A resistance welding apparatus for a vehicle body floor assembly and a welding method thereof

Abstract

The application relates to the technical field of welding devices, and particularly discloses a vehicle body bottom plate assembly resistance welding device and a welding method thereof, which comprises an electrode, movable plates and pressure rollers. Two groups of movable plates connected with the two pressure rollers are unfolded and moved downward by rotating the two extension rods towards each other. The two groups of pressure rollers are moved away from each other by supporting the movable plates through the bending rods. The pressure rollers rotate while moving, and the pressure rollers roll the surface of the plate to make the surface of the plate flat. The top and bottom of the plate are rolled flat by the four pressure rollers. The pressure rollers apply pressure to the plate while rolling the plate, so that the plate is fixed after deformation. The plate is in a fixed state for a long time during spot welding, so that the plate is shaped after deformation, the plate is effectively prevented from rebounding after welding, the phenomenon of brittle cracking of the welding spot is effectively avoided, the effect of the welding spot is ensured, and the welding quality is ensured.

Description

Technical Field

[0001] This invention relates to the field of welding equipment technology, and in particular to a resistance welding device and welding method for a vehicle body floor assembly. Background Technology

[0002] In the vehicle body structure, the floor (including the front floor, rear floor, central tunnel, longitudinal beams, and transverse beams) is the basic part of the entire body frame. Welding firmly connects these individual stamped steel plates together to form an integral platform with sufficient strength, rigidity, and geometric precision. This platform is the "foundation" of the passenger compartment, engine compartment, and luggage compartment, and also the reference surface for installing suspension, powertrain, seats, interior and other systems.

[0003] Currently, resistance welding is generally used to weld the vehicle body floor. Resistance welding, also known as resistance spot welding, uses the resistance heat generated by current passing through the contact surface of the workpiece to melt the metal and form a weld point. During welding, the plates need to be stacked together. There may be gaps between the plates when they are stacked. Spot welding is then performed, and the weld point will merge the plates together. Because the plates have poor toughness and there are gaps between them, the pressure applied by the electrode must cause the plates to deform to close the gaps. After the weld point is formed, the plates will try to spring back to their original state, that is, to restore the gaps. This springback tendency stores tensile stress in the plates and concentrates it at the newly formed weld nugget. Since it is difficult for the plates to disperse these concentrated tensile stresses through plastic deformation, the weld point will undergo brittle cracking under the action of springback stress. This causes the weld point to gradually fail, reducing the welding effect and lowering the quality of the welded vehicle body. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a resistance welding device and welding method for a vehicle body floor assembly, thereby solving the technical problem that the weld joints may crack and fail when welding plates with gaps.

[0005] The objective of this invention can be achieved through the following technical solutions: A resistance welding device for a vehicle body floor assembly includes a robotic arm, a clamp mounted on the robotic arm, and two extension rods mounted on the clamp. The device further includes: The electrode has a U-shaped frame at the end of the extension rod, a telescopic component is installed on the U-shaped frame, a connecting rod is connected to the output end of the telescopic component, and an electrode is provided at the other end of the connecting rod. The two sets of electrodes are arranged opposite to each other, and the electrodes pass through the U-shaped frame. The movable plate has four bent rods on the side of the U-shaped frame away from the telescopic component. The other end of each bent rod is connected to a movable plate. The movable plate has a sliding groove, and the ends of the bent rods are slidably installed in the sliding groove. The four movable plates are arranged in two parallel groups. Adjacent movable plates are elastically hinged, and both movable plates tend to rotate toward each other. When the two movable plates rotate, their hinged ends move toward the U-shaped frame. Pressure rollers are rotatably mounted on both ends of two sets of parallel movable plates.

[0006] As a preferred embodiment of the above technical solution, a pressure plate is installed between the two sets of movable plates. A through hole is provided on the pressure plate. A guide frame is provided on the side of the movable plate facing the U-shaped frame. When the two movable plates are hinged together and are on a straight line, the ends of the two guide frames on the two movable plates are aligned and overlapped. Four guide posts are provided on both sides of the pressure plate. The four guide posts are slidably installed in the four guide frames. A drive assembly is installed on the connecting rod. The drive assembly is connected to the pressure plate and drives the pressure plate to move.

[0007] As a preferred embodiment of the above technical solution, the driving component includes a rotating ring rotatably mounted on a U-shaped frame. The electrode and connecting rod pass through the rotating ring. A guide groove is provided around the connecting rod, and a guide block is provided inside the rotating ring. The guide block is slidably mounted in the guide groove. When the connecting rod moves toward the pressure plate, the rotating ring rotates in both directions through the guide groove. A toothed ring is provided around the rotating ring. Two sets of collecting components are symmetrically mounted on the U-shaped frame. A toothed plate is movably connected between the two sets of collecting components. The toothed plate meshes with the toothed ring, and a connecting plate connects the toothed plate to the pressure plate.

