Box girder steel reinforcement framework closed looping welding device and method

Abstract

The invention relates to a box girder steel reinforcement framework closed ring forming welding device and method, the device comprises a steel reinforcement butt welding machine, the steel reinforcement butt welding machine comprises a movable clamping seat and a fixed clamping seat, and a butt welding area is arranged between the movable clamping seat and the fixed clamping seat; the positioning mechanism comprises a positioning frame, a driving cylinder, a rack, a side clamping seat, a front clamping seat and a rear clamping seat; a cylinder body of the driving cylinder is fixed on the positioning frame, a driving seat is arranged at the front end of the driving cylinder, racks are fixed on two sides of the driving seat, and the racks are adaptively positioned and slidably sleeved on the positioning frame; the racks on the two sides are meshed with corresponding gears, rotating shafts of the gears on the two sides are in transmission connection with left-hand thread screws extending towards the two sides, side clamping bases are arranged on the upper portions of the two sliding sleeves, and side clamping areas are formed. And the front clamping seat and the rear clamping seat correspond to each other and are respectively positioned on the outer side and the inner side of the butt welding area. A positioning tool is provided for the butt welding forming process of the rectangular steel reinforcement framework, and the consistency and reliability of welding quality are ensured through a positioning system and a clamping system.

Description

Technical Field

[0001] This invention relates to the field of building engineering technology, specifically to a closed-loop welding device and method for the reinforcing steel skeleton of a box girder. Background Technology

[0002] The box girder's steel reinforcement cage has a rectangular structure. During the welding stage, the rectangular structure is welded using pressure welding technology. This method causes the two joints at the connection point to overlap, which not only increases unnecessary material consumption and wastes resources, but also causes misalignment problems during the welding process, affecting the integrity and aesthetics of the structure.

[0003] Butt welding of reinforcing bars refers to connecting two reinforcing bars by welding to strengthen them. This welding method mainly utilizes resistance heating or other heat sources to heat the end faces of the reinforcing bars to a plastic state, and then applies pressure to join them together. The working principle of the butt welding machine is as follows: electrodes are mounted on a fixed plate and a sliding plate, respectively, and the sliding plate can move freely on a guide rail. Current is transmitted to the electrodes through the secondary coil of a transformer. When the pressure mechanism applies pressure, it brings the ends of the two reinforcing bars into contact, forming a short circuit. The heat generated by the resistance heats the reinforcing bars. When the reinforcing bars reach a highly plastic state, additional compressive force is applied to firmly connect the two ends, completing the welding process.

[0004] With the increasing maturity of butt welding technology, although it has been applied to the welding of rectangular frames, the lack of a precise positioning structure during implementation leads to frequent manual correction and fixing of the rectangular frames, significantly reducing construction efficiency, increasing labor intensity, and causing considerable trouble for workers. Therefore, it is necessary to study a closed-loop welding device and method for the reinforcing steel skeleton of box girders. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a closed-loop welding device and method for box girder steel reinforcement cages, which effectively solves the problems of existing rectangular steel reinforcement cages lacking positioning structures during butt welding, resulting in high positioning difficulty, low butt welding efficiency, and poor butt welding accuracy.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a closed-loop welding device for box girder steel reinforcement skeleton, comprising a steel reinforcement butt welding machine, wherein the steel reinforcement butt welding machine comprises a movable clamping seat and a fixed clamping seat, and the area between the movable clamping seat and the fixed clamping seat is a butt welding area; characterized in that: it further comprises a positioning mechanism, wherein the positioning mechanism comprises a positioning frame, a drive cylinder, a rack, a side clamping seat, a front clamping seat and a rear clamping seat; the cylinder body of the drive cylinder is fixed on the positioning frame, and a drive seat is provided at its front end; racks are fixed on both sides of the drive seat; the racks are adapted to be positioned and slidably mounted on the positioning frame; under the action of the drive cylinder, the racks slide; the racks on both sides mesh with corresponding gears; the rotating shafts of the gears on both sides are connected to a reverse threaded screw extending to both sides; a sliding sleeve is threadedly connected to two different threaded sections of the reverse threaded screw; a side clamping seat is provided on the upper part of the two sliding sleeves; the side clamping seats are adapted to be mounted on the positioning frame and form a side clamping area; The front end of the drive seat is provided with a front retainer, and the front retainer and the rear retainer correspond to each other and are located on the outer and inner sides of the welding area, respectively; a corresponding retainer groove is provided between the front retainer and the rear retainer.

