: the welding gun spot welds into a seam, and the top pressure mechanism and the first spring buffer the thermal expansion deformation force during welding; in the melting stage, the temperature causes the thermistor to change the magnetic force of the electromagnet, driving the top pressure mechanism to increase the top pressure; when the welding gun moves, the second connecting plate is synchronized, and the top pressure mechanism is always directly below it; when reversing is required, the third shaft is rotated to switch the direction of the top pressure mechanism.

[0063] Working principle: Place the metal plate on the second pressing mechanism, rotate the first screw 310, drive the movable frame 302 to move upward, and then make the third pressing plate 306 and the fourth pressing plate 312 rise; at the same time, use the cooperation of the limit frame 305 and the slide plate 309 to make the second pressing plate 308 and the third pressing plate 306 move synchronously, so that the metal plate is firmly clamped by the first pressing plate 301, the second pressing plate 308, the third pressing plate 306 and the fourth pressing plate 312, in preparation for welding.

[0064] During welding, the welding gun 2 adopts spot welding; in the melting stage, the metal plate expands due to heat, and the top pressure mechanism interacts with the first spring 405 to offset part of the deformation force; as the temperature rises, the resistance of the NTC thermistor 415 decreases, and the magnetic force of the electromagnet 408 increases, driving the relevant components to move the second connecting plate 406 upward, driving the top pressure mechanism to increase the top pressure; in the cooling stage, the temperature drops, the resistance of the thermistor 415 increases, the magnetic force of the electromagnet 408 weakens, and the rebound component returns the second connecting plate 406 to its original position.

[0065] After completing a spot welding, the workbench controls the welding gun 2 to move to the next spot welding position. Since the driving belt 414 at the bottom of the top pressing mechanism is in contact with the metal plate, it moves by friction, which can not only reduce the moving friction, but also reduce the scratching of the metal plate. Since the U-shaped frame 401 connects the workbench 1 and the second connecting plate 406, the top pressing mechanism is always directly below the welding gun 1 to constrain each spot welding; when the moving direction of the welding gun 2 needs to be switched between horizontal and vertical, the third rotating shaft 425 is rotated to drive the driving disk 423 to rotate, and the driving column 424 toggles the toggle block 420 to rotate the second rotating shaft 421 ninety degrees, thereby realizing the switching of the moving direction of the top pressing mechanism, adapting to different welding requirements, and forming a weld through multi-spot welding.

[0066] The above describes an embodiment of the present invention, but this embodiment is not limited to the above specific implementation methods. The above specific implementation methods are merely illustrative and not restrictive. Under the guidance of this embodiment, ordinary technicians in this field can also make many forms, all of which are protected by this embodiment.

Claims

1. A robot welding device, comprising a workbench (1) on which a welding gun (2) is mounted, characterized in that: A first pressing mechanism, fixedly mounted on the workbench (1); A second pressing mechanism is fixedly mounted on the workbench (1) and cooperates with the first pressing mechanism to fix the metal plate; A second sliding tube (403) is located directly below the welding gun (2) and is fixedly connected to the workbench (1) via a U-shaped frame (401), and the first sliding tube (402) is slidably connected therein; An adjusting mechanism is installed inside the second sliding tube (403) and connected to the first sliding tube (402) via a back pressure assembly; A pressing mechanism, fixedly mounted on the top of the first sliding tube (402); During the welding process of the welding gun (2) on the metal plate, the adjustment component automatically offsets the deformation of the metal plate caused by thermal expansion; and during the melting stage and cooling stage of welding, the adjustment component adaptively adjusts the pressing mechanism to squeeze the metal plate.

2. A robot welding device according to claim 1, characterized in that: The first pressing mechanism comprises a first pressing plate (301) fixedly connected to the workbench (1); The first sliding rod (307) is fixedly mounted on the first pressing plate (301), and the second pressing plate (308) is slidably connected thereto.

3. A robot welding device according to claim 1, characterized in that: The second pressing mechanism comprises a first screw rod (310) rotatably connected to the workbench (1); A movable frame (302) is rotatably mounted on the first screw rod (310) and is slidably connected to the workbench (1), and has a sliding groove thereon; A third pressing plate (306), located above the first screw rod (310), and connected to the sliding block (304) via the first supporting rod (303), wherein the sliding block (304) is located inside the sliding groove; The fourth pressing plate (312) is located above the first screw rod (310) and is connected to the moving frame (302) via a second supporting rod (311).

