Bridge support welding tool and welding method

Abstract

The invention relates to a bridge support welding tool and a welding method. Comprising a base, a rotating plate arranged on the base, a bearing plate rotationally connected with the rotating plate, and a plurality of positioning blocks arranged on the peripheral side of the bearing plate in a sliding mode. The adjusting cylinder is arranged between the base and the rotating plate and used for adjusting the inclination angle of the rotating plate; the conveying mechanism is arranged on the side, away from the base, of the bearing plate; double positioning of the lower support plate and the limiting strip is achieved through the positioning block, the posture of the lower support plate is corrected through primary positioning, the lower support plate and the limiting strip are synchronously clamped through secondary positioning, and deviation caused by workpiece displacement and thermal deformation in the welding process is effectively avoided; meanwhile, the positioning block reserves a welding seam gap, the welding seam integrity is not affected, and the overall assembly precision of the bridge support is improved.

Description

Technical Field

[0001] This invention relates to the field of welding technology, specifically to a welding fixture and welding method for bridge bearings. Background Technology

[0002] As a core load-bearing component in bridge structures, bridge bearings directly determine the load-bearing stability and service life of the bridge through their connection strength and installation accuracy. In the production process of bridge bearings, the welding process between the lower bearing plate and the limiting strip is a critical step. The welding accuracy of the limiting strip directly affects the accuracy of subsequent observations of the displacement scale of the upper bearing plate, thus impacting the overall performance of the bridge bearing.

[0003] Currently, although specialized welding fixtures are used for bridge bearing welding operations, these fixtures still have many technical shortcomings, making it difficult to meet the demands of high-precision and high-efficiency production. Firstly, positioning accuracy is insufficient. Existing fixtures have simple positioning structures, often only able to roughly position the lower bearing plate. The locating strip is prone to shifting after placement, and the workpiece is also susceptible to displacement due to thermal deformation during welding, resulting in poor weld consistency between the locating strip and the lower bearing plate, affecting the accuracy of subsequent displacement calibration. Secondly, the welding posture adjustment capability is weak. Existing fixtures are mostly fixed structures or can only achieve simple angle adjustments, unable to adapt to the welding requirements of the inner and outer welds of the locating strip. The internal weld seam has a narrow operating space, hindering the movement of the welding torch and making it difficult to observe the molten pool, which easily leads to problems such as incomplete penetration and poor weld formation. Thirdly, the welding efficiency is low. Existing tooling is mostly configured with a single station or a single welding torch, requiring the welding of the inner and outer weld seams of each limit bar to be completed one by one. After welding, it is necessary to wait for the workpiece to cool down, resulting in poor process connection and inability to achieve synchronous operation. Fourthly, the automation adaptability is poor. Some tooling still requires manual assistance to complete operations such as limit bar placement and welding position calibration, which is labor-intensive and prone to workpiece damage due to human error, affecting the product qualification rate. At the same time, the tooling lacks versatility and is difficult to adapt to the welding requirements of different specifications of bridge bearings.

[0004] In view of the shortcomings of the existing technology, there is an urgent need for a bridge bearing welding fixture and welding method that can achieve precise positioning, flexible adjustment of workpiece posture, and improve welding efficiency and quality, so as to solve the problems of inaccurate positioning, difficult operation and low efficiency in the existing welding process. Summary of the Invention

[0005] In order to solve the above-mentioned problems in the existing technology, the present invention aims to provide a bridge bearing welding fixture and welding method.

[0006] The technical solution adopted in this invention is as follows: A bridge bearing welding fixture and welding method includes a base, a rotating plate disposed on the base, a bearing plate rotatably connected to the rotating plate, a plurality of positioning blocks slidably disposed on the periphery of the bearing plate, an adjusting cylinder disposed between the base and the rotating plate for adjusting the tilt angle of the rotating plate, and a conveying mechanism disposed on the side of the bearing plate away from the base. The bridge bearing includes a lower bearing plate, a plurality of limiting strips disposed on the lower bearing plate, and an upper bearing plate. The welding fixture is used to weld the lower bearing plate and the plurality of limiting strips.