[0008] As a preferred embodiment of the above technical solution, the collecting component two includes a sealing barrel two, which is installed on the side of the U-shaped frame. A piston two is movably installed inside the sealing barrel two. A push-pull rod two is provided on one side of the piston two. The push-pull rod two extends through the sealing barrel two and is fixedly connected to the end of the toothed plate three. A guide tube two is connected to the other end of the sealing barrel two. A suction groove one is opened in the pressure plate. The guide tube two is connected to the suction groove one. The suction groove one is connected to the through hole. A suction groove two is opened on the side of the pressure plate facing the pressure roller. The suction groove two is connected to the suction groove one. A discharge pipe is also connected to the sealing barrel two. Both the guide tube two and the discharge pipe are provided with one-way valves.

[0009] As a preferred embodiment of the above technical solution, the bottom of the pressure plate is provided with an outer hole, which is the same as the suction groove. The size of the outer hole is larger than the size of the through hole, and a wiping pad is installed on the bottom of the pressure plate.

[0010] As a preferred embodiment of the above technical solution, a collection assembly 1 is installed between the connecting rod and the pressure plate. The collection assembly 1 includes a sealing barrel 1, which is installed on the side of the U-shaped frame. A piston 1 is movably installed inside the sealing barrel 1. A push-pull rod 1 is provided on one side of the piston 1, extending through the sealing barrel 1. A transmission component is installed between the push-pull rod 1 and the connecting rod. The transmission component includes a toothed plate 1, a gear, and a toothed plate 2. The toothed plate 1 is provided on the connecting rod. The gear is rotatably installed on the U-shaped frame via a bracket. The gear meshes with the toothed plate 1. The toothed plate 2 is provided on the push-pull rod 1, meshing with the gear. A conical base is provided at the end of the inner cavity of the sealing barrel 1 away from the push-pull rod 1. A conical filter screen is installed inside the sealing barrel 1, located between the conical base and the piston 1. A conduit 1 is connected to the other end of the sealing barrel 1. A movable groove is opened inside the pressure plate, and the other end of the conduit 1 communicates with the movable groove.

[0011] As a preferred embodiment of the above technical solution, a scraping assembly is installed at the through hole of the pressure plate. The scraping assembly is close to the electrode. The scraping assembly includes a turbine fan. The movable groove is annular. The turbine fan is rotatably installed in the movable groove. A rotating cylinder is installed on the turbine fan. The rotating cylinder is located inside the through hole. Several scraper blades are provided on the inner wall of the rotating cylinder. Several support plates are installed at the end of the rotating cylinder away from the electrode. The several support plates are arranged in a ring array to form a sealed arc bottom. The several support plates are connected to the end of the rotating cylinder through an elastic connecting block. The elastic connecting block allows the support plates to rotate elastically. A receiving groove for accommodating the support plates is opened in the pressure plate. Scraper blades are provided on the support plates.

[0012] A welding method for a resistance welding apparatus for a vehicle body floor assembly, the method being applied to the resistance welding apparatus for a vehicle body floor assembly as described above, the method comprising the following steps: Step S1: Start the robotic arm to adjust the position of the clamps, and with the help of the two extension rods, position the two electrodes at the top and bottom of the plate respectively; Step S2: Start the clamp to make the two extension rods rotate in opposite directions, so that the pressure rollers contact the surface of the board. Several pressure rollers press the surface of the board. When the movable plate is in contact with the surface of the board, close the clamp. Several pressure rollers and several movable plates flatten the board. Step S3: Activate the telescopic component to move the electrode toward the plate, and further squeeze the plate through the drive assembly and pressure plate to keep the plate flat and in good contact; Step S4: When the electrode comes into contact with the plate, the electrode continues to move and presses the plate before stopping. Current is then applied to the electrode to complete the spot welding. After spot welding, the electrode is moved away from the plate, and at the same time, the two extension rods rotate in opposite directions to move the pressure roller away from the plate. The position of the clamp is adjusted to spot weld other parts of the plate.