4. A robot welding device according to claim 3, characterized in that: The second pressing mechanism further comprises a limiting frame (305) fixedly connected to the third pressing plate (306), a slide plate (309) being slidably connected inside the limiting frame (305), and the slide plate (309) being fixedly connected to the second pressing plate (308).

5. The robot welding device according to claim 1, characterized in that: The adjustment mechanism comprises a first connecting plate (404) fixedly connected to the first sliding tube (402); A second connecting plate (406) is slidably mounted inside the second connecting plate (406) and connected to the first connecting plate (404) via a first spring (405); The adjustment assembly is installed inside the second sliding tube (403) and connected to the second connecting plate (406).

6. A robot welding device according to claim 5, characterized in that: The adjustment assembly comprises a second screw rod (407) rotatably connected to the second sliding tube (403), and the second screw rod (407) is threadedly connected to the second connecting plate (406); A first gear (411) fixedly mounted on the second screw rod (407); A driving frame (410) is slidably mounted on the second sliding tube (403), and a row of latch teeth (412) is fixedly mounted inside the driving frame; A permanent magnet (409) is fixedly mounted on the driving frame (410); An electromagnet (408) fixedly mounted on the driving frame (410); A rebound component installed inside the U-shaped frame (401); The pressing mechanism comprises a first mounting frame (417), and the first mounting frame (417) is fixedly connected to the thermistor (415).

7. A robot welding device according to claim 6, characterized in that: The two ends of the U-shaped frame (401) are respectively fixedly connected to the second sliding tube (403) and the workbench (1), and a mounting groove is provided on the U-shaped frame (401); The rebound assembly comprises a push plate (413) fixedly connected to the driving frame (410), and the push plate (413) is slidably connected to the mounting groove; A second sliding rod (429) is fixedly mounted on the push plate (413) and slidably connected to the U-shaped frame (401), and a second spring (428) is sleeved thereon, and two ends of the second spring (428) are respectively fixedly connected to the push plate (413) and the U-shaped frame (401); The ball bearing (427) is rollingly mounted on the bottom of the U-shaped frame (401).

8. The robot welding device according to claim 6, characterized in that: The pressing mechanism further comprises a second mounting frame (419) fixedly connected to the first mounting frame (417); The first rotating shaft (418) is rotatably mounted on the second mounting frame (419), and a driving roller (416) is fixedly mounted on the first rotating shaft (418). A driving belt (414) connecting the two driving rollers (416); The rotating assembly is fixedly connected to the first sliding tube (402).

9. A robot welding device according to claim 8, characterized in that: The rotating assembly comprises a second rotating shaft (421) rotatably connected to the first sliding tube (402), and the second rotating shaft (421) is fixedly connected to the second mounting frame (419); A toggle block (420) is fixedly mounted on the second rotating shaft (421) and is provided with a plurality of driving grooves; The positioning plate (426) is fixedly mounted on the first sliding tube (402), and a third rotating shaft (425) is rotatably mounted on the positioning plate (426). The driving disk (423) is fixedly mounted on the driving disk (423), and an auxiliary disk (422) and a driving column (424) are fixedly mounted on the top of the driving disk (423).

10. A welding method for a robot welding device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Clamping the workpiece: rotating the first screw (310) to drive the pressing plate to move upward, placing the metal plate, moving the second pressing plate (308) and using the limiting frame (305) to synchronize it with the third pressing plate (306), and completing the clamping of the metal plate; S2, pre-adjustment preparation: the pressing mechanism presses the first spring (405) to obtain a supporting force that matches the thickness of the metal plate, ensuring that the series circuit of the electromagnet (408) and the thermistor (415) is normal; S3, welding operation: the welding gun (2) spot welds the seam, and the pressing mechanism and the first spring (405) buffer the thermal expansion deformation force during welding; in the melting stage, the temperature causes the thermistor (415) to change the magnetic force of the electromagnet (408), driving the pressing mechanism to increase the pressing force; when the welding gun (2) moves, the second connecting plate (406) is synchronized, and the pressing mechanism is always directly below it; when the direction needs to be changed, the third rotating shaft (425) is rotated to switch the direction of the pressing mechanism; S4, restoration to the original state: the welding gun (2) spot welds the seam, and during welding, the pressing mechanism and the first spring (405) buffer the thermal expansion deformation force; during the melting stage, the temperature causes the thermistor (415) to change the magnetic force of the electromagnet (408), driving the pressing mechanism to increase the pressing force; when the welding gun (2) moves, the second connecting plate (406) is synchronized, and the pressing mechanism is always directly below it; when reversing is required, the third rotating shaft (425) is rotated to switch the direction of the pressing mechanism.

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