[0007] Furthermore, there are two front and two rear card holders respectively, located on both sides of the welding area.

[0008] Furthermore, a rear adjustment cylinder is provided on the rear side of the rear card holder to adjust the distance between the rear card holder and the front card holder.

[0009] Furthermore, the slot is an isosceles trapezoidal slot with a larger outer end and a smaller inner end.

[0010] Furthermore, a reinforcing plate is provided on the rear side of the two racks, and the reinforcing plate is fitted onto the drive cylinder in a sliding manner.

[0011] A method for welding a closed ring of steel reinforcement cage for a box girder, applied to the above-mentioned device, includes the following steps; Step 1: Bend the reinforcing bars into a rectangular shape. Step 2: Place the two sides of the rectangular steel reinforcement cage in the side clamping areas on both sides; place the rectangular side with the notch between the front and rear clamping seats; Step 3: Start the drive cylinder. Under the action of the drive cylinder, the front clamp moves backward. Using the rack, gear and reverse thread screw structure, the side clamp tightens synchronously towards the center of the side clamping area, positioning the two sides of the rectangular frame at specific points. At the same time, the front clamp clamps the steel bar between the front and rear clamps from both sides of the notch, positioning the welded part of the steel bar in the middle area of ​​the weld area. Step 4: Activate the cylinders on the upper part of the moving and fixed clamping seats to move the upper clamping seat downwards and clamp the reinforcing bar from the top. Remove the front and rear clamping seats, activate the moving clamping seat, and move the reinforcing bar inwards to achieve butt welding of the reinforcing bar. Step 5: After welding is completed, the reinforcing bar can be removed.

[0012] Furthermore, both the front and rear card seats include a fixed seat and a trimming seat. The fixed seat is fixed to the fixed card seat side, and the trimming seat is slidably disposed on the movable card seat side and corresponds to the movable card seat. Under the action of the movable card seat, the trimming seat trims the weld bead produced by the butt welding. The front and rear card seats are respectively disposed on the front and rear drive seats. Slide grooves are provided on the front and rear drive seats. The trimming seat is fitted into the slide groove by a slider. The slider is fitted onto a slide rod, and a return spring is fitted onto the slide rod. The slider presses against the return spring.

[0013] Furthermore, the slot includes an enlarged section, a straight section, and a semicircular section; the semicircular section is adapted to the reinforcing bar, and the enlarged section is connected to the semicircular section via the straight section.

[0014] Furthermore, the front trimming seat and the rear trimming seat are staggered.

[0015] Furthermore, it also includes finishing processes; specifically, it includes the following steps; Step 1: After welding is completed in step 4, start the cylinder above the moving bracket to keep the fixed bracket in a fixed state and move the moving bracket to the side. Step two: The front and rear clamps move inward and engage with the reinforcing bars; Step 3: Move the movable card seat inward and push the front and rear card seats from the side to make them move along the steel bar to trim the lumps. Step 4: After the repair is completed, move the card slot back to its original position. The front and rear card slots will then be reset using springs. The repair is now complete. Step 5: Remove the steel bar.

[0016] The beneficial effects of the above technical solution are as follows: This invention provides a positioning fixture for forming and welding rectangular steel reinforcement cages, which can position the rectangular steel reinforcement cages at multiple points. This structure is driven by a cylinder. The cylinder moves forward and drives the rack to slide along the positioning frame. During the sliding process, the gear rotates. With the help of the reverse thread screw structure, the side clamps on both sides move inward synchronously along the preset centerline. That is, when the cylinder extends, the side clamps retract inward. When the side clamps are in place, the two sides of the rectangular steel reinforcement cage are positioned at a specific point. At the same time, the front clamp moves forward and pushes the steel reinforcement forward, moving the front side of the rectangular steel reinforcement cage to be welded to the welding area of ​​the steel reinforcement welding machine. That is, the front side is positioned. Then, the clamps of the welding machine itself are used to position the steel reinforcement from above and drive the steel reinforcement to complete the welding operation.

[0017] This invention, through the design of a positioning mechanism—namely, the structural cooperation between the side clamp, the front clamp, and the rear clamp—utilizes mechanical structures such as a drive cylinder, rack, gear, and reverse threaded screw to achieve automated operation, reduce manual intervention, improve production efficiency and consistency, achieve precise positioning and clamping of the reinforcing bar cage, enhance the stability and precision of the reinforcing bars during welding, and ensure welding quality.