[0013] The beneficial effects of this invention are as follows: 1. In this invention, by rotating two extension rods in opposite directions, two pressure rollers first contact the surface of the plate. As the rotation angle of the extension rods increases, the two pressure rollers will drive the two sets of movable plates connected to them to unfold and move downward. Supported by several bent rods, the two sets of pressure rollers move in opposite directions. At the same time, the pressure rollers rotate while moving, and the pressure rollers will roll and press the surface of the plate to make the surface of the plate flat. By rolling the top and bottom of the plate with four pressure rollers respectively, the top and bottom of the plate are rolled and flattened. When the pressure rollers rotate and roll and press the plate, they will apply pressure to the plate, thereby fixing the plate after deformation. When the electrodes are spot welded, the plate is in a fixed state for a long time, which promotes the shaping of the plate after deformation and effectively avoids the plate from springing back after welding. This effectively avoids the phenomenon of brittle cracking of the weld point, ensuring the effect of the weld point and ensuring the welding quality. 2. In this invention, the rolling range of the pressure roller is not limited to the weld point, but extends to the plate material near the weld point. This ensures that the plate material near the weld point is rolled and shaped, thus shifting the tensile stress that was originally concentrated near the weld point to a position farther away from the weld point. In other words, the tensile stress near the weld point is relatively reduced, which further effectively avoids the phenomenon of brittle cracking of the weld point, ensures the effect of the weld point, and ensures the welding quality. 3. In this invention, the electrode moves towards the plate material. When the connecting rod moves towards the plate material, the guide groove on the connecting rod cooperates with the guide block, causing the rotating ring to rotate clockwise and counterclockwise alternately, thereby causing the pressure plate to move back and forth. When the pressure plate moves back and forth, its bottom contacts the surface of the plate material, so that the pressure plate can further squeeze the surface of the plate material. The two pressure plates press the top and bottom of the plate material respectively, thereby keeping the surface of the plate material in a flat and close fit. With the pressure of several pressure rollers and several movable plates, the plate material near the weld point is further pressed and shaped, so that the tensile stress originally concentrated near the weld point is pushed to a position farther away from the weld point, effectively preventing the plate material from springing back after welding, and further effectively preventing the phenomenon of brittle cracking of the weld point, ensuring the effect of the weld point and ensuring the welding quality. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 Schematic diagram of clamp and extension rod structure; Figure 3 This is a schematic diagram of the upper and lower electrode structures; Figure 4 A schematic diagram of the electrode and its surrounding structure; Figure 5 This is a schematic diagram of the pressure roller and pressure plate structure; Figure 6 To collect schematic diagrams of the structure of Component 2 and the driver component; Figure 7A schematic diagram of the structure of component one is provided; Figure 8 This is a schematic diagram of the internal structure of the pressure plate; Figure 9 This is a schematic diagram of the scraping component structure; Figure 10 This is a schematic diagram of the structure after the scraping component is disassembled.

[0015] In the picture: 1. U-shaped frame; 2. Electrode; 21. Connecting rod; 211. Guide groove; 3. Bending rod; 4. Movable plate; 41. Pressure roller; 42. Slide groove; 43. Guide frame; 5. Pressure plate; 51. Guide column; 52. Through hole; 53. Movable groove; 54. Collection groove; 55. Suction groove one; 56. Suction groove two; 57. Outer hole; 58. Wiping pad; 6. Collection assembly one; 61. Sealing bucket one; 611. Conical base; 62. Piston one; 63. Push-pull rod one; 64. Transmission component; 641. Gear plate one; 642. Gear; 643. Gear Plate 2; 65. Conical filter screen; 66. Conduit 1; 7. Collection assembly 2; 71. Sealing barrel 2; 72. Piston 2; 73. Push-pull rod 2; 74. Conduit 2; 75. Discharge pipe; 8. Drive assembly; 81. Rotary ring; 811. Guide block; 82. Gear ring; 83. Gear plate 3; 831. Connecting plate; 9. Scraping assembly; 91. Turbine fan; 92. Rotary drum; 921. Scraper 1; 93. Support plate; 931. Elastic connecting block; 932. Scraper 2; 10. Telescopic component; 11. Extension rod; 12. Clamp; 13. Robotic arm. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] like Figures 1-6 As shown, a resistance welding device for a vehicle body floor assembly includes a robotic arm 13, a clamp 12 mounted on the robotic arm 13, and two extension rods 11 mounted on the clamp 12. The device further includes: Electrode 2, the end of extension rod 11 is provided with U-shaped frame 1, telescopic component 10 is installed on U-shaped frame 1, the output end of telescopic component 10 is connected to connecting rod 21, the other end of connecting rod 21 is provided with electrode 2, two sets of electrodes 2 are arranged opposite to each other, and electrode 2 passes through U-shaped frame 1. The movable plate 4 and the U-shaped frame 1 are provided with four bent rods 3 on the side away from the telescopic component 10. The other end of the bent rods 3 is connected to the movable plate 4. The movable plate 4 is provided with a sliding groove 42. The ends of the bent rods 3 are slidably installed in the sliding groove 42. The four movable plates 4 are arranged in two parallel groups. The two adjacent movable plates 4 are elastically hinged, and both movable plates 4 have a tendency to rotate towards each other. When the two movable plates 4 rotate, their hinged ends move towards the U-shaped frame 1. Pressure rollers 41 are rotatably mounted on both ends of two sets of parallel movable plates 4.

[0018] In one embodiment, a torsion spring can be provided at the hinged part of the two movable plates 4, so that the two movable plates 4 always tend to rotate toward each other. In the initial state, the two movable plates 4 are close to each other and located between two adjacent bent rods 3. The telescopic member 10 can be a cylinder or other components that can drive the electrode 2 to move and squeeze the plate. The robotic arm 13, the clamp 12 and the extension rod 11 are all prior art, and the present invention has not improved them, so there is no need to describe them in detail.