[0007] As a preferred embodiment of the present invention, a support frame is fixedly provided on the side of the base near the lower support plate, a rotating shaft is fixedly provided on the rotating plate, the rotating shaft is rotatably connected to the end of the support frame away from the base, a fixed seat is provided on one side of the support frame and fixedly connected to the base, and the cylinder barrel and piston rod of the adjusting cylinder are rotatably connected to the fixed seat and the rotating plate respectively.

[0008] As a preferred embodiment of the present invention, an adjusting motor is fixedly provided at one end of the rotating plate near the base, the output shaft of the adjusting motor passes through and is rotatably connected to the rotating plate, and the output shaft of the adjusting motor is fixedly connected to the bearing plate.

[0009] As a preferred embodiment of the present invention, a plurality of extension plates are fixedly provided on the periphery of the bearing plate, and the plurality of extension plates correspond one-to-one with the plurality of positioning blocks. Each extension plate is provided with a positioning cylinder at one end near the base. The cylinder barrel of the positioning cylinder is fixedly connected to the extension plate. A connecting plate is fixedly provided on the piston rod of the positioning cylinder, and the positioning block is mounted on the connecting plate.

[0010] As a preferred embodiment of the present invention, a connecting groove is provided on one side of the positioning block, and the positioning block is connected to the connecting plate through the connecting groove. A surface positioning part is provided at one end of the connecting groove, and an end positioning part one and an end positioning part two are respectively provided on both sides of the connecting groove. The surface positioning part is used to contact the surface of the lower support plate, the end positioning part one is used to abut against the end of the limiting strip, and the end positioning part two is used to abut against the side of the lower support plate.

[0011] As a preferred embodiment of the present invention, the conveying mechanism includes a mounting plate, a plurality of suction cups disposed on the mounting plate, and a plurality of limiting cylinders disposed on the side of the mounting plate away from the suction cups; the suction cups are used to adsorb the lower support plate, the cylinder of the limiting cylinder is fixedly connected to the mounting plate, one end of the piston rod of the limiting cylinder is fixedly provided with an abutment plate, and the plurality of abutment plates cooperate with the inner side of the limiting strip.

[0012] As a preferred embodiment of the present invention, it further includes two welding machines, each of which includes a welding torch. An inner weld is formed between the inner side of the limiting strip and the lower support plate, and an outer weld is formed between the outer side of the limiting strip and the lower support plate. The two welding torches cooperate with the limiting strips on opposite sides, with one welding torch used for welding the inner weld and the other welding torch used for welding the outer weld.

[0013] As a preferred embodiment of the present invention, a plurality of suspension ropes are fixedly provided on the side of the mounting plate away from the suction cup, the conveying mechanism is connected to the suspended conveyor through the suspension ropes, and the suction cup is connected to the air pump.

[0014] A bridge bearing welding method is disclosed, wherein the bridge bearing includes a lower bearing plate and an upper bearing plate, and a stainless steel plate, a flat polytetrafluoroethylene plate, a spherical steel liner plate, and a spherical polytetrafluoroethylene plate are disposed between the lower bearing plate and the upper bearing plate. Four limiting strips are provided on the periphery of the lower bearing plate, and four displacement scales are provided on the periphery of the upper bearing plate. The limiting strips are provided with observation marks that cooperate with the displacement scales. A temporary connecting piece is provided between the lower bearing plate and the upper bearing plate located on the periphery of the spherical steel liner plate. The connection method between the lower bearing plate and the limiting strips is welding. The welding method includes the following steps: S1. Loading: The adjusting cylinder is used to control the level of the rotating plate and the bearing plate, and the conveying mechanism is used to transport the lower support plate to the top of the bearing plate. S2. First positioning; control the positioning block to slide relative to the bearing plate, the positioning block clamps the four corners of the lower support plate to position the lower support plate, and the positioning block resets after positioning is completed; S3. Secondary positioning: Using a mechanical gripper, place the four limiting strips on the upper side of the lower support plate respectively, and control the positioning block to slide relative to the bearing plate again. The positioning block simultaneously clamps the four corners of the lower support plate and the four limiting strips, positioning the lower support plate and the four limiting strips. After positioning is completed, control the positioning block to maintain the current state. S4. Adjust the posture; use the adjusting cylinder to control the rotating plate, the bearing plate, the lower support plate and the limiting strip to rotate synchronously, and adjust the tilt angle of the lower support plate. S5. Welding; The welding machine is started to weld the two limit strips on the upper and lower sides respectively; S6. Adjust the welding position; control the bearing plate to rotate relative to the rotating plate, the lower support plate and the limiting strip rotate synchronously with the bearing plate, and the welding machine welds the lower support plate and the limiting strip again after rotation; S7. Unloading: The adjusting cylinder is used to control the horizontal level of the bearing plate and the positioning block to reset. The conveying mechanism is used to unload the workpiece after welding.