[0018] This invention also provides a tooling for trimming welded joints. This structure only requires the trimming seats of the front and rear clamps to be slidable. Utilizing the translational structure of the welding machine itself, it enables the trimming of weld bulges. It is easy to use and allows for rapid trimming of bulges during their initial formation stage, with minimal trimming difficulty. Through the design of the trimming seats, the device can automatically trim bulges at the weld joint after welding, which not only improves the aesthetics of the weld but also enhances the strength and stability of the rebar connection.

[0019] Therefore, this invention provides a positioning fixture for the butt welding process of rectangular steel reinforcement cages. Through a precise positioning and clamping system, and effective control of the welding process and results, it helps ensure the consistency and reliability of welding quality, improves product quality, reduces direct contact between operators and the welding process, and lowers safety risks caused by high temperatures and sparks. Combining welding and finishing significantly shortens the processing time of individual components, improves overall work efficiency, provides a convenient tool for butt welding rectangular steel reinforcement cages, and reduces processing difficulty. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the main structure of the present invention; Figure 3 This is a top view of the structure of the present invention; Figure 4 This is a bottom-view structural diagram of the present invention; Figure 5 This is a schematic diagram of the rear view structure of the present invention; Figure 6 This is a schematic diagram of the welding construction of the reinforcing steel cage; Figure 7 This is a schematic diagram of the structure after welding. Figure 8 This is a schematic diagram of the card slot's implementation structure.

[0021] Reference numerals: 1-Positioning frame, 2-Drive cylinder, 3-Drive seat, 4-Rack, 41-Slot, 5-Gear, 6-Reverse threaded screw, 7-Sliding sleeve, 8-Side seat, 9-Side clamping area, 10-Reinforcing plate, 11-Front seat, 12-Rear seat, 13-Moving seat, 14-Fixed seat, 15-Slot, 151-Enlarged section, 152-Straight section, 153-Semicircular section, 16-Side clamping part, 17-Front positioning part, 18-Upper positioning part, 19-Rectangular steel frame, 20-Nodule, 21-Adjusting seat, 22-Slider, 23-Slide groove, 24-Spring, 25-Fixed seat. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1: This example aims to provide a closed-loop welding device and method for the reinforcing steel cage of a box girder. It is mainly used in the fabrication of the reinforcing steel cage during the box girder production process, specifically involving the butt welding of rectangular reinforcing steel cages. Currently, the welding method for rectangular reinforcing steel cages is pressure welding. This welding method results in long overlaps and joints at the weld, leading to poor aesthetics and wasted reinforcing steel, which is detrimental to subsequent box girder assembly. While butt welding machine technology has matured, the lack of a precise positioning structure during implementation necessitates frequent manual correction and fixing of the rectangular frame, significantly reducing construction efficiency, increasing labor intensity, and causing considerable inconvenience to workers. Therefore, this example provides a closed-loop welding device for the reinforcing steel cage of a box girder.

[0023] like Figure 1-5 As shown, a box girder steel reinforcement cage closed ring welding device includes a steel reinforcement butt welding machine. The steel reinforcement butt welding machine includes a movable clamping seat 13 and a fixed clamping seat 14. The area between the movable clamping seat 13 and the fixed clamping seat 14 is the butt welding area. The movable clamping seat 13 and the fixed clamping seat 14 can clamp the steel reinforcement respectively. The movable clamping seat 13 can move and provide thrust. This is prior art and will not be described further here.

[0024] The basic concept of this embodiment is to add a positioning mechanism to the existing rebar welding machine. The positioning mechanism is used to locate the rectangular rebar skeleton at multiple points, so as to determine the specific points and improve the accuracy and efficiency of rebar welding.

[0025] The positioning mechanism includes a positioning frame 1, a drive cylinder 2, a rack 4, a side bracket 8, a front bracket 11, and a rear bracket 12. In this embodiment, the positioning frame 1 is fixed and is set on one side of the rebar welding machine. The cylinder body of the drive cylinder 2 is fixed on the positioning frame 1, and a drive seat 3 is set at its front end. Racks 4 are fixed on both sides of the drive seat 3. In this embodiment, there are two racks 4, which are arranged on the corresponding seats. The two racks 4 are connected as one unit through the drive seat 3. The racks 4 are fitted with a positioning sliding sleeve on the positioning frame 1. Under the action of the drive cylinder 2, the racks 4 slide, and the sliding direction of the racks 4 is towards the rebar welding machine.