[0019] In practical application, the robotic arm 13 adjusts the position of the clamp 12 so that the two extension rods 11 are positioned at the top and bottom of the plate to be welded, respectively. This also positions the two electrodes 2 at the top and bottom of the plate. The clamp 12 then rotates the two extension rods 11 closer together. During rotation, the two pressure rollers 41 initially contact the plate surface. As the rotation angle of the extension rods 11 increases, the two pressure rollers 41 drive the two connected movable plates 4 to unfold and move downwards. Supported by several bent rods 3, the two sets of pressure rollers 41 move in opposite directions. Simultaneously, the pressure rollers 41 rotate during movement, pressing the plate surface to make it flat. This process, achieved through the four pressure rollers 41, results in a smooth surface. The top and bottom of the plate are pressed flat by rollers. When two adjacent movable plates 4 rotate to a horizontal position and are attached to the plate surface, the four pressure rollers 41 and the two sets of movable plates 4 fix the plate to be welded and the surrounding position, so that the top and bottom of the plate are in a flat and attached state when being welded, that is, there is no gap between the plates. When the pressure rollers 41 rotate and press the plate, they will apply pressure to the plate, thereby fixing the plate after deformation. When the electrode 2 performs spot welding, the plate is in a fixed state for a long time, which promotes the shaping of the plate after deformation and effectively prevents the plate from springing back after welding. This effectively prevents the phenomenon of brittle cracking of the weld point, ensuring the effect of the weld point and ensuring the welding quality. The rolling range of the pressure roller 41 is not limited to the weld point, but extends to the plate material near the weld point. This ensures that the plate material near the weld point is rolled and shaped, thus shifting the tensile stress that was originally concentrated near the weld point to a position farther away from the weld point. In other words, the tensile stress near the weld point is relatively reduced, which further effectively avoids brittle cracking of the weld point, ensuring the weld effect and welding quality. In the above solution, if the distance between the two weld points is too close, the tensile stress will still be near the weld point, and the weld point will still experience brittle cracking. However, if the distance between the two weld points is too close, the current will be shunted when the electrode 2 performs spot welding, resulting in weak or incomplete welds. Therefore, the above solution is suitable for welding where the distance between the two weld points is within the normal range. A cleaning cloth can be installed on the surface of the pressure roller 41. When the pressure roller 41 rotates, the cleaning cloth on the surface of the pressure roller 41 can clean the oil, paint, dust particles and rust and other contaminants attached to the surface of the plate. This keeps the area to be welded clean, thereby effectively avoiding the increase in contact resistance between the electrode 2 and the plate caused by these contaminants. It also avoids the possibility of insufficient current causing weak or incomplete welds due to these uncertain factors, thus ensuring the welding quality of the weld joint.

[0020] Furthermore, a pressure plate 5 is installed between the two sets of movable plates 4. A through hole 52 is provided on the pressure plate 5. A guide frame 43 is provided on the side of the movable plate 4 facing the U-shaped frame 1. When the two movable plates 4 are hinged together and are on a straight line, the ends of the two guide frames 43 on the two movable plates 4 are aligned and overlapped. Four guide posts 51 are provided on both sides of the pressure plate 5. The four guide posts 51 are slidably installed in the four guide frames 43. A drive assembly 8 is installed on the connecting rod 21. The drive assembly 8 is connected to the pressure plate 5 and drives the pressure plate 5 to move.

[0021] Furthermore, the drive assembly 8 includes a rotating ring 81, which is rotatably mounted on the U-shaped frame 1. The electrode 2 and the connecting rod 21 pass through the rotating ring 81. A guide groove 211 is provided on the periphery of the connecting rod 21, and a guide block 811 is provided on the inner side of the rotating ring 81. The guide block 811 is slidably mounted in the guide groove 211. When the connecting rod 21 moves toward the pressure plate 5, the rotating ring 81 rotates in both directions through the guide groove 211. A toothed ring 82 is provided on the periphery of the rotating ring 81. Two sets of collection assemblies 7 are symmetrically mounted on the U-shaped frame 1. A toothed plate 83 is movably connected between the two sets of collection assemblies 7. The toothed plate 83 meshes with the toothed ring 82. A connecting plate 831 connects the toothed plate 83 to the pressure plate 5.

[0022] In one embodiment, the guide groove 211 has a vertical section and a spiral section. The spiral section consists of several clockwise spiral grooves and several counterclockwise spiral grooves, which are alternately connected together. Two vertical grooves are provided at both ends of the spiral section.