[0015] As a preferred embodiment of the present invention, in step S6, the welding machine sequentially welds the two limiting strips located on the upper and lower sides after each rotation by rotating 90 degrees, and the welding is completed after three rotations.

[0016] The beneficial effects of this invention are as follows: As a welding fixture and method for bridge bearings, this invention achieves dual positioning of the lower bearing plate and the limiting strip through a positioning block. The first positioning corrects the posture of the lower bearing plate, and the second positioning simultaneously clamps the lower bearing plate and the limiting strip, effectively avoiding deviations caused by workpiece displacement and thermal deformation during welding. At the same time, the positioning block reserves a weld gap, which does not affect the integrity of the weld and improves the overall assembly accuracy of the bridge bearing. The adjusting cylinder can drive the rotating plate to tilt the workpiece, so that both the inner and outer welds can be presented with the bevel facing upwards, expanding the operating field of vision and working space, facilitating the observation of the molten pool formation and weld formation, and accurately controlling the welding speed and filling amount. This solves the problems of limited operating space for the inner weld and obstructed movement of the welding torch in traditional processes, improves the weld formation quality, and avoids defects such as incomplete penetration and slag inclusions. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0018] Figure 1 This is an exploded structural diagram of the present invention; Figure 2 This is the present invention. Figure 1 A schematic diagram of the structure after installation; Figure 3 This is the present invention. Figure 2 A front view structural diagram; Figure 4 This is the present invention. Figure 1 A schematic diagram of the positioning block structure; Figure 5 This is the present invention. Figure 2 A schematic diagram of the structure that works in conjunction with the conveying mechanism; Figure 6 This is the present invention. Figure 5 A schematic diagram of the conveying mechanism structure; Figure 7 This is the present invention. Figure 2 A schematic diagram of the structure used in conjunction with an electric welding machine; Figure 8 This is the present invention. Figure 7 A front view structural diagram; Figure 9 This is a schematic diagram of the structure of the bridge support welded according to the present invention; Figure 10 This is the present invention. Figure 9 A schematic diagram of the explosion structure. Detailed Implementation

[0019] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0020] Combination Figures 1-10 A bridge bearing welding fixture includes a base 23, a rotating plate 22 disposed on the base 23, a bearing plate 19 rotatably connected to the rotating plate 22, a plurality of positioning blocks 14 slidably disposed around the bearing plate 19, an adjusting cylinder 20 disposed between the base 23 and the rotating plate 22 for adjusting the tilt angle of the rotating plate 22, and a conveying mechanism 29 disposed on the side of the lower bearing plate 19 away from the base 23. The adjusting cylinder 20 is used to adjust the angle of the lower bearing plate 11, so that the weld between the lower bearing plate 11 and the limiting strip 12 corresponds to the execution end of the electric welding machine at a certain angle, reducing the welding difficulty. The inner weld 39 and the outer weld 40 face upward at the same angle, solving the problem that the narrow operating space of the inner weld 39 makes it inconvenient to move the electric welding machine. The bevel angles of the inner and outer welds are consistent, avoiding insufficient accuracy of the limiting strip 12 due to welding deformation, so that the displacement of the welded bridge bearing can be accurately displayed.

[0021] The bridge bearing includes a lower bearing plate 11, a plurality of limiting strips 12 disposed on the lower bearing plate 11, and an upper bearing plate 35. The welding fixture is used to weld the lower bearing plate 11 and the plurality of limiting strips 12. The positioning block 14 performs targeted positioning of the lower bearing plate 11 and the limiting strips 12 respectively to ensure the accuracy of subsequent welding.