[0026] The racks 4 on both sides mesh with the corresponding gears. The specific gears are set at the bottom of the gears. The two ends of the gears are rotatably set on the positioning frame 1 and form a fixed base. The rotating shafts of the gears on both sides are connected to the reverse threaded screws 6 extending to both sides. Sliding sleeves 7 are threadedly connected to the two different threaded sections of the reverse threaded screws 6. Side retainers 8 are set on the upper part of the two sliding sleeves 7. The two retainers 8 are adapted to be installed on the positioning frame 1 and form a side clamping area 9.

[0027] In this embodiment, a sliding groove is provided on the positioning frame 1, and a limit rod is fixed on the upper part of the sliding sleeve. The limit rod is adapted to slide in the sliding groove to form a limit. The relative movement of the side clamping seat 8 is realized by the translation of the sliding sleeve, thereby forming a side clamping centerline on both sides. In order to ensure the stability of the rack 4, a reinforcing plate 10 is provided on the rear side of the two racks 4. The reinforcing plate 10 is adapted to slide on the drive cylinder 2. At the same time, a groove is provided on the side of the rack 4, and the positioning frame 1 is adapted to clamp in the groove, so that the rack 4 can be translated smoothly.

[0028] The front end of the drive seat 3 is provided with a front retainer 11, which corresponds to the rear retainer 12 and is located on the outer and inner sides of the welding area, respectively. A corresponding retainer groove 41 is provided between the front retainer 11 and the rear retainer 12. The retainer groove 41 is an isosceles trapezoidal groove with a larger outer end and a smaller inner end. The outer end of the isosceles trapezoidal groove has a large opening to facilitate the insertion and positioning of the reinforcing bar.

[0029] In practice, two front card holders 11 and two rear card holders 12 are provided, respectively, and are located on both sides of the welding area. A rear adjustment cylinder is provided on the rear side of the rear card holder 12 to adjust the distance between the rear card holder 12 and the front card holder 11.

[0030] During use, a cylinder is used for driving. The cylinder moves forward and drives the rack 4 to slide along the positioning frame 1. During the sliding process, the gear rotates. With the help of the reverse threaded screw 6 structure, the side clamps 8 on both sides move inward synchronously along the preset center line. That is, when the cylinder extends, the side clamps 8 retract inward. When the side clamps 8 are in place, the two sides of the rectangular steel reinforcement skeleton are positioned at a specific point. At the same time, the front clamp 11 moves forward and pushes the steel reinforcement forward, moving the front side of the rectangular steel reinforcement skeleton to be welded to the welding area of ​​the steel reinforcement welding machine. This achieves the positioning of the front side. Then, the clamps of the welding machine itself are used to position the steel reinforcement from above and drive the steel reinforcement to complete the welding operation.

[0031] When implementing Figure 6 As shown, the rectangular steel reinforcement cage has side clamping parts 16 on both sides, which are side clamping seats 8 forming a clamping structure. The front positioning part 17 is a combination of the front clamping seat and the rear clamping seat, and the upper positioning part 18 is the limit formed by the structure of the steel reinforcement welding machine itself.

[0032] This embodiment provides a method for welding a closed ring of steel reinforcement cage for a box girder, applied to the above-mentioned device, and includes the following steps; Step 1: Bend the reinforcing bars into a rectangular structure. During implementation, considering that welding requires a certain length, bends can be pre-set on the welding edge. After welding, the bends are reset to ensure the stability of the formed structure.

[0033] Step 2: Place the two sides of the rectangular steel reinforcement cage in the side clamping areas on both sides; place the rectangular side with the notch between the front clamp 11 and the rear clamp 12; Step 3: Start the drive cylinder 2. Under the action of the drive cylinder 2, the front clamp 11 moves backward. Using the structure of rack 4, gear and reverse threaded screw 6, the side clamp 8 is tightened synchronously towards the center of the side clamping area, positioning the two sides of the rectangular frame at specific points. At the same time, the front clamp 11 clamps the steel bar between the front clamp 11 and the rear clamp 12 from both sides of the notch, positioning the welded part of the steel bar in the middle area of ​​the welded area. Step 4: Activate the cylinders on the upper part of the movable clamping seat 13 and the fixed clamping seat 14 to move the upper clamping seat downwards and clamp the reinforcing bar from the top. Remove the front clamping seat 11 and the rear clamping seat 12, activate the movable clamping seat 13, and drive the reinforcing bar to move inwards to achieve butt welding of the reinforcing bar. Step 5: After welding is completed, the reinforcing bar can be removed.