[0023] In practical application, when the two sets of movable plates 4 are attached to the surface of the plate, the telescopic member 10 extends, causing the connecting rod 21 to move the electrode 2 toward the plate. As the connecting rod 21 moves toward the plate, the guide groove 211 on the connecting rod 21 engages with the guide block 811, causing the rotating ring 81 to rotate clockwise and counterclockwise alternately. This causes the toothed ring 82 to rotate in both directions, and the toothed plate 83 to move back and forth, thus causing the pressure plate 5 to move back and forth. When the pressure plate 5 moves back and forth, its bottom is in contact with... The two pressure plates 5 press against the top and bottom of the plate respectively, thus keeping the plate surface flat and in good contact. With the support of several pressure rollers 41 and several movable plates 4, the plate near the weld point is further pressed and shaped, and the tensile stress originally concentrated near the weld point is pushed to a position farther away from the weld point. This effectively prevents the plate from springing back after welding and further prevents brittle cracking of the weld point, ensuring the effect of the weld point and the quality of the welding.

[0024] When the guide block 811 moves to the vertical section of the guide groove 211, the rotating ring 81 stops rotating. By adjusting the guide groove 211, the through hole 52 of the guide block 811 coincides with the longitudinal direction of the electrode 2 when it enters the vertical section of the guide groove 211. When the electrode 2 continues to move downward, it passes through the through hole 52 and reaches the surface of the plate. At this time, when the electrode 2 is energized for spot welding, the weld point is pressed by the electrode 2, and the plate near the weld point is pressed by two pressure plates 5, as well as by several pressure rollers 41 and several movable plates 4. In this way, the plates are tightly fitted together during spot welding, thereby reducing the contact resistance between the electrode 2 and the plate, making the current distribution more uniform, thus making the weld nugget formation more stable, reducing weak welds and incomplete welds, making the size of the weld nugget more uniform, improving the shear strength of the weld point, effectively avoiding brittle cracking of the weld point, ensuring the effect of the weld point, and ensuring the welding quality.

[0025] like Figures 6-10 As shown, the collecting component 2 7 includes a sealing barrel 2 71, which is installed on the side of the U-shaped frame 1. A piston 2 72 is movably installed inside the sealing barrel 2 71. A push-pull rod 2 73 is provided on one side of the piston 2 72. The push-pull rod 2 73 extends through the sealing barrel 2 71 and is fixedly connected to the end of the toothed plate 3 83. The other end of the sealing barrel 2 71 is connected to a conduit 2 74. A suction groove 1 55 is opened in the pressure plate 5. The conduit 2 74 communicates with the suction groove 1 55. The suction groove 1 55 communicates with the through hole 52. A suction groove 2 56 is opened on the side of the pressure plate 5 facing the pressure roller 41. The suction groove 2 56 communicates with the suction groove 1 55. A discharge pipe 75 is also connected to the sealing barrel 2 71. Both the conduit 2 74 and the discharge pipe 75 are equipped with one-way valves.

[0026] Furthermore, the bottom of the pressure plate 5 is provided with an outer hole 57, which is connected to the suction groove 55. The size of the outer hole 57 is larger than the size of the through hole 52. A wiping pad 58 is installed at the bottom of the pressure plate 5.

[0027] It should be noted that the plate may produce fumes during spot welding. These fumes include zinc vapor or tiny particles (smoke-like) formed when the zinc layer of the plate (galvanized steel plate used in automobiles) melts and vaporizes due to localized high temperatures during spot welding. Additionally, contaminants such as oil, paint, dust particles, and rust on the plate surface may burn and decompose at high temperatures, producing organic fumes. These fumes may adhere to the surface of electrode 2 and the plate surface, forming an insulating layer. This increases the contact resistance between electrode 2 and the plate, resulting in weak or incomplete welds due to insufficient current.

[0028] In one embodiment, the one-way valves on the second conduit 74 and the discharge pipe 75 ensure that pollutants can only be discharged from the discharge pipe 75 and can only enter from the second conduit 74.

[0029] In practical application, during the movement of electrode 2 toward the plate, toothed plate 3 83 reciprocates left and right. This movement drives push-pull rod 2 73. When push-pull rod 2 73 moves toward toothed plate 3 83, piston 2 72 moves, reducing the pressure inside sealed barrel 2 71. This causes guide tube 2 74 to perform a suction action. As pressure plate 5 reciprocates, the wiping plate 58 at the bottom of pressure plate 5 wipes the plate surface. Combined with the initial cleaning by pressure roller 41, the plate surface is further cleaned. The dust or particles raised during cleaning pass through suction groove 1 55 and suction groove 2 56 and are sucked into sealed barrel 2 71 through guide tube 2 74, preventing these contaminants from re-entering the sealed barrel 2 71. The contaminants are initially attached to the surface of the plate. When the push-pull rod 73 moves away from the toothed plate 83, the piston 72 moves and the pressure inside the sealing barrel 71 increases. This causes the contaminants that have entered the sealing barrel 71 to be discharged through the discharge pipe 75. The discharge pipe 75 can be connected to an external collection box, where the contaminants are concentrated. In summary, through the movement of the pressure plate 5 and the cooperation of the collection component 7, the surface of the plate can be further cleaned, the area to be welded can be kept clean, and the increased contact resistance between the electrode 2 and the plate caused by these contaminants can be effectively avoided. This also avoids the possibility of insufficient current due to these uncertainties, resulting in weak or incomplete welds, thus ensuring the welding quality of the weld joint.