[0022] Advantageously, a support frame 18 is fixedly provided on the side of the base 23 near the lower support plate 11, and a rotating shaft 17 is fixedly provided on the rotating plate 22. The rotating shaft 17 is rotatably connected to the end of the support frame 18 away from the base 23. A fixed seat 21 fixedly connected to the base 23 is provided on one side of the support frame 18. The cylinder and piston rod of the adjusting cylinder 20 are rotatably connected to the fixed seat 21 and the rotating plate 22, respectively. The adjusting cylinder 20 controls the lower support plate 11 to rotate at a certain angle so that the weld bevel faces upward. The upward bevel has a wide field of vision and a large operating space, allowing direct observation of the formation of the molten pool and the weld formation, making it easier to control the welding speed and filling amount.

[0023] Advantageously, an adjusting motor 24 is fixedly mounted on one end of the rotating plate 22 near the base 23. The output shaft of the adjusting motor 24 passes through and is rotatably connected to the rotating plate 22, and the output shaft of the adjusting motor 24 is fixedly connected to the bearing plate 19. The adjusting motor 24 is used to change the proximity of different limit bars 12 to the welding machine, simplifying the movement path of the welding machine and allowing the workpiece to actively seek the welding machine at its welding position.

[0024] Advantageously, a plurality of extension plates 16 are fixedly provided on the periphery of the support plate 19, and each of the extension plates 16 corresponds one-to-one with a plurality of positioning blocks 14. Each extension plate 16 is provided with a positioning cylinder 15 at one end near the base 23. The cylinder barrel of the positioning cylinder 15 is fixedly connected to the extension plate 16, and a connecting plate 13 is fixedly provided on the piston rod of the positioning cylinder 15. The positioning blocks 14 are installed on the connecting plate 13. The positioning blocks 14 clamp the lower support plate 11 from the four corners and simultaneously position the limiting strip 12.

[0025] Advantageously, a connecting groove 25 is provided on one side of the positioning block 14, and the positioning block 14 is connected to the connecting plate 13 through the connecting groove 25. A surface positioning part 26 is provided at one end of the connecting groove 25, and an end positioning part 27 and an end positioning part 28 are respectively provided on both sides of the connecting groove 25. The surface positioning part 26 is used to contact the surface of the lower support plate 11, the end positioning part 27 is used to abut against the end of the limiting strip 12, and the end positioning part 28 is used to abut against the side of the lower support plate 11. There is a reserved gap between the end positioning part 27 and the end positioning part 28 to prevent contact with the end of the limiting strip 12, which does not affect the integrity of the weld of the limiting strip 12.

[0026] Advantageously, the conveying mechanism 29 includes a mounting plate 30, a plurality of suction cups 33 disposed on the mounting plate 30, and a plurality of limiting cylinders 32 disposed on the side of the mounting plate 30 away from the suction cups 33. The suction cups 33 are used to adsorb the lower support plate 11. The cylinder of the limiting cylinder 32 is fixedly connected to the mounting plate 30. One end of the piston rod of the limiting cylinder 32 is fixedly provided with an abutment plate 31. The plurality of abutment plates 31 cooperate with the inner side of the limiting strip 12. When the mechanical gripper places the limiting strip 12, the abutment plate 31 needs to restrict the position of the limiting strip 12 from the inside. After the positioning block 14 moves, it ensures that the limiting strip 12 can be located at the edge of the lower support plate 11.

[0027] Advantageously, the system also includes two welding machines, each comprising a welding torch 34. An inner weld 39 is formed between the inner edge of the limiting strip 12 and the lower support plate 11, and an outer weld 40 is formed between the outer edge of the limiting strip 12 and the lower support plate 11. The two welding torches 34 respectively cooperate with the limiting strips 12 on opposite sides. One welding torch 34 is used to weld the inner weld 39, and the other welding torch 34 is used to weld the outer weld 40. The two welding torches 34 not only improve welding efficiency but also solve the problem of inconsistent welding difficulty between the inner and outer sides, effectively utilizing the idle space of the welding fixture. The two welding torches 34 weld the inner weld 39 and the outer weld 40 respectively. When welding the other side of a limiting strip 12 again, the rotation of the lower support plate 11 and the welding process of the adjacent limiting strip 12 provide sufficient cooling time for that limiting strip 12.