[0034] This embodiment adds a positioning mechanism to the traditional rebar welding machine. It uses precise multi-point positioning (including side clamps 8, front clamps 11, and rear clamps 12) to fix the rectangular rebar cage, specifically positioning from both sides and the welding side of the rectangular rebar cage, thereby improving the accuracy and efficiency of the welding. Its advantage lies in the automated multi-point synchronous clamping achieved through mechanical structures such as the drive cylinder 2, rack 4, gears, and reverse-threaded screw 6. This not only simplifies the operation process but also significantly improves welding accuracy and work efficiency, ensuring the welding quality of the box girder rebar cage.

[0035] Example 2: This example, based on the structure in Example 1, further provides a trimming device after the butt welding is completed to remove the weld nodules, and further explains the specific trimming structure.

[0036] like Figure 7-8 As shown in the figure, in this embodiment, both the front card holder 11 and the rear card holder 12 include a fixed seat 25 and a trimming seat 21. The fixed seat 25 is fixed to the side of the fixed card holder 14, and the trimming seat is slidably disposed on the side of the movable card holder 13 and corresponds to the movable card holder 13. Under the action of the movable card holder 13, the trimming seat 21 trims the nodule 20 generated by butt welding. The front card holder 11 and the rear card holder 12 are respectively disposed on the front drive seat 3 and the rear drive seat 3. The front drive seat 3 and the rear drive seat 3 are provided with a sliding groove 23. The trimming seat is fitted into the sliding groove 23 by a slider. The slider 22 is fitted onto the slide rod, and a return spring 24 is fitted onto the slide rod. The slider presses against the return spring.

[0037] The slot 15 includes an enlarged section 151, a straight section 152, and a semicircular section 153; the semicircular section is adapted to the reinforcing bar, and the enlarged section is connected to the semicircular section via the straight section; the front trimming seat and the rear trimming seat are staggered.

[0038] Furthermore, it also includes finishing processes; specifically, it includes the following steps; Step 1: After the welding in step 4 is completed, start the cylinder above the movable bracket 13 to keep the fixed bracket 14 in a fixed state, and move the movable bracket 13 to the side. Step two, the front retainer 11 and the rear retainer 12 move inward and lock onto the steel bar; Step 3: Move the movable card seat 13 inward and push the front card seat 11 and the rear card seat 12 from the side, so that the front card seat 11 and the rear card seat 12 move along the steel bar to trim the lumps. Step 4: After the repair is completed, the movable card holder 13 is reset, and the front card holder 11 and the rear card holder 12 are reset by springs. The repair is then complete. Step 5: Remove the steel bar.

[0039] This embodiment further provides a trimming device, which optimizes the structure of the front clamping seat 11 and the rear clamping seat 12, serving not only for positioning but also for automatically trimming post-weld sprues. The front clamping seat 11 and the rear clamping seat 12 cooperate through a fixed seat and a sliding trimming seat, utilizing the thrust of the moving clamping seat 13 to trim the sprue. Simultaneously, the slot design optimizes the clamping and trimming effect of the reinforcing bar. Furthermore, a welding method including the trimming process is described in detail. Its advantages lie in that, through integrated design and automated operation, it not only improves welding accuracy but also achieves immediate trimming of post-weld sprues, significantly enhancing overall work efficiency and welding quality.

[0040] The embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. The basic concept of the present invention lies in the design of the positioning mechanism, namely the structural cooperation relationship between the side clamping seat 8, the front clamping seat 11, and the rear clamping seat 12. Using mechanical structures such as the drive cylinder 2, rack 4, gear, and anti-threaded screw 6, precise positioning and clamping of the reinforcing bar cage are achieved. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A closed-loop welding device for the reinforcing steel cage of a box girder, comprising a reinforcing steel butt welding machine, wherein the reinforcing steel butt welding machine includes a movable clamp and a fixed clamp, and the area between the movable clamp and the fixed clamp is a butt welding zone; characterized in that: It also includes a positioning mechanism, which comprises a positioning frame, a drive cylinder, a rack, side locators, a front locator, and a rear locator. The cylinder body of the drive cylinder is fixed on the positioning frame, and a drive seat is provided at its front end. Racks are fixed on both sides of the drive seat. The racks are fitted with positioning sliding sleeves on the positioning frame, and the racks slide under the action of the drive cylinder. The racks on both sides mesh with corresponding gears, and the shafts of the gears on both sides are connected to reverse threaded screws extending to both sides. Sliding sleeves are threadedly connected to two different threaded sections of the reverse threaded screws. Side locators are provided on the upper part of the two sliding sleeves. The side locators are fitted with the positioning frame and form a side clamping area. The front end of the drive seat is provided with a front retainer, and the front retainer and the rear retainer correspond to each other and are located on the outer and inner sides of the welding area, respectively; a corresponding retainer groove is provided between the front retainer and the rear retainer.