[0030] Furthermore, a collection assembly 6 is installed between the connecting rod 21 and the pressure plate 5. The collection assembly 6 includes a sealing barrel 61, which is installed on the side of the U-shaped frame 1. A piston 62 is movably installed inside the sealing barrel 61. A push-pull rod 63 is provided on one side of the piston 62, extending through the sealing barrel 61. A transmission component 64 is installed between the push-pull rod 63 and the connecting rod 21. The transmission component 64 includes a toothed plate 641, a gear 642, and a second toothed plate 643. The toothed plate 641 is provided on the connecting rod 21. The U-shaped frame 1 is supported by... The frame is rotatably mounted with a gear 642, which meshes with a toothed plate 641. A toothed plate 643 is mounted on a push-pull rod 63, which meshes with the gear 642. A conical base 611 is provided at the end of the inner cavity of the sealing barrel 61 away from the push-pull rod 63. A conical filter 65 is installed inside the sealing barrel 61, located between the conical base 611 and the piston 62. The other end of the sealing barrel 61 is connected to a conduit 66. A movable groove 53 is opened in the pressure plate 5, and the other end of the conduit 66 communicates with the movable groove 53.

[0031] Furthermore, a scraping assembly 9 is installed at the through hole 52 of the pressure plate 5. The scraping assembly 9 is close to the electrode 2. The scraping assembly 9 includes a turbine fan 91. The movable groove 53 is annular. The turbine fan 91 is rotatably installed in the movable groove 53. A rotating cylinder 92 is installed on the turbine fan 91. The rotating cylinder 92 is located inside the through hole 52. Several scraper blades 921 are provided on the inner wall of the rotating cylinder 92. Several support plates 93 are installed at the end of the rotating cylinder 92 away from the electrode 2. The several support plates 93 are arranged in a ring array to form a sealed arc bottom. The several support plates 93 are connected to the end of the rotating cylinder 92 through an elastic connecting block 931. The elastic connecting block 931 makes the support plates 93 rotate elastically. A receiving groove 54 is opened in the pressure plate 5 to accommodate the support plates 93. Scraper blades 932 are provided on the support plates 93.

[0032] In one embodiment, the rotating part of the turbine fan 91 may be equipped with a bearing, so that after the turbine fan 91 rotates, it continues to rotate due to inertia until the inertia disappears and it stops rotating without a power source.

[0033] In practical application, when electrode 2 moves downward and pressure plate 5 stops moving, toothed plate 641 on connecting rod 21 moves toward gear 642, causing gear 642 to rotate. The rotation of gear 642 causes toothed plate 643 to move, which in turn drives push-pull rod 63 to move away from sealing barrel 61. The movement of piston 62 reduces the pressure inside sealing barrel 61, causing conduit 66 to perform a suction action, thereby rotating turbine fan 91, rotating drum 92 and several support plates 93. When electrode 2 extends into drum 92, several scrapers 92 on the inner wall of drum 92... The electrode 1 will rotate along the surface of electrode 2, thereby scraping off the smoke adhering to the surface of electrode 2. At the same time, when the end of electrode 2 contacts several support plates 93, the scraper 932 on the support plate 93 will scrape off the smoke adhering to the end of electrode 2. As electrode 2 continues to move, it will spread out several support plates 93 and gradually press against the surface of the plate. In this way, the smoke adhering to the surface and end of electrode 2 is cleaned before the electrode 2 is spot welded, which further effectively avoids these contaminants from increasing the contact resistance between electrode 2 and plate, and avoids these uncertain factors from causing insufficient current, resulting in weak welding or incomplete welding, thereby ensuring the welding quality of the weld point. The cleaned-up smoke enters the sealed container 61 under the guidance of the turbine fan 91 and the duct 66, preventing the cleaned-up smoke from re-adhering to the electrode 2 or the plate surface. After entering the sealed container 61, the smoke is filtered by the conical filter 65 and stored at the inclined bottom of the conical base 611. A discharge valve can be installed on the sealed container 61 to clean up the smoke regularly. When electrode 2 comes into contact with the plate, the conduit 66 stops its suction action, while the turbine fan 91 continues to rotate due to inertia. At this time, electrode 2 is spot welded. The fumes generated during spot welding are guided upward by the turbine fan 91. Part of the fumes enter the suction groove 55 through the outer hole 57, and the other part enters the movable groove 53 or the conduit 66. This effectively prevents the fumes generated during spot welding from adhering to the surface of electrode 2 or the plate. It further effectively prevents these contaminants from increasing the contact resistance between electrode 2 and the plate, and avoids these uncertain factors from causing insufficient current, resulting in weak welding or incomplete welding, thereby ensuring the welding quality of the weld point. When electrode 2 is welded and moved away from the plate, push-pull rod 63 moves piston 62, which compresses the air in sealed barrel 61 into duct 66 and blows it towards turbine fan 91. At this time, turbine fan 91 blows air into pressure plate 5 in the opposite direction. Because several support plates 93 are spread open and block electrode 2, the smoke blown out of duct 66 flows downward into suction groove 55, effectively preventing smoke from contacting the surface of electrode 2. When turbine fan 91 rotates, because several support plates 93 are in a spread-open state, under the action of centrifugal force, several support plates 93 continue to expand outward. In this way, electrode 2 is not easily blocked by several support plates 93 when it moves; as electrode 2 continues to move, even if there is smoke on the surface of electrode 2, the smoke on the surface of electrode 2 will still be cleaned off by several scrapers 921, so that the surface of electrode 2 remains clean after it moves away from pressure plate 5. The cleaned-off smoke is blown into suction groove 55. When guide block 811 enters the spiral section of guide groove 211, pressure plate 5 begins to move back and forth, thereby cleaning the surface of the plate. The smoke originally located in suction groove 55 and the pollutants cleaned off at this time are sucked into sealed container 71 through conduit 74 to ensure that the surface of the plate is clean.