[0028] Advantageously, a plurality of suspension ropes 41 are fixedly provided on the side of the mounting plate 30 away from the suction cup 33. The conveying mechanism 29 is connected to the suspended conveyor via the suspension ropes 41, and the suction cup 33 is connected to the air pump. When the suspension ropes 41 are in a slack state, relative displacement with the suspended conveyor is allowed, which facilitates the calibration of the lower support plate 11.

[0029] A bridge bearing welding method is disclosed. The bridge bearing includes a lower bearing plate 11 and an upper bearing plate 35. A stainless steel plate, a flat polytetrafluoroethylene plate, a spherical steel liner, and a spherical polytetrafluoroethylene plate are disposed between the lower bearing plate 11 and the upper bearing plate 35. This part of the structure requires subsequent assembly and is not shown in the attached drawings. Four limiting strips 12 are provided on the periphery of the lower bearing plate 11, and four displacement scales 37 are provided on the periphery of the upper bearing plate 35. The limiting strips 12 are provided with observation marks 36 that cooperate with the displacement scales 37. A temporary connecting piece 38 is provided between the lower bearing plate 11 and the upper bearing plate 35 located on the periphery of the spherical steel liner. The lower bearing plate 11 and the limiting strips 12 are connected by welding. The welding method includes the following steps: S1. Loading: The adjusting cylinder 20 is used to control the rotating plate 22 and the bearing plate 19 to be horizontal, and the conveying mechanism 29 is used to convey the lower support plate 11 to the top of the bearing plate 19. S2, First positioning; control the positioning block 14 to slide relative to the bearing plate 19, the positioning block 14 clamps the four corners of the lower support plate 11 to position the lower support plate 11, and the positioning block 14 is reset after positioning is completed; S3. Secondary positioning: Using a mechanical gripper, place the four limiting strips 12 on the upper side of the lower support plate 11 respectively, and control the positioning block 14 to slide relative to the bearing plate 19 again. The positioning block 14 simultaneously clamps the four corners of the lower support plate 11 and the four limiting strips 12 to position the lower support plate 11 and the four limiting strips 12. After positioning is completed, control the positioning block 14 to maintain the current state. S4. Adjust the posture; use the adjusting cylinder 20 to control the rotating plate 22, the bearing plate 19, the lower support plate 11 and the limiting strip 12 to rotate synchronously, and adjust the tilt angle of the lower support plate 11. S5. Welding; The welding machine is started to weld the two limiting strips 12 on the upper and lower sides respectively; S6. Adjust the welding position; control the bearing plate 19 to rotate relative to the rotating plate 22, the lower support plate 11 and the limiting strip 12 rotate synchronously with the bearing plate 19, and the welding machine welds the lower support plate 11 and the limiting strip 12 again after rotation. S7. Unloading: The adjusting cylinder 20 is used to control the horizontal level of the bearing plate 19, and the positioning block 14 is controlled to reset. The conveying mechanism 29 is used to unload the workpiece after welding.

[0030] Advantageously, in step S6, the welding machine welds the two limiting strips 12 located on the upper and lower sides after each 90-degree rotation, and the welding is completed after three rotations.

[0031] Working principle of this invention: In the initial state, the support plate 19 is horizontal and the multiple positioning blocks 14 are far apart from each other.

[0032] The execution unit of the overhead conveyor moves to the stacking location of the lower support plate 11, the air pump starts, the suction cup 33 picks up the uppermost target lower support plate 11, the overhead conveyor controls the movement of the target lower support plate 11, and the suspension rope 41 is taut during this process. The lower support plate 11 moves to fall directly above the bearing plate 19, allowing for a small deviation in the placement position. After the lower support plate 11 contacts the bearing plate 19, the actuator of the suspended conveyor falls excessively, causing the suspension rope 41 to slack. At this time, a small range of relative displacement is allowed between the lower support plate 11 and the actuator of the suspended conveyor.

[0033] The positioning cylinder 15 is activated, controlling its piston rod to retract, the connecting plate 13 and the positioning block 14 move synchronously, and the end positioning part 28 of the positioning block 14 corrects the posture of the target lower support plate 11 and performs a positioning; during this process, the suction cup 33 and the lower support plate 11 remain in an adsorption state, and the mounting plate 30 and the lower support plate 11 move synchronously.