2. The box girder reinforcement cage closed-loop welding device according to claim 1, characterized in that: Two front and two rear card holders are provided, located on opposite sides of the welding area.

3. The box girder reinforcement cage closed-loop welding device according to claim 1, characterized in that: A rear adjustment cylinder is provided on the rear side of the rear card holder to adjust the distance between the rear card holder and the front card holder.

4. The box girder reinforcement cage closed-loop welding device according to claim 1, characterized in that: The slot is an isosceles trapezoidal slot that is larger at the outer end and smaller at the inner end.

5. The box girder reinforcement cage closed-loop welding device according to claim 1, characterized in that: Reinforcing plates are provided on the rear side of the two racks, and the reinforcing plates are fitted onto the drive cylinder in a sliding manner.

6. A method for welding a closed ring of steel reinforcement cage for a box girder, applied to the apparatus of claim 1, characterized in that, Includes the following steps; Step 1: Bend the reinforcing bars into a rectangular shape. Step 2: Place the two sides of the rectangular steel reinforcement cage in the side clamping areas on both sides; place the rectangular side with the notch between the front and rear clamping seats; Step 3: Start the drive cylinder. Under the action of the drive cylinder, the front clamp moves backward. Using the rack, gear and reverse thread screw structure, the side clamp tightens synchronously towards the center of the side clamping area, positioning the two sides of the rectangular frame at specific points. At the same time, the front clamp clamps the steel bar between the front and rear clamps from both sides of the notch, positioning the welded part of the steel bar in the middle area of ​​the weld area. Step 4: Activate the cylinders on the upper part of the moving and fixed clamping seats to move the upper clamping seat downwards and clamp the reinforcing bar from the top. Remove the front and rear clamping seats, activate the moving clamping seat, and move the reinforcing bar inwards to achieve butt welding of the reinforcing bar. Step 5: After welding is completed, the reinforcing bar can be removed.

7. The box girder reinforcement cage closed-loop welding device according to claim 1, characterized in that: Both the front and rear card seats include a fixed seat and a trimming seat. The fixed seat is fixed to the fixed card seat side, and the trimming seat is slidably disposed on the movable card seat side and corresponds to the movable card seat. Under the action of the movable card seat, the trimming seat trims the weld bead produced by the butt welding. The front and rear card seats are respectively disposed on the front and rear drive seats. The front and rear drive seats are provided with sliding grooves. The trimming seat is fitted into the sliding grooves by a slider. The slider is fitted onto a slide rod, and a return spring is fitted onto the slide rod. The slider presses against the return spring.

8. The box girder reinforcement cage closed-loop welding device according to claim 7, characterized in that: The slot includes an enlarged section, a straight section, and a semicircular section; the semicircular section is adapted to the reinforcing bar, and the enlarged section is connected to the semicircular section via the straight section.

9. The box girder reinforcement cage closed-loop welding device according to claim 8, characterized in that: The front trimming seat and the rear trimming seat are staggered.

10. The method for welding the closed ring of the reinforcing steel cage of a box girder according to claim 6, applied to the apparatus of any one of claims 7-9, characterized in that: It also includes finishing processes; specifically, it includes the following steps; Step 1: After welding is completed in step 4, start the cylinder above the moving bracket to keep the fixed bracket in a fixed state and move the moving bracket to the side. Step two: The front and rear clamps move inward and engage with the reinforcing bars; Step 3: Move the movable card seat inward and push the front and rear card seats from the side to make them move along the steel bar to trim the lumps. Step 4: After the repair is completed, move the card slot back to its original position. The front and rear card slots will then be reset using springs. The repair is now complete. Step 5: Remove the steel bar.

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