[0034] A welding method for a resistance welding apparatus for a vehicle body floor assembly, the method being applied to the resistance welding apparatus for a vehicle body floor assembly as described above, the method comprising the following steps: Step S1: Start the robotic arm 13 to adjust the position of the clamp 12. Under the action of the two extension rods 11, the two electrodes 2 are respectively located at the top and bottom of the plate. Step S2: Start clamp 12 to make the two extension rods 11 rotate towards each other, so that the pressure roller 41 contacts the surface of the board. Several pressure rollers 41 roll the surface of the board. When the movable plate 4 is in contact with the surface of the board, close clamp 12. Several pressure rollers 41 and several movable plates 4 flatten the board. Step S3: Activate the telescopic component 10 to move the electrode 2 toward the plate, and further squeeze the plate through the drive component 8 and the pressure plate 5 to keep the plate flat and in good contact; Step S4: When electrode 2 comes into contact with the plate, electrode 2 continues to move and presses the plate before stopping. Current is applied to electrode 2 to complete spot welding. After spot welding, electrode 2 is moved away from the plate, and at the same time, the two extension rods 11 rotate in opposite directions to move the pressure roller 41 away from the plate. The position of clamp 12 is adjusted to spot weld other parts of the plate.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A resistance welding device for a vehicle body floor assembly, comprising a robotic arm (13), a clamp (12) mounted on the robotic arm (13), and two extension rods (11) mounted on the clamp (12), characterized in that, The device further includes: Electrode (2), the end of the extension rod (11) is provided with a U-shaped frame (1), a telescopic component (10) is installed on the U-shaped frame (1), the output end of the telescopic component (10) is connected to a connecting rod (21), the other end of the connecting rod (21) is provided with an electrode (2), the two sets of electrodes (2) are arranged opposite to each other, and the electrode (2) passes through the U-shaped frame (1); The movable plate (4) has four bent rods (3) on the side of the U-shaped frame (1) away from the telescopic member (10). The other end of the bent rod (3) is connected to the movable plate (4). The movable plate (4) has a sliding groove (42). The end of the bent rod (3) is slidably installed in the sliding groove (42). The four movable plates (4) are arranged in two parallel groups. The two adjacent movable plates (4) are elastically hinged, and both movable plates (4) tend to rotate towards each other. When the two movable plates (4) rotate, their hinged ends move towards the U-shaped frame (1). Pressure rollers (41) are rotatably installed at both ends of two sets of parallel movable plates (4). A pressure plate (5) is installed between the two sets of movable plates (4). A through hole (52) is provided on the pressure plate (5). A guide frame (43) is provided on the side of the movable plate (4) facing the U-shaped frame (1). When the two movable plates (4) are hinged together and are on a straight line, the ends of the two guide frames (43) on the two movable plates (4) are aligned. Four guide posts (51) are provided on both sides of the pressure plate (5). The four guide posts (51) are slidably installed in the four guide frames (43). A drive assembly (8) is installed on the connecting rod (21). The drive assembly (8) is connected to the pressure plate (5) and drives the pressure plate (5) to move. The driving component (8) includes a rotating ring (81), which is rotatably mounted on the U-shaped frame (1). The electrode (2) and the connecting rod (21) pass through the rotating ring (81). A guide groove (211) is provided around the connecting rod (21). A guide block (811) is provided inside the rotating ring (81). The guide block (811) is slidably mounted in the guide groove (211). When the connecting rod (21) moves toward the pressure plate (5), the rotating ring (81) rotates forward and backward through the guide groove (211). A toothed ring (82) is provided around the rotating ring (81). Two sets of collection components (7) are symmetrically mounted on the U-shaped frame (1). A toothed plate (83) is movably connected between the two sets of collection components (7). The toothed plate (83) meshes with the toothed ring (82). A connecting plate (831) is connected between the toothed plate (83) and the pressure plate (5).