[0034] After the first positioning is completed, the positioning cylinder 15 controls the positioning block 14 to reset, and at the same time the limit cylinder 32 is activated, controlling its piston rod to extend, the abutment plate 31 moves synchronously, the mechanical gripper is activated, and the four limit strips 12 are placed on the edge position of the lower support plate 11 from all sides. The abutment plate 31 restricts the placement position of the limit strips 12. After the placement is completed, the positioning cylinder 15 controls the positioning blocks 14 to move closer to each other again. While the second end positioning part 28 clamps the lower support plate 11, the first end positioning part 27 also clamps the limit strips 12, completing the second positioning.

[0035] After the secondary positioning is completed, the positioning cylinder 15 controls the positioning block 14 to remain in its current state, the air pump controls the suction cup 33 to release the lower support plate 11, and the suspended conveyor controls its execution unit to leave the target lower support plate 11.

[0036] When the regulating cylinder 20 is activated, its piston rod is retracted, which drives the rotating plate 22 to rotate around the rotating shaft 17. The bearing plate 19 and the lower support plate 11 rotate synchronously with the rotating plate 22, and the target lower support plate 11 is tilted at a certain angle.

[0037] When the two welding machines are started, their end effectors respectively drive the two welding torches 34 to move, as shown in the attached diagram. Figure 7 and attached Figure 8 As shown, the two welding torches 34, one high and one low, move horizontally along the weld length at a certain angle. The higher welding torch 34 welds the outer weld 40 of the upper limiting strip 12, while the lower welding torch 34 welds the inner weld 39 of the lower limiting strip 12.

[0038] After a certain cooling time is allowed after each welding operation, the welding torch 34 of the electric welding machine is moved aside, and the motor 24 is started to control its output shaft to rotate, so that the rotating plate 22, the bearing plate 19 and the lower support plate 11 rotate 90 degrees synchronously. The welding torch 34 of the electric welding machine moves closer to the new welding position to weld again. After rotating three times, a total of four welding operations are performed, and the inner weld 39 and the outer weld 40 of each limit bar 12 are welded to complete the welding task.

[0039] During material unloading, the welding machine resets, and multiple positioning blocks 14 move away from each other. The overhead conveyor controls the conveying mechanism 29 to move above the target lower support plate 11. The suction cup 33 picks up the lower support plate 11 after welding and transfers it to the semi-finished lower support plate 11 stacking area for the next step of processing.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A welding fixture for bridge bearings, characterized in that: It includes a base, a rotating plate disposed on the base, a support plate rotatably connected to the rotating plate, a plurality of positioning blocks slidably disposed around the periphery of the support plate, an adjusting cylinder disposed between the base and the rotating plate for adjusting the tilt angle of the rotating plate, and a conveying mechanism disposed on the side of the support plate away from the base. The bridge bearing includes a lower bearing plate, a plurality of limiting strips disposed on the lower bearing plate, and an upper bearing plate. The welding fixture is used to weld the lower bearing plate and the plurality of limiting strips.

2. The bridge bearing welding fixture according to claim 1, characterized in that: A support frame is fixedly provided on the side of the base near the lower support plate. A rotating shaft is fixedly provided on the rotating plate. The rotating shaft is rotatably connected to the end of the support frame away from the base. A fixed seat is provided on one side of the support frame and is fixedly connected to the base. The cylinder barrel and piston rod of the adjusting cylinder are rotatably connected to the fixed seat and the rotating plate, respectively.

3. The bridge bearing welding fixture according to claim 1, characterized in that: An adjustment motor is fixedly installed at one end of the rotating plate near the base. The output shaft of the adjustment motor passes through and is rotatably connected to the rotating plate. The output shaft of the adjustment motor is fixedly connected to the support plate.

4. The bridge bearing welding fixture according to claim 1, characterized in that: Multiple extension plates are fixedly provided on the periphery of the bearing plate, and each of the multiple extension plates corresponds to a multiple of the positioning blocks. Each extension plate is provided with a positioning cylinder at one end near the base. The cylinder barrel of the positioning cylinder is fixedly connected to the extension plate. A connecting plate is fixedly provided on the piston rod of the positioning cylinder, and the positioning block is installed on the connecting plate.

5. The bridge bearing welding fixture according to claim 1, characterized in that: The positioning block has a connecting groove on one side, and the positioning block is connected to the connecting plate through the connecting groove. One end of the connecting groove has a surface positioning part, and the two sides of the connecting groove have an end positioning part one and an end positioning part two, respectively. The surface positioning part is used to contact the surface of the lower support plate, the end positioning part one is used to abut against the end of the limiting strip, and the end positioning part two is used to abut against the side of the lower support plate.

6. The bridge bearing welding fixture according to claim 1, characterized in that: The conveying mechanism includes a mounting plate, multiple suction cups disposed on the mounting plate, and multiple limiting cylinders disposed on the side of the mounting plate away from the suction cups; the suction cups are used to adsorb the lower support plate, the cylinder of the limiting cylinder is fixedly connected to the mounting plate, one end of the piston rod of the limiting cylinder is fixedly provided with an abutment plate, and the multiple abutment plates cooperate with the inner side of the limiting strip.

7. The bridge bearing welding fixture according to claim 1, characterized in that: It also includes two welding machines, each of which includes a welding torch. An inner weld is formed between the inner side of the limiting strip and the lower support plate, and an outer weld is formed between the outer side of the limiting strip and the lower support plate. The two welding torches cooperate with the limiting strips on opposite sides, with one welding torch used to weld the inner weld and the other welding torch used to weld the outer weld.

8. A bridge bearing welding fixture according to claim 6, characterized in that: Multiple suspension ropes are fixedly installed on the side of the mounting plate away from the suction cup. The conveying mechanism is connected to the suspended conveyor through the suspension ropes, and the suction cup is connected to the air pump.

9. A method for welding bridge bearings, using a bridge bearing welding fixture as described in any one of claims 1-8, characterized in that: The bridge bearing includes a lower bearing plate and an upper bearing plate. A stainless steel plate, a flat polytetrafluoroethylene plate, a spherical steel liner plate, and a spherical polytetrafluoroethylene plate are provided between the lower bearing plate and the upper bearing plate. Four limiting strips are provided on the periphery of the lower bearing plate, and four displacement scales are provided on the periphery of the upper bearing plate. The limiting strips are provided with observation marks that cooperate with the displacement scales. A temporary connecting piece is provided between the lower bearing plate and the upper bearing plate located on the periphery of the spherical steel liner plate. The lower bearing plate and the limiting strips are connected by welding. The welding method includes the following steps: S1. Loading: The adjusting cylinder is used to control the level of the rotating plate and the bearing plate, and the conveying mechanism is used to transport the lower support plate to the top of the bearing plate. S2. First positioning; control the positioning block to slide relative to the bearing plate, the positioning block clamps the four corners of the lower support plate to position the lower support plate, and the positioning block resets after positioning is completed; S3. Secondary positioning: Using a mechanical gripper, place the four limiting strips on the upper side of the lower support plate respectively, and control the positioning block to slide relative to the bearing plate again. The positioning block simultaneously clamps the four corners of the lower support plate and the four limiting strips, positioning the lower support plate and the four limiting strips. After positioning is completed, control the positioning block to maintain the current state. S4. Adjust the posture; use the adjusting cylinder to control the rotating plate, the bearing plate, the lower support plate and the limiting strip to rotate synchronously, and adjust the tilt angle of the lower support plate. S5. Welding; The welding machine is started to weld the two limit strips on the upper and lower sides respectively; S6. Adjust the welding position; control the bearing plate to rotate relative to the rotating plate, the lower support plate and the limiting strip rotate synchronously with the bearing plate, and the welding machine welds the lower support plate and the limiting strip again after rotation; S7. Unloading: The adjusting cylinder is used to control the horizontal level of the bearing plate and the positioning block to reset. The conveying mechanism is used to unload the workpiece after welding.

10. A bridge bearing welding method according to claim 9, characterized in that: In step S6, the welding machine rotates 90 degrees each time and welds the two limiting strips located on the upper and lower sides after each rotation. The welding is completed after three rotations.

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