2. The resistance welding apparatus for the vehicle body floor assembly according to claim 1, characterized in that, The collecting component two (7) includes a sealing barrel two (71), which is installed on the side of the U-shaped frame (1). A piston two (72) is movably installed inside the sealing barrel two (71). A push-pull rod two (73) is provided on one side of the piston two (72). The push-pull rod two (73) extends through the sealing barrel two (71) and is fixedly connected to the end of the toothed plate three (83). The other end of the sealing barrel two (71) is connected to a conduit two (74). The pressure plate (5) has a suction groove (55) inside. The guide tube (74) is connected to the suction groove (55). The suction groove (55) is connected to the through hole (52). The pressure plate (5) has a suction groove (56) on the side facing the pressure roller (41). The suction groove (56) is connected to the suction groove (55). The sealing barrel (71) is also connected to a discharge pipe (75). Both the guide tube (74) and the discharge pipe (75) are equipped with one-way valves.

3. The resistance welding apparatus for the vehicle body floor assembly according to claim 2, characterized in that, The pressure plate (5) has an outer hole (57) at the bottom, which is connected to the suction groove (55). The size of the outer hole (57) is larger than that of the through hole (52). A wiping pad (58) is installed at the bottom of the pressure plate (5).

4. The resistance welding apparatus for the vehicle body floor assembly according to claim 1, characterized in that, A collection assembly (6) is installed between the connecting rod (21) and the pressure plate (5). The collection assembly (6) includes a sealing barrel (61), which is installed on the side of the U-shaped frame (1). A piston (62) is movably installed inside the sealing barrel (61). A push-pull rod (63) is provided on one side of the piston (62). The push-pull rod (63) extends through the sealing barrel (61). A transmission component (64) is installed between the push-pull rod (63) and the connecting rod (21). The transmission component (64) includes a toothed plate (641), a gear (642), and a toothed plate (643). The toothed plate (641) is provided on the connecting rod (21). The U-shaped frame (1) passes through... The bracket is rotatably mounted with a gear (642), which meshes with a toothed plate (641). A toothed plate (643) is provided on the push-pull rod (63), which meshes with the gear (642). A conical base (611) is provided at the end of the inner cavity of the sealing barrel (61) away from the push-pull rod (63). A conical filter (65) is installed inside the sealing barrel (61), which is located between the conical base (611) and the piston (62). The other end of the sealing barrel (61) is connected to a conduit (66). A movable groove (53) is opened in the pressure plate (5), and the other end of the conduit (66) is connected to the movable groove (53).

5. The vehicle floor panel assembly resistance welding apparatus according to claim 4, wherein, A scraping assembly (9) is installed at the through hole (52) of the pressure plate (5). The scraping assembly (9) is close to the electrode (2). The scraping assembly (9) includes a turbine fan (91). The movable groove (53) is annular. The turbine fan (91) is rotatably installed in the movable groove (53). A rotating cylinder (92) is installed on the turbine fan (91). The rotating cylinder (92) is located inside the through hole (52). Several scraper blades (921) are provided on the inner wall of the rotating cylinder (92). The rotating drum (92) is equipped with several support plates (93) at the end away from the electrode (2). The support plates (93) are arranged in a ring to form a sealed arc bottom. The support plates (93) are connected to the end of the rotating drum (92) through elastic connecting blocks (931). The elastic connecting blocks (931) make the support plates (93) rotate elastically. The pressure plate (5) has a storage groove (54) for accommodating the support plates (93). The support plates (93) are provided with scraper two (932).

6. A welding method for a resistance welding apparatus for a vehicle body floor assembly, the method being applied to the resistance welding apparatus for a vehicle body floor assembly as described in any one of claims 1-5, the method comprising the following steps: Step S1: Start the robotic arm (13) and adjust the position of the clamp (12). Under the action of the two extension rods (11), the two electrodes (2) are positioned at the top and bottom of the plate respectively. Step S2: Start the clamp (12) to make the two extension rods (11) rotate towards each other, so that the pressure roller (41) contacts the surface of the board. Several pressure rollers (41) roll the surface of the board. When the movable plate (4) is in contact with the surface of the board, close the clamp (12). Several pressure rollers (41) and several movable plates (4) flatten the board. Step S3: Activate the telescopic component (10) to move the electrode (2) toward the plate, and further squeeze the plate through the drive component (8) and the pressure plate (5) to keep the plate flat and in good contact; Step S4: When the electrode (2) comes into contact with the plate, the electrode (2) continues to move and presses the plate before stopping. Current is passed into the electrode (2) to complete the spot welding. After spot welding, the electrode (2) is moved away from the plate, and the two extension rods (11) rotate in opposite directions to move the pressure roller (41) away from the plate. The position of the clamp (12) is adjusted to spot weld other positions on the plate.

Images